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Sample records for active power method

  1. Communication Systems and Study Method for Active Distribution Power systems

    DEFF Research Database (Denmark)

    Wei, Mu; Chen, Zhe

    Due to the involvement and evolvement of communication technologies in contemporary power systems, the applications of modern communication technologies in distribution power system are becoming increasingly important. In this paper, the International Organization for Standardization (ISO......) reference seven-layer model of communication systems, and the main communication technologies and protocols on each corresponding layer are introduced. Some newly developed communication techniques, like Ethernet, are discussed with reference to the possible applications in distributed power system....... The suitability of the communication technology to the distribution power system with active renewable energy based generation units is discussed. Subsequently the typical possible communication systems are studied by simulation. In this paper, a novel method of integrating communication system impact into power...

  2. Evaluation of harmonic detection methods for active power filter applications

    DEFF Research Database (Denmark)

    Asiminoaei, Lucian; Blaabjerg, Frede; Hansen, Steffan

    2005-01-01

    In the attempt to minimize the harmonic disturbances created by the non-linear loads the choice of the active power filters comes out to improve the filtering efficiency and to solve many issues existing with classical passive filters. One of the key points for a proper implementation of an active...... theories. Then, the work here proposes a simulation setup that decouples the harmonic reference generator from the active filter model and its controller. In this way the selected methods can be equally analyzed and compared with respect to their performance, which helps anticipating possible...

  3. Multi-objective Design Method for Hybrid Active Power Filter

    Science.gov (United States)

    Yu, Jingrong; Deng, Limin; Liu, Maoyun; Qiu, Zhifeng

    2017-10-01

    In this paper, a multi-objective optimal design for transformerless hybrid active power filter (HAPF) is proposed. The interactions between the active and passive circuits is analyzed, and by taking the interactions into consideration, a three-dimensional objective problem comprising of performance, efficiency and cost of HAPF system is formulated. To deal with the multiple constraints and the strong coupling characteristics of the optimization model, a novel constraint processing mechanism based on distance measurement and adaptive penalty function is presented. In order to improve the diversity of optimal solution and the local searching ability of the particle swarm optimization (PSO) algorithm, a chaotic mutation operator based on multistage neighborhood is proposed. The simulation results show that the optimums near the ordinate origin of the three-dimension space make better tradeoff among the performance, efficiency and cost of HAPF, and the experimental results of transformerless HAPF verify the effectiveness of the method for multi-objective optimization and design.

  4. Reducing vibration transfer from power plants by active methods

    Science.gov (United States)

    Kiryukhin, A. V.; Milman, O. O.; Ptakhin, A. V.

    2017-12-01

    The possibility of applying the methods of active damping of vibration and pressure pulsations for reducing their transfer from power plants into the environment, the seating, and the industrial premises are considered. The results of experimental works implemented by the authors on the active broadband damping of vibration and dynamic forces after shock-absorption up to 15 dB in the frequency band up to 150 Hz, of water pressure pulsations in the pipeline up to 20 dB in the frequency band up to 600 Hz, and of spatial low-frequency air noise indoors of a diesel generator at discrete frequency up to 20 dB are presented. It is shown that a reduction of vibration transfer through a vibration-isolating junction (expansion joints) of pipelines with liquid is the most complicated and has hardly been developed so far. This problem is essential for vibration isolation of power equipment from the seating and the environment through pipelines with water and steam in the power and transport engineering, shipbuilding, and in oil and gas pipelines in pumping stations. For improving efficiency, reducing the energy consumption, and decreasing the overall dimensions of equipment, it is advisable to combine the work of an active system with passive damping means, the use of which is not always sufficient. The executive component of the systems of active damping should be placed behind the vibration isolators (expansion joints). It is shown that the existence of working medium and connection of vibration with pressure pulsations in existing designs of pipeline expansion joints lead to growth of vibration stiffness of the expansion joint with the environment by two and more orders as compared with the static stiffness and makes difficulties for using the active methods. For active damping of vibration transfer through expansion joints of pipelines with a liquid, it is necessary to develop expansion joint structures with minimal connection of vibrations and pulsations and minimal

  5. The Method of Optimization of Hydropower Plant Performance for Use in Group Active Power Controller

    Directory of Open Access Journals (Sweden)

    Glazyrin G.V.

    2017-04-01

    Full Text Available The problem of optimization of hydropower plant performance is considered in this paper. A new method of calculation of optimal load-sharing is proposed. The method is based on application of incremental water flow curves representing relationship between the per unit increase of water flow and active power. The optimal load-sharing is obtained by solving the nonlinear equation governing the balance of total active power and the station power set point with the same specific increase of water flow for all turbines. Unlike traditional optimization techniques, the solution of the equation is obtained without taking into account unit safe operating zones. Instead, if calculated active power of a unit violates the permissible power range, load-sharing is recalculated for the remaining generating units. Thus, optimal load-sharing algorithm suitable for digital control systems is developed. The proposed algorithm is implemented in group active power controller in Novosibirsk hydropower plant. An analysis of operation of group active power controller proves that the application of the proposed method allows obtaining optimal load-sharing at each control step with sufficient precision.

  6. Design of Passive Power Filter for Hybrid Series Active Power Filter using Estimation, Detection and Classification Method

    Science.gov (United States)

    Swain, Sushree Diptimayee; Ray, Pravat Kumar; Mohanty, K. B.

    2016-06-01

    This research paper discover the design of a shunt Passive Power Filter (PPF) in Hybrid Series Active Power Filter (HSAPF) that employs a novel analytic methodology which is superior than FFT analysis. This novel approach consists of the estimation, detection and classification of the signals. The proposed method is applied to estimate, detect and classify the power quality (PQ) disturbance such as harmonics. This proposed work deals with three methods: the harmonic detection through wavelet transform method, the harmonic estimation by Kalman Filter algorithm and harmonic classification by decision tree method. From different type of mother wavelets in wavelet transform method, the db8 is selected as suitable mother wavelet because of its potency on transient response and crouched oscillation at frequency domain. In harmonic compensation process, the detected harmonic is compensated through Hybrid Series Active Power Filter (HSAPF) based on Instantaneous Reactive Power Theory (IRPT). The efficacy of the proposed method is verified in MATLAB/SIMULINK domain and as well as with an experimental set up. The obtained results confirm the superiority of the proposed methodology than FFT analysis. This newly proposed PPF is used to make the conventional HSAPF more robust and stable.

  7. An Active Power Sharing Method among Distributed Energy Sources in an Islanded Series Micro-Grid

    Directory of Open Access Journals (Sweden)

    Wei-Man Yang

    2014-11-01

    Full Text Available Active power-sharing among distributed energy sources (DESs is not only an important way to realize optimal operation of micro-grids, but also the key to maintaining stability for islanded operation. Due to the unique configuration of series micro-grids (SMGs, the power-sharing method adopted in an ordinary AC, DC, and hybrid AC/DC system cannot be directly applied into SMGs. Power-sharing in one SMG with multiple DESs involves two aspects. On the one hand, capacitor voltage stability based on an energy storage system (ESS in the DC link must be complemented. Actually, this is a problem of power allocation between the generating unit and the ESS in the DES; an extensively researched, similar problem has been grid-off distributed power generation, for which there are good solutions. On the other hand, power-sharing among DESs should be considered to optimize the operation of a series micro-grid. In this paper, a novel method combining master control with auxiliary control is proposed. Master action of a quasi-proportional resonant controller is responsible for stability of the islanded SMG; auxiliary action based on state of charge (SOC realizes coordinated allocation of load power among the source. At the same time, it is important to ensure that the auxiliary control does not influence the master action.

  8. A New Synchronous Reference Frame-Based Method for Single-Phase Shunt Active Power Filters

    DEFF Research Database (Denmark)

    Monfared, Mohammad; Golestan, Saeed; Guerrero, Josep M.

    2013-01-01

    This paper deals with the design of a novel method in the synchronous reference frame (SRF) to extract the reference compensating current for single-phase shunt active power filters (APFs). Unlike previous works in the SRF, the proposed method has an innovative feature that it does not need...... the fictitious current signal. Frequency-independent operation, accurate reference current extraction and relatively fast transient response are other key features of the presented strategy. The effectiveness of the proposed method is investigated by means of detailed mathematical analysis. The results confirm...

  9. Development of quench protection system for HTS coils by active power method

    International Nuclear Information System (INIS)

    Nanato, N.; Tsumiyama, Y.; Kim, S.B.; Murase, S.; Seong, K.-C.; Kim, H.-J.

    2007-01-01

    Recently, HTS coils have been developed for electric power apparatuses. In superconducting coils, local and excessive joule heating may give damage to the superconducting windings when a quench occurs and therefore it is essential that the quench is detected quickly and precisely so that the coils can be safely discharged. Resistive voltage measurement method is universally used for the quench detection, however, it is vulnerable to an electromagnetic noise which causes insufficient quench detection and at least needs a central voltage tap in windings. In a large superconducting coil, a lead-wire from the central voltage tap may cause a short-circuit when high voltage will be applied. In this paper, we present a quench protection system based on the active power method which detects a quench by measuring the instantaneous active power generated in a superconducting coil. The protection system based on this method is very strong against to the noise and no more needs a central voltage tap. The performance of system developed by us is confirmed by using test coil wound with Bi-2223 HTS tapes

  10. Active Power Dispatch Method for a Wind Farm Central Controller Considering Wake Effect

    DEFF Research Database (Denmark)

    Tian, Jie; Su, Chi; N. Soltani, Mohsen

    2014-01-01

    With the increasing integration of the wind power into the power system, wind farm are required to be controlled as a single unit and have all the same control tasks as conventional power plants. The wind farm central controller receives control orders from Transmission System Operator (TSO), the...... Optimization (PSO) is used to obtain the optimal wind power for each wind turbine. A case study is carried out. The available wind power of the wind farm was compared between the traditional dispatch method and the proposed dispatch method with the consideration of the wake effect....

  11. Quench Detection and Protection for High Temperature Superconducting Transformers by Using the Active Power Method

    Science.gov (United States)

    Nanato, N.; Kobayashi, Y.

    AC high temperature superconducting (HTS) coils have been developed for transformers, motors and so on. Quench detection and protection system are essential for safety operations of the AC HTS facilities. The balance voltage method is universally used for the quench detection and protection, however especially for AC operations, the method has risks in terms of high voltage sparks. Because the method needs a voltage tap soldered to a midpoint of the coil winding and the AC HTS facilities generally operate at high voltages and therefore high voltage sparks may occur at the midpoint with no insulation. We have proposed the active power method for the quench detection and protection. The method requires no voltage tap on the midpoint of the coil winding and therefore it has in-built effectiveness for the AC HTS facilities. In this paper, we show that the method can detect the quench in an HTS transformer and moreover our proposed quench protection circuits which consist of thyristors are simple and useful for the AC HTS facilities.

  12. A Decoupling Control Method for Shunt Hybrid Active Power Filter Based on Generalized Inverse System

    Directory of Open Access Journals (Sweden)

    Xin Li

    2017-01-01

    Full Text Available In this paper, a novel decoupling control method based on generalized inverse system is presented to solve the problem of SHAPF (Shunt Hybrid Active Power Filter possessing the characteristics of 2-input-2-output nonlinearity and strong coupling. Based on the analysis of operation principle, the mathematical model of SHAPF is firstly built, which is verified to be invertible using interactor algorithm; then the generalized inverse system of SHAPF is obtained to connect in series with the original system so that the composite system is decoupled under the generalized inverse system theory. The PI additional controller is finally designed to control the decoupled 1-order pseudolinear system to make it possible to adjust the performance of the subsystem. The simulation results demonstrated by MATLAB show that the presented generalized inverse system strategy can realise the dynamic decoupling of SHAPF. And the control system has fine dynamic and static performance.

  13. Matrix pencil method-based reference current generation for shunt active power filters

    DEFF Research Database (Denmark)

    Terriche, Yacine; Golestan, Saeed; Guerrero, Josep M.

    2018-01-01

    response and works well under distorted and unbalanced voltage. Moreover, the proposed method can estimate the voltage phase accurately; this property enables the algorithm to compensate for both power factor and current unbalance. The effectiveness of the proposed method is verified using simulation...... are using the discrete Fourier transform (DFT) in the frequency domain or the instantaneous p–q theory and the synchronous reference frame in the time domain. The DFT, however, suffers from the picket-fence effect and spectral leakage. On the other hand, the DFT takes at least one cycle of the nominal...... frequency. The time-domain methods show a weakness under voltage distortion, which requires prior filtering techniques. The aim of this study is to present a fast yet effective method for generating the RCC for SAPFs. The proposed method, which is based on the matrix pencil method, has a fast dynamic...

  14. Development of quench detection/protection system based on active power method for superconducting magnet by using capacitor circuit

    International Nuclear Information System (INIS)

    Nanato, N.; Otsuka, T.; Hesaka, S.; Murase, S.

    2013-01-01

    Highlights: ► The authors have presented an active power method for quench detection. ► A method for improving its characteristics using a capacitor circuit was proposed. ► Quench detection/protection test for a Bi2223 superconducting coil was carried out. ► The proposed method was more useful than the conventional one. -- Abstract: When a quench occurs in a superconducting magnet, excessive joule heating in normal region may damage the magnet. It is necessary to detect the quench as soon as possible and discharge magnetic energy stored in the magnet. The authors have presented a quench detection/protection system based on an active power method which detects the quench regardless of a self-inductive and mutual-inductive voltages and electromagnetic noise. In the conventional active power method, the inductive voltages are removed by cancel coils. In this paper, the authors propose a method to cancel an inductive voltage using a capacitor circuit. The quench detection/protection system becomes more precise and smaller than the conventional system through the capacitor circuit

  15. Power manager and method for managing power

    NARCIS (Netherlands)

    Burchard, A.T.; Kersten, G.; Molnos, A.M.; Milutinovic, A.; Goossens, K.G.W.; Steffens, E.F.M.

    2009-01-01

    A power manager (106) and method for managing the power supplied to an electronic device is provided. Furthermore, a system wherein the power supplied to an electronic device is managed is provided. The power manager (106) is operative to monitor a hardware monitor (104) during a monitoring time

  16. Automated assessment of joint synovitis activity from medical ultrasound and power doppler examinations using image processing and machine learning methods

    Directory of Open Access Journals (Sweden)

    Rafal Cupek

    2016-11-01

    Full Text Available Objectives : Rheumatoid arthritis is the most common rheumatic disease with arthritis, and causes substantial functional disability in approximately 50% patients after 10 years. Accurate measurement of the disease activity is crucial to provide an adequate treatment and care to the patients. The aim of this study is focused on a computer aided diagnostic system that supports an assessment of synovitis severity. Material and methods : This paper focus on a computer aided diagnostic system that was developed within joint Polish–Norwegian research project related to the automated assessment of the severity of synovitis. Semiquantitative ultrasound with power Doppler is a reliable and widely used method of assessing synovitis. Synovitis is estimated by ultrasound examiner using the scoring system graded from 0 to 3. Activity score is estimated on the basis of the examiner’s experience or standardized ultrasound atlases. The method needs trained medical personnel and the result can be affected by a human error. Results : The porotype of a computer-aided diagnostic system and algorithms essential for an analysis of ultrasonic images of finger joints are main scientific output of the MEDUSA project. Medusa Evaluation System prototype uses bone, skin, joint and synovitis area detectors for mutual structural model based evaluation of synovitis. Finally, several algorithms that support the semi-automatic or automatic detection of the bone region were prepared as well as a system that uses the statistical data processing approach in order to automatically localize the regions of interest. Conclusions : Semiquantitative ultrasound with power Doppler is a reliable and widely used method of assessing synovitis. Activity score is estimated on the basis of the examiner’s experience and the result can be affected by a human error. In this paper we presented the MEDUSA project which is focused on a computer aided diagnostic system that supports an

  17. Implementation of the SFRA method as valuable tool for detection of power transformer active part deformation

    Directory of Open Access Journals (Sweden)

    Milić Saša D.

    2014-01-01

    Full Text Available The paper presents the SFRA (Sweep Frequency Response Analysis-SFRA method for analyzing frequency response of transformer windings in order to identify potential defects in the geometry of the core and winding. The most frequent problems (recognized by SFRA are: core shift, shorted or open winding, unwanted contact between core and mass, etc. Comparative analysis of this method with conventional methods is carried out in situ transformer in real hard industrial conditions. Benefits of SFRA method are great reliability and repeatability of the measurements. This method belongs to the non-invasive category. Due to the high reliability and repeatability of the measurements it is very suitable for detection of changes in the geometry of the coil and the core during prophylactic field testing, or after transporting the transformer.

  18. Outline of a method for final storage of low- and medium-active waste from possible Danish power reactors

    International Nuclear Information System (INIS)

    Brodersen, K.; Jensen, J.; Oestergaard, K.

    1977-02-01

    A method is outlined for the final storage of Danish low-and medium-active power reactor waste. The waste drums are contained in large concretre blocks placed just below the ground surface. A plant for storing waste by means of this method is sketched. It consists of a system of reinforced concrete pits with the top level with the ground surface. Each pit measures c. 5 x 5 m and is c. 6 m deep. The pits are envisaged cast with a permanent inside, step-like shuttering of thin steel plates. The volume between the drums will be cast with concrete when a pit is filled. Calculations are given of the construction and running costs. It is estimated that the final storage of reactor wastes is only a small problem regarding economy and space, and also that there is hardly doubt that full safety can be achieved. (B.P.)

  19. Series active power filter in power conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Turunen, J.

    2009-07-01

    Power quality has become an important issue nowadays for several reasons, e.g. modern society's growing dependence on electricity and the fact that poor power quality may generate significant economic losses in few moments. Probable power quality problems are, e.g. harmonics, flicker, voltage dips and supply interruptions. The power quality may be improved by using filters and compensators.The purpose of this thesis is to research the operation of the series active power filter (SAPF) in power conditioning. Therefore, this thesis presents a comparison of three series hybrid active power filters (SHAPFs) in current harmonics filtering. In addition to this, it is shown how the voltage dip compensation performance of the SAPF is improved in a unified power quality conditioner (UPQC) application.The three SHAPFs included in the comparison are series connected topology (SCT), filter connected topology (FCT) and electrically tuned LC shunt circuit (ETLC). The operating principle of these filters is to direct the harmonic currents produced by the load to flow in the LC shunt circuits instead of the supply. In the case of the SCT this phenomenon is boosted by applying so-called active resistance in the supply branch using the SAPF. In the case of the FCT a similar action is achieved by applying the compensation voltage in series with the LC shunt circuits using the SAPF. In the case of the ETLC the performance of the LC shunt circuit is enhanced by applying so-called active inductances in series with the LC shunt circuit using the SAPF. The SHAPFs are compared by searching for their best current filtering performance using various main circuit and control system configurations and loads. The operation of the SHAPFs is first analysed mathematically. After this, the current filtering performance of the SHAPFs is inspected using simulations and experimental tests. The experimental tests are carried out using SHAPF prototypes. As a result, it is shown that the current

  20. Study on Soft Phase Locked Method to Solving the Synchronization Problem of Active Power Filter in Stand-alone Power Grid

    DEFF Research Database (Denmark)

    Zhuo, Fang; Wu, Longhui; Chen, Zhe

    2009-01-01

    on zero-cross detection can't work effectively in small rating stand-alone power grid. Then a soft phase locked loop with additional filter is proposed. It can lock the phase angle on to the positive sequence of fundamental voltage accurately and rapidly. It ensures the performance of APF applied...... in the small rating stand-alone power grid. Moreover, the soft phase locked loop is easy to be implemented in a Digital Signal Processor (DSP). Simulation and experimental results validate that the soft phase locked loop has satisfactory performance.......Traditional LC filters can't work stably in small rating stand-alone power grid. So active power filter (APF) is becoming an important tool to solve the power quality problem in small rating stand-alone power grid. In most current detection algorithm of APF, it needs a synchronizing signal. Firstly...

  1. Proposal and field practice of a 'hiyarihatto' activity method for promotion of statements of participants for nuclear power plant organization

    International Nuclear Information System (INIS)

    Aoyagi, Saizo; Fujino, Hidenori; Ishii, Hirotake; Shimoda, Hiroshi; Sakuda, Hiroshi; Yoshikawa, Hidekazu; Sugiman, Toshio

    2011-01-01

    In a 'hiyarihatto' activity, workers report and discuss incident cases related to their work. Such an activity is particularly effective for cultivating participants' attitudes about safety. Nevertheless, a conventional face-to-face hiyarihatto activity includes features that are inappropriate for conduct in a nuclear power plant organization. For example, workers at nuclear power plants are geographically distributed and busy. Therefore, they have great difficulty in participating in a face-to-face hiyarihatto activity. Furthermore, workers' hesitation in discussing problems inhibits the continuation of their active participation. This study is conducted to propose a hiyarihatto activity with an asynchronous and distributed computer-mediated communication (CMC) for a nuclear power plant organization, with the demonstration of its effectiveness through field practice. The proposed method also involves the introduction of special participants who follow action guidelines for the promotion of the continuation of the activity. The method was used in an actual nuclear power plant organization. Results showed that the method is effective under some conditions, such as during periods without facility inspection. Special participants promoted the activity in some cases. Moreover, other factors affecting the activity and some improvements were identified. (author)

  2. Method of decreasing nuclear power

    International Nuclear Information System (INIS)

    Masuda, Hiromi

    1987-01-01

    Purpose: To easily attain the power decreasing in a HWLWR type reactor and improve the reactor safety. Method: The method is applied to a nuclear reactor in which the reactor reactivity is controlled by control rods and liquid posions dissolved in moderators. Means for forecasting the control rod operation amount required for the reactor power down and means for removing liquid poisons in the moderators are provided. The control rod operation amount required for the power down is forecast before the power down and the liquid poisons in the moderators are removed. Then, the control rods are inserted into a deep insertion position to reduce the reactor power. This invention can facilitate easy power down, as well as provide effects of improving the controllability in the usual operation and of avoiding abrupt power down which leads to an improved availability. (Kamimura, M.)

  3. A Data-Driven Stochastic Reactive Power Optimization Considering Uncertainties in Active Distribution Networks and Decomposition Method

    DEFF Research Database (Denmark)

    Ding, Tao; Yang, Qingrun; Yang, Yongheng

    2018-01-01

    To address the uncertain output of distributed generators (DGs) for reactive power optimization in active distribution networks, the stochastic programming model is widely used. The model is employed to find an optimal control strategy with minimum expected network loss while satisfying all......, in this paper, a data-driven modeling approach is introduced to assume that the probability distribution from the historical data is uncertain within a confidence set. Furthermore, a data-driven stochastic programming model is formulated as a two-stage problem, where the first-stage variables find the optimal...... control for discrete reactive power compensation equipment under the worst probability distribution of the second stage recourse. The second-stage variables are adjusted to uncertain probability distribution. In particular, this two-stage problem has a special structure so that the second-stage problem...

  4. Method of forecasting power distribution

    International Nuclear Information System (INIS)

    Kaneto, Kunikazu.

    1981-01-01

    Purpose: To obtain forecasting results at high accuracy by reflecting the signals from neutron detectors disposed in the reactor core on the forecasting results. Method: An on-line computer transfers, to a simulator, those process data such as temperature and flow rate for coolants in each of the sections and various measuring signals such as control rod positions from the nuclear reactor. The simulator calculates the present power distribution before the control operation. The signals from the neutron detectors at each of the positions in the reactor core are estimated from the power distribution and errors are determined based on the estimated values and the measured values to determine the smooth error distribution in the axial direction. Then, input conditions at the time to be forecast are set by a data setter. The simulator calculates the forecast power distribution after the control operation based on the set conditions. The forecast power distribution is corrected using the error distribution. (Yoshino, Y.)

  5. Ground assessment methods for nuclear power plant

    International Nuclear Information System (INIS)

    1985-01-01

    It is needless to say that nuclear power plant must be constructed on the most stable and safe ground. Reliable assessment method is required for the purpose. The Ground Integrity Sub-committee of the Committee of Civil Engineering of Nuclear Power Plant started five working groups, the purpose of which is to systematize the assessment procedures including geological survey, ground examination and construction design. The works of working groups are to establishing assessment method of activities of faults, standardizing the rock classification method, standardizing assessment and indication method of ground properties, standardizing test methods and establishing the application standard for design and construction. Flow diagrams for the procedures of geological survey, for the investigation on fault activities and ground properties of area where nuclear reactor and important outdoor equipments are scheduled to construct, were established. And further, flow diagrams for applying investigated results to design and construction of plant, and for determining procedure of liquidification nature of ground etc. were also established. These systematized and standardized methods of investigation are expected to yield reliable data for assessment of construction site of nuclear power plant and lead to the safety of construction and operation in the future. In addition, the execution of these systematized and detailed preliminary investigation for determining the construction site of nuclear power plant will make much contribution for obtaining nation-wide understanding and faith for the project. (Ishimitsu, A.)

  6. Health State Monitoring of Bladed Machinery with Crack Growth Detection in BFG Power Plant Using an Active Frequency Shift Spectral Correction Method

    Directory of Open Access Journals (Sweden)

    Weifang Sun

    2017-08-01

    Full Text Available Power generation using waste-gas is an effective and green way to reduce the emission of the harmful blast furnace gas (BFG in pig-iron producing industry. Condition monitoring of mechanical structures in the BFG power plant is of vital importance to guarantee their safety and efficient operations. In this paper, we describe the detection of crack growth of bladed machinery in the BFG power plant via vibration measurement combined with an enhanced spectral correction technique. This technique enables high-precision identification of amplitude, frequency, and phase information (the harmonic information belonging to deterministic harmonic components within the vibration signals. Rather than deriving all harmonic information using neighboring spectral bins in the fast Fourier transform spectrum, this proposed active frequency shift spectral correction method makes use of some interpolated Fourier spectral bins and has a better noise-resisting capacity. We demonstrate that the identified harmonic information via the proposed method is of suppressed numerical error when the same level of noises is presented in the vibration signal, even in comparison with a Hanning-window-based correction method. With the proposed method, we investigated vibration signals collected from a centrifugal compressor. Spectral information of harmonic tones, related to the fundamental working frequency of the centrifugal compressor, is corrected. The extracted spectral information indicates the ongoing development of an impeller blade crack that occurred in the centrifugal compressor. This method proves to be a promising alternative to identify blade cracks at early stages.

  7. Health State Monitoring of Bladed Machinery with Crack Growth Detection in BFG Power Plant Using an Active Frequency Shift Spectral Correction Method.

    Science.gov (United States)

    Sun, Weifang; Yao, Bin; He, Yuchao; Chen, Binqiang; Zeng, Nianyin; He, Wangpeng

    2017-08-09

    Power generation using waste-gas is an effective and green way to reduce the emission of the harmful blast furnace gas (BFG) in pig-iron producing industry. Condition monitoring of mechanical structures in the BFG power plant is of vital importance to guarantee their safety and efficient operations. In this paper, we describe the detection of crack growth of bladed machinery in the BFG power plant via vibration measurement combined with an enhanced spectral correction technique. This technique enables high-precision identification of amplitude, frequency, and phase information (the harmonic information) belonging to deterministic harmonic components within the vibration signals. Rather than deriving all harmonic information using neighboring spectral bins in the fast Fourier transform spectrum, this proposed active frequency shift spectral correction method makes use of some interpolated Fourier spectral bins and has a better noise-resisting capacity. We demonstrate that the identified harmonic information via the proposed method is of suppressed numerical error when the same level of noises is presented in the vibration signal, even in comparison with a Hanning-window-based correction method. With the proposed method, we investigated vibration signals collected from a centrifugal compressor. Spectral information of harmonic tones, related to the fundamental working frequency of the centrifugal compressor, is corrected. The extracted spectral information indicates the ongoing development of an impeller blade crack that occurred in the centrifugal compressor. This method proves to be a promising alternative to identify blade cracks at early stages.

  8. Development of an Active Power Reserve Management Method for DC Applied Wave-Wind Combined Generation Systems

    Directory of Open Access Journals (Sweden)

    Seungmin Jung

    2015-11-01

    Full Text Available A system that combines a wind turbine and a wave generator can share the off-shore platform and therefore mix the advantages of the transmission system construction and the power conversion system. The current hybrid generation system considers output limitation according to the instructions of the transmission system operator (TSO, and controls the profile using wind turbine pitch control. However, the integrated wave generation system utilizing a DC network does not adapt a power limitation scheme due to its mechanical constraints. In this paper, a control plan focusing on the electrical section of wave generators is formed in order to effectively manage the output profile of the hybrid generation system. The plan pays attention to power reserve flexibility for the utility grid using the analysis of the controllable elements. Comparison with the existing system is performed based on real offshore conditions. With the help of power system computer aided design (PSCAD simulation, the ability of the novel technique is estimated by proposing the real power control based on the reference signal of TSO and the reactive power capacity it produces.

  9. Analysis of thermal power calibration method

    International Nuclear Information System (INIS)

    Zagar, T.; Ravnik, M.; Persic, A.

    2000-01-01

    The methods for determining fuel element burnup have recently become interesting because of activities related to the shipment of highly enriched fuel elements back to the United States for final disposal before 2009. The most common and practical method for determining fuel element burnup in research reactors is reactor calculation. Experience has shown that burnup calculations become complicated and biased with uncertainties if a long period of reactor operation must be reproduced. Besides this, accuracy of calculated burnup is always limited with accuracy of reactor power calibration, since burnup calculation is based on calculated power density distribution, which is usually expressed in terms of power released per fuel element and normalised to the reactor power It is obvious that reactor thermal power calibration is very important for precise fuel element burnup calculation. Calculated fuel element burnup is linearly dependent on the thermal reactor power. The reactor power level may be determined from measured absolute thermal flux distribution across the core in the horizontal and vertical planes. Flux distributions are measured with activation of cadmium covered and bare foils irradiated by the steady reactor power. But it should be realised that this method is time consuming and not accurate. This method is practical only for zero power reactors and is in practice very seldom performed for other reactors (e.g. for TRIGA reactor in Ljubljana absolute thermal flux distribution was not performed since reactor reconstruction in 1991). In case of power reactors and research reactors in which a temperature rise across the core is produced and measured than a heat balance method is the most common and accurate method of determining the power output of the core. The purpose of this paper is to analyse the accuracy of calorimetric reactor power calibration method and to analyse the influence of control rod position on nuclear detector reading for TRIGA reactors

  10. Improved power performance assessment methods

    Energy Technology Data Exchange (ETDEWEB)

    Frandsen, S; Antoniou, I; Dahlberg, J A [and others

    1999-03-01

    The uncertainty of presently-used methods for retrospective assessment of the productive capacity of wind farms is unacceptably large. The possibilities of improving the accuracy have been investigated and are reported. A method is presented that includes an extended power curve and site calibration. In addition, blockage effects with respect to reference wind speed measurements are analysed. It is found that significant accuracy improvements are possible by the introduction of more input variables such as turbulence and wind shear, in addition to mean wind speed and air density. Also, the testing of several or all machines in the wind farm - instead of only one or two - may provide a better estimate of the average performance. (au)

  11. A method and system for power management

    NARCIS (Netherlands)

    Burchard, Arthur Tadeusz; Goossens, Koos Gerard Willen; Milutinovic, A.; Molnos, Anca Mariana; Steffens, Elisabeth Francisca Maria

    2009-01-01

    A method and system for power management is provided. To control power supplied to a second electronic device (106), an electronic system (100) comprises a power management subsystem (110), a first electronic device (102); The power management subsystem (110) monitors the power consumed by the first

  12. Computational methods assuring nuclear power plant structural integrity and safety: an overview of the recent activities at VTT

    International Nuclear Information System (INIS)

    Keinaenen, H.; Talja, H.; Rintamaa, R.

    1998-01-01

    Numerical, simplified engineering and standardised methods are applied in the safety analyses of primary circuit components and reactor pressure vessels. The integrity assessment procedures require input relating both to the steady state and transient loading actual material properties data and precise knowledge of the size and geometry of defects. Current procedures bold extensive information regarding these aspects. It is important to verify the accuracy of the different assessment methods especially in the case of complex structures and loading. The focus of this paper is on the recent results and development of computational fracture assessment methods at VTT Manufacturing Technology. The methods include effective engineering type tools for rapid structural integrity assessments and more sophisticated finite-element based methods. An integrated PC-based program system MASI for engineering fracture analysis is described. A summary of the verification of the methods in computational benchmark analyses and against the results of large scale experiments is presented. (orig.)

  13. Methods for Estimation of Market Power in Electric Power Industry

    Science.gov (United States)

    Turcik, M.; Oleinikova, I.; Junghans, G.; Kolcun, M.

    2012-01-01

    The article is related to a topical issue of the newly-arisen market power phenomenon in the electric power industry. The authors point out to the importance of effective instruments and methods for credible estimation of the market power on liberalized electricity market as well as the forms and consequences of market power abuse. The fundamental principles and methods of the market power estimation are given along with the most common relevant indicators. Furthermore, in the work a proposal for determination of the relevant market place taking into account the specific features of power system and a theoretical example of estimating the residual supply index (RSI) in the electricity market are given.

  14. Power generation systems and methods

    Science.gov (United States)

    Jones, Jack A. (Inventor); Chao, Yi (Inventor)

    2011-01-01

    A power generation system includes a plurality of submerged mechanical devices. Each device includes a pump that can be powered, in operation, by mechanical energy to output a pressurized output liquid flow in a conduit. Main output conduits are connected with the device conduits to combine pressurized output flows output from the submerged mechanical devices into a lower number of pressurized flows. These flows are delivered to a location remote of the submerged mechanical devices for power generation.

  15. Active Power Measurement Based on Multiwavelet Transforms

    Directory of Open Access Journals (Sweden)

    Xiao-Bing Zhang

    2014-01-01

    Full Text Available This paper discusses a new method for calculating active power in the multiwavelet domain. When the voltage and current waveforms are analyzed using multiwavelet, the active power can be calculated by simply adding the products of the multiwavelet coefficients without having to reconstruct the signals back to the time domain first and then using the traditional integration. From the simulation result, we can see that the results using multiwavelet are better than the ones using wavelet and Fourier Transforms no matter which prefilter is used.

  16. Voting Power and Shareholder Activism

    DEFF Research Database (Denmark)

    Strand, Therese; Poulsen, Thomas; Thomsen, Steen

    2010-01-01

    The article discusses the development of a voting power theory that is applied to a unique data set on Swedish shareholder meetings. The authors hypothesize that there is a positive relationship between shareholder activism and the largest shareholder's sensitivity to greater participation by small...... shareholders. It is shown that firms' amenability to small shareholder influence results in more proposals by nomination committees that are dominated by large shareholders, but fewer proposals by other shareholders. The importance of local institutions are highlighted and a call for more research regarding...... shareholder activism in alternative institutional settings is mad...

  17. Power controlling method for BWR type reactors

    International Nuclear Information System (INIS)

    Yoshida, Kenji.

    1983-01-01

    Purpose: To enable reactor operation exactly following after an aimed curve in the high power resuming and maintaining period without failures in cladding tubes. Method: Upon recovery of the reactor power to a high power level after changing the reactor power from the high power to the low power level, control rod is operated under such conditions that the linear power density after operation of the control rod does not exceed the PC envelope in the low power period, and the core flow rate is coordinated to the control rod operation. The linear power density can be suppressed within an allowable linear power density by the above operation during high power resuming and maintaining period and, as the result, PCI failures can be prevented. (Kamimura, M.)

  18. Reactor power control method upon accidents of electrical power system

    International Nuclear Information System (INIS)

    Hirose, Masao.

    1983-01-01

    Purpose: To enable to continue the operation of a BWR type reactor by avoiding the scram while suppressing the reactor power, just after the external disturbance such as earth-trouble in power-transmission network. Method: Steep power drop of an electrical generator is to be detected not only by a current-type power-load-unbalance relay but also with a power-type power-load-unbalance-relay. If steep power-drop was detected by the latter relay, a previously selected control rod is rapidly inserted into the reactor. In this way, in the case where there is a possibility of the reactor scram, the scram can be avoided by suppressing the reactor power, thus the reactor operation can be continued. (Kamimura, M.)

  19. Geometrical methods for power network analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bellucci, Stefano; Tiwari, Bhupendra Nath [Istituto Nazioneale di Fisica Nucleare, Frascati, Rome (Italy). Lab. Nazionali di Frascati; Gupta, Neeraj [Indian Institute of Technology, Kanpur (India). Dept. of Electrical Engineering

    2013-02-01

    Uses advanced geometrical methods to analyse power networks. Provides a self-contained and tutorial introduction. Includes a fully worked-out example for the IEEE 5 bus system. This book is a short introduction to power system planning and operation using advanced geometrical methods. The approach is based on well-known insights and techniques developed in theoretical physics in the context of Riemannian manifolds. The proof of principle and robustness of this approach is examined in the context of the IEEE 5 bus system. This work addresses applied mathematicians, theoretical physicists and power engineers interested in novel mathematical approaches to power network theory.

  20. Computational methods in power system analysis

    CERN Document Server

    Idema, Reijer

    2014-01-01

    This book treats state-of-the-art computational methods for power flow studies and contingency analysis. In the first part the authors present the relevant computational methods and mathematical concepts. In the second part, power flow and contingency analysis are treated. Furthermore, traditional methods to solve such problems are compared to modern solvers, developed using the knowledge of the first part of the book. Finally, these solvers are analyzed both theoretically and experimentally, clearly showing the benefits of the modern approach.

  1. Monitoring Biological Activity at Geothermal Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Peter Pryfogle

    2005-09-01

    The economic impact of microbial growth in geothermal power plants has been estimated to be as high as $500,000 annually for a 100 MWe plant. Many methods are available to monitor biological activity at these facilities; however, very few plants have any on-line monitoring program in place. Metal coupon, selective culturing (MPN), total organic carbon (TOC), adenosine triphosphate (ATP), respirometry, phospholipid fatty acid (PLFA), and denaturing gradient gel electrophoresis (DGGE) characterizations have been conducted using water samples collected from geothermal plants located in California and Utah. In addition, the on-line performance of a commercial electrochemical monitor, the BIoGEORGE?, has been evaluated during extended deployments at geothermal facilities. This report provides a review of these techniques, presents data on their application from laboratory and field studies, and discusses their value in characterizing and monitoring biological activities at geothermal power plants.

  2. Reactor power reduction system and method

    International Nuclear Information System (INIS)

    Bruno, S.J.; Dunn, S.A.; Raber, M.

    1978-01-01

    A method of operating a nuclear power reactor is disclosed which enables an accelerated power reduction of the reactor without completely shutting the reactor down. The method includes monitoring the incidents which, upon their occurrence, would require an accelerated power reduction in order to maintain the reactor in a safe operation mode; calculating the power reduction required on the occurrence of such an incident; determining a control rod insertion sequence for the normal operation of the reactor, said sequence being chosen to optimize reactor power capability; selecting the number of control rods necessary to respond to the accelerated power reduction demand, said selection being made according to a priority determined by said control rod insertion sequence; and inserting said selected control rods into the reactor core. 11 claims, 13 figures

  3. Apparatus and method for thermal power generation

    International Nuclear Information System (INIS)

    Cohen, P.; Redding, A.H.

    1978-01-01

    An improved thermal power plant and method of power generation is described which minimizes thermal stress and chemical impurity buildup in the vaporizing component, particularly beneficial under loss of normal feed fluid and startup conditions. The invention is particularly applicable to a liquid metal fast breeder reactor plant

  4. Active Power Regulation based on Droop for AC Microgrid

    DEFF Research Database (Denmark)

    Li, Chendan; Coelho, Ernane A. A.; Firoozabadi, Mehdi Savaghebi

    2015-01-01

    In this paper, two different control strategies are proposed to address the active power regulation issue in AC microgrids. The principle of power regulation in the droop controller is firstly introduced. Frequency scheduling and droop gain scheduling on top of droop control is proposed...... to successfully follow the active power command. The limitation of each method is discussed in term of small signal stability and light load sharing, respectively. Discussion on the effects of power command is also given. The simulation is carried out for both the strategies to verify the active power control...

  5. Improving RF Transmit Power and Received Signal Strength in 2.4 GHz ZigBee Based Active RFID System with Embedded Method

    Science.gov (United States)

    Po'ad, F. A.; Ismail, W.; Jusoh, J. F.

    2017-08-01

    This paper describes the experiments and analysis conducted on 2.4 GHz embedded active Radio Frequency Identification (RFID) - Wireless Sensor Network (WSN) based system that has been developed for the purposes of location tracking and monitoring in indoor and outdoor environments. Several experiments are conducted to test the effectiveness and performance of the developed system and two of them is by measuring the Radio Frequency (RF) transmitting power and Received Signal Strength (RSS) to prove that the embedded active RFID tag is capable to generate higher transmit power during data transmission and able to provide better RSS reading compared to standalone RFID tag. Experiments are carried out on two RFID tags which are active RFID tag embedded with GPS and GSM (ER2G); and standalone RFID tag communicating with the same active RFID reader. The developed ER2G contributes 12.26 % transmit power and 6.47 % RSS reading higher than standalone RFID tag. The results conclude that the ER2G gives better performance compared to standalone RFID tag and can be used as guidelines for future design improvements.

  6. Efficient Load Scheduling Method For Power Management

    Directory of Open Access Journals (Sweden)

    Vijo M Joy

    2015-08-01

    Full Text Available An efficient load scheduling method to meet varying power supply needs is presented in this paper. At peak load times the power generation system fails due to its instability. Traditionally we use load shedding process. In load shedding process disconnect the unnecessary and extra loads. The proposed method overcomes this problem by scheduling the load based on the requirement. Artificial neural networks are used for this optimal load scheduling process. For generate economic scheduling artificial neural network has been used because generation of power from each source is economically different. In this the total load required is the inputs of this network and the power generation from each source and power losses at the time of transmission are the output of the neural network. Training and programming of the artificial neural networks are done using MATLAB.

  7. Active Power Controls from Wind Power: Bridging the Gaps

    Energy Technology Data Exchange (ETDEWEB)

    Ela, E. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gevorgian, V. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Fleming, P. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Zhang, Y. C. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Singh, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Muljadi, E. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Scholbrook, A. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Aho, J. [Univ. of Colorado, Boulder, CO (United States); Buckspan, A. [Univ. of Colorado, Boulder, CO (United States); Pao, L. [Univ. of Colorado, Boulder, CO (United States); Singhvi, V. [Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); Tuohy, A. [Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); Pourbeik, P. [Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); Brooks, D. [Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); Bhatt, N. [Electric Power Research Inst. (EPRI), Palo Alto, CA (United States)

    2014-01-01

    This paper details a comprehensive study undertaken by the National Renewable Energy Laboratory, Electric Power Research Institute, and the University of Colorado to understand how the contribution of wind power providing active power control (APC) can benefit the total power system economics, increase revenue streams, improve the reliability and security of the power system, and provide superior and efficient response while reducing any structural and loading impacts that may reduce the life of the wind turbine or its components. The study includes power system simulations, control simulations, and actual field tests using turbines at NREL's National Wind Technology Center (NWTC). The study focuses on synthetic inertial control, primary frequency control, and automatic generation control, and analyzes timeframes ranging from milliseconds to minutes to the lifetime of wind turbines, locational scope ranging from components of turbines to large wind plants to entire synchronous interconnections, and additional topics ranging from economics to power system engineering to control design.

  8. Method for analysing the adequacy of electric power systems with wind power plants and energy storages

    Directory of Open Access Journals (Sweden)

    Perzhabinsky Sergey

    2017-01-01

    Full Text Available Currently, renewable energy sources and energy storage devices are actively introduced into electric power systems. We developed method to analyze the adequacy of these electric power systems. The method takes into account the uncertainty of electricity generation by wind power plants and the processes of energy storage. The method is based on the Monte Carlo method and allowed to use of long-term meteorological data in open access. The performed experimental research of electrical power system is constructed on the basis of the real technical and meteorological data. The method allows to estimate of effectiveness of introducing generators based on renewable energy sources and energy storages in electric power systems.

  9. Power decoupling method for single phase differential buck converter

    DEFF Research Database (Denmark)

    Yao, Wenli; Tang, Yi; Zhang, Xiaobin

    2015-01-01

    inverter to improve the dc link power quality, and an improved active power decoupling method is proposed to achieve ripple power reduction for both AC-DC and DC-AC conversions. The ripple energy storage is realized by the filter capacitors, which are connected between the output terminal and the negative...... generation technique is proposed to provide accurate ripple power compensation, and closed-loop controllers are also designed based on small signal models. The effectiveness of this power decoupling method is verified by detailed simulation studies as well as laboratory prototype experimental results....... dc bus. By properly controlling the differential mode voltage of the capacitors, it is possible to transfer desired energy between the DC port and AC port. The common mode voltage is controlled in such a way that the ripple power on the dc side will be reduced. Furthermore, an autonomous reference...

  10. Second Order Generalized Integrator Based Reference Current Generation Method for Single-Phase Shunt Active Power Filters Under Adverse Grid Conditions

    DEFF Research Database (Denmark)

    Golestan, Saeed; Monfared, Mohammad; Guerrero, Josep M.

    2013-01-01

    The reference current generation (RCG) is a crucial part in the control of a shunt active power filter (APF). A variety of RCG techniques have been proposed in literature. Among these, the instantaneous reactive power theory, called pq theory, is probably the most widely used technique. The pq...... theory offers advantages such as satisfactory steady-state and dynamic performance, and at the same time simple digital implementation, however its application was limited to three-phase systems. To exploit the advantages of pq theory in single-phase systems, the single-phase pq theory has been proposed...... recently. In this paper, a simple and effective implementation of the single phase pq theory for single-phase shunt APFs is proposed. The suggested approach is based on employing second order generalized integrators (SOGI), and a phase locked loop (PLL). To fine tune the control parameters, a systematic...

  11. Hydrothermal optimal power flow using continuation method

    International Nuclear Information System (INIS)

    Raoofat, M.; Seifi, H.

    2001-01-01

    The problem of optimal economic operation of hydrothermal electric power systems is solved using powerful continuation method. While in conventional approach, fixed generation voltages are used to avoid convergence problems, in the algorithm, they are treated as variables so that better solutions can be obtained. The algorithm is tested for a typical 5-bus and 17-bus New Zealand networks. Its capabilities and promising results are assessed

  12. Method of operating BWR type power plants

    International Nuclear Information System (INIS)

    Koyama, Kazuaki.

    1981-01-01

    Purpose: To improve the operation efficiency of BWR type reactors by reducing the time from the start-up of the reactor to the start-up of the turbine and electrical generator, as well as decrease the pressure difference in each of the sections of the pressure vessel to thereby extend its life span. Method: The operation comprises switching the nuclear reactor from the shutdown mode to the start-up mode, increasing the reactor power to a predetermined level lower than a rated power while maintaining the reactor pressure to a predetermined level lower than a rated pressure, starting up a turbine and an electrical generator in the state of the predetermined reactor pressure and the reactor power to connect the electrical generator to the power transmission system and, thereafter, increasing the reactor pressure and the reactor power to the predetermined rated pressure and rated power respectively. This can shorten the time from the start-up of the reactor to the start of the power transmission system, whereby the operation efficiency of the power plant can be improved. (Moriyama, K.)

  13. New method in obtaining correction factor of power confirming

    International Nuclear Information System (INIS)

    Deng Yongjun; Li Rundong; Liu Yongkang; Zhou Wei

    2010-01-01

    Westcott theory is the most widely used method in reactor power calibration, which particularly suited to research reactor. But this method is very fussy because lots of correction parameters which rely on empirical formula to special reactor type are needed. The incidence coefficient between foil activity and reactor power was obtained by Monte-Carlo calculation, which was carried out with precise description of the reactor core and the foil arrangement position by MCNP input card. So the reactor power was determined by the core neutron fluence profile and the foil activity placed in the position for normalization use. The characteristic of this new method is simpler, more flexible and accurate than Westcott theory. In this paper, the results of SPRR-300 obtained by the new method in theory were compared with the experimental results, which verified the possibility of this new method. (authors)

  14. Comparison of power curve monitoring methods

    Directory of Open Access Journals (Sweden)

    Cambron Philippe

    2017-01-01

    Full Text Available Performance monitoring is an important aspect of operating wind farms. This can be done through the power curve monitoring (PCM of wind turbines (WT. In the past years, important work has been conducted on PCM. Various methodologies have been proposed, each one with interesting results. However, it is difficult to compare these methods because they have been developed using their respective data sets. The objective of this actual work is to compare some of the proposed PCM methods using common data sets. The metric used to compare the PCM methods is the time needed to detect a change in the power curve. Two power curve models will be covered to establish the effect the model type has on the monitoring outcomes. Each model was tested with two control charts. Other methodologies and metrics proposed in the literature for power curve monitoring such as areas under the power curve and the use of statistical copulas have also been covered. Results demonstrate that model-based PCM methods are more reliable at the detecting a performance change than other methodologies and that the effectiveness of the control chart depends on the types of shift observed.

  15. Power to Production: Activity Guide.

    Science.gov (United States)

    Massachusetts Univ., Lowell. Tsongas Industrial History Center.

    This field trip program consists of a 90-minute interpretive tour and a 90-minute hands-on workshop. The tour and workshop explore the role of water power in the Industrial Revolution. On the tour, students discover firsthand the unique resources of Lowell, Massachusetts, and the Park, while the workshop brings these historic resources to life as…

  16. Power system damping - Structural aspects of controlling active power

    Energy Technology Data Exchange (ETDEWEB)

    Samuelsson, O.

    1997-04-01

    Environmental and economical aspects make it difficult to build new power lines and to reinforce existing ones. The continued growth in demand for electric power must therefore to a great extent be met by increased loading of available lines. A consequence is that power system damping is reduced, leading to a risk of poorly damped power oscillations between the generators. This thesis proposes the use of controlled active loads to increase damping of such electro-mechanical oscillations. The focus is on structural aspects of controller interaction and of sensor and actuator placement. On-off control based on machine frequency in a single machine infinite bus system is analysed using energy function analysis and phase plane plots. An on-off controller with estimated machine frequency as input has been implemented. At a field test it damped oscillations of a 0.9 MW hydro power generator by controlling a 20kW load. The linear analysis uses two power system models with three and twenty-three machines respectively. Each damper has active power as output and local bus frequency or machine frequency as input. The power system simulator EUROSTAG is used both for generation of the linearized models and for time simulations. Measures of active power mode controllability and phase angle mode observability are obtained from the eigenvectors of the differential-algebraic models. The geographical variation in the network of these quantities is illustrated using the resemblance to bending modes of flexible mechanical structures. Eigenvalue sensitivities are used to determine suitable damper locations. A spring-mass equivalent to an inter-area mode provides analytical expressions, that together with the concept of impedance matching explain the structural behaviour of the power systems. For large gains this is investigated using root locus plots. 64 refs, 99 figs, 20 tabs

  17. Atomic power plant and its operation method

    International Nuclear Information System (INIS)

    Yamamoto, Fumiaki; Higashio, Satoru.

    1986-01-01

    Purpose: To improve operation performance by partially restraining local over power in the axial power distribution of the reactor core by properly controlling the reactor pressure and furthermore by smoothly and properly performing reactor start-up operation in a short time while maintaining fuel integrity. Method: With the reactor pressure input to the pressure controller from the pressure detector, the valve opening of the main steam adjusting valve is adjusted so that the pressure will decrease when the reactor is started up. Also the adjusting valve is controlled so that the pressure will be lower than the set value of rated pressure, thus changing the axial distribution of void. In the meantime, with the stored state of xenon stored along with the increase of reactor power taken into consideration, the reactor pressure is increased as high as the rated value until the reactor power reaches to the rated power, thereby alleviating the local increase of reactor power without changing the whole reactor power and also enabling substantial reduction of reactor start-up time while maintaining reactor integrity. (Horiuchi, T.)

  18. LED lamp power management system and method

    Science.gov (United States)

    Gaines, James; Clauberg, Bernd; Van Erp, Josephus A. M.

    2013-03-19

    An LED lamp power management system and method including an LED lamp having an LED controller 58; a plurality of LED channels 60 operably connected to the LED controller 58, each of the plurality of LED channels 60 having a channel switch 62 in series with at least one shunted LED circuit 83, the shunted LED circuit 83 having a shunt switch 68 in parallel with an LED source 80. The LED controller 58 reduces power loss in one of the channel switch 62 and the shunt switch 68 when LED lamp electronics power loss (P.sub.loss) exceeds an LED lamp electronics power loss limit (P.sub.lim); and each of the channel switches 62 receives a channel switch control signal 63 from the LED controller 58 and each of the shunt switches 68 receives a shunt switch control signal 69 from the LED controller 58.

  19. Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices

    Science.gov (United States)

    Chassin, David P [Pasco, WA; Donnelly, Matthew K [Kennewick, WA; Dagle, Jeffery E [Richland, WA

    2011-12-06

    Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices are described. In one aspect, an electrical power distribution control method includes providing electrical energy from an electrical power distribution system, applying the electrical energy to a load, providing a plurality of different values for a threshold at a plurality of moments in time and corresponding to an electrical characteristic of the electrical energy, and adjusting an amount of the electrical energy applied to the load responsive to an electrical characteristic of the electrical energy triggering one of the values of the threshold at the respective moment in time.

  20. Method and apparatus for thermal power generation

    International Nuclear Information System (INIS)

    Mangus, J.D.

    1979-01-01

    A method is described for power generation from a recirculating superheat-reheat circuit with multiple expansion stages which alleviates complex control systems and minimizes thermal cycling of system components, particularly the reheater. The invention includes preheating cold reheat fluid from the first expansion stage prior to its entering the reheater with fluid from the evaporator or drum component

  1. Analysis and control of a shunt active power filter

    Energy Technology Data Exchange (ETDEWEB)

    Ottersten, R.; Petersson, Andreas [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Electric Power Engineering

    1999-09-01

    This report deals with active power filtering of low-frequency current harmonics. The active filter consists of a forced-commutated voltage source inverter with a digital control system. The aim of this master thesis is to investigate the performance of a shunt active power filter, and the parameters influence on the system performance. Three different harmonic identification methods are presented and compared. The shunt active power filter is very well suited for harmonic current reduction, provided that the phase shift due to the digital implementation of the control system is compensated. The performance of the active power filter depends on the switching frequency. When using individual harmonic detection methods the amount of compensation can be fully controlled for each current harmonic.

  2. Active Learning Methods

    Science.gov (United States)

    Zayapragassarazan, Z.; Kumar, Santosh

    2012-01-01

    Present generation students are primarily active learners with varied learning experiences and lecture courses may not suit all their learning needs. Effective learning involves providing students with a sense of progress and control over their own learning. This requires creating a situation where learners have a chance to try out or test their…

  3. A simplified method of power calibration

    International Nuclear Information System (INIS)

    Jones, M.; Elliott, A.

    1974-01-01

    The Nuclear Reactor Facility, University of Missouri Rolla, has developed a unique method of power calibration for pool type reactors. Since water is incompressible it can be assumed that a rise in the water level of the pool while operating at power can be attributed to the heat input from the reactor core. Water level changes of a small magnitude are easily detectable. This method has proven to be less costly, less time consuming, and more reproducible than the conventional gold foil calibration, and has proven to be more accurate than a heat balance because several problems with heat flow through the walls and to the atmosphere are automatically compensated for with this method. The accuracy of this means of calibration depends upon the accuracy of the measurement of the water level and can normally be expected to be two to four percent. (author)

  4. A simplified method of power calibration

    Energy Technology Data Exchange (ETDEWEB)

    Jones, M; Elliott, A [University of Missouri-Rolla (United States)

    1974-07-01

    The Nuclear Reactor Facility, University of Missouri Rolla, has developed a unique method of power calibration for pool type reactors. Since water is incompressible it can be assumed that a rise in the water level of the pool while operating at power can be attributed to the heat input from the reactor core. Water level changes of a small magnitude are easily detectable. This method has proven to be less costly, less time consuming, and more reproducible than the conventional gold foil calibration, and has proven to be more accurate than a heat balance because several problems with heat flow through the walls and to the atmosphere are automatically compensated for with this method. The accuracy of this means of calibration depends upon the accuracy of the measurement of the water level and can normally be expected to be two to four percent. (author)

  5. Nuclear power company activity based costing management analysis

    International Nuclear Information System (INIS)

    Xu Dan

    2012-01-01

    With Nuclear Energy Industry development, Nuclear Power Company has the continual promoting stress of inner management to the sustainable marketing operation development. In view of this, it is very imminence that Nuclear Power Company should promote the cost management levels and built the nuclear safety based lower cost competitive advantage. Activity based costing management (ABCM) transfer the cost management emphases from the 'product' to the 'activity' using the value chain analysis methods, cost driver analysis methods and so on. According to the analysis of the detail activities and the value chains, cancel the unnecessary activity, low down the resource consuming of the necessary activity, and manage the cost from the source, achieve the purpose of reducing cost, boosting efficiency and realizing the management value. It gets the conclusion from the detail analysis with the nuclear power company procedure and activity, and also with the selection to 'pieces analysis' of the important cost related project in the nuclear power company. The conclusion is that the activities of the nuclear power company has the obviously performance. It can use the management of ABC method. And with the management of the procedure and activity, it is helpful to realize the nuclear safety based low cost competitive advantage in the nuclear power company. (author)

  6. A calorimetric method to determine water activity.

    Science.gov (United States)

    Björklund, Sebastian; Wadsö, Lars

    2011-11-01

    A calorimetric method to determine water activity covering the full range of the water activity scale is presented. A dry stream of nitrogen gas is passed either over the solution whose activity should be determined or left dry before it is saturated by bubbling through water in an isothermal calorimeter. The unknown activity is in principle determined by comparing the thermal power of vaporization related to the gas stream with unknown activity to that with zero activity. Except for three minor corrections (for pressure drop, non-perfect humidification, and evaporative cooling) the unknown water activity is calculated solely based on the water activity end-points zero and unity. Thus, there is no need for calibration with references with known water activities. The method has been evaluated at 30 °C by measuring the water activity of seven aqueous sodium chloride solutions ranging from 0.1 mol kg(-1) to 3 mol kg(-1) and seven saturated aqueous salt solutions (LiCl, MgCl(2), NaBr, NaCl, KCl, KNO(3), and K(2)SO(4)) with known water activities. The performance of the method was adequate over the complete water activity scale. At high water activities the performance was excellent, which is encouraging as many other methods used for water activity determination have limited performance at high water activities. © 2011 American Institute of Physics

  7. Simple Activities for Powerful Impact

    Science.gov (United States)

    LaConte, K.; Shupla, C. B.; Dusenbery, P.; Harold, J. B.; Holland, A.

    2016-12-01

    STEM education is having a transformational impact on libraries across the country. The STAR Library Education Network (STAR_Net) provides free Science-Technology Activities & Resources that are helping libraries to engage their communities in STEM learning experiences. Hear the results of a national 2015 survey of library and STEM professionals and learn what STEM programming is currently in place in public libraries and how libraries approach and implement STEM programs. Experience hands-on space science activities that are being used in library programs with multiple age groups. Through these hands-on activities, learners explore the nature of science and employ science and engineering practices, including developing and using models, planning and carrying out investigations, and engaging in argument from evidence (NGSS Lead States, 2013). Learn how STAR_Net can help you print (free!) mini-exhibits and educator guides. Join STAR_Net's online community and access STEM resources and webinars to work with libraries in your local community.

  8. THE PHASE REACTOR INDUCTANCE SELECTION TECHNIQUE FOR POWER ACTIVE FILTER

    Directory of Open Access Journals (Sweden)

    D. V. Tugay

    2016-12-01

    Full Text Available Purpose. The goal is to develop technique of the phase inductance power reactors selection for parallel active filter based on the account both low-frequency and high-frequency components of the electromagnetic processes in a power circuit. Methodology. We have applied concepts of the electrical circuits theory, vector analysis, mathematical simulation in Matlab package. Results. We have developed a new technique of the phase reactors inductance selection for parallel power active filter. It allows us to obtain the smallest possible value of THD network current. Originality. We have increased accuracy of methods of the phase reactor inductance selection for power active filter. Practical value. The proposed technique can be used in the design and manufacture of the active power filter for real objects of energy supply.

  9. Development of low-activation design method for reduction of radioactive waste (2). Precise neutron flux and activation estimation of nuclear power plants using MATXSLIB-J33T10

    International Nuclear Information System (INIS)

    Uematsu, Mikio; Hayashi, Katsumi; Nemezawa, Shigeki; Ogata, Tomohiro; Nakata, Mikihiro; Kinno, Masaharu; Yamaguchi, Katsuyoshi; Saito, Minoru; Hasegawa, Akira

    2008-01-01

    We have been developing low-activation concrete for biological shielding wall of nuclear power plants, for the purpose of reducing large amount of radioactive waste. Based on measurement of Eu and Co content in various aggregate candidates, limestone and electro-fused alumina were selected as the most feasible aggregate for low activation concrete. Induced activity in shielding wall was calculated for both low activation concrete and ordinary concrete using neutron flux obtained from DORT two-dimensional calculation made for typical ABWR and APWR models. We have prepared new cross section library named 'MATXSLIB-J33T10 that has multi-group structure in thermal energy. The library was processed from evaluated cross section library JENDL 3.3 by using NJOY 99.83. Activation cross section library for ORIGEN-79 code is prepared for each activation calculation case by collapsing JENDL-3.3 originated 183-group constants into 3-group activation cross section using 183-group neutron flux. One-group activation cross section was also prepared in the same manner for ORIGEN2 calculation. The ΣD/C value results for low-activation concrete was sufficiently low comparing to the ordinary concrete. By using the developed low-activation concrete, activation level of biological shielding wall concrete will be effectively decreased. The use of the developed low-activation concrete will contribute to economization of nuclear power plants decommissioning by reducing large amount of radioactive concrete waste. (author)

  10. Selection of low activation materials for fusion power plants using ACAB system: the effect of computational methods and cross section uncertainties on waste management assessment

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, M.; Sanz, J.; Rodriguez, A.; Falquina, R. [Universidad Nacional de Educacion a Distancia (UNED), Dept. of Power Engineering, Madrid (Spain); Cabellos, O.; Sanz, J. [Universidad Politecnica de Madrid, Instituto de Fusion Nuclear (UPM) (Spain)

    2003-07-01

    The feasibility of nuclear fusion as a realistic option for energy generation depends on its radioactive waste management assessment. In this respect, the production of high level waste is to be avoided and the reduction of low level waste volumes is to be enhanced. Three different waste management options are commonly regarded in fusion plants: Hands-on Recycling, Remote Recycling and Shallow Land Burial (SLB). Therefore, important research work has been undertaken to find low activation structural materials. In performing this task, a major issue is to compute the concentration limits (CLs) for all natural elements, which will be used to select the intended constituent elements of a particular Low Activation Material (LAM) and assess how much the impurities can deteriorate the waste management properties. Nevertheless, the reliable computation of CLs depends on the accuracy of nuclear data (mainly activation cross-sections) and the suitability of the computational method both for inertial and magnetic fusion environments. In this paper the importance of nuclear data uncertainties and mathematical algorithms used in different activation calculations for waste management purposes will be studied. Our work is centred on the study of {sup 186}W activation under first structural wall conditions of Hylife-II inertial fusion reactor design. The importance of the dominant transmutation/decay sequence has been documented in several publications. From a practical point of view, W is used in low activation materials for fusion applications: Cr-W ferritic/martensitic steels, and the need to better compute its activation has been assessed, in particular in relation to the cross-section uncertainties for reactions leading to Ir isotopes. {sup 192n}Ir and {sup 192}Ir reach a secular equilibrium, and {sup 192n}Ir is the critical one for waste management, with a half life of 241 years. From a theoretical point of view, this is one of the most complex chains appearing in

  11. SPEED POWER AFTER DIFFERENT TRAINING METHODS

    Directory of Open Access Journals (Sweden)

    Milan Gužvica

    2011-09-01

    Full Text Available As the strength is a very important capability, with which are more or less, related and all other motor skills relevant to the successful conduct of sports fight in karate, we were interested in what extent the ability of the speed of force development changes under the influence of different types of loads. For this purpose we used two different methods: the development of speed power with weights and plyometric method. Research is organized on a sample of 20 subjects (first year students of the College of Internal Affairs in Banja Luka, divided into two groups, of which only 12 students responded to the demands of research. The program was implemented during the period of six weeks for two hours per week. Before beginning and three days after the training process, we also tested levels of speed power using eight specific motor tests. After completion of the initial and final measurements, data were analyzed by appropriate statistical procedures, where all respondents, across the various tests, achieved better results. However, statistically significant differences were not obtained in both groups. Specifically, statistically significant differences were obtained in the group T across the various tests, while in group P, statistically significant differences were not obtained in three tests conducted. Given results allowed us that, with caution, we conclude that the method of working with weights, in a limited period of time, when it comes to beginners, is still more efficient than the plyometric method of work. Therefore recommendation for increasing the speed power, in a limited period of time, is to use a method of working with weights.

  12. Effective Methods of Nuclear Power Technology Transfer

    International Nuclear Information System (INIS)

    Shave, D. F.; Kent, G. F.; Giambusso, A.

    1987-01-01

    An effective technology transfer program is a necessary and significant step towards independence in nuclear power technology. Attaining success in the conduct of such a program is a result of a) the donor and recipient jointly understanding the fundamental concepts of the learning process, b) sharing a mutual philosophy involving a partnership relationship, c) joint and careful planning, d) rigorous adherence to proven project management techniques, and e) presence of adequate feedback to assure continuing success as the program proceeds. Several years ago, KEPCO President Park, Jung-KI presented a paper on technology in which he stated, 'Nuclear technology is an integration of many unit disciplines, and thus requires extensive investment and training in order to establish the base for efficient absorption of transferred technology.' This paper addresses President Park's observations by discussing the philosophy, approach, and mechanisms that are necessary to support an efficient and effective process of nuclear power technology transfer. All technical content and presentation methods discussed are based on a technology transfer program developed by Stone and Webster, as an Engineer/Constructor for nuclear power plants, and are designed and implemented to promote the primary program goal - the ability of the trainees and the organization to perform specific nuclear power related multi-discipline function independently and competitively

  13. Indirect control of a single-phase active power filter

    Directory of Open Access Journals (Sweden)

    Mihai CULEA

    2006-12-01

    Full Text Available The control of shunt active power filters using PWM inverters consists in generating a reference by separating, using different methods, the harmonics to be eliminated. The methods used are time-consuming and need dedicated control and signal processing equipments. To avoid these setbacks a new method is proposed in the paper. The active power filter is a current PWM rectifier with voltage output and with a capacitor on the DC side. The PWM rectifier is controlled so that the sum of its current and the load’s current is a sinusoid. The control block as well as simulation results are presented.

  14. Method of diagnosing a nuclear power plant

    International Nuclear Information System (INIS)

    Tamaoki, Tetsuo; Kawano, Koji

    1983-01-01

    Purpose : To exactly diagnose a nuclear power plant even upon occurrence of an abnormal state. Method : A statistical data calculation device prepares multidimensional vectors on every statistical amount for the unit of flowrate, pressure, temperature and neutron flux data in a nuclear power plant. A comparison-and-reference device compares them with the statistical amount rendered into multi-dimensional vectors corresponding to the generation of abnormality on every time in a normal operation for each of the fluctuation amount stored in a comparison and reference-value-store device. The diagnosis device performs diagnosis while using both of the standard pattern previously prepared and stored in the comparison and standard-value-store device and the pattern learnt and stored in the comparison and reference-value-store device. (Seki, T.)

  15. Early Prevention Method for Power Systems Instability

    DEFF Research Database (Denmark)

    Dmitrova, Evgenia

    containing no voltage sources). The main functionality of the early prevention method is to deliver control solution allowing escape from instability on the basis of data obtained by PMU measurements. The developed algorithm performs identification of the optimal node for countermeasure application...... instability was created. Utilizing synthetic PMU data, the early prevention method proposed a location and an amount of the countermeasure which will prevent instability; the prediction of the resulting stability margins corresponding to application of the suggested countermeasure was carried out....... The predicted effect of the suggested countermeasure application is in a good agreement with the results obtained by RMS dynamic simulation. Developed method enables adaptive preventive control for near real-time stability maintenance. The achieved results are opening promising perspective for power system...

  16. Requirements Specication for Ampliers and Power Supplies in Active Loudspeakers

    DEFF Research Database (Denmark)

    Schneider, Henrik; Jensen, Lasse Crone; Petersen, Lars Press

    2014-01-01

    This work aims to provide designers with a method to develop a requirements specication for power supplies and ampliers in active loudspeakers. The motivation is to avoid over-sizing and unnecessary cost. A realistic estimation of the power supplied during playback of audio in a given loudspeaker...... is obtained by considering a wide range of audio source material, loudness normalization of the source material, crossover ltering, driver characteristics as well as a perceived maximum loudness/volume level. The results from analysing a sub-woofer and a woofer reveals the peak power, peak voltage, peak...... current and apparent power - thus providing a solid foundation for a requirement specication....

  17. A simple approach to calculate active power of electrosurgical units

    Directory of Open Access Journals (Sweden)

    André Luiz Regis Monteiro

    Full Text Available Abstract Introduction: Despite of more than a hundred years of electrosurgery, only a few electrosurgical equipment manufacturers have developed methods to regulate the active power delivered to the patient, usually around an arbitrary setpoint. In fact, no manufacturer has a method to measure the active power actually delivered to the load. Measuring the delivered power and computing it fast enough so as to avoid injury to the organic tissue is challenging. If voltage and current signals can be sampled in time and discretized in the frequency domain, a simple and very fast multiplication process can be used to determine the active power. Methods This paper presents an approach for measuring active power at the output power stage of electrosurgical units with mathematical shortcuts based on a simple multiplication procedure of discretized variables – frequency domain vectors – obtained through Discrete Fourier Transform (DFT applied on time-sampled voltage and current vectors. Results Comparative results between simulations and a practical experiment are presented – all being in accordance with the requirements of the applicable industry standards. Conclusion An analysis is presented comparing the active power analytically obtained through well-known voltage and current signals against a computational methodology based on vector manipulation using DFT only for time-to-frequency domain transformation. The greatest advantage of this method is to determine the active power of noisy and phased out signals with neither complex DFT or ordinary transform methodologies nor sophisticated computing techniques such as convolution. All results presented errors substantially lower than the thresholds defined by the applicable standards.

  18. System and method for advanced power management

    Science.gov (United States)

    Atcitty, Stanley [Albuquerque, NM; Symons, Philip C [Surprise, AZ; Butler, Paul C [Albuquerque, NM; Corey, Garth P [Albuquerque, NM

    2009-07-28

    A power management system is provided that includes a power supply means comprising a plurality of power supply strings, a testing means operably connected to said plurality of power supply strings for evaluating performance characteristics of said plurality of power supply strings, and a control means for monitoring power requirements and comprising a switching means for controlling switching of said plurality of power supply strings to said testing means.

  19. Activity based costing (ABC Method

    Directory of Open Access Journals (Sweden)

    Prof. Ph.D. Saveta Tudorache

    2008-05-01

    Full Text Available In the present paper the need and advantages are presented of using the Activity BasedCosting method, need arising from the need of solving the information pertinence issue. This issue has occurreddue to the limitation of classic methods in this field, limitation also reflected by the disadvantages ofsuch classic methods in establishing complete costs.

  20. Diagnosing method for nuclear power plant

    International Nuclear Information System (INIS)

    Sonoda, Yukio.

    1991-01-01

    When an abnormality occurs in a nuclear power plant, the abnormality is diagnosed, at present, graphic waveforms obtained by applying signal processing such as high speed Fourier transformation, etc. to fluctuation ingredients (noises) of process signals such as neutron fluxes, and plotting a power spectral density relative to a frequency. However, expert technical knowledges are required for interpreting the waveforms and it is difficult for field operators and persons for maintenance to judge them. Then, in the present invention, patterns of the power spectral density are inputted for pattern recognition by using a neural net so that any of patterns experienced in the past can be identified. If an unknown pattern appears, it is automatically studied for identification in subsequent cases. Then, the known abnormality of the plant can be monitored and causes thereof can be identified in an early stage, as well as it is possible to diagnose unknown abnormalities in subsequent situation. This method is effective for monitoring and maintaining the integrity, and can avoid unnecessary scram to improve plant operation factor. (N.H.)

  1. The Power Quality Compensation Strategy for Power Distribution System Based on Hybrid Parallel Active Power Filters

    Directory of Open Access Journals (Sweden)

    Rachid DEHINI

    2010-12-01

    Full Text Available In this paper, the main aim is to confront the performance of shunt active power filter (SAPF and the shunt hybrid active power filter (SHAPF to achieve flexibility and reliability of the filter devices. Both of the two devices used the classical proportional-integral controller for pulse generation to trigger the inventers MOSFET’s. In the adopted hybrid active filter there is a passive power filter with high power rating to filter the low order harmonies and one active filter with low power rating to filter the other high order harmonies. In order to investigate the effectiveness of (SHAPF, the studies have been accomplished using simulation with the MATLAB-SIMULINK. The results show That (SHAPF is more effective than (SAPF, and has lower cost.

  2. Design and control of hybrid active power filters

    CERN Document Server

    Lam, Chi-Seng

    2014-01-01

    Design and Control of Hybrid Active Power Filters presents an overview of the current quality problems and their compensators. To get a balance between the system cost and performance, hybrid active power filters (HAPFs) are valuable. The book presents the coverage of resonance phenomena prevention capability, filtering performance and system robustness analysis of HAPF; nonlinear inverter current slope characteristics and their linear operation region requirement analysis of the hysteresis PWM for the HAPF; minimum inverter capacity design procedure of HAPF, adaptive dc-link voltage controller for the HAPF and the real design example of a 220V 10kVA HAPF, in which the system performance analysis method, minimum dc voltage deduction concept and adaptive dc voltage idea can be further extended into the other active compensators, such as APF, static synchronous compensator STATCOM, etc. This book will benefit researchers, graduate students, and electrical power engineers in the field of power-quality compensati...

  3. Method for reducing power consumption in a state retaining circuit, state reaining circuit and electronic device.

    NARCIS (Netherlands)

    2006-01-01

    A method for reducing the power consumption in a state retaining circuit during a standby mode is disclosed comprising, in an active state, providing a regular power supply (VDD) and a standby power supply (VDD STANDBY) to the state retaining circuit; for a transition from an active state to a

  4. Power Ramp Limitation capabilities of Large PV Power Plants with Active Power Reserves

    DEFF Research Database (Denmark)

    Bogdan, Craciun; Kerekes, Tamas; Sera, Dezso

    2017-01-01

    Power Ramp Limitation (PRL) is likely to become a requirement for large scale photovoltaic power plants (LPVPPs) in order to allow the increase of PV penetration levels. Especially in islands with reduced inertia capability, this problem is more stringent: high power ramp can be caused by either...... fast irradiance changes or other participant generators for example wind power, or loads. In order to compensate for the power mismatch, LPVPPs must use Active Power Reserve (APR), by either curtailment or auxiliary storage. The paper proposes a PRL control structure for dynamic APR sizing...... and deployment. The selected test case is the power system of Puerto Rico (PREPA), modeled using the modified IEEE 12 bus benchmark system, with different levels of PV penetration. It is shown that LPVPP with PRL can effectively reduce the ramping rate of the participating generators. Considering that the large...

  5. Neutron activation analysis: principle and methods

    International Nuclear Information System (INIS)

    Reddy, A.V.R.; Acharya, R.

    2006-01-01

    Neutron activation analysis (NAA) is a powerful isotope specific nuclear analytical technique for simultaneous determination of elemental composition of major, minor and trace elements in diverse matrices. The technique is capable of yielding high analytical sensitivity and low detection limits (ppm to ppb). Due to high penetration power of neutrons and gamma rays, NAA experiences negligible matrix effects in the samples of different origins. Depending on the sample matrix and element of interest NAA technique is used non-destructively, known as instrumental neutron activation analysis (INAA), or through chemical NAA methods. The present article describes principle of NAA, different methods and gives a overview some applications in the fields like environment, biology, geology, material sciences, nuclear technology and forensic sciences. (author)

  6. Direct current power delivery system and method

    Science.gov (United States)

    Zhang, Di; Garces, Luis Jose; Dai, Jian; Lai, Rixin

    2016-09-06

    A power transmission system includes a first unit for carrying out the steps of receiving high voltage direct current (HVDC) power from an HVDC power line, generating an alternating current (AC) component indicative of a status of the first unit, and adding the AC component to the HVDC power line. Further, the power transmission system includes a second unit for carrying out the steps of generating a direct current (DC) voltage to transfer the HVDC power on the HVDC power line, wherein the HVDC power line is coupled between the first unit and the second unit, detecting a presence or an absence of the added AC component in the HVDC power line, and determining the status of the first unit based on the added AC component.

  7. Active learning methods for interactive image retrieval.

    Science.gov (United States)

    Gosselin, Philippe Henri; Cord, Matthieu

    2008-07-01

    Active learning methods have been considered with increased interest in the statistical learning community. Initially developed within a classification framework, a lot of extensions are now being proposed to handle multimedia applications. This paper provides algorithms within a statistical framework to extend active learning for online content-based image retrieval (CBIR). The classification framework is presented with experiments to compare several powerful classification techniques in this information retrieval context. Focusing on interactive methods, active learning strategy is then described. The limitations of this approach for CBIR are emphasized before presenting our new active selection process RETIN. First, as any active method is sensitive to the boundary estimation between classes, the RETIN strategy carries out a boundary correction to make the retrieval process more robust. Second, the criterion of generalization error to optimize the active learning selection is modified to better represent the CBIR objective of database ranking. Third, a batch processing of images is proposed. Our strategy leads to a fast and efficient active learning scheme to retrieve sets of online images (query concept). Experiments on large databases show that the RETIN method performs well in comparison to several other active strategies.

  8. Modern methodic of power cardio training in students’ physical education

    Directory of Open Access Journals (Sweden)

    A.Yu. Osipov

    2016-12-01

    Full Text Available Purpose: significant increase of students’ physical condition and health level at the account of application of modern power cardio training methodic. Material: 120 students (60 boys and 60 girls participated in the research. The age of the tested was 19 years. The research took one year. We used methodic of power and functional impact on trainees’ organism (HOT IRON. Such methodic is some systems of physical exercises with weights (mini-barbells, to be fulfilled under accompaniment of specially selected music. Results: we showed advantages of power-cardio and fitness trainings in students’ health improvement and in elimination obesity. Control tests showed experimental group students achieved confidently higher physical indicators. Boys demonstrated increase of physical strength and general endurance indicators. Girls had confidently better indicators of physical strength, flexibility and general endurance. Increase of control group students’ body mass can be explained by students’ insufficient physical activity at trainings, conducted as per traditional program. Conclusions: students’ trainings by power-cardio methodic with application HOT IRON exercises facilitate development the following physical qualities: strength and endurance in boys and strength, flexibility and endurance in girls. Besides, it was found that such systems of exercises facilitate normalization of boys’ body mass and correction of girls’ constitution.

  9. A New Power Calculation Method for Single-Phase Grid-Connected Systems

    DEFF Research Database (Denmark)

    Yang, Yongheng; Blaabjerg, Frede

    2013-01-01

    A new method to calculate average active power and reactive power for single-phase systems is proposed in this paper. It can be used in different applications where the output active power and reactive power need to be calculated accurately and fast. For example, a grid-connected photovoltaic...... system in low voltage ride through operation mode requires a power feedback for the power control loop. Commonly, a Discrete Fourier Transform (DFT) based power calculation method can be adopted in such systems. However, the DFT method introduces at least a one-cycle time delay. The new power calculation...... method, which is based on the adaptive filtering technique, can achieve a faster response. The performance of the proposed method is verified by experiments and demonstrated in a 1 kW single-phase grid-connected system operating under different conditions.Experimental results show the effectiveness...

  10. Harmonic Analysis and Active Filtering in Offshore Wind Power Plants

    DEFF Research Database (Denmark)

    Chaudhary, Sanjay Kumar; Freijedo Fernandez, Francisco Daniel; Guerrero, Josep M.

    2015-01-01

    Due to presence of long high voltage cable networks, and power transformers for the grid connection, the offshore wind power plants (OWPPs) are susceptible to harmonic distortion and resonances. The grid connection of OWPP should not cause the harmonic distortion beyond the permissible limits...... at the point of common coupling (PCC). The resonance conditions should be avoided in all cases. This paper describes the harmonic analysis techniques applied on an OWPP network model. A method is proposed to estimate the harmonic current compensation from a shunt-connected active power filter to mitigate...

  11. Vce-based methods for temperature estimation of high power IGBT modules during power cycling - A comparison

    DEFF Research Database (Denmark)

    Amoiridis, Anastasios; Anurag, Anup; Ghimire, Pramod

    2015-01-01

    . This experimental work evaluates the validity and accuracy of two Vce based methods applied on high power IGBT modules during power cycling tests. The first method estimates the chip temperature when low sense current is applied and the second method when normal load current is present. Finally, a correction factor......Temperature estimation is of great importance for performance and reliability of IGBT power modules in converter operation as well as in active power cycling tests. It is common to be estimated through Thermo-Sensitive Electrical Parameters such as the forward voltage drop (Vce) of the chip...

  12. IMPROVEMENT EFFORTS TO LEARN LESSONS ACTIVITIES CHASSIS POWER TRANSFER STANDARD COMPETENCE AND CORRECT STEERING SYSTEM WITH LEARNING METHOD DISCOVERY INQUIRY CLASS XIB SMK MUHAMMADIYAH GAMPING ACADEMIC YEAR 2013/2014

    Directory of Open Access Journals (Sweden)

    Harry Suharto

    2013-12-01

    Full Text Available The purpose of the study to determine the increase learners' learning activities subjects chassis and power transfer competency standard steering system repair discovery learning through the implementation of class XI inquiry Lightweight Vehicle Technology SMK Muhammadiyah Gamping, Sleman academic year 2013/2014. This research including action research   Research conducted at SMK Muhammadiyah Gamping XIB class academic year 2013/2014 with a sample of 26 students. Techniques of data collection using questionnaire sheet, observation sheets and documentation to determine the increase in student activity. Instrument validation study using experts judgment. Analysis using descriptive statistics using the technique .   The results showed that the increased activity of the first cycle to the second cycle include an increase of 57.7 % Visual activities; Oral activities amounted to 61.6 %; Listening activities amounted to 23.04 %; Writing activities by 8.7 %; Mental activities of 73.1 %; Emotional activities of 42.3 % ( for the spirit of the students in learning activities ; Motor activities amounted to -7.7 % ( decrease negative activity . Based on these results can be known to most students in SMK Muhammadiyah Gamping gave a positive opinion on the use of inquiry and discovery learning method has a view that the use of inquiry discovery learning methods can be useful for students and schools themselves. Learners who have a good perception of the use of discovery learning method of inquiry he has known and fully aware of the standards of achievement of competence theory fix the steering system. Learning discovery learning methods on achievement of competency standards inquiry repair steering systems theory pleased with the learning process, they are also able to: 1 increase the motivation to learn, 2 improving learning achievement; 3 enhancing creativity; 4 listen, respect, and accept the opinion of the participants other students; 5 reduce boredom

  13. Junction temperature estimation for an advanced active power cycling test

    DEFF Research Database (Denmark)

    Choi, Uimin; Blaabjerg, Frede; Jørgensen, S.

    2015-01-01

    estimation method using on-state VCE for an advanced active power cycling test is proposed. The concept of the advanced power cycling test is explained first. Afterwards the junction temperature estimation method using on-state VCE and current is presented. Further, the method to improve the accuracy...... of the maximum junction temperature estimation is also proposed. Finally, the validity and effectiveness of the proposed method is confirmed by experimental results.......On-state collector-emitter voltage (VCE) is a good indicator to determine the wear-out condition of power device modules. Further, it is a one of the Temperature Sensitive Electrical Parameters (TSEPs) and thus can be used for junction temperature estimation. In this paper, the junction temperature...

  14. DSP control of photovoltaic power generation system adding the function of shunt active power filter

    Energy Technology Data Exchange (ETDEWEB)

    Seo, H.-R.; Kim, K.-H.; Park, Y.-G.; Park, M.; Yu, I.-K. [Changwon National Univ., SarimDong (Korea, Republic of). Dept. of Electrical Engineering

    2007-07-01

    The growing number of power electronics-based equipment has created a problem on the quality of electric power supply since both high power industrial loads and domestic loads cause harmonics in the network voltage. Power quality problems can occur in the system or can be caused by the consumer. Active filter (AF) is widely used to compensate current harmonics and/or current imbalance of harmonic-producing loads. The power output of a photovoltaic (PV) system is directly affected by weather conditions. When alternating current (AC) power supply is required, power conversion by an inverter and an MPPT control is necessary. The proliferation of nonlinear loads such as inverter of PV power generation system can be treated as a harmonic source for the power distribution system. As such, the PV system combined with the function of the active filter system can be useful for the application in power distribution systems. This paper described a PV-AF system using DSP to prove that it is possible to combine AF theory to the three phase PV system connected to utility and verify it through experimental results. The paper described the control method of the PV-AF system, with reference to the photovoltaic power generation system, shunt active filter and PV-AF system. The experimental set-up was also presented. A laboratory system was designed and constructed to confirm the viability of the proposed PV-AF system. The test results revealed the stability and effectiveness of the proposed PV-AF system. 12 refs., 1 tabs., 12 figs.

  15. Device for measuring active, reactive and apparent power

    Energy Technology Data Exchange (ETDEWEB)

    Bartosinski, E.; Wieland, J.

    1982-09-30

    The plan consists of a traditional electrodynamic mechanism for measuring power (IM) supplemented by three switches, two rectifiers, resistor, included in parallel, and phaseshifting throttle included in series with the voltage coil of the IM. This makes it possible by selection to perform three types of measurements: active power of alternating current or power of direct current, only the voltage coils and the IM current are engaged; reactive power, the resistor and the throttle are additionally engaged by the aforementioned method; complete (apparent) power--the current and the voltage are supplied directly to the IM coils, but in contrast to the first case, through rectifiers. The influence of the highest harmonic components of voltage and current which are not significant for industrial measurements can be eliminated in necessary cases using filtering devices.

  16. Power operation, measurement and methods of calculation of power distribution

    International Nuclear Information System (INIS)

    Lindahl, S.O.; Bernander, O.; Olsson, S.

    1982-01-01

    During the initial fuel loading of a BWR core, extensive checks and measurements of the fuel are performed. The measurements are designed to verify that the reactor can always be safely operated in compliance with the regulatory constraints. The power distribution within the reactor core is evaluated by means of instrumentation and elaborate computer calculations. The power distribution forms the basis for the evaluation of thermal limits. The behaviour of the reactor during the ordinary modes of operation as well as during transients shall be well understood and such that the integrity of the fuel and the reactor systems is always well preserved. (author)

  17. Wireless power pad with local power activation for portable devices

    NARCIS (Netherlands)

    Waffenschmidt, E.; Zheglov, V.

    2007-01-01

    Wireless power transfer by magnetic induction offers a simple to use way to recharge mobile devices like e.g. mobile phone, music players or medical sensors. As shown by a previous report and an existing Power Pad demonstrator, wireless inductive power transfer is possible with a good power

  18. Method and device for controlling reactor power

    International Nuclear Information System (INIS)

    Oohashi, Masahisa; Masuda, Hiroyuki.

    1982-01-01

    Purpose: To enable load following-up operation of a reactor adapted to perform power conditioning by the control of the liquid poison density in the core and by the control rods. Constitution: In a case where the reactor power is repeatedly changed in a reactor having a liquid poison density control device and control rods, the time period for the power control is divided depending on the magnitude of the change with time in the reactivity and the optimum values are set for the injection and removal amount of the liquid poison within the divided period. Then, most parts of the control required for the power change are alloted to the liquid poison that gives no effect on the power distribution while minimizing the movement of the control rods, whereby the power change in the reactor as in the case of the load following-up operation can be practiced with ease. (Kawakami, Y.)

  19. On Variable Reverse Power Flow-Part I: Active-Reactive Optimal Power Flow with Reactive Power of Wind Stations

    Directory of Open Access Journals (Sweden)

    Aouss Gabash

    2016-02-01

    Full Text Available It has recently been shown that using battery storage systems (BSSs to provide reactive power provision in a medium-voltage (MV active distribution network (ADN with embedded wind stations (WSs can lead to a huge amount of reverse power to an upstream transmission network (TN. However, unity power factors (PFs of WSs were assumed in those studies to analyze the potential of BSSs. Therefore, in this paper (Part-I, we aim to further explore the pure reactive power potential of WSs (i.e., without BSSs by investigating the issue of variable reverse power flow under different limits on PFs in an electricity market model. The main contributions of this work are summarized as follows: (1 Introducing the reactive power capability of WSs in the optimization model of the active-reactive optimal power flow (A-R-OPF and highlighting the benefits/impacts under different limits on PFs. (2 Investigating the impacts of different agreements for variable reverse power flow on the operation of an ADN under different demand scenarios. (3 Derivation of the function of reactive energy losses in the grid with an equivalent-π circuit and comparing its value with active energy losses. (4 Balancing the energy curtailment of wind generation, active-reactive energy losses in the grid and active-reactive energy import-export by a meter-based method. In Part-II, the potential of the developed model is studied through analyzing an electricity market model and a 41-bus network with different locations of WSs.

  20. Activity – based costing method

    Directory of Open Access Journals (Sweden)

    Èuchranová Katarína

    2001-06-01

    Full Text Available Activity based costing is a method of identifying and tracking the operating costs directly associated with processing items. It is the practice of focusing on some unit of output, such as a purchase order or an assembled automobile and attempting to determine its total as precisely as poccible based on the fixed and variable costs of the inputs.You use ABC to identify, quantify and analyze the various cost drivers (such as labor, materials, administrative overhead, rework. and to determine which ones are candidates for reduction.A processes any activity that accepts inputs, adds value to these inputs for customers and produces outputs for these customers. The customer may be either internal or external to the organization. Every activity within an organization comprimes one or more processes. Inputs, controls and resources are all supplied to the process.A process owner is the person responsible for performing and or controlling the activity.The direction of cost through their contact to partial activity and processes is a new modern theme today. Beginning of this method is connected with very important changes in the firm processes.ABC method is a instrument , that bring a competitive advantages for the firm.

  1. Reactor power control method and device

    International Nuclear Information System (INIS)

    Fushimi, Atsushi; Ishii, Yoshihiko; Miyamoto, Yoshiyuki; Ishii, Kazuhiko; Kiyoharu, Norihiko; Aizawa, Yuko.

    1997-01-01

    The present invention provides a method and a device suitable to rise the temperature and increase the pressure of the reactor to an aimed pressure in accordance with an aimed value for a reactor water temperature changing rate in the course of rising temperature and increasing pressure of the reactor upon start up of a BWR type power plant. Namely, neutron fluxes in the reactor and the temperature of reactor water are detected respectively. The maximum value among the detected values for the neutron fluxes is detected. The reactor water temperature changing rate is calculated based on the detected values of the reactor water temperature, from which the maximum value of the reactor water temperature changing rate is detected. An aimed value for the neutron flux is calculated in accordance with both detected maximum values and the aimed value of the reactor water temperature changing rate. The position of control rods is adjusted in accordance with the aimed value for the calculated neutron flux. Then, an aimed value for the neutron flux for realizing the aimed value for the reactor water temperature changing rate can be obtained accurately with no influence of the sensitivity of the detected values of the neutron fluxes and the time delay of the reactor water temperature changing rate. (I.S.)

  2. Virginia Power thermal-hydraulics methods

    International Nuclear Information System (INIS)

    Anderson, R.C.; Basehore, K.L.; Harrell, J.R.

    1987-01-01

    Virginia Power's nuclear safety analysis group is responsible for the safety analysis of reload cores for the Surry and North Anna power stations, including the area of core thermal-hydraulics. Postulated accidents are evaluated for potential departure from nucleate boiling violations. In support of these tasks, Virginia Power has employed the COBRA code and the W-3 and WRB-1 DNB correlations. A statistical DNBR methodology has also been developed. The code, correlations and statistical methodology are discussed

  3. Managing Siting Activities for Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-06-15

    One of the IAEA's statutory objectives is to ''seek to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world''. One way this objective is achieved is through the publication of a range of technical series. Two of these are the IAEA Nuclear Energy Series and the IAEA Safety Standards Series. According to Article III.A.6 of the IAEA Statute, the safety standards establish 'standards of safety for protection of health and minimization of danger to life and property.' The safety standards include the Safety Fundamentals, Safety Requirements and Safety Guides. These standards are written primarily in a regulatory style, and are binding on the IAEA for its own programmes. The principal users are the regulatory bodies in Member States and other national authorities. The IAEA Nuclear Energy Series comprises reports designed to encourage and assist R and D on, and application of, nuclear energy for peaceful uses. This includes practical examples to be used by owners and operators of utilities in Member States, implementing organizations, academia, and government officials, among others. This information is presented in guides, reports on technology status and advances, and best practices for peaceful uses of nuclear energy based on inputs from international experts. The IAEA Nuclear Energy Series complements the IAEA Safety Standards Series. The introduction of nuclear power brings new challenges to States - one of them being the selection of appropriates sites. It is a project that needs to begin early, be well managed, and deploy good communications with all stakeholders; including regulators. This is important, not just for those States introducing nuclear power for the first time, but for any State looking to build a new nuclear power plant. The purpose of the siting activities goes beyond choosing a suitable site and acquiring a licence. A large part of the project is about producing and maintaining a validated

  4. Managing Siting Activities for Nuclear Power Plants

    International Nuclear Information System (INIS)

    2012-01-01

    One of the IAEA's statutory objectives is to ''seek to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world''. One way this objective is achieved is through the publication of a range of technical series. Two of these are the IAEA Nuclear Energy Series and the IAEA Safety Standards Series. According to Article III.A.6 of the IAEA Statute, the safety standards establish 'standards of safety for protection of health and minimization of danger to life and property.' The safety standards include the Safety Fundamentals, Safety Requirements and Safety Guides. These standards are written primarily in a regulatory style, and are binding on the IAEA for its own programmes. The principal users are the regulatory bodies in Member States and other national authorities. The IAEA Nuclear Energy Series comprises reports designed to encourage and assist R and D on, and application of, nuclear energy for peaceful uses. This includes practical examples to be used by owners and operators of utilities in Member States, implementing organizations, academia, and government officials, among others. This information is presented in guides, reports on technology status and advances, and best practices for peaceful uses of nuclear energy based on inputs from international experts. The IAEA Nuclear Energy Series complements the IAEA Safety Standards Series. The introduction of nuclear power brings new challenges to States - one of them being the selection of appropriates sites. It is a project that needs to begin early, be well managed, and deploy good communications with all stakeholders; including regulators. This is important, not just for those States introducing nuclear power for the first time, but for any State looking to build a new nuclear power plant. The purpose of the siting activities goes beyond choosing a suitable site and acquiring a licence. A large part of the project is about producing and maintaining a validated

  5. Power system protection 2 systems and methods

    CERN Document Server

    1995-01-01

    The worldwide growth in demand for electricity has forced the pace of developments in electrical power system design to meet consumer needs for reliable, secure and cheap supplies. Power system protection, as a technology essential to high quality supply, is widely recognised as a specialism of growing and often critical importance, in which power system needs and technological progress have combined to result in rapid developments in policy and practice in recent years. In the United Kingdom, the need for appropriate training in power system protection was recognised in the early 1960s with t

  6. Active learning for noisy oracle via density power divergence.

    Science.gov (United States)

    Sogawa, Yasuhiro; Ueno, Tsuyoshi; Kawahara, Yoshinobu; Washio, Takashi

    2013-10-01

    The accuracy of active learning is critically influenced by the existence of noisy labels given by a noisy oracle. In this paper, we propose a novel pool-based active learning framework through robust measures based on density power divergence. By minimizing density power divergence, such as β-divergence and γ-divergence, one can estimate the model accurately even under the existence of noisy labels within data. Accordingly, we develop query selecting measures for pool-based active learning using these divergences. In addition, we propose an evaluation scheme for these measures based on asymptotic statistical analyses, which enables us to perform active learning by evaluating an estimation error directly. Experiments with benchmark datasets and real-world image datasets show that our active learning scheme performs better than several baseline methods. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. An Accurate Transmitting Power Control Method in Wireless Communication Transceivers

    Science.gov (United States)

    Zhang, Naikang; Wen, Zhiping; Hou, Xunping; Bi, Bo

    2018-01-01

    Power control circuits are widely used in transceivers aiming at stabilizing the transmitted signal power to a specified value, thereby reducing power consumption and interference to other frequency bands. In order to overcome the shortcomings of traditional modes of power control, this paper proposes an accurate signal power detection method by multiplexing the receiver and realizes transmitting power control in the digital domain. The simulation results show that this novel digital power control approach has advantages of small delay, high precision and simplified design procedure. The proposed method is applicable to transceivers working at large frequency dynamic range, and has good engineering practicability.

  8. Photovoltaic solar system connected to the electric power grid operating as active power generator and reactive power compensator

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, F.L.; Moraes, A.J.; Guimaraes, G.C.; Sanhueza, S.M.R.; Vaz, A.R. [Federal University of Uberlandia (UFU), MG (Brazil)

    2009-07-01

    In the case of photovoltaic solar systems (PV) acting as a distributed generation (DG), the DC energy obtained is fed through the power-conditioning unit (inverter) to the grid. The majority of contemporary inverters used in DG systems are current source inverters (CSI) operating at unity power factor. If, however, we assume that voltage source inverters (VSI) can be utilized instead of CSI, we can generate reactive power commensurate with the remaining unused capacity at any given point in time. According to the theory of instantaneous power, the reactive and active power of inverter can be regulated by changing the amplitude and the phase of the output voltage of the inverter. Based on this theory, the active power output and the reactive power compensation (RPC) of the system are realized simultaneously. When the insolation is weak or the PV modules are inoperative at night, the RPC feature of PV system can still be used to improve the utilization factor of the inverter. The MATLAB simulation results validate the feasibility of the method. (author)

  9. Adaptive intelligent power systems: Active distribution networks

    International Nuclear Information System (INIS)

    McDonald, Jim

    2008-01-01

    Electricity networks are extensive and well established. They form a key part of the infrastructure that supports industrialised society. These networks are moving from a period of stability to a time of potentially major transition, driven by a need for old equipment to be replaced, by government policy commitments to cleaner and renewable sources of electricity generation, and by change in the power industry. This paper looks at moves towards active distribution networks. The novel transmission and distribution systems of the future will challenge today's system designs. They will cope with variable voltages and frequencies, and will offer more flexible, sustainable options. Intelligent power networks will need innovation in several key areas of information technology. Active control of flexible, large-scale electrical power systems is required. Protection and control systems will have to react to faults and unusual transient behaviour and ensure recovery after such events. Real-time network simulation and performance analysis will be needed to provide decision support for system operators, and the inputs to energy and distribution management systems. Advanced sensors and measurement will be used to achieve higher degrees of network automation and better system control, while pervasive communications will allow networks to be reconfigured by intelligent systems

  10. EVALUATING DEGREE OF ACTIVE POWER LOSSES REDUCTION IN THE ELECTRIC POWER LINES WITH REACTIVE POWER COMPENSATION

    Directory of Open Access Journals (Sweden)

    V. N. Radkevich

    2016-01-01

    Full Text Available The paper considers evaluation procedure for the degree of active power losses reduction in the power transmission lines under 1 kV and 6–10 kV of the systems of electric power supply of industrial enterprises with compensating installations mounted at the side of the customer. The capacitor installations conform to the applied voltage level and factor in dielectric losses in the capacitors. The voltage at the compensating device terminal changes from 0.95 to 1.05 of the capacitors nominal voltage. The study did not account for reactive power losses in the line, nor did it for its charge capacity, conditioned by relative shortness of the cable lines generally operating in the mains of industrial enterprises. For this reason, the quantities of reactive power being consumed and generated by the transmission line are negligible and do not significantly affect the reactive power flux. The researchers obtain functional relations that allow estimating the degree of power loss reduction in the transmission line factoring in its explicit initial data. They perform mathematical analysis of the obtained functional relations and study the function by means of derivatives. The function extremum points are found as well as the intervals of its increment and decrement. A graphical research of the obtained functional relation is performed. It is ascertained that reduction of the active power losses is contingent on the line and the capacitor-installation engineering factors, the electrical energy consumer reactive load value as well as the voltage applied to the capacitor installation. The functional relations presented in the article can be employed in scoping calculation necessary for decision making on the reactive power compensation in systems of the industrial facilities electric power supply. Their account will allow a more accurate estimate of technical and economic effect of the capacitor bank installation in the electrical mains under 1 kV and 6

  11. Nuclear power reactor analysis, methods, algorithms and computer programs

    International Nuclear Information System (INIS)

    Matausek, M.V

    1981-01-01

    Full text: For a developing country buying its first nuclear power plants from a foreign supplier, disregarding the type and scope of the contract, there is a certain number of activities which have to be performed by local stuff and domestic organizations. This particularly applies to the choice of the nuclear fuel cycle strategy and the choice of the type and size of the reactors, to bid parameters specification, bid evaluation and final safety analysis report evaluation, as well as to in-core fuel management activities. In the Nuclear Engineering Department of the Boris Kidric Institute of Nuclear Sciences (NET IBK) the continual work is going on, related to the following topics: cross section and resonance integral calculations, spectrum calculations, generation of group constants, lattice and cell problems, criticality and global power distribution search, fuel burnup analysis, in-core fuel management procedures, cost analysis and power plant economics, safety and accident analysis, shielding problems and environmental impact studies, etc. The present paper gives the details of the methods developed and the results achieved, with the particular emphasis on the NET IBK computer program package for the needs of planning, construction and operation of nuclear power plants. The main problems encountered so far were related to small working team, lack of large and powerful computers, absence of reliable basic nuclear data and shortage of experimental and empirical results for testing theoretical models. Some of these difficulties have been overcome thanks to bilateral and multilateral cooperation with developed countries, mostly through IAEA. It is the authors opinion, however, that mutual cooperation of developing countries, having similar problems and similar goals, could lead to significant results. Some activities of this kind are suggested and discussed. (author)

  12. Analysis and study on core power capability with margin method

    International Nuclear Information System (INIS)

    Liu Tongxian; Wu Lei; Yu Yingrui; Zhou Jinman

    2015-01-01

    Core power capability analysis focuses on the power distribution control of reactor within the given mode of operation, for the purpose of defining the allowed normal operating space so that Condition Ⅰ maneuvering flexibility is maintained and Condition Ⅱ occurrences are adequately protected by the reactor protection system. For the traditional core power capability analysis methods, such as synthesis method or advanced three dimension method, usually calculate the key safety parameters of the power distribution, and then verify that these parameters meet the design criteria. For PWR with on-line power distribution monitoring system, core power capability analysis calculates the most power level which just meets the design criteria. On the base of 3D FAC method of Westinghouse, the calculation model of core power capability analysis with margin method is introduced to provide reference for engineers. The core power capability analysis of specific burnup of Sanmen NPP is performed with the margin method. The results demonstrate the rationality of the margin method. The calculation model of the margin method not only helps engineers to master the core power capability analysis for AP1000, but also provides reference for engineers for core power capability analysis of other PWR with on-line power distribution monitoring system. (authors)

  13. Study on A Control Method of PAPF for Resonance Damping and Harmonics Compensation in Power System

    DEFF Research Database (Denmark)

    Zhou, Fang; Wu, Longhui; Chen, Zhe

    2009-01-01

    In power system, capacitors are widely used to compensate reactive power, which generally cause resonance problems in harmonic distorted network. In this paper, A method of using a parallel active power filter (PAPF) to damp the resonances is proposed. The proposed method is compound with traditi......In power system, capacitors are widely used to compensate reactive power, which generally cause resonance problems in harmonic distorted network. In this paper, A method of using a parallel active power filter (PAPF) to damp the resonances is proposed. The proposed method is compound...... with traditional method, it shows that whether the capacitor current is included in the detecting current of PAPF or not. Also the PAPF with proposed method has strong ability in harmonic compensation. Finally, the experiment results are presented to verify the analysis....

  14. Development of methods for evaluating active faults

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-15

    The report for long-term evaluation of active faults was published by the Headquarters for Earthquake Research Promotion on Nov. 2010. After occurrence of the 2011 Tohoku-oki earthquake, the safety review guide with regard to geology and ground of site was revised by the Nuclear Safety Commission on Mar. 2012 with scientific knowledges of the earthquake. The Nuclear Regulation Authority established on Sep. 2012 is newly planning the New Safety Design Standard related to Earthquakes and Tsunamis of Light Water Nuclear Power Reactor Facilities. With respect to those guides and standards, our investigations for developing the methods of evaluating active faults are as follows; (1) For better evaluation on activities of offshore fault, we proposed a work flow to date marine terrace (indicator for offshore fault activity) during the last 400,000 years. We also developed the analysis of fault-related fold for evaluating of blind fault. (2) To clarify the activities of active faults without superstratum, we carried out the color analysis of fault gouge and divided the activities into thousand of years and tens of thousands. (3) To reduce uncertainties of fault activities and frequency of earthquakes, we compiled the survey data and possible errors. (4) For improving seismic hazard analysis, we compiled the fault activities of the Yunotake and Itozawa faults, induced by the 2011 Tohoku-oki earthquake. (author)

  15. Harmonic Mitigation Methods in Large Offshore Wind Power Plants

    DEFF Research Database (Denmark)

    Kocewiak, Łukasz Hubert; Chaudhary, Sanjay; Hesselbæk, Bo

    2013-01-01

    Various sources of harmonic problems in large wind power plants (WPPs) and optimized harmonic mitigation methods are presented in this paper. The harmonic problems such as sources of harmonic emission and amplification as well as harmonic stability are identified. Also modern preventive...... and remedial harmonic mitigation methods in terms of passive and active filtering are described. It is shown that WPP components such as long HVAC cables and park transformers can introduce significant low-frequency resonances which can affect wind turbine control system operation and overall WPP stability...... as well as amplification of harmonic distortion. It is underlined that there is a potential in terms of active filtering in modern grid-side converters in e.g. wind turbines, STATCOMs or HVDC stations utilized in modern large WPPs. It is also emphasized that the grid-side converter controller should...

  16. Reactive power control methods for improved reliability of wind power inverters under wind speed variations

    DEFF Research Database (Denmark)

    Ma, Ke; Liserre, Marco; Blaabjerg, Frede

    2012-01-01

    method to relieve the thermal cycling of power switching devices under severe wind speed variations, by circulating reactive power among the parallel power converters in a WTS or among the WTS's in a wind park. The amount of reactive power is adjusted to limit the junction temperature fluctuation...

  17. New laser power sensor using weighing method

    Science.gov (United States)

    Pinot, P.; Silvestri, Z.

    2018-01-01

    We present a set-up using a piece of pyrolytic carbon (PyC) to measure laser power in the range from a few milliwatts to a few watts. The experimental configuration consists in measuring the magnetic repulsion force acting between a piece of PyC placed on a weighing pan and in a magnetic induction generated by a magnet array in a fixed position above the PyC sheet. This involves a repulsion force on the PyC piece which is expressed in terms of mass by the balance display. The quantities affecting the measurement results have been identified. An example of metrological characterization in terms of accuracy, linearity and sensitivity is given. A relative uncertainty of optical power measurement for the first experimental set-up is around 1%. The wavelength and power density dependence on power response of this device has been demonstrated. This PyC-based device presented here in weighing configuration and the other one previously studied in levitation configuration offer a new technique for measuring optical power.

  18. Method of estimating the reactor power distribution

    International Nuclear Information System (INIS)

    Mitsuta, Toru; Fukuzaki, Takaharu; Doi, Kazuyori; Kiguchi, Takashi.

    1984-01-01

    Purpose: To improve the calculation accuracy for the power distribution thereby improve the reliability of power distribution monitor. Constitution: In detector containing strings disposed within a reactor core, movable type neutron flux monitors are provided in addition to position fixed type neutron monitors conventionally disposed so far. Upon periodical monitoring, a power distribution X1 is calculated from a physical reactor core model. Then, a higher power position X2 is detected by position detectors and value X2 is sent to a neutron flux monitor driving device to displace the movable type monitors to a higher power position in each of the strings. After displacement, the value X1 is amended by an amending device using measured values from the movable type and fixed type monitors and the amended value is sent to a reactor core monitor device. Upon failure of the fixed type monitors, the position is sent to the monitor driving device and the movable monitors are displaced to that position for measurement. (Sekiya, K.)

  19. Methods of assessing nuclear power plant risks

    International Nuclear Information System (INIS)

    Skvarka, P.; Kovacz, Z.

    1985-01-01

    The concept of safety evalution is based on safety criteria -standards or set qualitative values of parameters and indices used in designing nuclear power plants, incorporating demands on the quality of equipment and operation of the plant, its siting and technical means for achieving nuclear safety. The concepts are presented of basic and optimal risk values. Factors are summed up indispensable for the evaluation of the nuclear power plant risk and the present world trend of evaluation based on probability is discussed. (J.C.)

  20. Reviewing surveillance activities in nuclear power plants

    International Nuclear Information System (INIS)

    1989-03-01

    This document provides guidance to Operational Safety Review Teams (OSARTs) for reviewing surveillance activities at a nuclear power plant. In addition, the document contains reference material to support the review of surveillance activities, to assist within the Technical Support area and to ensure consistency between individual reviews. Drafts of the document have already been used on several OSART missions and found to be useful. The document first considers the objectives of an excellent surveillance programme. Investigations to determine the quality of the surveillance programme are then discussed. The attributes of an excellent surveillance programme are listed. Advice follows on how to phrase questions so as to obtain an informative response on surveillance features. Finally, specific equipment is mentioned that should be considered when reviewing functional tests. Four annexes provide examples drawn from operating nuclear power plants. They were selected to supplement the main text of the document with the best international practices as found in OSART reviews. They should in no way limit the acceptance and development of alternative approaches that lead to equivalent or better results. Refs, figs and tabs

  1. Shunt hybrid active power filter for harmonic mitigation: A practical ...

    Indian Academy of Sciences (India)

    The increasing importance of Power Quality problems has been responsible for several improvements in Active Power Filter (APF) typologies in the last decade. The increased cost and switching losses make a pure shunt APF economically impractical for high power applications. In higher power levels shunt Hybrid Active ...

  2. Method and apparatus for thermal power generation

    International Nuclear Information System (INIS)

    1981-01-01

    A thermal power plant reheat cycle system is described in which the discharge from a first expansion stage is reheated prior to expansion in a subsequent expansion stage. The primary coolant has a high sheet transfer rate and can accommodate temperature changes in the reheat vapor. (U.K.)

  3. Methods to enhance blanket power density

    International Nuclear Information System (INIS)

    Hsu, P.Y.; Miller, L.G.; Bohn, T.S.; Deis, G.A.; Longhurst, G.R.; Masson, L.S.; Wessol, D.E.; Abdou, M.A.

    1982-06-01

    The overall objective of this task is to investigate the extent to which the power density in the FED/INTOR breeder blanket test modules can be enhanced by artificial means. Assuming a viable approach can be developed, it will allow advanced reactor blanket modules to be tested on FED/INTOR under representative conditions

  4. Controlled thermonuclear fusion power apparatus and method

    International Nuclear Information System (INIS)

    Bussard, R.W.; Coppi, B.

    1982-01-01

    This invention provides a modular fusion reactor system containing several fusion power cores, each of relatively small size and low cost. Energy from the cores is absorbed in the core structure and within a surrounding blanket, and the cores themselves may be individually removed from the blanket and replaced as they deteriorate from high radiation flux damage

  5. Research on psychological evaluation method for nuclear power plant operators

    International Nuclear Information System (INIS)

    Fang Xiang; He Xuhong; Zhao Bingquan

    2007-01-01

    The qualitative and quantitative psychology evaluation methods to the nuclear power plant operators were analyzed and discussed in the paper. The comparison analysis to the scope and result of application was carried out between method of outline figure fitted and method of fuzzy synthetic evaluation. The research results can be referenced to the evaluation of nuclear power plant operators. (authors)

  6. Design and Tuning Methodology of Active Power Controller in Wind Power Plants

    DEFF Research Database (Denmark)

    Ionita, Claudiu; Raducu, Alin George; Iov, Florin

    2017-01-01

    This paper presents a method to design and tune the main controller of a Wind Power Plant (WPP), with focus on the active power and frequency control. The controller requirements are based on the Danish grid codes. The controller functionality is successfully verified using the model and the layout...... of an actual WPP rated at 160 MW, that consists of 80 wind turbines. Two reference dispatch strategies are investigated, equal and proportional. The proportional dispatch is preferred due to better tracking accuracy and robustness. The work described in this article is meant to help WPP developers...

  7. Singularities of projection of an active power in frequency converter

    Directory of Open Access Journals (Sweden)

    Є.К. Батуревич

    2005-03-01

    Full Text Available  The level of security of static single-phase watt-hour meters of an electric energy concerning a possibility of unauthorized takeoff of an electric energy by electric methods is analyses. The shortages of an active power in a pulse frequency converter are marked which are used in such watt-hour meters. The solutions on their refinement are offered.

  8. Methods of formation of efficiency indexes of electric power sources integration in regional electric power systems

    International Nuclear Information System (INIS)

    Marder, L.I.; Myzin, A.I.

    1993-01-01

    A methodic approach to the grounding of the integration process efficiency within the Unified electric power system is given together with the selection of a rational areal structure and concentration of power-generating source capacities. Formation of an economic functional according to alternative scenavies including the cost components taking account of the regional interests is considered. A method for estimation and distribution of the effect from electric power production integration in the power systems under new economic conditions is proposed

  9. APPLICATION OF MODIFIED POWER FLOW TRACING METHOD FOR REACTIVE POWER PRICING IN PRACTICAL UTILITY SYSTEM

    Directory of Open Access Journals (Sweden)

    M. SUSITHRA

    2017-01-01

    Full Text Available Competitive trend towards restructuring and unbundling of transmission services has resulted in the need to discover the impact of a particular generator to load. This paper initially presents the analysis of three different reactive power valuation methods namely, Modified Ybus , Virtual flow approach and modified power flow tracing to compute the reactive power output from a particular generator to particular load. Among these methods, the modified power flow electricity tracing method is identified as the best method to trace the reactive power contribution from various reactive power sources to loads, transmission line, etc. Also this proposed method breakdown the total reactive power loss in a transmission line into components to be allocated to individual loads. Secondly, based on this Method a novel allocation method for reactive power service for practical system is proposed. Hence, this method can be useful in providing additional insight into power system operation and can be used to modify existing tariffs of charging for reactive power transmission loss and reactive power transmission services. Simulation and comparison results are shown by taking WSCC 9 and IEEE 30 bus system as test system.

  10. Power generating system and method utilizing hydropyrolysis

    Science.gov (United States)

    Tolman, R.

    1986-12-30

    A vapor transmission cycle is described which burns a slurry of coal and water with some of the air from the gas turbine compressor, cools and cleans the resulting low-Btu fuel gas, burns the clean fuel gas with the remaining air from the compressor, and extracts the available energy in the gas turbine. The cycle lends itself to combined-cycle cogeneration for the production of steam, absorption cooling, and electric power.

  11. Switched-mode power supply apparatus and method

    NARCIS (Netherlands)

    2013-01-01

    The present invention relates to a switched-mode power supply apparatus and a corresponding method. For an effective compensation of non-linearities caused by dead- time and voltage drops in the switching power amplifier of the apparatus, an apparatus is proposed comprising a switching power

  12. Switched-mode power supply apparatus and method

    NARCIS (Netherlands)

    2013-01-01

    The present invention relates to a switched-mode power supply apparatus and a corresponding method. For an effective compensation of non-linearities caused by dead-time and voltage drops in the switching power amplifier of the apparatus, an apparatus is proposed comprising a switching power

  13. Adaptive decoupled power control method for inverter connected DG

    DEFF Research Database (Denmark)

    Sun, Xiaofeng; Tian, Yanjun; Chen, Zhe

    2014-01-01

    an adaptive droop control method based on online evaluation of power decouple matrix for inverter connected distributed generations in distribution system. Traditional decoupled power control is simply based on line impedance parameter, but the load characteristics also cause the power coupling, and alter...

  14. A method of reactor power decrease by 2DOF control system during BWR power oscillation

    International Nuclear Information System (INIS)

    Ishikawa, Nobuyuki; Suzuki, Katsuo

    1998-09-01

    Occurrence of power oscillation events caused by void feedback effects in BWRs operated at low-flow and high-power condition has been reported. After thoroughly examining these events, BWRs have been equipped with the SRI (Selected Rod Insertion) system to avoid the power oscillation by decreasing the power under such reactor condition. This report presents a power control method for decreasing the reactor power stably by a two degree of freedom (2DOF) control. Performing a numerical simulation by utilizing a simple reactor dynamics model, it is found that the control system designed attains a satisfactory control performance of power decrease from a viewpoint of setting time and oscillation. (author)

  15. Nuclear Power and Safety Division activity

    International Nuclear Information System (INIS)

    Pazdera, F.

    1991-01-01

    History of the Division is briefly described. Present research is centered on reliability analyses and thermal hydraulic analyses of transients and accidents. Some results of the safety analyses have been applied at nuclear power plants. A characterization is presented of computer codes for analyzing the behavior of fuel in normal and accident conditions. Research activities in the field of water chemistry and corrosion are oriented to the corrosion process at high temperatures and high pressures, and the related mass and radioactivity transfer; the effect of some chemical processes on primary coolant circuit materials; optimization of PWR filtration systems; and the development of the requisite monitoring instrumentation. A computerized operator support system has been developed, and at present it is tested at the Dukovany nuclear power plant. A program of nuclear fuel cycle strategy and economy has been worked out for nuclear fuel performance evaluation. Various options for better fuel exploitation, alternatives for advanced fuelling, and fuel cycle costs are assessed, and out-of-reactor fuel cycle options are compared. (M.D.). 7 refs., 32 refs

  16. Wind Powering America FY07 Activities Summary

    Energy Technology Data Exchange (ETDEWEB)

    2008-02-01

    The Wind Powering America FY07 Activities Summary reflects the accomplishments of our state wind working groups, our programs at the National Renewable Energy Laboratory, and our partner organizations. The national WPA team remains a leading force for moving wind energy forward in the United States. WPA continues to work with its national, regional, and state partners to communicate the opportunities and benefits of wind energy to a diverse set of stakeholders. WPA now has 30 state wind working groups (welcoming Georgia and Wisconsin in 2007) that form strategic alliances to communicate wind's benefits to the state stakeholders. More than 140 members of national and state public and private sector organizations from 39 U.S. states and Canada attended the 6th Annual WPA All-States Summit in Los Angeles in June. WPA's emphasis remains on the rural agricultural sector, which stands to reap the significant economic development benefits of wind energy development. Additionally, WPA continues its program of outreach, education, and technical assistance to Native American communities, public power entities, and regulatory and legislative bodies.

  17. Wind Powering America FY06 Activities Summary

    Energy Technology Data Exchange (ETDEWEB)

    2007-02-01

    The Wind Powering America FY06 Activities Summary reflects the accomplishments of our state wind working groups, our programs at the National Renewable Energy Laboratory, and our partner organizations. The national WPA team remains a leading force for moving wind energy forward in the United States. WPA continues to work with its national, regional, and state partners to communicate the opportunities and benefits of wind energy to a diverse set of stakeholders. WPA now has 29 state wind working groups (welcoming New Jersey, Indiana, Illinois, and Missouri in 2006) that form strategic alliances to communicate wind's benefits to the state stakeholders. More than 120 members of national and state public and private sector organizations from 34 states attended the 5th Annual WPA All-States Summit in Pittsburgh in June.

  18. Analysis and experimental evaluation of shunt active power filter for power quality improvement based on predictive direct power control.

    Science.gov (United States)

    Aissa, Oualid; Moulahoum, Samir; Colak, Ilhami; Babes, Badreddine; Kabache, Nadir

    2017-10-12

    This paper discusses the use of the concept of classical and predictive direct power control for shunt active power filter function. These strategies are used to improve the active power filter performance by compensation of the reactive power and the elimination of the harmonic currents drawn by non-linear loads. A theoretical analysis followed by a simulation using MATLAB/Simulink software for the studied techniques has been established. Moreover, two test benches have been carried out using the dSPACE card 1104 for the classic and predictive DPC control to evaluate the studied methods in real time. Obtained results are presented and compared in this paper to confirm the superiority of the predictive technique. To overcome the pollution problems caused by the consumption of fossil fuels, renewable energies are the alternatives recommended to ensure green energy. In the same context, the tested predictive filter can easily be supplied by a renewable energy source that will give its impact to enhance the power quality.

  19. Active power line conditioners design, simulation and implementation for improving power quality

    CERN Document Server

    Revuelta, Patricio Salmeron; Litrán, Salvador Pérez

    2015-01-01

    Active Power Line Conditioners: Design, Simulation and Implementation for Improving Power Quality presents a rigorous theoretical and practical approach to active power line conditioners, one of the subjects of most interest in the field of power quality. Its broad approach offers a journey that will allow power engineering professionals, researchers, and graduate students to learn more about the latest landmarks on the different APLC configurations for load active compensation. By introducing the issues and equipment needs that arise when correcting the lack of power quality in power grids

  20. Resonant power processors. II - Methods of control

    Science.gov (United States)

    Oruganti, R.; Lee, F. C.

    1984-01-01

    The nature of resonant converter control is discussed. Employing the state-portrait, different control methods for series resonant converter are identified and their performance evaluated based on their stability, response to control and load changes and range of operation. A new control method, optimal-trajectory control, is proposed which, by utilizing the state trajectories as control laws, continuously monitors the energy level of the resonant tank. The method is shown to have superior control properties especially under transient operation.

  1. Apparatus and Method for Communication over Power Lines

    Science.gov (United States)

    Krasowski, Michael J. (Inventor); Prokop, Norman F. (Inventor); Greer, III, Lawrence C. (Inventor); Nappier, Jennifer M. (Inventor)

    2017-01-01

    An apparatus and method are provided for communicating over power lines. The apparatus includes a coupling modem that is situated between a power line and a device. The coupling modem is configured to demodulate a signal received from the power line into a sine signal and a cosine signal. The coupling modem is also configured to modulate a communicated bit stream received from the device into a transmitted signal in order to impose the transmitted signal onto the power line.

  2. A Dynamic Programming based method for optimizing power system restoration with high wind power penetration

    DEFF Research Database (Denmark)

    Hu, Rui; Hu, Weihao; Li, Pengfei

    2016-01-01

    and relatively low cost. Thus, many countries are increasing the wind power penetration in their power system step by step, such as Denmark, Spain and Germany. The incremental wind power penetration brings a lot of new issues in operation and programming. The power system sometimes will operate close to its...... stable limits. Once the blackout happens, a well-designed restoration strategy is significant. This paper focuses on how to ameliorate the power system restoration procedures to adapt the high wind power penetration and how to take full advantages of the wind power plants during the restoration....... In this paper, the possibility to exploit the stochastic wind power during restoration was discussed, and a Dynamic Programming (DP) method was proposed to make wind power contribute in the restoration rationally as far as possible. In this paper, the method is tested and verified by a modified IEEE 30 Buses...

  3. Monitoring method of an atomic power plant

    International Nuclear Information System (INIS)

    Koba, Akitoshi; Goto, Seiichiro; Ohashi, Hideaki.

    1975-01-01

    Object: To make a monitoring vehicle, which is loaded with various detecting elements, go round along the monorail disposed so as to surround various devices to thereby early discover various abnormal conditions. Structure: The monitoring vehicle is travelled on the monorail disposed so as to surround the periphery of various devices in an atomic power plant so that detection signals from an ITV camera, temperature and radioactive rays and sound detecting elements, and the like are received through a slide contact between the wheel and transmitting and receiving line disposed in the wheel groove to transmit the signals to a central control panel. (Yoshihara, H.)

  4. Probabilistic Power Flow Method Considering Continuous and Discrete Variables

    Directory of Open Access Journals (Sweden)

    Xuexia Zhang

    2017-04-01

    Full Text Available This paper proposes a probabilistic power flow (PPF method considering continuous and discrete variables (continuous and discrete power flow, CDPF for power systems. The proposed method—based on the cumulant method (CM and multiple deterministic power flow (MDPF calculations—can deal with continuous variables such as wind power generation (WPG and loads, and discrete variables such as fuel cell generation (FCG. In this paper, continuous variables follow a normal distribution (loads or a non-normal distribution (WPG, and discrete variables follow a binomial distribution (FCG. Through testing on IEEE 14-bus and IEEE 118-bus power systems, the proposed method (CDPF has better accuracy compared with the CM, and higher efficiency compared with the Monte Carlo simulation method (MCSM.

  5. Hybrid robust predictive optimization method of power system dispatch

    Science.gov (United States)

    Chandra, Ramu Sharat [Niskayuna, NY; Liu, Yan [Ballston Lake, NY; Bose, Sumit [Niskayuna, NY; de Bedout, Juan Manuel [West Glenville, NY

    2011-08-02

    A method of power system dispatch control solves power system dispatch problems by integrating a larger variety of generation, load and storage assets, including without limitation, combined heat and power (CHP) units, renewable generation with forecasting, controllable loads, electric, thermal and water energy storage. The method employs a predictive algorithm to dynamically schedule different assets in order to achieve global optimization and maintain the system normal operation.

  6. Perturbation methods for power and reactivity reconstruction

    International Nuclear Information System (INIS)

    Palmiotti, G.; Salvatores, M.; Estiot, J.C.; Broccoli, U.; Bruna, G.; Gomit, J.M.

    1987-01-01

    This paper deals with recent developments and applications in perturbation methods. Two types of methods are used. The first one is an explicit method, which allows the explicit reconstruction of a perturbed flux using a linear combination of a library of functions. In our application, these functions are the harmonics (i.e. the high order eigenfunctions of the system). The second type is based on the Generalized Perturbation Theory GPT and needs the calculation of an importance function for each integral parameter of interest. Recent developments of a particularly useful high order formulation allows to obtain satisfactory results also for very large perturbations

  7. Early Prevention Method for Power System Instability

    DEFF Research Database (Denmark)

    Dmitrova, Evgenia; Wittrock, Martin Lindholm; Jóhannsson, Hjörtur

    2015-01-01

    are then determined, using a grid transformation coefficient (GTC) and a numerical, iterative solution to an equation system. The stability criteriacan then be assessed to evaluate the sufficiency of a suggested counter measure. The method is demonstrated on a synthetic 8-bus network and a 464-bus model...... of the Western Denm ark transmission grid. The method successfully demonstrates its ability to efficiently identify and evaluate counter measures for a large, practical system....

  8. Building method for nuclear power plant

    International Nuclear Information System (INIS)

    Iba, Tsutomu.

    1993-01-01

    Outer shielding buildings and inner concretes are dismantled and removed. In this case, foundations are left as they are. Then, new outer shielding buildings and inner concretes are constructed on the old foundations by way of rubber a laminates. The outer shielding buildings and the inner concretes supported by the rubber laminates have an earthquake-proof structure and vibrations upon occurrence of earthquakes can be moderated by the rubber laminates. Therefore, it is not required to make the outer shielding buildings so strong, and the weight of them can be reduced. Accordingly, the weight of the buildings is reduced compared with the buildings before dismantling, so that they can be sufficiently supported by the old foundations. This enables to build a nuclear power plant without ensuring new construction sites. (I.N.)

  9. Method of operating a MHD power plant

    International Nuclear Information System (INIS)

    Wysk, S.R.

    1982-01-01

    A fossil fuel is burned substoichiometrically in the combustor of a mhd power plant to produce a high temperature, fuelrich product gas. The product gas is passed through a mhd channel to generate electricity. A reducing agent, preferably natural gas or hydrocarbon, is injected into the fuelrich product gas leaving the mhd generator; and the resulting mixture is held at a temperature in the range of 950 to 1500 0 C for about 1 second to permit the reducing agent to decompose a portion of the nitrogen oxides formed in the combustor. The fuel-rich product gas then passes thru an afterburner wherein combustion is completed and any excess reducing agent is consumed

  10. Controlled thermonuclear fusion power apparatus and method

    International Nuclear Information System (INIS)

    Bussaro, R.W.; Coppi, B.

    1977-01-01

    A fusion power device is described comprising: a) a plurality of plasma containment means for containing fusible plasma within a region, b) blanket means surrounding a substantial portion of each of the plurality of containment means, c) means for feeding a fusible fuel into each of the plurality of containment means for forming the plasma, d) each of the plurality of containment means separable from the blanket means for replacement of the containment means by other containment means, and e) means connected to at least one of each of the plurality of plasma containment means and the blanket means for extracting thermal energy therefrom and for converting same into electrical energy and/or into mechanical energy

  11. Some lemma on spectrum of eigen value regarding power method

    Science.gov (United States)

    Jamali, A. R. M. Jalal Uddin; Alam, Md. Sah

    2017-04-01

    Eigen value problems arise in almost all science and engineering fields. There exist some smart methods in literature in which most of them are able to find only Eigen values but could not find corresponding Eigen vectors. There exist many engineering as well as scientific fields in which both largest as well as smallest Eigen pairs are required. Power method is very simple but a powerful tool for finding largest Eigen value and corresponding Eigen vector (Eigen-pair). Again Inverse Power method is applied to find out smallest Eigen-pair and/or desire Eigen-pairs. But it is known that Inverse Power method is computationally very costly. On the other hand by using shifting property, Power method can find further Eigen-pairs. But the position of this Eigen value in the set of spectrum of the Eigen values is not identified. In this regard we proposed four lemma associate with Modified Power method. Each Lemma is proved ornately. The Modified Power method is implemented and illustrates an example for the verification of the Lemma. By using lemma the modified power algorithm is able to find out both largest and smallest Eigen-pairs successfully and efficiently in some cases. Moreover by the help of the Lemma, algorithm is able to detect the nature (positive and negative) of the Eigen values.

  12. Shunt hybrid active power filter for harmonic mitigation: A practical ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... The increasing importance of Power Quality problems has been responsible for several improvements in Active Power Filter (APF) typologies in the last decade. The increased cost and switching losses make a pure shunt APF economically impractical for high power applications. In higher power levels ...

  13. Usefulness of DC power flow for active power flow analysis with flow controlling devices

    NARCIS (Netherlands)

    Van Hertem, D.; Verboomen, J.; Purchala, K.; Belmans, R.; Kling, W.L.

    2006-01-01

    DC power flow is a commonly used tool for contingency analysis. Recently, due to its simplicity and robustness, it also becomes increasingly used for the real-time dispatch and techno-economic analysis of power systems. It is a simplification of a full power flow looking only at active power.

  14. Activating teaching methods in french language teaching

    OpenAIRE

    Kulhánková, Anna

    2009-01-01

    The subject of this diploma thesis is activating teaching methods in french language teaching. This thesis outlines the issues acitvating teaching methods in the concept of other teaching methods. There is a definition of teaching method, classification of teaching methods and characteristics of each activating method. In the practical part of this work are given concrete forms of activating teaching methods appropriate for teaching of french language.

  15. An Optimal Power Flow (OPF) Method with Improved Power System Stability

    DEFF Research Database (Denmark)

    Su, Chi; Chen, Zhe

    2010-01-01

    This paper proposes an optimal power flow (OPF) method taking into account small signal stability as additional constraints. Particle swarm optimization (PSO) algorithm is adopted to realize the OPF process. The method is programmed in MATLAB and implemented to a nine-bus test power system which...... has large-scale wind power integration. The results show the ability of the proposed method to find optimal (or near-optimal) operating points in different cases. Based on these results, the analysis of the impacts of wind power integration on the system small signal stability has been conducted....

  16. IMP: Integrated method for power analysis

    Energy Technology Data Exchange (ETDEWEB)

    1989-03-01

    An integrated, easy to use, economical package of microcomputer programs has been developed which can be used by small hydro developers to evaluate potential sites for small scale hydroelectric plants in British Columbia. The programs enable evaluation of sites located far from the nearest stream gauging station, for which streamflow data are not available. For each of the province's 6 hydrologic regions, a streamflow record for one small watershed is provided in the data base. The program can then be used to generate synthetic streamflow records and to compare results obtained by the modelling procedure with the actual data. The program can also be used to explore the significance of modelling parameters and to develop a detailed appreciation for the accuracy which can be obtained under various circumstances. The components of the program are an atmospheric model of precipitation; a watershed model that will generate a continuous series of streamflow data, based on information from the atmospheric model; a flood frequency analysis system that uses site-specific topographic data plus information from the atmospheric model to generate a flood frequency curve; a hydroelectric power simulation program which determines daily energy output for a run-of-river or reservoir storage site based on selected generation facilities and the time series generated in the watershed model; and a graphic analysis package that provides direct visualization of data and modelling results. This report contains a description of the programs, a user guide, the theory behind the model, the modelling methodology, and results from a workshop that reviewed the program package. 32 refs., 16 figs., 18 tabs.

  17. Method of operating nuclear power plant

    International Nuclear Information System (INIS)

    Kodama, Tasuku.

    1991-01-01

    The present invention concerns a method of operating a plant in which the inside of a reactor container is filled with inert gases. That is, the pressure at the inside of the pressure vessel is controlled based on the values sent from an absolute pressure gage and a pressure low gage during usual operation. A pressure high alarm and a pressure high scram signal are generated from a pressure high detector and a scram pressure detector. With such a constitution, since the pressure at the inside of the reactor is always kept at a slightly positive level relative to the surrounding atmospheric pressure even when high atmospheric pressure approaches to the plant site, air does not flow into the reactor container. Accordingly, the oxygen concentration is not increased. When a low atmospheric pressure approaches, the control operation for the pressure at the inside of the container is not necessary. The amount of the inert gases consumed and the amount of radioactive materials released to the atmosphere are decreased. The method of the present invention improves the safety and the reliability of the reactor operation. (N.H.)

  18. Agent-based power sharing scheme for active hybrid power sources

    Science.gov (United States)

    Jiang, Zhenhua

    The active hybridization technique provides an effective approach to combining the best properties of a heterogeneous set of power sources to achieve higher energy density, power density and fuel efficiency. Active hybrid power sources can be used to power hybrid electric vehicles with selected combinations of internal combustion engines, fuel cells, batteries, and/or supercapacitors. They can be deployed in all-electric ships to build a distributed electric power system. They can also be used in a bulk power system to construct an autonomous distributed energy system. An important aspect in designing an active hybrid power source is to find a suitable control strategy that can manage the active power sharing and take advantage of the inherent scalability and robustness benefits of the hybrid system. This paper presents an agent-based power sharing scheme for active hybrid power sources. To demonstrate the effectiveness of the proposed agent-based power sharing scheme, simulation studies are performed for a hybrid power source that can be used in a solar car as the main propulsion power module. Simulation results clearly indicate that the agent-based control framework is effective to coordinate the various energy sources and manage the power/voltage profiles.

  19. Fossil fuel combined cycle power generation method

    Science.gov (United States)

    Labinov, Solomon D [Knoxville, TN; Armstrong, Timothy R [Clinton, TN; Judkins, Roddie R [Knoxville, TN

    2008-10-21

    A method for converting fuel energy to electricity includes the steps of converting a higher molecular weight gas into at least one mixed gas stream of lower average molecular weight including at least a first lower molecular weight gas and a second gas, the first and second gases being different gases, wherein the first lower molecular weight gas comprises H.sub.2 and the second gas comprises CO. The mixed gas is supplied to at least one turbine to produce electricity. The mixed gas stream is divided after the turbine into a first gas stream mainly comprising H.sub.2 and a second gas stream mainly comprising CO. The first and second gas streams are then electrochemically oxidized in separate fuel cells to produce electricity. A nuclear reactor can be used to supply at least a portion of the heat the required for the chemical conversion process.

  20. POWER ANALYSIS FOR COMPLEX MEDIATIONAL DESIGNS USING MONTE CARLO METHODS

    OpenAIRE

    Thoemmes, Felix; MacKinnon, David P.; Reiser, Mark R.

    2010-01-01

    Applied researchers often include mediation effects in applications of advanced methods such as latent variable models and linear growth curve models. Guidance on how to estimate statistical power to detect mediation for these models has not yet been addressed in the literature. We describe a general framework for power analyses for complex mediational models. The approach is based on the well known technique of generating a large number of samples in a Monte Carlo study, and estimating power...

  1. Comparison of electric field exposure measurement methods under power lines

    International Nuclear Information System (INIS)

    Korpinen, L.; Kuisti, H.; Tarao, H.; Paeaekkoenen, R.; Elovaara, J.

    2014-01-01

    The object of the study was to investigate extremely low frequency (ELF) electric field exposure measurement methods under power lines. The authors compared two different methods under power lines: in Method A, the sensor was placed on a tripod; and Method B required the measurer to hold the meter horizontally so that the distance from him/her was at least 1.5 m. The study includes 20 measurements in three places under 400 kV power lines. The authors used two commercial three-axis meters, EFA-3 and EFA-300. In statistical analyses, they did not find significant differences between Methods A and B. However, in the future, it is important to take into account that measurement methods can, in some cases, influence ELF electric field measurement results, and it is important to report the methods used so that it is possible to repeat the measurements. (authors)

  2. Power Analysis for Complex Mediational Designs Using Monte Carlo Methods

    Science.gov (United States)

    Thoemmes, Felix; MacKinnon, David P.; Reiser, Mark R.

    2010-01-01

    Applied researchers often include mediation effects in applications of advanced methods such as latent variable models and linear growth curve models. Guidance on how to estimate statistical power to detect mediation for these models has not yet been addressed in the literature. We describe a general framework for power analyses for complex…

  3. Method for controlling power flow between an electrochemical cell and a power grid

    International Nuclear Information System (INIS)

    Coleman, A. K.

    1981-01-01

    A method is disclosed for controlling a force-commutated inverter coupled between an electrochemical cell and a power grid for adjusting the magnitude and direction of the electrical energy flowing therebetween. Both the real power component and the reactive power component of ac electrical energy flow can be independently VARied through the switching waveform presented to the intermediately coupled inverter. A VAR error signal is derived from a comparison of a var command signal with a signal proportional to the actual reactive power circulating between the inverter and the power grid. This signal is presented to a voltage controller which essentially varies only the effective magnitude of the fundamental voltage waveform out of the inverter , thereby leaving the real power component substantially unaffected. In a similar manner, a power error signal is derived by a comparison of a power command signal with a signal proportional to the actual real power flowing between the electrochemical cell and the power grid. This signal is presented to a phase controller which varies only the phase of the fundamental component of the voltage waveform out of the inverter relative to that of the power grid and changes only the real power in proportion thereto, thus leaving the reactive power component substantially unaffected

  4. Active Power Flow Optimization of Industrial Power Supply with Regard to the Transmission Line Conductor Heating

    Directory of Open Access Journals (Sweden)

    Leyzgold D.Yu.

    2015-04-01

    Full Text Available This article studies the problem of the transmission line conductor heating effect on the active power flows optimization in the local segment of industrial power supply. The purpose is to determine the optimal generation rating of the distributed power sources, in which the power flow values will correspond to the minimum active power losses in the power supply. The timeliness is the need to define the most appropriate rated power values of distributed sources which will be connected to current industrial power supply. Basing on the model of active power flow optimization, authors formulate the description of the nonlinear transportation problem considering the active power losses depending on the transmission line conductor heating. Authors proposed a new approach to the heating model parameters definition based on allowable current loads and nominal parameters of conductors as part of the optimization problem. Analysis of study results showed that, despite the relatively small active power losses reduction to the tune 0,45% due to accounting of the conductors heating effect for the present configuration of power supply, there are significant fluctuations in the required generation rating in nodes of the network to 9,32% within seasonal changes in the outer air temperature. This fact should be taken into account when selecting the optimum power of distributed generation systems, as exemplified by an arbitrary network configuration.

  5. Social power and approach-related neural activity

    OpenAIRE

    Boksem, Maarten; Smolders, Ruud; Cremer, David

    2009-01-01

    textabstractIt has been argued that power activates a general tendency to approach whereas powerlessness activates a tendency to inhibit. The assumption is that elevated power involves reward-rich environments, freedom and, as a consequence, triggers an approach-related motivational orientation and attention to rewards. In contrast, reduced power is associated with increased threat, punishment and social constraint and thereby activates inhibition-related motivation. Moreover, approach motiva...

  6. Development of power change maneuvering method for BWR

    International Nuclear Information System (INIS)

    Fukuzaki, Takaharu; Yamada, Naoyuki; Kiguchi, Takashi; Sakurai, Mikio.

    1985-01-01

    A power change maneuvering method for BWR has been proposed to generate an optimal power control maneuver, which realizes the power change operation closest to a power change demand pattern under operating constraints. The method searches for the maneuver as an optimization problem, where the variables are thermal power levels sampled from the demand pattern, the performance index is defined to express the power mismatch between demand and feasible patterns, and the constraints are limit lines on the thermal power-core flow rate map and limits on keeping fuel integrity. The usable feasible direction method is utilized as the optimization algorithm, with newly developed techniques for initial value generation and step length determination, which apply one-dimensional search and inverse-interpolation methods, respectively, to realize the effective search of the optimal solution. Simulation results show that a typical computing time is about 5 min by a general purpose computer and the method has been verified to be practical even for on-line use. (author)

  7. THORs Power Method for Hydrokinetic Devices - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    J. Turner Hunt; Joel Rumker

    2012-08-08

    Ocean current energy represents a vast untapped source of renewable energy that exists on the outer continental shelf areas of the 5 major continents. Ocean currents are unidirectional in nature and are perpetuated by thermal and salinity sea gradients, as well as coriolis forces imparted from the earth's rotation. This report details THORs Power Method, a breakthrough power control method that can provide dramatic increases to the capacity factor over and above existing marine hydrokinetic (MHK) devices employed in the extraction of energy from ocean currents. THORs Power Method represents a constant speed, variable depth operational method that continually locates the ocean current turbine at a depth at which the rated power of the generator is routinely achieved. Variable depth operation is achieved by using various vertical force effectors, including ballast tanks for variable weight, a hydrodynamic wing for variable lift or down force and drag flaps for variable vehicle drag forces.

  8. The Power Context of Method-in-Action

    DEFF Research Database (Denmark)

    Munk-Madsen, Andreas

    2008-01-01

    Important parts of the knowledge within the field of information systems are represented as methods. Methods focus on the development process. Although methods are applied in complex settings, involving different actors with different interests and power bases, this is normally not reflected...

  9. Control of Solar Power Plants Connected Grid with Simple Calculation Method on Residential Homes

    Science.gov (United States)

    Kananda, Kiki; Nazir, Refdinal

    2017-12-01

    One of the most compatible renewable energy in all regions to apply is solar energy. Solar power plants can be built connected to existing or stand-alone power grids. In assisting the residential electricity in which there is a power grid, then a small scale solar energy power plants is very appropriate. However, the general constraint of solar energy power plants is still low in terms of efficiency. Therefore, this study will explain how to control the power of solar power plants more optimally, which is expected to reactive power to zero to raise efficiency. This is a continuation of previous research using Newton Rapshon control method. In this study we introduce a simple method by using ordinary mathematical calculations of solar-related equations. In this model, 10 PV modules type of ND T060M1 with a 60 Wp capacity are used. The calculations performed using MATLAB Simulink provide excellent value. For PCC voltage values obtained a stable quantity of approximately 220 V. At a maximum irradiation condition of 1000 W / m2, the reactive power value of Q solar generating system maximum 20.48 Var and maximum active power of 417.5 W. In the condition of lower irradiation, value of reactive power Q almost close to zero 0.77Var. This simple mathematical method can provide excellent quality control power values.

  10. Method of controlling power distribution in FBR type reactors

    International Nuclear Information System (INIS)

    Sawada, Shusaku; Kaneto, Kunikazu.

    1982-01-01

    Purpose: To attain the power distribution flattening with ease by obtaining a radial power distribution substantially in a constant configuration not depending on the burn-up cycle. Method: As the fuel burning proceeds, the radial power distribution is effected by the accumulation of fission products in the inner blancket fuel assemblies which varies the effect thereof as the neutron absorbing substances. Taking notice of the above fact, the power distribution is controlled in a heterogeneous FBR type reactor by varying the core residence period of the inner blancket assemblies in accordance with the charging density of the inner blancket assemblies in the reactor core. (Kawakami, Y.)

  11. Methods for tornado frequency calculation of nuclear power plant

    International Nuclear Information System (INIS)

    Liu Haibin; Li Lin

    2012-01-01

    In order to take probabilistic safety assessment of nuclear power plant tornado attack event, a method to calculate tornado frequency of nuclear power plant is introduced based on HAD 101/10 and NUREG/CR-4839 references. This method can consider history tornado frequency of the plant area, construction dimension, intensity various along with tornado path and area distribution and so on and calculate the frequency of different scale tornado. (authors)

  12. Active Splitting in Longitudinal Power Systems based on a WAMPC

    Directory of Open Access Journals (Sweden)

    Felipe Arraño-Vargas

    2017-12-01

    Full Text Available This paper proposes an active splitting scheme especially suitable for longitudinal power systems (LPS. The proposed scheme is based on a modified out-of-step (OOS algorithm combined with an angle difference method using synchrophasor measurements. The remedial actions are based on the detection of possible loss of synchronism due to severe disturbances. The scheme was tested on a detailed dynamic model of the Central Interconnected System of Chile, a good example of extreme LPS. Obtained results show that remedial actions taken by the proposed protection scheme are able to avoid the total collapse of the system during critical contingencies.

  13. Evaluation of hazards from industrial activities near nuclear power plants

    International Nuclear Information System (INIS)

    Lannoy, A.; Gobert, T.

    1980-01-01

    Among the potential hazards which could arise from industrial activity near nuclear power plants, fires and explosions of dangerous products are of particular concern. Indeed, thermal radiation from an adjacent fire could endanger the resistance of a plant's structures. Likewise, an accident explosion would induce an overpressure wave which could affect buildings' integrity. This paper presents the methodology developed by Electricite de France to evaluate the consequences of accidents affecting: - Industrial facilities: refineries, chemical and petrochemical plants, storage areas, pipelines of gaseous, liquid and liquefied materials. - Transportation routes (roads, railways, inland waterways) used to carry dangerous substances (solid explosives, liquid, gaseous or liquefied hydrocarbons). Probabilistic methods have been developed by analysis of actual accident statistics (e.g. risks induced by transportation routes) and realistic and representative accident scenarios have been set up. Five sequences have been identified: Formation of a fluid jet at a breach. Evaporation and possible formation of a liquid layer. Atmospheric dispersion and drift of a gaseous cloud. Heat radiation from fire. Unconfined explosion of a gaseous cloud. This paper gives an overview of the methods and the main assumptions used to deal with each sequence. Those methods, presently applied by Electricite de France, provide a coherent and realistic approach for the evaluation of the risks at nuclear power plants induced by industrial activity. (orig.)

  14. Approaches and methods for econometric analysis of market power

    DEFF Research Database (Denmark)

    Perekhozhuk, Oleksandr; Glauben, Thomas; Grings, Michael

    2017-01-01

    , functional forms, estimation methods and derived estimates of the degree of market power. Thereafter, we use our framework to evaluate several structural models based on PTA and GIM to measure oligopsony power in the Ukrainian dairy industry. The PTA-based results suggest that the estimated parameters......This study discusses two widely used approaches in the New Empirical Industrial Organization (NEIO) literature and examines the strengths and weaknesses of the Production-Theoretic Approach (PTA) and the General Identification Method (GIM) for the econometric analysis of market power...... in agricultural and food markets. We provide a framework that may help researchers to evaluate and improve structural models of market power. Starting with the specification of the approaches in question, we compare published empirical studies of market power with respect to the choice of the applied approach...

  15. Site selection of active damper for stabilizing power electronics based power distribution system

    DEFF Research Database (Denmark)

    Yoon, Changwoo; Wang, Xiongfei; Bak, Claus Leth

    2015-01-01

    electronics based power device, which provides an adjustable damping capability to the power system where the voltage harmonic instability is measured. It can stabilize by adjusting the equivalent node impedance with its plug and play feature. This feature gives many degrees of freedom of its installation......Stability in the nowadays distribution power system is endangered by interaction problems that may arise from newly added power-electronics based power devices. Recently, a new concept to deal with this higher frequency instability, the active damper, has been proposed. The active damper is a power...... point when the system has many nodes. Therefore, this paper addresses the proper placement of an active damper in an unstable small-scale power distribution system. A time-domain model of the Cigre benchmark low-vltage network is used as a test field. The result shows the active damper location...

  16. Design methods for high temperature power plant structures

    International Nuclear Information System (INIS)

    Townley, C.H.A.

    1984-01-01

    The subject is discussed under the headings: introduction (scope of paper - reviews of design methods and design criteria currently in use for both nuclear and fossil fuelled power plant; examples chosen are (a) BS 1113, representative of design codes employed for power station boiler plant; (b) ASME Code Case N47, which is being developed for high temperature nuclear reactors, especially the liquid metal fast breeder reactor); design codes for power station boilers; Code Case N47 (design in the absence of thermal shock and thermal fatigue; design against cyclic loading at high temperature; further research in support of high temperature design methods and criteria for LMFBRs); concluding remarks. (U.K.)

  17. Employment of kernel methods on wind turbine power performance assessment

    DEFF Research Database (Denmark)

    Skrimpas, Georgios Alexandros; Sweeney, Christian Walsted; Marhadi, Kun S.

    2015-01-01

    A power performance assessment technique is developed for the detection of power production discrepancies in wind turbines. The method employs a widely used nonparametric pattern recognition technique, the kernel methods. The evaluation is based on the trending of an extracted feature from...... the kernel matrix, called similarity index, which is introduced by the authors for the first time. The operation of the turbine and consequently the computation of the similarity indexes is classified into five power bins offering better resolution and thus more consistent root cause analysis. The accurate...

  18. Fish sampling with active methods

    Czech Academy of Sciences Publication Activity Database

    Kubečka, Jan; Godo, O. R.; Hickley, P.; Prchalová, Marie; Říha, Milan; Rudstam, L.; Welcomme, R.

    2012-01-01

    Roč. 123, July (2012), s. 1-3 ISSN 0165-7836 Institutional support: RVO:60077344 Keywords : fish stock assessment * active and passive gear * intercalibration Subject RIV: EH - Ecology, Behaviour Impact factor: 1.695, year: 2012

  19. Indirect Control of a low power Single-Phase Active Power Filter

    Directory of Open Access Journals (Sweden)

    SILVIU EPURE

    2010-12-01

    Full Text Available This paper deals with a low power, single phase active filter used to compensate nonlinear loads. The filter uses the indirect control method and it is based on a particular connection between filter, polluting load and grid to avoid timeconsuming mathematic operations or signal processing computations and assures good rejection of harmonic currents injected by the nonlinear load into the grid. A scale model was first simulated in Simulink and then physically implemented. The paper presents simulation and experimental results, and highlight problems encountered during experiments.

  20. Model based active power control of a wind turbine

    DEFF Research Database (Denmark)

    Mirzaei, Mahmood; Soltani, Mohsen; Poulsen, Niels Kjølstad

    2014-01-01

    in the electricity market that selling the reserve power is more profitable than producing with the full capacity. Therefore wind turbines can be down-regulated and sell the differential capacity as the reserve power. In this paper we suggest a model based approach to control wind turbines for active power reference...

  1. Investigation of Improved Methods in Power Transfer Efficiency for Radiating Near-Field Wireless Power Transfer

    Directory of Open Access Journals (Sweden)

    Hesheng Cheng

    2016-01-01

    Full Text Available A metamaterial-inspired efficient electrically small antenna is proposed, firstly. And then several improving power transfer efficiency (PTE methods for wireless power transfer (WPT systems composed of the proposed antenna in the radiating near-field region are investigated. Method one is using a proposed antenna as a power retriever. This WPT system consisted of three proposed antennas: a transmitter, a receiver, and a retriever. The system is fed by only one power source. At a fixed distance from receiver to transmitter, the distance between the transmitter and the retriever is turned to maximize power transfer from the transmitter to the receiver. Method two is using two proposed antennas as transmitters and one antenna as receiver. The receiver is placed between the two transmitters. In this system, two power sources are used to feed the two transmitters, respectively. By adjusting the phase difference between the two feeding sources, the maximum PTE can be obtained at the optimal phase difference. Using the same configuration as method two, method three, where the maximum PTE can be increased by regulating the voltage (or power ratio of the two feeding sources, is proposed. In addition, we combine the proposed methods to construct another two schemes, which improve the PTE at different extent than classical WPT system.

  2. Impact of thermostatically controlled loads' demand response activation on aggregated power: A field experiment

    DEFF Research Database (Denmark)

    Lakshmanan, Venkatachalam; Marinelli, Mattia; Kosek, Anna Magdalena

    2015-01-01

    activation. The outcome of this experimental study quantifies the actual flexibility of household TCLs and the consequence for the different parties with respect to power behaviour. Each DR activation method adopts different scenarios to meet the power reduction, and has different impacts on the parameters......This paper describes the impacts of different types of DR (demand response) activation on TCLs' (thermostatically controlled loads) aggregated power. The different parties: power system operators, DR service providers (or aggregators) and consumers, have different objectives in relation to DR....... The experiments are conducted with real domestic refrigerators representing TCL. Activating refrigerators for DR with a delay reduces the ISE (integral square error) in power limitation by 28.46%, overshoot by 7.69%. The delay in refrigerator activation causes reduction in power ramp down rate by 39.90%, ramp up...

  3. A Hybrid Optimization Method for Reactive Power and Voltage Control Considering Power Loss Minimization

    DEFF Research Database (Denmark)

    Liu, Chengxi; Qin, Nan; Bak, Claus Leth

    2015-01-01

    This paper proposes a hybrid optimization method to optimally control the voltage and reactive power with minimum power loss in transmission grid. This approach is used for the Danish automatic voltage control (AVC) system which is typically a non-linear non-convex problem mixed with both...

  4. Economic Valuation Methods: The Perception of the Accountants of the Hydroeletric Power Sector in Brazil

    OpenAIRE

    Aracéli Cristina de S. Ferreira; Hélio Arthur Irigaray

    2015-01-01

    The aim of the present study was to verify how accountants perceive the electric power companies in Brazil, regarding the use of economic valuation methods for measuring environmental impacts on hydroelectric power generation. These methods would be used in the internalisation of impacts in compliance with accounting theory criteria of recognition, measurement and disclosure of relevant economic activities. This is an exploratory study based on the conclusion regarding the collected data from...

  5. Electric power economy: comparative study of electric power consumption in many methods of outfloor control

    International Nuclear Information System (INIS)

    Kubota, Hideo; Tsitiya, Milton Tomoyuki

    1989-01-01

    This work presents a comparative study of the electric power consumption of a water elevatory station in order to verify which method is the most suitable in energy economy through the outflow variation in function of the demand

  6. Methods for surveillance of noise signals from nuclear power plants using auto power spectra

    International Nuclear Information System (INIS)

    Streich, M.

    1988-01-01

    A survey of methods for noise diagnostics applied in the nuclear power plant 'Bruno Leuschner' for surveillance of primary circuit is given. Considering a special example concept of surveillance of standard deviations is explained. (author)

  7. Compensating active power imbalances in power system with large-scale wind power penetration

    DEFF Research Database (Denmark)

    Basit, Abdul; Hansen, Anca Daniela; Altin, Müfit

    2016-01-01

    Large-scale wind power penetration can affectthe supply continuity in the power system. This is a matterof high priority to investigate, as more regulating reservesand specified control strategies for generation control arerequired in the future power system with even more highwind power penetrat...

  8. Social power and approach-related neural activity

    NARCIS (Netherlands)

    M.A.S. Boksem (Maarten); R. Smolders (Ruud); D. de Cremer (David)

    2009-01-01

    textabstractIt has been argued that power activates a general tendency to approach whereas powerlessness activates a tendency to inhibit. The assumption is that elevated power involves reward-rich environments, freedom and, as a consequence, triggers an approach-related motivational orientation and

  9. Magnetic stirring welding method applied to nuclear power plant

    International Nuclear Information System (INIS)

    Hirano, Kenji; Watando, Masayuki; Morishige, Norio; Enoo, Kazuhide; Yasuda, Yuuji

    2002-01-01

    In construction of a new nuclear power plant, carbon steel and stainless steel are used as base materials for the bottom linear plate of Reinforced Concrete Containment Vessel (RCCV) to achieve maintenance-free requirement, securing sufficient strength of structure. However, welding such different metals is difficult by ordinary method. To overcome the difficulty, the automated Magnetic Stirring Welding (MSW) method that can demonstrate good welding performance was studied for practical use, and weldability tests showed the good results. Based on the study, a new welding device for the MSW method was developed to apply it weld joints of different materials, and it practically used in part of a nuclear power plant. (author)

  10. Development of Early Warning Methods for Electric Power Systems

    DEFF Research Database (Denmark)

    Jóhannsson, Hjörtur

    This thesis concerns the development of methods that can provide, in realtime, an early warning for an emerging blackout in electric power systems. The blackout in E-Denmark and S-Sweden on September 23, 2003 is the main motivation for the method development. The blackout was caused by occurrence...

  11. New method for designing serial resonant power converters

    Science.gov (United States)

    Hinov, Nikolay

    2017-12-01

    In current work is presented one comprehensive method for design of serial resonant energy converters. The method is based on new simplified approach in analysis of such kind power electronic devices. It is grounded on supposing resonant mode of operation when finding relation between input and output voltage regardless of other operational modes (when controlling frequency is below or above resonant frequency). This approach is named `quasiresonant method of analysis', because it is based on assuming that all operational modes are `sort of' resonant modes. An estimation of error was made because of the a.m. hypothesis and is compared to the classic analysis. The `quasiresonant method' of analysis gains two main advantages: speed and easiness in designing of presented power circuits. Hence it is very useful in practice and in teaching Power Electronics. Its applicability is proven with mathematic modelling and computer simulation.

  12. Nuclear Power Plants Fault Diagnosis Method Based on Data Fusion

    International Nuclear Information System (INIS)

    Xie Chunli; Liu Yongkuo; Xia Hong

    2009-01-01

    The data fusion is a method suit for complex system fault diagnosis such as nuclear power plants, which is multisource information processing technology. This paper uses data fusion information hierarchical thinking and divides nuclear power plants fault diagnosis into three levels. Data level adopts data mining method to handle data and reduction attributes. Feature level uses three parallel neural networks to deal with attributes of data level reduction and the outputs of three networks are as the basic probability assignment of Dempster-Shafer (D-S) evidence theory. The improved D-S evidence theory synthesizes the outputs of neural networks in decision level, which conquer the traditional D-S evidence theory limitation which can't dispose conflict information. The diagnosis method was tested using correlation data of literature. The test results indicate that the data fusion diagnosis system can diagnose nuclear power plants faults accurately and the method has application value. (authors)

  13. Grid-Connection Half-Bridge PV Inverter System for Power Flow Controlling and Active Power Filtering

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2012-01-01

    Full Text Available A half-bridge photovoltaic (PV system is proposed, which can not only deal with bidirectional power flowing but also improve power quality. According to varying insolation, the system conditions real power for dc and ac loads to accommodate different amounts of PV power. Furthermore, the system eliminates current harmonics and improves power factor simultaneously. As compared with conventional PV inverter, the total number of active switches and current sensors can be reduced so that its cost is lower significantly. For current command determination, a linear-approximation method (LAM is applied to avoid the complicated calculation and achieve the maximum power point tracking (MPPT feature. For current controlling, a direct-source-current-shaping (DSCS algorithm is presented to shape the waveform of line current. Simulation results and practical measurements also demonstrate the feasibility of the proposed half-bridge PV system.

  14. Method for assessing wind power integration in a hydro based power system

    International Nuclear Information System (INIS)

    Norheim, I.; Palsson, M.; Tande, J.O.G.; Uhlen, K.

    2006-01-01

    The present paper demonstrates a method for assessment of how much wind power that can be integrated in a system with limited transmission capacity. Based on hydro inflow data and wind measurements (for different locations of planned wind farms in an area) it is possible to assess how much wind power that can be fed into a certain point in the transmission network without violating the transmission capacity limits. The proposed method combines the use of market modelling and detailed network analysis in order to assess the probability of network congestions rather than focusing on extreme cases. By computing the probability distribution of power flow on critical corridors in the grid it is possible to assess the likelihood of network congestions and the amount of energy that must be curtailed to fulfil power system security requirements (n-1). This way the assessment is not only made of worst case scenarios, assuming maximal flow from hydro plants and maximal wind power production. As extreme case scenarios are short term and may be solved by market mechanisms or automatic system protection schemes (disconnection of wind power or hydro power), the proposed method may reveal that it would be economic to install more wind power than if only based on analysis of worst case scenarios. (orig.)

  15. Methods and Algorithms for Economic MPC in Power Production Planning

    DEFF Research Database (Denmark)

    Sokoler, Leo Emil

    in real-time. A generator can represent a producer of electricity, a consumer of electricity, or possibly both. Examples of generators are heat pumps, electric vehicles, wind turbines, virtual power plants, solar cells, and conventional fuel-fired thermal power plants. Although this thesis is mainly...... concerned with EMPC for minutes-ahead production planning, we show that the proposed EMPC scheme can be extended to days-ahead planning (including unit commitment) as well. The power generation from renewable energy sources such as wind and solar power is inherently uncertain and variable. A portfolio...... design an algorithm based on the alternating direction method of multipliers (ADMM) to solve input-constrained OCPs with convex objective functions. The OCPs that occur in EMPC of dynamically decoupled subsystems, e.g. power generators, have a block-angular structure. Subsystem decomposition algorithms...

  16. CNEN activities and brazilian nuclear power policy

    International Nuclear Information System (INIS)

    Costa, E.M. da

    1989-01-01

    The goal of the brazilian policy in nuclear power is to provide its use in a pacific way to promote the well being of our people. It is intended, as well, to finish the construction of Angra II and III and proceed with the implementation of the nuclear fuel cycle, progressively fomenting its nationalization. (A.C.A.S.)

  17. Method for assigning sites to projected generic nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Holter, G.M.; Purcell, W.L.; Shutz, M.E.; Young, J.R.

    1986-07-01

    Pacific Northwest Laboratory developed a method for forecasting potential locations and startup sequences of nuclear power plants that will be required in the future but have not yet been specifically identified by electric utilities. Use of the method results in numerical ratings for potential nuclear power plant sites located in each of the 10 federal energy regions. The rating for each potential site is obtained from numerical factors assigned to each of 5 primary siting characteristics: (1) cooling water availability, (2) site land area, (3) power transmission land area, (4) proximity to metropolitan areas, and (5) utility plans for the site. The sequence of plant startups in each federal energy region is obtained by use of the numerical ratings and the forecasts of generic nuclear power plant startups obtained from the EIA Middle Case electricity forecast. Sites are assigned to generic plants in chronological order according to startup date.

  18. Method for assigning sites to projected generic nuclear power plants

    International Nuclear Information System (INIS)

    Holter, G.M.; Purcell, W.L.; Shutz, M.E.; Young, J.R.

    1986-07-01

    Pacific Northwest Laboratory developed a method for forecasting potential locations and startup sequences of nuclear power plants that will be required in the future but have not yet been specifically identified by electric utilities. Use of the method results in numerical ratings for potential nuclear power plant sites located in each of the 10 federal energy regions. The rating for each potential site is obtained from numerical factors assigned to each of 5 primary siting characteristics: (1) cooling water availability, (2) site land area, (3) power transmission land area, (4) proximity to metropolitan areas, and (5) utility plans for the site. The sequence of plant startups in each federal energy region is obtained by use of the numerical ratings and the forecasts of generic nuclear power plant startups obtained from the EIA Middle Case electricity forecast. Sites are assigned to generic plants in chronological order according to startup date

  19. Review of Active and Reactive Power Sharing Strategies in Hierarchical Controlled Microgrids

    DEFF Research Database (Denmark)

    Han, Yang; Li, Hong; Shen, Pan

    2017-01-01

    Microgrids consist of multiple parallel-connected distributed generation (DG) units with coordinated control strategies, which are able to operate in both grid-connected and islanded mode. Microgrids are attracting more and more attention since they can alleviate the stress of main transmission...... systems, reduce feeder losses, and improve system power quality. When the islanded microgrids are concerned, it is important to maintain system stability and achieve load power sharing among the multiple parallel-connected DG units. However, the poor active and reactive power sharing problems due...... in this paper for active power sharing. Moreover, nonlinear and unbalanced loads could further affect the reactive power sharing when regulating the active power, and it is difficult to share the reactive power accurately only by using the enhanced virtual impedance method. Therefore, the hierarchical control...

  20. Optimal PMU placement using topology transformation method in power systems

    Directory of Open Access Journals (Sweden)

    Nadia H.A. Rahman

    2016-09-01

    Full Text Available Optimal phasor measurement units (PMUs placement involves the process of minimizing the number of PMUs needed while ensuring the entire power system completely observable. A power system is identified observable when the voltages of all buses in the power system are known. This paper proposes selection rules for topology transformation method that involves a merging process of zero-injection bus with one of its neighbors. The result from the merging process is influenced by the selection of bus selected to merge with the zero-injection bus. The proposed method will determine the best candidate bus to merge with zero-injection bus according to the three rules created in order to determine the minimum number of PMUs required for full observability of the power system. In addition, this paper also considered the case of power flow measurements. The problem is formulated as integer linear programming (ILP. The simulation for the proposed method is tested by using MATLAB for different IEEE bus systems. The explanation of the proposed method is demonstrated by using IEEE 14-bus system. The results obtained in this paper proved the effectiveness of the proposed method since the number of PMUs obtained is comparable with other available techniques.

  1. Optimal PMU placement using topology transformation method in power systems.

    Science.gov (United States)

    Rahman, Nadia H A; Zobaa, Ahmed F

    2016-09-01

    Optimal phasor measurement units (PMUs) placement involves the process of minimizing the number of PMUs needed while ensuring the entire power system completely observable. A power system is identified observable when the voltages of all buses in the power system are known. This paper proposes selection rules for topology transformation method that involves a merging process of zero-injection bus with one of its neighbors. The result from the merging process is influenced by the selection of bus selected to merge with the zero-injection bus. The proposed method will determine the best candidate bus to merge with zero-injection bus according to the three rules created in order to determine the minimum number of PMUs required for full observability of the power system. In addition, this paper also considered the case of power flow measurements. The problem is formulated as integer linear programming (ILP). The simulation for the proposed method is tested by using MATLAB for different IEEE bus systems. The explanation of the proposed method is demonstrated by using IEEE 14-bus system. The results obtained in this paper proved the effectiveness of the proposed method since the number of PMUs obtained is comparable with other available techniques.

  2. Social power and approach-related neural activity.

    Science.gov (United States)

    Boksem, Maarten A S; Smolders, Ruud; De Cremer, David

    2012-06-01

    It has been argued that power activates a general tendency to approach whereas powerlessness activates a tendency to inhibit. The assumption is that elevated power involves reward-rich environments, freedom and, as a consequence, triggers an approach-related motivational orientation and attention to rewards. In contrast, reduced power is associated with increased threat, punishment and social constraint and thereby activates inhibition-related motivation. Moreover, approach motivation has been found to be associated with increased relative left-sided frontal brain activity, while withdrawal motivation has been associated with increased right sided activations. We measured EEG activity while subjects engaged in a task priming either high or low social power. Results show that high social power is indeed associated with greater left-frontal brain activity compared to low social power, providing the first neural evidence for the theory that high power is associated with approach-related motivation. We propose a framework accounting for differences in both approach motivation and goal-directed behaviour associated with different levels of power.

  3. A New Method Presentation for Fault Location in Power Transformers

    OpenAIRE

    Hossein Mohammadpour; Rahman Dashti

    2011-01-01

    Power transformers are among the most important and expensive equipments in the electric power systems. Consequently the transformer protection is an essential part of the system protection. This paper presents a new method for locating transformer winding faults such as turn-to-turn, turn-to-core, turn-totransformer body, turn-to-earth, and high voltage winding to low voltage winding. In this study the current and voltage signals of input and output terminals of the tran...

  4. Method of safety evaluation in nuclear power plants

    International Nuclear Information System (INIS)

    Kuraszkiewicz, P.; Zahn, P.

    1988-01-01

    A novel quantitative technique for evaluating safety of subsystems of nuclear power plants based on expert estimations is presented. It includes methods of mathematical psychology recognizing the effect of subjective factors in the expert estimates and, consequently, contributes to further objectification of evaluation. It may be applied to complementing probabilistic safety assessment. As a result of such evaluations a characteristic 'safety of nuclear power plants' is obtained. (author)

  5. Method for treatment of wastewater of nuclear power plants

    International Nuclear Information System (INIS)

    Ito, Kazutoshi; Suzuki, Katsumi; Suzuki, Mamoru; Minato, Akira.

    1984-01-01

    A method for treatment of wastewater of nuclear power plants is characterized by the fact that concentration and volume reduction are performed after Ca and Mg as components for the formation of an adhering scale is converted to an 8-oxyquinoline complex, which is hardly soluble in water, and does not precipitate out as an adhering scale, by the addition of 8-oxyquinoline into nuclear power plant wastewater

  6. A new computational method for reactive power market clearing

    International Nuclear Information System (INIS)

    Zhang, T.; Elkasrawy, A.; Venkatesh, B.

    2009-01-01

    After deregulation of electricity markets, ancillary services such as reactive power supply are priced separately. However, unlike real power supply, procedures for costing and pricing reactive power supply are still evolving and spot markets for reactive power do not exist as of now. Further, traditional formulations proposed for clearing reactive power markets use a non-linear mixed integer programming formulation that are difficult to solve. This paper proposes a new reactive power supply market clearing scheme. Novelty of this formulation lies in the pricing scheme that rewards transformers for tap shifting while participating in this market. The proposed model is a non-linear mixed integer challenge. A significant portion of the manuscript is devoted towards the development of a new successive mixed integer linear programming (MILP) technique to solve this formulation. The successive MILP method is computationally robust and fast. The IEEE 6-bus and 300-bus systems are used to test the proposed method. These tests serve to demonstrate computational speed and rigor of the proposed method. (author)

  7. Study and Handling Methods of Power IGBT Module Failures in Power Electronic Converter Systems

    DEFF Research Database (Denmark)

    Choi, Uimin; Blaabjerg, Frede; Lee, Kyo-Beum

    2015-01-01

    Power electronics plays an important role in a wide range of applications in order to achieve high efficiency and performance. Increasing efforts are being made to improve the reliability of power electronics systems to ensure compliance with more stringent constraints on cost, safety......, and availability in different applications. This paper presents an overview of the major failure mechanisms of IGBT modules and their handling methods in power converter systems improving reliability. The major failure mechanisms of IGBT modules are presented first, and methods for predicting lifetime...... and estimating the junction temperature of IGBT modules are then discussed. Subsequently, different methods for detecting open- and short-circuit faults are presented. Finally, fault-tolerant strategies for improving the reliability of power electronic systems under field operation are explained and compared...

  8. Rapid Active Power Control of Photovoltaic Systems for Grid Frequency Support

    Energy Technology Data Exchange (ETDEWEB)

    Hoke, Anderson; Shirazi, Mariko; Chakraborty, Sudipta; Muljadi, Eduard; Maksimovic, Dragan

    2017-01-01

    As deployment of power electronic coupled generation such as photovoltaic (PV) systems increases, grid operators have shown increasing interest in calling on inverter-coupled generation to help mitigate frequency contingency events by rapidly surging active power into the grid. When responding to contingency events, the faster the active power is provided, the more effective it may be for arresting the frequency event. This paper proposes a predictive PV inverter control method for very fast and accurate control of active power. This rapid active power control method will increase the effectiveness of various higher-level controls designed to mitigate grid frequency contingency events, including fast power-frequency droop, inertia emulation, and fast frequency response, without the need for energy storage. The rapid active power control method, coupled with a maximum power point estimation method, is implemented in a prototype PV inverter connected to a PV array. The prototype inverter's response to various frequency events is experimentally confirmed to be fast (beginning within 2 line cycles and completing within 4.5 line cycles of a severe test event) and accurate (below 2% steady-state error).

  9. Power quality events recognition using a SVM-based method

    Energy Technology Data Exchange (ETDEWEB)

    Cerqueira, Augusto Santiago; Ferreira, Danton Diego; Ribeiro, Moises Vidal; Duque, Carlos Augusto [Department of Electrical Circuits, Federal University of Juiz de Fora, Campus Universitario, 36036 900, Juiz de Fora MG (Brazil)

    2008-09-15

    In this paper, a novel SVM-based method for power quality event classification is proposed. A simple approach for feature extraction is introduced, based on the subtraction of the fundamental component from the acquired voltage signal. The resulting signal is presented to a support vector machine for event classification. Results from simulation are presented and compared with two other methods, the OTFR and the LCEC. The proposed method shown an improved performance followed by a reasonable computational cost. (author)

  10. Nuclear power plant construction activity, 1986

    International Nuclear Information System (INIS)

    1987-01-01

    Cost estimates, chronological data on construction progress, and the physical characteristics of nuclear units in commercial operation and units in the construction pipeline as of December 31, 1986, are presented. This report, which is updated annually, was prepared to provide an overview of the nuclear power plant construction industry. The report contains information on the status of nuclear generating units, average construction costs and lead-times, and construction milestones for individual reactors

  11. Reliability and discriminatory power of methods for dental plaque quantification

    Directory of Open Access Journals (Sweden)

    Daniela Prócida Raggio

    2010-04-01

    Full Text Available OBJECTIVE: This in situ study evaluated the discriminatory power and reliability of methods of dental plaque quantification and the relationship between visual indices (VI and fluorescence camera (FC to detect plaque. MATERIAL AND METHODS: Six volunteers used palatal appliances with six bovine enamel blocks presenting different stages of plaque accumulation. The presence of plaque with and without disclosing was assessed using VI. Images were obtained with FC and digital camera in both conditions. The area covered by plaque was assessed. Examinations were done by two independent examiners. Data were analyzed by Kruskal-Wallis and Kappa tests to compare different conditions of samples and to assess the inter-examiner reproducibility. RESULTS: Some methods presented adequate reproducibility. The Turesky index and the assessment of area covered by disclosed plaque in the FC images presented the highest discriminatory powers. CONCLUSION: The Turesky index and images with FC with disclosing present good reliability and discriminatory power in quantifying dental plaque.

  12. Active power compensator of the current harmonics based on the instantaneous power theory

    Directory of Open Access Journals (Sweden)

    Marian GAICEANU

    2005-12-01

    Full Text Available The quality of the electrical current becomes a major concern. The proliferation of the power electronic converters, which are used extensively to control electrical apparatus in industrial and commercial applications (dc and ac variable speed motor drives, induction furnaces, power line conditioners, and industrial power supplies, is at the origin of the AC current distribution network pollution and the reactive power demand. These power electronic converters typically draw non-sinusoidal currents from the utility, causing interference with adjacent sensitive loads and limit the utilization of the available electrical supply. The quality of the electrical current thus becomes a significant concern for the distributors of energy and their customers. Recent progress as regards technology of the power electronics brings a capacity of compensation and correction of the harmonic distortion generated by the nonlinear loads. In this paper a parallel active filter prototype capable of reducing the total harmonic distortion in the supply for most current source or adjustable speed drive type loads is presented. A 33 kVA active power filter was developed for harmonic and reactive power compensation based on the instantaneous power theory. The active filter configuration requires the measurement of both the load and filter currents. Experimental results from a prototype active power filter confirm the suitability of the proposed approach. The actual 33kVA prototype converter has been built and tested in the SIEI S.p.A. (Italy laboratory under the Marie Curie Post Doctoral research. The active power compensator is controlled by a high performance DSP platform, resulting in the following active filter features: source current reduction up to the 25th harmonic, 10% THD achievable for current source type loads, efficiency above 97%, does not cause resonance with other loads, operation in the presence of unbalanced loads, reactive power and harmonics

  13. An Analysis of Variable-Speed Wind Turbine Power-Control Methods with Fluctuating Wind Speed

    Directory of Open Access Journals (Sweden)

    Seung-Il Moon

    2013-07-01

    Full Text Available Variable-speed wind turbines (VSWTs typically use a maximum power-point tracking (MPPT method to optimize wind-energy acquisition. MPPT can be implemented by regulating the rotor speed or by adjusting the active power. The former, termed speed-control mode (SCM, employs a speed controller to regulate the rotor, while the latter, termed power-control mode (PCM, uses an active power controller to optimize the power. They are fundamentally equivalent; however, since they use a different controller at the outer control loop of the machine-side converter (MSC controller, the time dependence of the control system differs depending on whether SCM or PCM is used. We have compared and analyzed the power quality and the power coefficient when these two different control modes were used in fluctuating wind speeds through computer simulations. The contrast between the two methods was larger when the wind-speed fluctuations were greater. Furthermore, we found that SCM was preferable to PCM in terms of the power coefficient, but PCM was superior in terms of power quality and system stability.

  14. Activation of Students with Various Teaching Methods

    DEFF Research Database (Denmark)

    Andersen, Shuang Ma

    2011-01-01

    A group of teaching methodes to active engineer students have been tried out. The methodes are developed based on the Pedagogical Cyclic Workflow (PCW). Comparing with earlier evaluation, positive feedback is achieved among the students.......A group of teaching methodes to active engineer students have been tried out. The methodes are developed based on the Pedagogical Cyclic Workflow (PCW). Comparing with earlier evaluation, positive feedback is achieved among the students....

  15. Grid-Connected Photovoltaic System with Active Power Filtering Functionality

    Directory of Open Access Journals (Sweden)

    Joaquín Vaquero

    2018-01-01

    Full Text Available Solar panels are an attractive and growing source of renewable energy in commercial and residential applications. Its use connected to the grid by means of a power converter results in a grid-connected photovoltaic system. In order to optimize this system, it is interesting to integrate several functionalities into the power converter, such as active power filtering and power factor correction. Nonlinear loads connected to the grid generate current harmonics, which deteriorates the mains power quality. Active power filters can compensate these current harmonics. A photovoltaic system with added harmonic compensation and power factor correction capabilities is proposed in this paper. A sliding mode controller is employed to control the power converter, implemented on the CompactRIO digital platform from National Instruments Corporation, allowing user friendly operation and easy tuning. The power system consists of two stages, a DC/DC boost converter and a single-phase inverter, and it is able to inject active power into the grid while compensating the current harmonics generated by nonlinear loads at the point of common coupling. The operation, design, simulation, and experimental results for the proposed system are discussed.

  16. Sustainable Buildings. Using Active Solar Power

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, M. Keith [Univ. of Louisville, KY (United States); Barnett, Russell [Univ. of Louisville, KY (United States)

    2015-04-20

    The objective of this project is to promote awareness and knowledge of active solar energy technologies by installing and monitoring the following demonstration systems in Kentucky: 1) Pool heating system, Churchill Park School, 2) Water heating and daylighting systems, Middletown and Aiken Road Elementary Schools, 3) Photovoltaic street light comparison, Louisville Metro, 4) up to 25 domestic water heating systems across Kentucky. These tasks will be supported by outreach activities, including a solar energy installer training workshop and a Kentucky Solar Energy Conference.

  17. Development of methods for monitoring and controlling power in nuclear reactors

    International Nuclear Information System (INIS)

    Mesquita, Amir Zacarias; Rezende, Hugo Cesar; Santos, Andre Augusto Campagnole dos; Silva, Vitor Vasconcelos Araujo

    2012-01-01

    Redundancy and diversity are two important criteria for power measurement in nuclear reactors. Other criteria such as accuracy, reliability and response speed are also of major concern. Power monitoring of nuclear reactors is normally done by means of neutronic instruments, i.e. by the measurement of neutron flux. The greater the number of channels for power measuring the greater is the reliability and safety of reactor operations. The aim of this research is to develop new methodologies for on-line monitoring of nuclear reactor power using other reliable processes. One method uses the temperature difference between an instrumented fuel element and the pool water below the reactor core. Another method consists of the steady-state energy balance of the primary and secondary reactor cooling loops. A further method is the calorimetric procedure whereby a constant reactor power is monitored as a function of the temperature-rise rate and the system heat capacity. Another methodology, which does not employ thermal methods, is based on measurement of Cherenkov radiation produced within and around the core. The first three procedures, fuel temperature, energy balance and calorimetric, were implemented in the IPR-R1 TRIGA nuclear research reactor at Belo Horizonte (Brazil) and are the focus of the work described here. Knowledge of the reactor thermal power is very important for precise neutron flux and fuel element burnup calculations. The burnup is linearly dependent on the reactor thermal power and its accuracy is important in the determination of the mass of burned 235 U, fission products, fuel element activity, decay heat power generation and radiotoxicity. The thermal balance method developed in this project is now the standard methodology used for IPR-R1 TRIGA reactor power calibration and the fuel temperature measuring is the most reliable way of on-line monitoring of the reactor power. This research project primarily aims at increasing the reliability and safety of

  18. VLSI scaling methods and low power CMOS buffer circuit

    International Nuclear Information System (INIS)

    Sharma Vijay Kumar; Pattanaik Manisha

    2013-01-01

    Device scaling is an important part of the very large scale integration (VLSI) design to boost up the success path of VLSI industry, which results in denser and faster integration of the devices. As technology node moves towards the very deep submicron region, leakage current and circuit reliability become the key issues. Both are increasing with the new technology generation and affecting the performance of the overall logic circuit. The VLSI designers must keep the balance in power dissipation and the circuit's performance with scaling of the devices. In this paper, different scaling methods are studied first. These scaling methods are used to identify the effects of those scaling methods on the power dissipation and propagation delay of the CMOS buffer circuit. For mitigating the power dissipation in scaled devices, we have proposed a reliable leakage reduction low power transmission gate (LPTG) approach and tested it on complementary metal oxide semiconductor (CMOS) buffer circuit. All simulation results are taken on HSPICE tool with Berkeley predictive technology model (BPTM) BSIM4 bulk CMOS files. The LPTG CMOS buffer reduces 95.16% power dissipation with 84.20% improvement in figure of merit at 32 nm technology node. Various process, voltage and temperature variations are analyzed for proving the robustness of the proposed approach. Leakage current uncertainty decreases from 0.91 to 0.43 in the CMOS buffer circuit that causes large circuit reliability. (semiconductor integrated circuits)

  19. Active and reactive power control of a current-source PWM-rectifier using space vectors

    Energy Technology Data Exchange (ETDEWEB)

    Salo, M.; Tuusa, H. [Tampere University of Technology (Finland). Department of Electrical Engineering, Power Electronics

    1997-12-31

    In this paper the current-source PWM-rectifier with active and reactive power control is presented. The control system is realized using space vector methods. Also, compensation of the reactive power drawn by the line filter is discussed. Some simulation results are shown. (orig.) 8 refs.

  20. New energy replacement method for resonant power supplies

    International Nuclear Information System (INIS)

    Karady, G.G.; Thiessen, H.A.

    1989-01-01

    The Resonant Power Supply is an economically and technically advanced solution for Rapid Cycling Accelerators. Several papers dealt with the design and operation of these power supplies, however, the energy replacement methods were not discussed in the past. This paper analyzes different energy-replacement methods and presents a new method. This method uses a 24-pulse converter to regulate the magnet current during flat-top and injection periods and replaces the energy loss by charging the accelerator capacitor bank during the flat-top, reset and injection periods, charge is injected in the circuit during the acceleration period, when it replaces the energy loss. This paper compares the new method with the existing ones. The analyses proved the feasibility of the proposed method. The operation of the proposed method was verified by a model experiment, which showed that the new circuit can be controlled accurately and operates with smaller disturbances to the power line than the existing systems. 2 refs., 6 figs., 1 tab

  1. A review on power reducing methods of neural recording amplifiers

    Directory of Open Access Journals (Sweden)

    samira mehdipour

    2016-10-01

    Full Text Available Implantable multi-channel neural recording Microsystems comprise a large number of neural amplifiers, that can affect the overall power consumption and chip area of the analog part of the system.power, noise, size and dc offset are the main challenge faced by designers. Ideally the output of the opamp should be at zero volts when the inputs are grounded.In reality the input terminals are at slightly different dc potentials.The input offset voltage is defined as the voltage that must be applied between the two input terminals of the opamp to obtain zero volts at the output. Amplifier must have capability to reject this dc offset. First method that uses a capacitor feedback network with ac coupling of input devices to reject the offset is very popular in designs.very small low-cutoff frequency.The second method employs a closed-loop resistive feedback and electrode capacitance to form a highpass filter.Moreover,The third method adopts the symmetric floating resistor the feedback path of low noise amplifier to achieve low-frequency cutoff and rejects DC offset voltage. .In some application we can use folded cascade topology.The telescopic topology is a good candidate in terms of providing large gain and phase margin while dissipating small power. the cortical VLSI neuron model reducing power consumption of circuits.Power distribution is the best way to reduce power, noise and silicon area. The total power consumption of the amplifier array is reduced by applying the partial OTA sharing technique. The silicon area is reduced as a benefit of sharing the bulky capacitor.

  2. Cathode power distribution system and method of using the same for power distribution

    Science.gov (United States)

    Williamson, Mark A; Wiedmeyer, Stanley G; Koehl, Eugene R; Bailey, James L; Willit, James L; Barnes, Laurel A; Blaskovitz, Robert J

    2014-11-11

    Embodiments include a cathode power distribution system and/or method of using the same for power distribution. The cathode power distribution system includes a plurality of cathode assemblies. Each cathode assembly of the plurality of cathode assemblies includes a plurality of cathode rods. The system also includes a plurality of bus bars configured to distribute current to each of the plurality of cathode assemblies. The plurality of bus bars include a first bus bar configured to distribute the current to first ends of the plurality of cathode assemblies and a second bus bar configured to distribute the current to second ends of the plurality of cathode assemblies.

  3. Methods and apparatus of analyzing electrical power grid data

    Science.gov (United States)

    Hafen, Ryan P.; Critchlow, Terence J.; Gibson, Tara D.

    2017-09-05

    Apparatus and methods of processing large-scale data regarding an electrical power grid are described. According to one aspect, a method of processing large-scale data regarding an electrical power grid includes accessing a large-scale data set comprising information regarding an electrical power grid; processing data of the large-scale data set to identify a filter which is configured to remove erroneous data from the large-scale data set; using the filter, removing erroneous data from the large-scale data set; and after the removing, processing data of the large-scale data set to identify an event detector which is configured to identify events of interest in the large-scale data set.

  4. Statistic method of research reactors maximum permissible power calculation

    International Nuclear Information System (INIS)

    Grosheva, N.A.; Kirsanov, G.A.; Konoplev, K.A.; Chmshkyan, D.V.

    1998-01-01

    The technique for calculating maximum permissible power of a research reactor at which the probability of the thermal-process accident does not exceed the specified value, is presented. The statistical method is used for the calculations. It is regarded that the determining function related to the reactor safety is the known function of the reactor power and many statistically independent values which list includes the reactor process parameters, geometrical characteristics of the reactor core and fuel elements, as well as random factors connected with the reactor specific features. Heat flux density or temperature is taken as a limiting factor. The program realization of the method discussed is briefly described. The results of calculating the PIK reactor margin coefficients for different probabilities of the thermal-process accident are considered as an example. It is shown that the probability of an accident with fuel element melting in hot zone is lower than 10 -8 1 per year for the reactor rated power [ru

  5. Detection of forced oscillations in power systems with multichannel methods

    Energy Technology Data Exchange (ETDEWEB)

    Follum, James D. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

    2015-09-30

    The increasing availability of high fidelity, geographically dispersed measurements in power systems improves the ability of researchers and engineers to study dynamic behaviors in the grid. One such behavior that is garnering increased attention is the presence of forced oscillations. Power system engineers are interested in forced oscillations because they are often symptomatic of the malfunction or misoperation of equipment. Though the resulting oscillation is not always large in amplitude, the root cause may be serious. In this report, multi-channel forced oscillation detection methods are developed. These methods leverage previously developed detection approaches based on the periodogram and spectral-coherence. Making use of geographically distributed channels of data is shown to improved detection performance and shorten the delay before an oscillation can be detected in the online environment. Results from simulated and measured power system data are presented.

  6. Development of Discrete Power Supply with Charge Pump Method for High Powered Sonar System

    Directory of Open Access Journals (Sweden)

    Kristian Ismail

    2012-07-01

    Full Text Available Power supply is one of the electronic devices that can provide electric energy for electronic systems or other systems. There are several types of power supplies that can be applied depend on the requirement and functions. One example is the use of power supply for sonar systems. Sonar system is a device which can be used to detect a target under water. The sonar system is an electronic circuit that requires a power supply with specific characteristics when the sonar functions as a transmitter and a receiver in the specific span time (when on and the specific lag time (when off. This paper discusses the design of power supply for high-powered sonar systems with discrete methods in which high power supply is only applied when the acoustic waves radiated under water. Charge pump was used to get the appropriate output voltage from lower input voltage. Charge pump utilized a combination of series and parallel connections of capacitors. The working mode of this power supply used the lag time as the calculation of time to charge charge pump capacitors in parallel while the span time was used for the calculation of discharging the charge pump capacitors in series.

  7. Nuclear power plants - active environment protection|

    International Nuclear Information System (INIS)

    Aegerter, I.

    1987-01-01

    The Federal Commission, which is studying energy scenarios, will doubtlessly come to the conclusion that a withdrawal from nuclear energy is technically and economically feasible. Feasibility alone however is no justification for action. Have the questions been asked correctly by the parliamentarians? Are the real problems being bypassed? Is the demand for a withdrawal from nuclear energy soundly based? Is it not oversimplified? Many people are afraid of nuclear energy because they do not understand it. It is necessary that specialists formulate their ideas so that the layman can easily understand them. The broad public can be educated to lose their fear of nuclear power plants which they compare with the nuclear bombs. They can also be educated to lose their fear of radioactivity. The public should also realize that the CO 2 problem is actual and very serious, and that nuclear energy can in fact help to alleviate this particular problem. 7 refs., 2 figs., 1 tab

  8. Novel TPPO Based Maximum Power Point Method for Photovoltaic System

    Directory of Open Access Journals (Sweden)

    ABBASI, M. A.

    2017-08-01

    Full Text Available Photovoltaic (PV system has a great potential and it is installed more when compared with other renewable energy sources nowadays. However, the PV system cannot perform optimally due to its solid reliance on climate conditions. Due to this dependency, PV system does not operate at its maximum power point (MPP. Many MPP tracking methods have been proposed for this purpose. One of these is the Perturb and Observe Method (P&O which is the most famous due to its simplicity, less cost and fast track. But it deviates from MPP in continuously changing weather conditions, especially in rapidly changing irradiance conditions. A new Maximum Power Point Tracking (MPPT method, Tetra Point Perturb and Observe (TPPO, has been proposed to improve PV system performance in changing irradiance conditions and the effects on characteristic curves of PV array module due to varying irradiance are delineated. The Proposed MPPT method has shown better results in increasing the efficiency of a PV system.

  9. Calculation of degenerated Eigenmodes with modified power method

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Peng; Lee, Hyun Suk; Lee, Deok Jung [School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2017-02-15

    The modified power method has been studied by many researchers to calculate the higher Eigenmodes and accelerate the convergence of the fundamental mode. Its application to multidimensional problems may be unstable due to degenerated or near-degenerated Eigenmodes. Complex Eigenmode solutions are occasionally encountered in such cases, and the shapes of the corresponding eigenvectors may change during the simulation. These issues must be addressed for the successful implementation of the modified power method. Complex components are examined and an approximation method to eliminate the usage of the complex numbers is provided. A technique to fix the eigenvector shapes is also provided. The performance of the methods for dealing with those aforementioned problems is demonstrated with two dimensional one group and three dimensional one group homogeneous diffusion problems.

  10. Improved Method for PD-Quantification in Power Cables

    DEFF Research Database (Denmark)

    Holbøll, Joachim T.; Villefrance, Rasmus; Henriksen, Mogens

    1999-01-01

    n this paper, a method is described for improved quantification of partial discharges(PD) in power cables. The method is suitable for PD-detection and location systems in the MHz-range, where pulse attenuation and distortion along the cable cannot be neglected. The system transfer function...... was calculated and measured in order to form basis for magnitude calculation after each measurements. --- Limitations and capabilities of the method will be discussed and related to relevant field applications of high frequent PD-measurements. --- Methods for increased signal/noise ratio are easily implemented...

  11. A fast method for optimal reactive power flow solution

    Energy Technology Data Exchange (ETDEWEB)

    Sadasivam, G; Khan, M A [Anna Univ., Madras (IN). Coll. of Engineering

    1990-01-01

    A fast successive linear programming (SLP) method for minimizing transmission losses and improving the voltage profile is proposed. The method uses the same compactly stored, factorized constant matrices in all the LP steps, both for power flow solution and for constructing the LP model. The inherent oscillatory convergence of SLP methods is overcome by proper selection of initial step sizes and their gradual reduction. Detailed studies on three systems, including a 109-bus system, reveal the fast and reliable convergence property of the method. (author).

  12. A simulation method for lightning surge response of switching power

    International Nuclear Information System (INIS)

    Wei, Ming; Chen, Xiang

    2013-01-01

    In order to meet the need of protection design for lighting surge, a prediction method of lightning electromagnetic pulse (LEMP) response which is based on system identification is presented. Experiments of switching power's surge injection were conducted, and the input and output data were sampled, de-noised and de-trended. In addition, the model of energy coupling transfer function was obtained by system identification method. Simulation results show that the system identification method can predict the surge response of linear circuit well. The method proposed in the paper provided a convenient and effective technology for simulation of lightning effect.

  13. Dynamic baseline detection method for power data network service

    Science.gov (United States)

    Chen, Wei

    2017-08-01

    This paper proposes a dynamic baseline Traffic detection Method which is based on the historical traffic data for the Power data network. The method uses Cisco's NetFlow acquisition tool to collect the original historical traffic data from network element at fixed intervals. This method uses three dimensions information including the communication port, time, traffic (number of bytes or number of packets) t. By filtering, removing the deviation value, calculating the dynamic baseline value, comparing the actual value with the baseline value, the method can detect whether the current network traffic is abnormal.

  14. Preassembly method for construction of nuclear power station

    International Nuclear Information System (INIS)

    Shimazaki, Yasuyoshi

    1986-01-01

    Recently preassembly method for construction are generally popular in Japan and this trend is prevailing all over the world. They provide good solutions to the problems that the Japanese construction industry faces and also they meet the needs for construction of nuclear power plants having heavily reinforced concrete structures. We have already established basic technologies for the methods, developing more advanced methods (more systematic, larger sized, more applicable, etc.). In the near future, they will be further developed up to a complete system called 'Industrialized construction method'. This system will include the use of precast concrete component, steel concrete composit structures and construction robots. (author)

  15. Active teaching methods, studying responses and learning

    DEFF Research Database (Denmark)

    Christensen, Hans Peter; Vigild, Martin Etchells; Thomsen, Erik Vilain

    2010-01-01

    Students’ study strategies when exposed to activating teaching methods are measured, analysed and compared to study strategies in more traditional lecture-based teaching. The resulting learning outcome is discussed.......Students’ study strategies when exposed to activating teaching methods are measured, analysed and compared to study strategies in more traditional lecture-based teaching. The resulting learning outcome is discussed....

  16. Active teaching methods, studying responses and learning

    DEFF Research Database (Denmark)

    Christensen, Hans Peter; Vigild, Martin Etchells; Thomsen, Erik Vilain

    Students’ study strategies when exposed to activating teaching methods are measured, analysed and compared to study strategies in more traditional lecture-based teaching.......Students’ study strategies when exposed to activating teaching methods are measured, analysed and compared to study strategies in more traditional lecture-based teaching....

  17. A Power-Efficient Propulsion Method for Magnetic Microrobots

    Directory of Open Access Journals (Sweden)

    Gioia Lucarini

    2014-07-01

    Full Text Available Current magnetic systems for microrobotic navigation consist of assemblies of electromagnets, which allow for the wireless accurate steering and propulsion of sub-millimetric bodies. However, large numbers of windings and/or high currents are needed in order to generate suitable magnetic fields and gradients. This means that magnetic navigation systems are typically cumbersome and require a lot of power, thus limiting their application fields. In this paper, we propose a novel propulsion method that is able to dramatically reduce the power demand of such systems. This propulsion method was conceived for navigation systems that achieve propulsion by pulling microrobots with magnetic gradients. We compare this power-efficient propulsion method with the traditional pulling propulsion, in the case of a microrobot swimming in a micro-structured confined liquid environment. Results show that both methods are equivalent in terms of accuracy and the velocity of the motion of the microrobots, while the new approach requires only one ninth of the power needed to generate the magnetic gradients. Substantial equivalence is demonstrated also in terms of the manoeuvrability of user-controlled microrobots along a complex path.

  18. Methodical recommendations for power unit comprehensive engineering and radiation survey

    International Nuclear Information System (INIS)

    Nosovskij, A.V.

    2000-01-01

    The article describes power unit radiation survey methods developed and applied during conduction of Ch NPP unit I Comprehensive Engineering Radiation Survey. Special requirements for units under decommissioning, main survey principals, criteria for definition of volume and the order of survey for various systems of a NPP Unit are included

  19. Effect of different methods of pulse width modulation on power losses in an induction motor

    Science.gov (United States)

    Gulyaev, Alexander; Fokin, Dmitrii; Shuharev, Sergey; Ten, Evgenii

    2017-10-01

    We consider the calculation of modulation power losses in a system “induction motor-inverter” for various pulse width modulation (PWM) methods of the supply voltage. Presented values of modulation power losses are the result of modeling a system “DC link - two-level three-phase voltage inverter - induction motor - load”. In this study the power losses in a system “induction motor - inverter” are computed, as well as losses caused by higher harmonics of PWM supply voltage, followed by definition of active power consumed by the DC link for a specified value mechanical power on the induction motor shaft. Mechanical power was determined by the rotation speed and the torque on the motor shaft in various quasi-sinusoidal supply voltage PWM modes. These calculations reveal the best coefficient of performance (COP) in a system of a variable frequency drive (VFD) with independent voltage inverter controlled by induction motor PWM.

  20. Design of nuclear power generation plants adopting model engineering method

    International Nuclear Information System (INIS)

    Waki, Masato

    1983-01-01

    The utilization of model engineering as the method of design has begun about ten years ago in nuclear power generation plants. By this method, the result of design can be confirmed three-dimensionally before actual production, and it is the quick and sure method to meet the various needs in design promptly. The adoption of models aims mainly at the improvement of the quality of design since the high safety is required for nuclear power plants in spite of the complex structure. The layout of nuclear power plants and piping design require the model engineering to arrange rationally enormous quantity of things in a limited period. As the method of model engineering, there are the use of check models and of design models, and recently, the latter method has been mainly taken. The procedure of manufacturing models and engineering is explained. After model engineering has been completed, the model information must be expressed in drawings, and the automation of this process has been attempted by various methods. The computer processing of design is in progress, and its role is explained (CAD system). (Kako, I.)

  1. Small Spacecraft Integrated Power System with Active Thermal Control

    Data.gov (United States)

    National Aeronautics and Space Administration — This project will develop an integrated power generation and energy storage system with an active thermal management system. Carbon fiber solar panels will contain...

  2. Power system frequency estimation based on an orthogonal decomposition method

    Science.gov (United States)

    Lee, Chih-Hung; Tsai, Men-Shen

    2018-06-01

    In recent years, several frequency estimation techniques have been proposed by which to estimate the frequency variations in power systems. In order to properly identify power quality issues under asynchronously-sampled signals that are contaminated with noise, flicker, and harmonic and inter-harmonic components, a good frequency estimator that is able to estimate the frequency as well as the rate of frequency changes precisely is needed. However, accurately estimating the fundamental frequency becomes a very difficult task without a priori information about the sampling frequency. In this paper, a better frequency evaluation scheme for power systems is proposed. This method employs a reconstruction technique in combination with orthogonal filters, which may maintain the required frequency characteristics of the orthogonal filters and improve the overall efficiency of power system monitoring through two-stage sliding discrete Fourier transforms. The results showed that this method can accurately estimate the power system frequency under different conditions, including asynchronously sampled signals contaminated by noise, flicker, and harmonic and inter-harmonic components. The proposed approach also provides high computational efficiency.

  3. Assessment methods for the landscaping of a power plant

    International Nuclear Information System (INIS)

    Wakatani, Yoshiji; Yamamoto, Kimio; Higuchi, Tadahiko

    1983-01-01

    The purpose of this study is to make clear the quantitative relations between the scenic influence produced by the construction of a power plant, and the indexes for landscape evaluation. For that purpose, we made a psychological experiment using montage photographie, and analyzed the experiment results from phychometrics. This report treats of three subjects in that quantitative relations, i.e. ''Scenic harmony between a power plant and a hill for a background'', ''Unity and orderliness influenced by arrangement and configuration of power plant equipments'' and ''Color harmony between a power plant and surrounding environment''. The results of the study are summarized as follows. 1) The landscape evaluation of ''Scenic harmony'', derived from the evaluation function, is related to the index of ''Scale proportion (i.e. the height proportion of a power plant to a hill for a background)''. 2) By the semantic differential method we extracted the three factor axes in the landscape evaluation of ''Unity and orderliness''. 3) As the results of the phychological experiment for a color arrangement, a group of blue and beige is desirable to a color of a power plant. (author)

  4. Health-safety and environmental risk assessment of power plants using multi criteria decision making method

    Directory of Open Access Journals (Sweden)

    Jozi Ali Seyed

    2011-01-01

    Full Text Available Growing importance of environmental issues at global and regional levels including pollution of water, air etc. as well as the outcomes such as global warming and climate change has led to being considered environmental aspects as effective factors for power generation. Study ahead, aims at examination of risks resulting from activities of Yazd Combined Cycle Power Plant located in Iran. Method applied in the research is analytical hierarchy process. After identification of factors causing risk, the analytical hierarchy structure of the power plant risks were designed and weight of the criteria and sub-criteria were calculated by intensity probability product using Eigenvector Method and EXPERT CHOICE Software as well. Results indicate that in technological, health-safety, biophysical and socio economic sections of the power plant, factors influenced by the power plant activities like fire and explosion, hearing loss, quantity of groundwater, power generation are among the most important factors causing risk in the power plant. The drop in underground water levels is the most important natural consequence influenced on Yazd Combined Cycle Power Plant.

  5. Design and implementation of predictive filtering system for current reference generation of active power filter

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, Tomislav; Milun, Stanko; Petrovic, Goran [FESB University of Split, Faculty of Electrical Engineering, Machine Engineering and Naval Architecture, R. Boskovica bb, 21000, Split (Croatia)

    2007-02-15

    The shunt active power filters are used to attenuate the harmonic currents in power systems by injecting equal but opposite compensating currents. Successful control of the active filters requires an accurate current reference. In this paper the current reference determination based on predictive filtering structure is presented. Current reference was obtained by taking the difference of load current and its fundamental harmonic. For fundamental harmonic determination with no time delay a combination of digital predictive filter and low pass filter is used. The proposed method was implemented on a laboratory prototype of a three-phase active power filter. The algorithm for current reference determination was adapted and implemented on DSP controller. Simulation and experimental results show that the active power filter with implemented predictive filtering structure gives satisfactory performance in power system harmonic attenuation. (author)

  6. Three phase active power filter with selective harmonics elimination

    Directory of Open Access Journals (Sweden)

    Sozański Krzysztof

    2016-03-01

    Full Text Available This paper describes a three phase shunt active power filter with selective harmonics elimination. The control algorithm is based on a digital filter bank. The moving Discrete Fourier Transformation is used as an analysis filter bank. The correctness of the algorithm has been verified by simulation and experimental research. The paper includes exemplary results of current waveforms and their spectra from a three phase active power filter.

  7. Using active power filter to compensate the current component of asymmetrical non-linear load in the four wire network

    Directory of Open Access Journals (Sweden)

    Руслан Володимирович Власенко

    2016-07-01

    Full Text Available Electricity quality improving is extremely relevant nowadays. With such industrial loads as induction motors, induction furnaces, welding machines, controlled or uncontrolled rectifiers, frequency converters and others reactive power, harmonics and unbalance are generated in power grid. Reactive power, higher harmonic currents and asymmetry loads influence the functioning of electric devices and electrical mains. An effective technical solution is the use of new compensating devices, that is active power filters. The emergence of consumers with a unit capacity of four wire networks requires a new approach to building system control active power filter. When designing the active power filter control system the current flowing in the neutral wire must be taken into account. To assess the power balance in the four wire active power filter, scientists have proposed to apply pqr theory of power based on the Clarke transformation. There are different topologies of three-phase four wire active power filters. A visual simulation of Matlab / Simulink model with an active power filter based on pqr theory of power has been created. A method of pulse width modulation with four control channels was used as pulses forming systems with transistor keys. Operating conditions of three-phase four wire active power filter with asymmetry, non-sinosoidal voltage source and asymmetric load have been studied. The correction taking into account the means improving the active power filter has been offered as pqr theory of power does not take into account non-sinosoidal voltage

  8. Synchronization Methods for Three Phase Distributed Power Generation Systems

    DEFF Research Database (Denmark)

    Timbus, Adrian Vasile; Teodorescu, Remus; Blaabjerg, Frede

    2005-01-01

    Nowadays, it is a general trend to increase the electricity production using Distributed Power Generation Systems (DPGS) based on renewable energy resources such as wind, sun or hydrogen. If these systems are not properly controlled, their connection to the utility network can generate problems...... on the grid side. Therefore, considerations about power generation, safe running and grid synchronization must be done before connecting these systems to the utility network. This paper is mainly dealing with the grid synchronization issues of distributed systems. An overview of the synchronization methods...

  9. Regularization methods for inferential sensing in nuclear power plants

    International Nuclear Information System (INIS)

    Hines, J.W.; Gribok, A.V.; Attieh, I.; Uhrig, R.E.

    2000-01-01

    Inferential sensing is the use of information related to a plant parameter to infer its actual value. The most common method of inferential sensing uses a mathematical model to infer a parameter value from correlated sensor values. Collinearity in the predictor variables leads to an ill-posed problem that causes inconsistent results when data based models such as linear regression and neural networks are used. This chapter presents several linear and non-linear inferential sensing methods including linear regression and neural networks. Both of these methods can be modified from their original form to solve ill-posed problems and produce more consistent results. We will compare these techniques using data from Florida Power Corporation's Crystal River Nuclear Power Plant to predict the drift in a feedwater flow sensor. According to a report entitled 'Feedwater Flow Measurement in U.S. Nuclear Power Generation Stations' that was commissioned by the Electric Power Research Institute, venturi meter fouling is 'the single most frequent cause' for derating in Pressurized Water Reactors. This chapter presents several viable solutions to this problem. (orig.)

  10. Reliability methods in nuclear power plant ageing management

    International Nuclear Information System (INIS)

    Simola, K.

    1999-01-01

    The aim of nuclear power plant ageing management is to maintain an adequate safety level throughout the lifetime of the plant. In ageing studies, the reliability of components, systems and structures is evaluated taking into account the possible time-dependent degradation. The phases of ageing analyses are generally the identification of critical components, identification and evaluation of ageing effects, and development of mitigation methods. This thesis focuses on the use of reliability methods and analyses of plant- specific operating experience in nuclear power plant ageing studies. The presented applications and method development have been related to nuclear power plants, but many of the approaches can also be applied outside the nuclear industry. The thesis consists of a summary and seven publications. The summary provides an overview of ageing management and discusses the role of reliability methods in ageing analyses. In the publications, practical applications and method development are described in more detail. The application areas at component and system level are motor-operated valves and protection automation systems, for which experience-based ageing analyses have been demonstrated. Furthermore, Bayesian ageing models for repairable components have been developed, and the management of ageing by improving maintenance practices is discussed. Recommendations for improvement of plant information management in order to facilitate ageing analyses are also given. The evaluation and mitigation of ageing effects on structural components is addressed by promoting the use of probabilistic modelling of crack growth, and developing models for evaluation of the reliability of inspection results. (orig.)

  11. Reliability methods in nuclear power plant ageing management

    Energy Technology Data Exchange (ETDEWEB)

    Simola, K. [VTT Automation, Espoo (Finland). Industrial Automation

    1999-07-01

    The aim of nuclear power plant ageing management is to maintain an adequate safety level throughout the lifetime of the plant. In ageing studies, the reliability of components, systems and structures is evaluated taking into account the possible time-dependent degradation. The phases of ageing analyses are generally the identification of critical components, identification and evaluation of ageing effects, and development of mitigation methods. This thesis focuses on the use of reliability methods and analyses of plant- specific operating experience in nuclear power plant ageing studies. The presented applications and method development have been related to nuclear power plants, but many of the approaches can also be applied outside the nuclear industry. The thesis consists of a summary and seven publications. The summary provides an overview of ageing management and discusses the role of reliability methods in ageing analyses. In the publications, practical applications and method development are described in more detail. The application areas at component and system level are motor-operated valves and protection automation systems, for which experience-based ageing analyses have been demonstrated. Furthermore, Bayesian ageing models for repairable components have been developed, and the management of ageing by improving maintenance practices is discussed. Recommendations for improvement of plant information management in order to facilitate ageing analyses are also given. The evaluation and mitigation of ageing effects on structural components is addressed by promoting the use of probabilistic modelling of crack growth, and developing models for evaluation of the reliability of inspection results. (orig.)

  12. Interdisciplinary Study of Numerical Methods and Power Plants Engineering

    Directory of Open Access Journals (Sweden)

    Ioana OPRIS

    2014-08-01

    Full Text Available The development of technology, electronics and computing opened the way for a cross-disciplinary research that brings benefits by combining the achievements of different fields. To prepare the students for their future interdisciplinary approach,aninterdisciplinary teaching is adopted. This ensures their progress in knowledge, understanding and ability to navigate through different fields. Aiming these results, the Universities introduce new interdisciplinary courses which explore complex problems by studying subjects from different domains. The paper presents a problem encountered in designingpower plants. The method of solvingthe problem isused to explain the numerical methods and to exercise programming.The goal of understanding a numerical algorithm that solves a linear system of equations is achieved by using the knowledge of heat transfer to design the regenerative circuit of a thermal power plant. In this way, the outcomes from the prior courses (mathematics and physics are used to explain a new subject (numerical methods and to advance future ones (power plants.

  13. New activities in nuclear power plants maintenance

    International Nuclear Information System (INIS)

    Mico, F.; Specht, J.

    2006-01-01

    This article addresses the consequences of the progressive deregulation of the electricity market of several key countries on the maintenance practices and techniques face to the growing pressures on O and M costs. The responses of the nuclear maintenance industry to make maintenance activities more efficient maintaining if not enhancing the safety of NPP's are briefly described. The article also analyses the potential impact of shortage of experience maintenance personnel to serve the NPP's in the future as some countries are already experiencing. (Author)

  14. The method of the correlation and dispersion defining of the total power components in the electric transport devices

    Directory of Open Access Journals (Sweden)

    A. V. Nikitenko

    2013-04-01

    Full Text Available Purpose. Development and theoretical ground of the analytical method for the calculation of the active, reactive and total powers in the electric traction devices, taking into consideration the non-stationary character of the stochastic processes change of the voltage and current in the elements of these systems. Methodology. The mathematical methods of the random processes theory and the “discrete electrical engineering” methods are used for solving the main problem of this paper. Findings. The Method of the Correlation and Dispersion is developed for definition of the active power, the reactive power by Fryse and the total power of the devices in the elements of the electric traction system of the main-line railways. The method is based on the well-known concepts of auto- and inter-correlation functions of the random processes which govern the feeder voltages and the currents in the traction power supply subsystem as well as the currents and voltages of the electric rolling stock. The method developed in this paper allows estimating the powers of both stationary and non-stationary processes. This method can be used for the analysis of both the traction mode and the regenerative braking mode of the electric rolling stock. The total power components were calculated for the one of the feeder areas of the Prydniprovsk railway using this method. The results show the significant flow of the reactive power in the traction power supply system. This fact is also confirmed by the high values of the reactive power coefficient. Originality. Scientific novelty of the research is consisted in the following. Firstly, for defining the active and reactive powers in elements of the traction power supply system the new method (the Method of Correlation and Dispersion is created and grounded. This method is different from other existing methods because it takes into consideration the varying non-stationary character of the chance processes of the feeder and

  15. Application of data mining methods for power forecast of wind power plants

    Energy Technology Data Exchange (ETDEWEB)

    Arnoldt, Alexander; Koenig, Stefan; Bretschneider, Peter [Fraunhofer Institute for Optronics, System Technology, and Image Exploitation - Application Centre System Technology (IOSB-AST), Ilmenau (Germany). Energy Systems Group; Mikut, Ralf [Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (DE). Inst. for Applied Computer Science (IAI)

    2010-07-01

    Since the last decade power systems underlie a drastic change due to increased exploitation of renewable energy resources (RES) such as wind and photovoltaic power plants. A result of this process is a significant increase of fluctuating generation in low, middle and high voltage grids. Consequently, impacts on short and middle term capacity planning of power plants occur and must be handled to avoid imbalances between generation and demand at any time. Therefore, forecasts of wind and photovoltaic generation play a very important role. Quality improvements potentially ease planning and lead to cost reductions. This work investigated the dependencies of input parameters. The optimal parameter selection was achieved through application of data mining methods. Finally, the wind power prediction was demonstrated with Artificial Neural Networks and Physical Models. (orig.)

  16. Analysis of future nuclear power plants competitiveness with stochastic methods

    International Nuclear Information System (INIS)

    Feretic, D.; Tomsic, Z.

    2004-01-01

    To satisfy the increased demand it is necessary to build new electrical power plants, which could in an optimal way meet, the imposed acceptability criteria. The main criteria are potential to supply the required energy, to supply this energy with minimal (or at least acceptable) costs, to satisfy licensing requirements and be acceptable to public. The main competitors for unlimited electricity production in next few decades are fossil power plants (coal and gas) and nuclear power plants. New renewable power plants (solar, wind, biomass) are also important but due to limited energy supply potential and high costs can be only supplement to the main generating units. Large hydropower plans would be competitive under condition of existence of suitable sites for construction of such plants. The paper describes the application of a stochastic method for comparing economic parameters of future electrical power generating systems including conventional and nuclear power plants. The method is applied to establish competitive specific investment costs of future nuclear power plants when compared with combined cycle gas fired units combined with wind electricity generators using best estimated and optimistic input data. The bases for economic comparison of potential options are plant life time levelized electricity generating costs. The purpose is to assess the uncertainty of several key performance and cost of electricity produced in coal fired power plant, gas fired power plant and nuclear power plant developing probability distribution of levelized price of electricity from different Power Plants, cumulative probability of levelized price of electricity for each technology and probability distribution of cost difference between the technologies. The key parameters evaluated include: levelized electrical energy cost USD/kWh,, discount rate, interest rate for credit repayment, rate of expected increase of fuel cost, plant investment cost , fuel cost , constant annual

  17. Development and testing of improved statistical wind power forecasting methods.

    Energy Technology Data Exchange (ETDEWEB)

    Mendes, J.; Bessa, R.J.; Keko, H.; Sumaili, J.; Miranda, V.; Ferreira, C.; Gama, J.; Botterud, A.; Zhou, Z.; Wang, J. (Decision and Information Sciences); (INESC Porto)

    2011-12-06

    (with spatial and/or temporal dependence). Statistical approaches to uncertainty forecasting basically consist of estimating the uncertainty based on observed forecasting errors. Quantile regression (QR) is currently a commonly used approach in uncertainty forecasting. In Chapter 3, we propose new statistical approaches to the uncertainty estimation problem by employing kernel density forecast (KDF) methods. We use two estimators in both offline and time-adaptive modes, namely, the Nadaraya-Watson (NW) and Quantilecopula (QC) estimators. We conduct detailed tests of the new approaches using QR as a benchmark. One of the major issues in wind power generation are sudden and large changes of wind power output over a short period of time, namely ramping events. In Chapter 4, we perform a comparative study of existing definitions and methodologies for ramp forecasting. We also introduce a new probabilistic method for ramp event detection. The method starts with a stochastic algorithm that generates wind power scenarios, which are passed through a high-pass filter for ramp detection and estimation of the likelihood of ramp events to happen. The report is organized as follows: Chapter 2 presents the results of the application of ITL training criteria to deterministic WPF; Chapter 3 reports the study on probabilistic WPF, including new contributions to wind power uncertainty forecasting; Chapter 4 presents a new method to predict and visualize ramp events, comparing it with state-of-the-art methodologies; Chapter 5 briefly summarizes the main findings and contributions of this report.

  18. Power Mobility Training Methods for Children: A Systematic Review.

    Science.gov (United States)

    Kenyon, Lisa K; Hostnik, Lisa; McElroy, Rachel; Peterson, Courtney; Farris, John P

    2018-01-01

    To summarize and critically appraise the existing evidence related to power mobility training methods used in research studies conducted with children 21 years or younger. A systematic review was conducted using 16 electronic databases to identify primary source quantitative studies published in peer-reviewed journals. Data extraction, determination of level of evidence, evaluation of methodological rigor, and assessment of the risk of bias were completed. The Evidence Alert Traffic Light Grading System (EATLS) was used. Twenty-seven studies were included in the review. Levels of evidence were II to V; scientific rigor scores were 2 to 7. An overall Yellow EATLS level of evidence was found indicating that therapists should use caution when providing power mobility training interventions and measure outcomes related to established goals in areas such as development, functional skills, or use of a power mobility device.

  19. Taiwan Power Company's power distribution analysis and fuel thermal margin verification methods for pressurized water reactors

    International Nuclear Information System (INIS)

    Huang, P.H.

    1995-01-01

    Taiwan Power Company's (TPC's) power distribution analysis and fuel thermal margin verification methods for pressurized water reactors (PWRs) are examined. The TPC and the Institute of Nuclear Energy Research started a joint 5-yr project in 1989 to establish independent capabilities to perform reload design and transient analysis utilizing state-of-the-art computer programs. As part of the effort, these methods were developed to allow TPC to independently perform verifications of the local power density and departure from nucleate boiling design bases, which are required by the reload safety evaluation for the Maanshan PWR plant. The computer codes utilized were extensively validated for the intended applications. Sample calculations were performed for up to six reload cycles of the Maanshan plant, and the results were found to be quite consistent with the vendor's calculational results

  20. Experimental study on using a high-temperature superconducting inductor for power loss reduction in an active power filter

    International Nuclear Information System (INIS)

    Chao, C; To, H P; Grantham, C; Rahman, M F

    2006-01-01

    An active power filter improves the electric power quality through the compensation of harmonics in the power network. A current-source active power filter using a conventional copper inductor for its energy storage has a significant power loss. The loss in the copper inductor can be substantially reduced by using a high-temperature superconducting (HTS) inductor instead. Experiments have been conducted on a prototype current-source active power filter for studying the power loss reduction effect and harmonics compensation performance of the active power filter using a HTS inductor. Experimental results are analysed and discussed in this paper

  1. A decomposition method for network-constrained unit commitment with AC power flow constraints

    International Nuclear Information System (INIS)

    Bai, Yang; Zhong, Haiwang; Xia, Qing; Kang, Chongqing; Xie, Le

    2015-01-01

    To meet the increasingly high requirement of smart grid operations, considering AC power flow constraints in the NCUC (network-constrained unit commitment) is of great significance in terms of both security and economy. This paper proposes a decomposition method to solve NCUC with AC power flow constraints. With conic approximations of the AC power flow equations, the master problem is formulated as a MISOCP (mixed integer second-order cone programming) model. The key advantage of this model is that the active power and reactive power are co-optimised, and the transmission losses are considered. With the AC optimal power flow model, the AC feasibility of the UC result of the master problem is checked in subproblems. If infeasibility is detected, feedback constraints are generated based on the sensitivity of bus voltages to a change in the unit reactive power generation. They are then introduced into the master problem in the next iteration until all AC violations are eliminated. A 6-bus system, a modified IEEE 30-bus system and the IEEE 118-bus system are used to validate the performance of the proposed method, which provides a satisfactory solution with approximately 44-fold greater computational efficiency. - Highlights: • A decomposition method is proposed to solve the NCUC with AC power flow constraints • The master problem considers active power, reactive power and transmission losses. • OPF-based subproblems check the AC feasibility using parallel computing techniques. • An effective feedback constraint interacts between the master problem and subproblem. • Computational efficiency is significantly improved with satisfactory accuracy

  2. Research on stochastic power-flow study methods. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Heydt, G. T. [ed.

    1981-01-01

    A general algorithm to determine the effects of uncertainty in bus load and generation on the output of conventional power flow analysis is presented. The use of statistical moments is presented and developed as a means for representing the stochastic process. Statistical moments are used to describe the uncertainties, and facilitate the calculations of single and multivarlate probability density functions of input and output variables. The transformation of the uncertainty through the power flow equations is made by the expansion of the node equations in a multivariate Taylor series about an expected operating point. The series is truncated after the second order terms. Since the power flow equations are nonlinear, the expected values of output quantities is in general not the solution to the conventional load flow problem using expected values of input quantities. The second order transformation offers a correction vector and allows the consideration of larger uncertainties which have caused significant error in the current linear transformation algorithms. Voltage controlled busses are included with consideration of upper and lower limits. The finite reactive power available at generation sites, and fixed ranges of transformer tap movement may have a significant effect on voltage and line power flow statistics. A method is given which considers limitation constraints in the evaluation of all output quantities. The bus voltages, line power flows, transformer taps, and generator reactive power requirements are described by their statistical moments. Their values are expressed in terms of the probability that they are above or below specified limits, and their expected values given that they do fall outside the limits. Thus the algorithm supplies information about severity of overload as well as probability of occurrence. An example is given for an eleven bus system, evaluating each quantity separately. The results are compared with Monte Carlo simulation.

  3. Advanced methods in evaluation of thermal power systems effectiveness

    International Nuclear Information System (INIS)

    Barnak, N.; Jakubcek, P.; Zadrazil, J.

    1993-01-01

    The universal method for thermodynamic systems process irreversibility evaluation based on exergetic approach is elaborated in this article. The method uses the basic property of exergy as extensive state parameter -additivity. Division of the system onto some hierarchic levels is considered and relation between exergetic system characteristics and its parts is defined. There are system structure coefficients in common form expressed article they are analysed. The criteria for technical and economical optimization of the system using expressed structure coefficients are defined. In the article, there are common approaches defined for the method application in the area of nuclear power plant secondary circuits and the method is used for nuclear power plant WWER-1000 secondary circuit analysis. For this, individual exergetic characteristics of secondary circuit and its parts are expressed and some of secondary circuit parameters are optimized. Proposals for practical realisation of the results are stated in the conclusions of the article, mainly in the area of computerized evaluation of technical and economical parameters of nuclear power plant and effectiveness of its operation

  4. Power systems with nuclear-electric generators - Modelling methods

    International Nuclear Information System (INIS)

    Valeca, Serban Constantin

    2002-01-01

    This is a vast analysis on the issue of sustainable nuclear power development with direct conclusions regarding the Nuclear Programme of Romania. The work is targeting specialists and decision making boards. Specific to the nuclear power development is its public implication, the public being most often misinformed by non-professional media. The following problems are debated thoroughly: - safety, nuclear risk, respectively, is treated in chapter 1 and 7 aiming at highlighting the quality of nuclear power and consequently paving the way to public acceptance; - the environment considered both as resource of raw materials and medium essential for life continuation, which should be appropriately protected to ensure healthy and sustainable development of human society; its analysis is also presented in chapter 1 and 7, where the problem of safe management of radioactive waste is addressed too; - investigation methods based on information science of nuclear systems, applied in carrying out the nuclear strategy and planning are widely analyzed in the chapter 2, 3 and 6; - optimizing the processes by following up the structure of investment and operation costs, and, generally, the management of nuclear units is treated in the chapter 5 and 7; - nuclear weapon proliferation as a possible consequence of nuclear power generation is treated as a legal issue. The development of Romanian NPP at Cernavoda, practically, the core of the National Nuclear Programme, is described in chapter 8. Actually, the originality of the present work consists in the selection and adaptation from a multitude of mathematical models applicable to the local and specific conditions of nuclear power plant at Cernavoda. The Romanian economy development and power development oriented towards reduction of fossil fuel consumption and protection of environment, most reliably ensured by the nuclear power, is discussed in the frame of the world trends of the energy production. Various scenarios are

  5. An Active Capacitor with Self-Power and Internal Feedback Control Signals

    DEFF Research Database (Denmark)

    Wang, Haoran; Wang, Huai

    2017-01-01

    This paper proposes a concept of two-terminal active capacitor implemented by power semiconductor switches and passive elements. The active capacitor has the same level of convenience as a passive one with two power terminals only. A control strategy that does not require any external feedback...... signal is proposed and a self-power scheme for gate drivers and the controller is applied to achieve the two-terminal active capacitor. The concept, control method, self-power scheme, efficiency, and impedance characteristics of the active capacitor are presented. A case study of the proposed active...... capacitor for a capacitive DC-link application is discussed. The results reveal a significantly lower overall energy storage of passive elements and a reduced cost to fulfill a specific reliability target, compared to a passive capacitor solution. Proof-of-concept experimental results are given to verify...

  6. Non-intrusive load monitoring based on low frequency active power measurements

    Directory of Open Access Journals (Sweden)

    Chinthaka Dinesh

    2016-03-01

    Full Text Available A Non-Intrusive Load Monitoring (NILM method for residential appliances based on active power signal is presented. This method works effectively with a single active power measurement taken at a low sampling rate (1 s. The proposed method utilizes the Karhunen Loéve (KL expansion to decompose windows of active power signals into subspace components in order to construct a unique set of features, referred to as signatures, from individual and aggregated active power signals. Similar signal windows were clustered in to one group prior to feature extraction. The clustering was performed using a modified mean shift algorithm. After the feature extraction, energy levels of signal windows and power levels of subspace components were utilized to reduce the number of possible appliance combinations and their energy level combinations. Then, the turned on appliance combination and the energy contribution from individual appliances were determined through the Maximum a Posteriori (MAP estimation. Finally, the proposed method was modified to adaptively accommodate the usage patterns of appliances at each residence. The proposed NILM method was validated using data from two public databases: tracebase and reference energy disaggregation data set (REDD. The presented results demonstrate the ability of the proposed method to accurately identify and disaggregate individual energy contributions of turned on appliance combinations in real households. Furthermore, the results emphasise the importance of clustering and the integration of the usage behaviour pattern in the proposed NILM method for real households.

  7. Method of estimating investment decisions effectiveness in power engineering

    International Nuclear Information System (INIS)

    Kamrat, W.

    1996-01-01

    A new concept of determining efficient power plants investment decision-making is proposed.The results of research on capital expenditures for building and modernization of power plants are presented. The model introduced is based on the well-known Annual Cost Model which is modified by adding annual risk costs. So the formula for annual costs is: K = K f + K v + K r , where: K f are annual fixed costs, K v - annual variables costs, K r -annual risk costs. The annual risk costs can be calculated by the expression: K r = e i x K c , where e i is the investment risk factor, and K c - leveled capital investment. The risk factor was created on the basis of some elements of the taxonometric method with a high level of estimation probability. The essential problem is the selection of risk investment variables, most important of which are economic, financial, technical, social, political, legal. These variables create a multidimensional space. A so called 'ideal' model of the power plant is created taking into account capacity, type, fuel used, etc. The values of the multidimensional risk factor e i lie within limit and make it possible to rank the planned plants in series according to the estimated level of risk. This method can be used not only for risk evaluation in power engineering but also for investment efficiency studies in different industrial branches

  8. Single-Phase Active Boost Rectifier with Power Factor Correction for Wireless Power Transfer Applications

    Energy Technology Data Exchange (ETDEWEB)

    Chinthavali, Madhu Sudhan [ORNL; Onar, Omer C [ORNL; Miller, John M [ORNL; Tang, Lixin [ORNL

    2013-01-01

    Wireless Power Transfer (WPT) technology is a novel research area in the charging technology that bridges utility and the automotive industries. There are various solutions that are currently being evaluated by several research teams to find the most efficient way to manage the power flow from the grid to the vehicle energy storage system. There are different control parameters that can be utilized to compensate for the change in the impedance. To understand the power flow through the system this paper presents a novel approach to the system model and the impact of different control parameters on the load power. The implementation of an active front-end rectifier on the grid side for power factor control and voltage boost capability for load power regulation is also discussed.

  9. THERMODYNAMIC ANALYSIS OF CARBON SEQUESTRATION METHODS IN LIGNITE POWER PLANTS

    International Nuclear Information System (INIS)

    Koroneos J. Christopher; Sakiltzis Christos; Rovas C. Dimitrios

    2008-01-01

    The green house effect is a very pressing issue of our times due to the big impact it will have in the future of life in our planet. The temperature increase of the earth which is the major impact of the greenhouse effect may change forever the climate and the way of life in many countries. It may lead to the reduction of agricultural production and at the end to famine, in several nations. The minimization of CO2 emissions and the introduction of new energy sources is the only solution to the catastrophe that is coming if inaction prevails. The objective of this work is to analyze the methods of the CO2 removal from the flue gases of power plants that use solid fuels. It is especially fit to the Greek conditions where the main fuel used is lignite. Three methods have been examined and compared thermodynamically. These are: (a) Removal of CO2 from the flue gas stream by absorption, (b) The combustion of lignite with pure oxygen and (c) The gasification of lignite. The lignite used in the analysis is the Greek lignite, produced at the Western Macedonia mines. The power plant, before carbon sequestration, has an efficiency of 39%, producing 330MW of electric power. After sequestration, the CO2 is compressed to pressures between 80-110 atm, before its final disposal. In the first method, the sequestration of CO2 is done utilizing a catalyst. The operation requires electricity and high thermal load which is received from low pressure steam extracted from the turbines. Additionally, electricity is required for the compression of the CO2 to 100 bars. This leads to a lower efficiency of the power plant by by 13%. In the second method, the lignite combustion is done with pure O2 produced at an air separation unit. The flue gasses are made up of CO2 and water vapor. This method requires electricity for carbon dioxide compression and the Air Separation unit, thus, the power plant efficiency is lowered by 26%. In the lignite gasification method, the products are a mixture of

  10. Applicability of the proposed evaluation method for social infrastructures to nuclear power plants

    International Nuclear Information System (INIS)

    Ichimura, Tomiyasu

    2015-01-01

    This study proposes an evaluation method for social infrastructures, and verifies the applicability of the proposed evaluation method to social infrastructures by applying it to nuclear power plants, which belong to social infrastructures. In the proposed evaluation method for social infrastructures, the authors chose four evaluation viewpoints and proposed common evaluation standards for the evaluation indexes obtained from each viewpoint. By applying this system to the evaluation of nuclear power plants, the evaluation index examples were obtained from the evaluation viewpoints. Furthermore, when the level of the common evaluation standards of the proposed evaluation method was applied to the evaluation of the activities of nuclear power plants based on the regulations, it was confirmed that these activities are at the highest level. Through this application validation, it was clarified that the proposed evaluation method for social infrastructures had certain effectiveness. The four evaluation viewpoints are 'service,' 'environment,' 'action factor,' and 'operation and management.' Part of the application examples to a nuclear power plant are as follows: (1) in the viewpoint of service: the operation rate of the power plant, and operation costs, and (2) in the viewpoint of environment: external influence related to nuclear waste and radioactivity, and external effect related to cooling water. (A.O.)

  11. Methods for reconstruction of the density distribution of nuclear power

    International Nuclear Information System (INIS)

    Pessoa, Paulo O.; Silva, Fernando C.; Martinez, Aquilino S.

    2015-01-01

    Highlights: • Two methods for reconstruction of the pin power distribution are presented. • The ARM method uses analytical solution of the 2D diffusion equation. • The PRM method uses polynomial solution without boundary conditions. • The maximum errors in pin power reconstruction occur in the peripheral water region. • The errors are significantly less in the inner area of the core. - Abstract: In analytical reconstruction method (ARM), the two-dimensional (2D) neutron diffusion equation is analytically solved for two energy groups (2G) and homogeneous nodes with dimensions of a fuel assembly (FA). The solution employs a 2D fourth-order expansion for the axial leakage term. The Nodal Expansion Method (NEM) provides the solution average values as the four average partial currents on the surfaces of the node, the average flux in the node and the multiplying factor of the problem. The expansion coefficients for the axial leakage are determined directly from NEM method or can be determined in the reconstruction method. A new polynomial reconstruction method (PRM) is implemented based on the 2D expansion for the axial leakage term. The ARM method use the four average currents on the surfaces of the node and four average fluxes in corners of the node as boundary conditions and the average flux in the node as a consistency condition. To determine the average fluxes in corners of the node an analytical solution is employed. This analytical solution uses the average fluxes on the surfaces of the node as boundary conditions and discontinuities in corners are incorporated. The polynomial and analytical solutions to the PRM and ARM methods, respectively, represent the homogeneous flux distributions. The detailed distributions inside a FA are estimated by product of homogeneous distribution by local heterogeneous form function. Moreover, the form functions of power are used. The results show that the methods have good accuracy when compared with reference values and

  12. METHOD OF SUPPRESSING GASTROINTESTINAL UREASE ACTIVITY

    Science.gov (United States)

    Visek, W.J.

    1963-04-23

    This patent shows a method of increasing the growth rate of chicks. Certain diacyl substituted ureas such as alloxan, murexide, and barbituric acid are added to their feed, thereby suppressing gastrointestinal urease activity and thus promoting growth. (AEC)

  13. Activating teaching methods, studying responses and learning

    OpenAIRE

    Christensen, Hans Peter; Vigild, Martin E.; Thomsen, Erik; Szabo, Peter; Horsewell, Andy

    2009-01-01

    Students’ study strategies when exposed to activating teaching methods are measured, analysed and compared to study strategies in more traditional lecture-based teaching. The resulting learning outcome is discussed. Peer Reviewed

  14. Power-generation method using combined gas and steam turbines

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C; Radtke, K; Keller, H J

    1997-03-20

    The invention concerns a method of power generation using a so-called COGAS (combined gas and steam) turbine installation, the aim being to improve the method with regard to the initial costs and energy consumption so that power can be generated as cheaply as possible. This is achieved by virtue of the fact that air taken from the surrounding atmosphere is splint into an essentially oxygen-containing stream and an essentially nitrogen-containing stream and the two streams fed further at approximately atmospheric pressure. The essentially nitrogen-containing stream is mixed with an air stream to form a mixed nitrogen/air stream and the mixed-gas stream thus produced is brought to combustion chamber pressure in the compressor of the gas turbine, the combustion of the combustion gases in the combustion chamber of the gas turbine being carried out with the greater part of this compressed mixed-gas stream. (author) figs.

  15. Improvement of active filter for HIMAC power sources

    Energy Technology Data Exchange (ETDEWEB)

    Kumada, Masayuki [National Inst. of Radiological Sciences, Chiba (Japan); Kubo, Hiroshi; Furuzeki, Shoichiro; Kanazawa, Toru

    1996-03-01

    For the power sources of the synchrotron electromagnets for the heavy particle beam cancer therapy apparatus HIMAC in National Institute of Radiological Science, in order to stabilize the taken-out beam, the ripple property as low as below 1 x 10{sup -6} is required. As for this electromagnet power sources, various devices were applied to lower ripples, and the required specifications have been satisfied. Also the beam spill is stable, but slight variation has been observed, therefore, by improving the performance of the active filter, the ripples were improved. The specifications of the electromagnet power sources and the whole constitution of the power source system are shown. In the HIMAC power sources, the means for having realized the low ripple performance so far are explained. Those are the absorption of the ineffective power generated from the power sources, the control of the ripples of common made due to the transducer thyristor, and the sure compensation of ripples by the control circuit for the power sources. By adding the band pass filters to the active filter, its characteristics were improved. As the result, 1200 Hz ripple component was reduced by 41 db, thus the sufficient effect was obtained. Hereafter, by the high sensitivity measurement of the current of electromagnets and the evaluation of magnetic fields, the validity will be evaluated. (K.I.)

  16. Large-signal modeling method for power FETs and diodes

    Energy Technology Data Exchange (ETDEWEB)

    Sun Lu; Wang Jiali; Wang Shan; Li Xuezheng; Shi Hui; Wang Na; Guo Shengping, E-mail: sunlu_1019@126.co [School of Electromechanical Engineering, Xidian University, Xi' an 710071 (China)

    2009-06-01

    Under a large signal drive level, a frequency domain black box model of the nonlinear scattering function is introduced into power FETs and diodes. A time domain measurement system and a calibration method based on a digital oscilloscope are designed to extract the nonlinear scattering function of semiconductor devices. The extracted models can reflect the real electrical performance of semiconductor devices and propose a new large-signal model to the design of microwave semiconductor circuits.

  17. Large-signal modeling method for power FETs and diodes

    International Nuclear Information System (INIS)

    Sun Lu; Wang Jiali; Wang Shan; Li Xuezheng; Shi Hui; Wang Na; Guo Shengping

    2009-01-01

    Under a large signal drive level, a frequency domain black box model of the nonlinear scattering function is introduced into power FETs and diodes. A time domain measurement system and a calibration method based on a digital oscilloscope are designed to extract the nonlinear scattering function of semiconductor devices. The extracted models can reflect the real electrical performance of semiconductor devices and propose a new large-signal model to the design of microwave semiconductor circuits.

  18. Nuclear power generating station equipment qualification method and apparatus

    International Nuclear Information System (INIS)

    Fero, A.H.; Potochnik, L.M.; Riling, R.W.; Semethy, K.F.

    1990-01-01

    This patent describes a method of monitoring an object piece of qualified equipment in a nuclear power plant. It comprises providing a first passive mimic means for mimicking the effect of radiation received by the object piece on the object piece; providing a second mimic means for mimicking the effect of a thermal history of the object piece on the object piece and mounting the first passive mimic means and the second mimic means in close proximity to the object piece

  19. The power series method in the effectiveness factor calculations

    OpenAIRE

    Filipich, C. P.; Villa, L. T.; Grossi, Ricardo Oscar

    2017-01-01

    In the present paper, exact analytical solutions are obtained for nonlinear ordinary differential equations which appear in complex diffusionreaction processes. A technique based on the power series method is used. Numerical results were computed for a number of cases which correspond to boundary value problems available in the literature. Additionally, new numerical results were generated for several important cases. Fil: Filipich, C. P.. Universidad Tecnológica Nacional. Facultad Regiona...

  20. Activities of the IAEA International Working Group on Life Management of Nuclear Power Plants (IWG-LMNPP)

    International Nuclear Information System (INIS)

    Ianko, L.

    1994-01-01

    Activities of the IAEA international working group on life management of nuclear power plants are outlined with emphasis on objectives, scope of activities, methods of work, organizational matters, financing

  1. Modelling and Design of Active Thermal Controls for Power Electronics of Motor Drive Applications

    DEFF Research Database (Denmark)

    Vernica, Ionut; Blaabjerg, Frede; Ma, Ke

    2017-01-01

    of active thermal control methods for the power devices of a motor drive application. The motor drive system together with the thermal cycling of the power devices have been modelled, and adverse temperature swings could be noticed during the start-up and deceleration periods of the motor. Based...... on the electrical response of the system, the junction temperature of the semiconductor devices is estimated, and consequently three active thermal control methods are proposed and practically designed with respect to the following parameters: switching frequency, deceleration slope and modulation technique....... Finally, experimental results are provided in order to validate the effectiveness of the proposed control methods....

  2. Multivariable control in nuclear power stations -survey of design methods

    International Nuclear Information System (INIS)

    Mcmorran, P.D.

    1979-12-01

    The development of larger nuclear generating stations increases the importance of dynamic interaction between controllers, because each control action may affect several plant outputs. Multivariable control provides the techniques to design controllers which perform well under these conditions. This report is a foundation for further work on the application of multivariable control in AECL. It covers the requirements of control and the fundamental mathematics used, then reviews the most important linear methods, based on both state-space and frequency-response concepts. State-space methods are derived from analysis of the system differential equations, while frequency-response methods use the input-output transfer function. State-space methods covered include linear-quadratic optimal control, pole shifting, and the theory of state observers and estimators. Frequency-response methods include the inverse Nyquist array method, and classical non-interactive techniques. Transfer-function methods are particularly emphasized since they can incorporate ill-defined design criteria. The underlying concepts, and the application strengths and weaknesses of each design method are presented. A review of significant applications is also given. It is concluded that the inverse Nyquist array method, a frequency-response technique based on inverse transfer-function matrices, is preferred for the design of multivariable controllers for nuclear power plants. This method may be supplemented by information obtained from a modal analysis of the plant model. (auth)

  3. Method for Prediction of the Power Output from Photovoltaic Power Plant under Actual Operating Conditions

    Science.gov (United States)

    Obukhov, S. G.; Plotnikov, I. A.; Surzhikova, O. A.; Savkin, K. D.

    2017-04-01

    Solar photovoltaic technology is one of the most rapidly growing renewable sources of electricity that has practical application in various fields of human activity due to its high availability, huge potential and environmental compatibility. The original simulation model of the photovoltaic power plant has been developed to simulate and investigate the plant operating modes under actual operating conditions. The proposed model considers the impact of the external climatic factors on the solar panel energy characteristics that improves accuracy in the power output prediction. The data obtained through the photovoltaic power plant operation simulation enable a well-reasoned choice of the required capacity for storage devices and determination of the rational algorithms to control the energy complex.

  4. Methods to enhance blanket power density in low-power fusion devices

    International Nuclear Information System (INIS)

    Hsu, P.Y.; Miller, L.G.; Bohn, T.S.; Deis, G.A.; Longhurst, G.R.; Masson, L.S.; Wessol, D.E.; Abdou, M.A.

    1982-06-01

    The overall objective of this task is to investigate the extent to which the power density in the FED breeder blanket test modules can be enhanced by artificial means. Assuming a viable approach can be developed, it will allow testing of advanced reactor blanket modules on INTOR at representative conditions. The tentative approach adopted for this task consists of three parts. First, the requirements for augmented heating of the test module are outlined for different applications of interest. Second, methods are identified which have potential for augmenting the heating power in a test module, and this list of methods is narrowed to those which appear to be most useful. Finally, these methods are examined in more detail to determine the practical benefits of employing each

  5. Optimization methods for activities selection problems

    Science.gov (United States)

    Mahad, Nor Faradilah; Alias, Suriana; Yaakop, Siti Zulaika; Arshad, Norul Amanina Mohd; Mazni, Elis Sofia

    2017-08-01

    Co-curriculum activities must be joined by every student in Malaysia and these activities bring a lot of benefits to the students. By joining these activities, the students can learn about the time management and they can developing many useful skills. This project focuses on the selection of co-curriculum activities in secondary school using the optimization methods which are the Analytic Hierarchy Process (AHP) and Zero-One Goal Programming (ZOGP). A secondary school in Negeri Sembilan, Malaysia was chosen as a case study. A set of questionnaires were distributed randomly to calculate the weighted for each activity based on the 3 chosen criteria which are soft skills, interesting activities and performances. The weighted was calculated by using AHP and the results showed that the most important criteria is soft skills. Then, the ZOGP model will be analyzed by using LINGO Software version 15.0. There are two priorities to be considered. The first priority which is to minimize the budget for the activities is achieved since the total budget can be reduced by RM233.00. Therefore, the total budget to implement the selected activities is RM11,195.00. The second priority which is to select the co-curriculum activities is also achieved. The results showed that 9 out of 15 activities were selected. Thus, it can concluded that AHP and ZOGP approach can be used as the optimization methods for activities selection problem.

  6. An economical method of maintenance for nuclear power plants

    International Nuclear Information System (INIS)

    Zhang Mengyi; Wu Liming; Zhong Zhimin

    2014-01-01

    A new method of enhancing operation economy without loss any reliability method is called Proactive Ageing Management (PAM in short). PAM can be used for generic and specific plant in almost all situations that concern reliability and economy problem. PAM 2.0 software, which is a professional software during PAM process application, plays an important role to help analysts evaluate all strategies showed above and also provides decision advises to nuclear power plant manager using Net Present Values (NPV) criteria. Additionally, one case was taken as an example to illustrate PAM process, the role of software and explain the results for use. (authors)

  7. Systems and methods for an integrated electrical sub-system powered by wind energy

    Science.gov (United States)

    Liu, Yan [Ballston Lake, NY; Garces, Luis Jose [Niskayuna, NY

    2008-06-24

    Various embodiments relate to systems and methods related to an integrated electrically-powered sub-system and wind power system including a wind power source, an electrically-powered sub-system coupled to and at least partially powered by the wind power source, the electrically-powered sub-system being coupled to the wind power source through power converters, and a supervisory controller coupled to the wind power source and the electrically-powered sub-system to monitor and manage the integrated electrically-powered sub-system and wind power system.

  8. A colorimetric method to quantify endo-polygalacturonase activity.

    Science.gov (United States)

    Torres, Sebastián; Sayago, Jorge E; Ordoñez, Roxana M; Isla, María Inés

    2011-02-08

    We report a new colorimetric assay to quantify endo-polygalacturonase activity, which hydrolyzes polygalacturonic acid to produce smaller chains of galacturonate. Some of the reported polygalacturonase assays measure the activity by detecting the appearance of reducing ends such as the Somogyi-Nelson method. As a result of being general towards reducing groups, the Somogyi-Nelson method is not appropriate when studying polygalacturonase and polygalacturonase inhibitors in plant crude extracts, which often have a strong reducing power. Ruthenium Red is an inorganic dye that binds polygalacturonic acid and causes its precipitation. In the presence of polygalacturonase, polygalacturonic acid is hydrolyzed bringing about a corresponding gain in soluble Ruthenium Red. The described assay utilizes Ruthenium Red as the detection reagent which has been used previously in plate-based assays but not in liquid medium reactions. The new method measures the disappearance of the substrate polygalacturonic acid and is compared to the Somogyi-Nelson assay. The experimental results using lemon peel, a fern fronds and castor leaf crude extracts demonstrate that the new method provides a way to the quickly screening of polygalacturonase activity and polygalacturonase inhibitors in plant crude extracts containing high amounts of reducing power. On the other hand, the Ruthenium Red assay is not able to determine the activity of an exo-polygalacturonase as initial velocity and thus would allow the differentiation between endo- and exo-polygalacturonase activities. Copyright © 2010 Elsevier Inc. All rights reserved.

  9. Active Power Control of Waked Wind Farms: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, Paul A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); van Wingerden, Jan-Willem [Delft University of Technology; Pao, Lucy [University of Colorado; Aho, Jacob [University of Colorado

    2017-08-15

    Active power control can be used to balance the total power generated by wind farms with the power consumed on the electricity grid. With the increasing penetration levels of wind energy, there is an increasing need for this ancillary service. In this paper, we show that the tracking of a certain power reference signal provided by the transmission system operator can be significantly improved by using feedback control at the wind farm level. We propose a simple feedback control law that significantly improves the tracking behavior of the total power output of the farm, resulting in higher performance scores. The effectiveness of the proposed feedback controller is demonstrated using high-fidelity computational fluid dynamics simulations of a small wind farm.

  10. A multiscale forecasting method for power plant fleet management

    Science.gov (United States)

    Chen, Hongmei

    In recent years the electric power industry has been challenged by a high level of uncertainty and volatility brought on by deregulation and globalization. A power producer must minimize the life cycle cost while meeting stringent safety and regulatory requirements and fulfilling customer demand for high reliability. Therefore, to achieve true system excellence, a more sophisticated system-level decision-making process with a more accurate forecasting support system to manage diverse and often widely dispersed generation units as a single, easily scaled and deployed fleet system in order to fully utilize the critical assets of a power producer has been created as a response. The process takes into account the time horizon for each of the major decision actions taken in a power plant and develops methods for information sharing between them. These decisions are highly interrelated and no optimal operation can be achieved without sharing information in the overall process. The process includes a forecasting system to provide information for planning for uncertainty. A new forecasting method is proposed, which utilizes a synergy of several modeling techniques properly combined at different time-scales of the forecasting objects. It can not only take advantages of the abundant historical data but also take into account the impact of pertinent driving forces from the external business environment to achieve more accurate forecasting results. Then block bootstrap is utilized to measure the bias in the estimate of the expected life cycle cost which will actually be needed to drive the business for a power plant in the long run. Finally, scenario analysis is used to provide a composite picture of future developments for decision making or strategic planning. The decision-making process is applied to a typical power producer chosen to represent challenging customer demand during high-demand periods. The process enhances system excellence by providing more accurate market

  11. Nuclear power development and nuclear data activities in Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Gui Ah Auu [Malaysian Institute for Nuclear Technology Research, Ministry of Science, Technology and the Environment, Selangor (Malaysia)

    1999-03-01

    In this paper, research activities on nuclear power requirement carried out jointly by MINT and other organizations are described. Also discussed are activities on neutronics such as TRIGA reactor fuel management, storage pool criticality, and reactor fuel transfer cask calculations. In addition, recent work on radiation transport activities in MINT such as skyshine and photon phantom dose calculations using the MCNP and MRIPP computer codes are presented. Finally, nuclear data measurement works by researchers in Malaysian universities are described. (author)

  12. Nuclear power development and nuclear data activities in Malaysia

    International Nuclear Information System (INIS)

    Gui Ah Auu

    1999-01-01

    In this paper, research activities on nuclear power requirement carried out jointly by MINT and other organizations are described. Also discussed are activities on neutronics such as TRIGA reactor fuel management, storage pool criticality, and reactor fuel transfer cask calculations. In addition, recent work on radiation transport activities in MINT such as skyshine and photon phantom dose calculations using the MCNP and MRIPP computer codes are presented. Finally, nuclear data measurement works by researchers in Malaysian universities are described. (author)

  13. Method for building a nuclear power plant and layout thereof

    International Nuclear Information System (INIS)

    Matsuura, Tadashi; Ushiroda, Kouchi; Tajiri, Akinori; Yoshida, Naoto; Takeda, Masakado; Makita, Tasuo; Maezawa, Sumito; Yoshizaki, Masatoshi.

    1997-01-01

    The present invention relates to a technical field of building a nuclear power plant, and its technical issue is to reduce the scale of investment for cranes to be used in building a plurality of nuclear power plant units. In order to resolve the technical issue, in the present invention, a nuclear power plant building method is employed in building a plurality of nuclear plant units in which while an earlier building unit out of the plurality of units which is started to be built earlier is being built, a later building unit that is to be started to be built later than the earlier building unit is started to be built, and in which a common mobile crane is adapted to move between a crane operating area for the earlier building unit and a crane operating area for the later building unit so that the common mobile crane ban be used in building the plurality of units. The present invention is primarily intended for the construction of a nuclear power plant. (author) figs

  14. Method and device for controlling nuclear reactor power

    International Nuclear Information System (INIS)

    Takigawa, Yukio; Ebata, Shigeo.

    1988-01-01

    Purpose: To detect and suppress the special power oscillations in the reactor core. Method: Four pairs of LPRM detectors, each pair comprising two detectors are disposed at an identical axial direction of the reactor core and situated at substantially insymmetrical positions at least in longitudinal, vertical and orthogonal directions with respect to the center of te reactor core and LPRM signals from them are inputted into a device for judging special power oscillations. In this case, a standardized mutual relation function is determined on every pair for the respective LPRM signals. Generation of special power oscillations in the reactor core is judged when it is detected that peaks appearing at least in one of the function forms for each pair are negative and have absolute values exceeding a predetermined value and that time of peak is within a predetermined time. The judged signal is inputted to a selected control rod insertion device. The selected control rod insertion device, upon preceiving the signal, inserts selected control rods into the reactor core to suppress the special power oscillations. Accordingly, it is possible to improve the fuel integrity. (Horiuchi, T.)

  15. High power RF window deposition apparatus, method, and device

    Science.gov (United States)

    Ives, Lawrence R.; Lucovsky, Gerald; Zeller, Daniel

    2017-07-04

    A process for forming a coating for an RF window which has improved secondary electron emission and reduced multipactor for high power RF waveguides is formed from a substrate with low loss tangent and desirable mechanical characteristics. The substrate has an RPAO deposition layer applied which oxygenates the surface of the substrate to remove carbon impurities, thereafter has an RPAN deposition layer applied to nitrogen activate the surface of the substrate, after which a TiN deposition layer is applied using Titanium tert-butoxide. The TiN deposition layer is capped with a final RPAN deposition layer of nitridation to reduce the bound oxygen in the TiN deposition layer. The resulting RF window has greatly improved titanium layer adhesion, reduced multipactor, and is able to withstand greater RF power levels than provided by the prior art.

  16. IAEA activities in nuclear power plant personnel training and qualification

    International Nuclear Information System (INIS)

    Mautner-Markhof, F.

    1993-01-01

    Training to achieve and maintain the qualification and competence of nuclear power personnel is essential for safe and economic nuclear power. Technical Cooperation Meeting on Training-Related Activities for Nuclear Power Plant (NPP) Personnel in the countries of Central and Eastern Europe (CEEC) and of the former Soviet Union (FSU) has as its main objective the identification, through information exchange and discussion, of possible Technical Cooperation (TC) projects to assist Member States in meeting NPP personnel training needs and priorities, including the enhancing of training capabilities

  17. Nuclear power reactor safety research activities in CIAE

    International Nuclear Information System (INIS)

    Pu Shendi; Huang Yucai; Xu Hanming; Zhang Zhongyue

    1994-01-01

    The power reactor safety research activities in CIAE are briefly reviewed. The research work performed in 1980's and 1990's is mainly emphasised, which is closely related to the design, construction and licensing review of Qinshan Nuclear Power Plant and the safety review of Guangdong Nuclear Power Station. Major achievements in the area of thermohydraulics, nuclear fuel, probabilistic safety assessment and severe accident researches are summarized. The foreseeable research plan for the near future, relating to the design and construction of 600 MWe PWR NPP at Qinshan Site (phase II development) is outlined

  18. Gamma power is phase-locked to posterior alpha activity.

    Directory of Open Access Journals (Sweden)

    Daria Osipova

    Full Text Available Neuronal oscillations in various frequency bands have been reported in numerous studies in both humans and animals. While it is obvious that these oscillations play an important role in cognitive processing, it remains unclear how oscillations in various frequency bands interact. In this study we have investigated phase to power locking in MEG activity of healthy human subjects at rest with their eyes closed. To examine cross-frequency coupling, we have computed coherence between the time course of the power in a given frequency band and the signal itself within every channel. The time-course of the power was calculated using a sliding tapered time window followed by a Fourier transform. Our findings show that high-frequency gamma power (30-70 Hz is phase-locked to alpha oscillations (8-13 Hz in the ongoing MEG signals. The topography of the coupling was similar to the topography of the alpha power and was strongest over occipital areas. Interestingly, gamma activity per se was not evident in the power spectra and only became detectable when studied in relation to the alpha phase. Intracranial data from an epileptic subject confirmed these findings albeit there was slowing in both the alpha and gamma band. A tentative explanation for this phenomenon is that the visual system is inhibited during most of the alpha cycle whereas a burst of gamma activity at a specific alpha phase (e.g. at troughs reflects a window of excitability.

  19. Introduction to the methods of estimating nuclear power generating costs

    Energy Technology Data Exchange (ETDEWEB)

    1961-11-01

    The present report prepared by the Agency with the guidance and assistance of a panel of experts from Member States, the names of whom will be found at the end of this report, represents the first step in the methods of cost evaluation. The main objectives of the report are: (1) The preparation of a full list of the cost items likely to be encountered so that the preliminary estimates for a given nuclear power system can be relied upon in deciding on its economic merits. (2) A survey of the methods currently used for the estimation of the generating costs of the power produced by a nuclear station. The survey is intended for a wide audience ranging from engineers to public officials with an interest in the prospects of nuclear power. An attempt has therefore been made to refrain from detailed technical discussions in order to make the presentation easily understandable to readers with only a very general knowledge of the principles of nuclear engineering. 3 figs, tabs.

  20. Introduction to the methods of estimating nuclear power generating costs

    International Nuclear Information System (INIS)

    1961-01-01

    The present report prepared by the Agency with the guidance and assistance of a panel of experts from Member States, the names of whom will be found at the end of this report, represents the first step in the methods of cost evaluation. The main objectives of the report are: (1) The preparation of a full list of the cost items likely to be encountered so that the preliminary estimates for a given nuclear power system can be relied upon in deciding on its economic merits. (2) A survey of the methods currently used for the estimation of the generating costs of the power produced by a nuclear station. The survey is intended for a wide audience ranging from engineers to public officials with an interest in the prospects of nuclear power. An attempt has therefore been made to refrain from detailed technical discussions in order to make the presentation easily understandable to readers with only a very general knowledge of the principles of nuclear engineering. 3 figs, tabs

  1. Activation method for measuring the neutron spectra parameters. Computer software

    International Nuclear Information System (INIS)

    Efimov, B.V.; Ionov, V.S.; Konyaev, S.I.; Marin, S.V.

    2005-01-01

    The description of mathematical statement of a task for definition the spectral characteristics of neutron fields with use developed in RRC KI unified activation detectors (UKD) is resulted. The method of processing of results offered by authors activation measurements and calculation of the parameters used for an estimation of the neutron spectra characteristics is discussed. Features of processing of the experimental data received at measurements of activation with using UKD are considered. Activation detectors UKD contain a little bit specially the picked up isotopes giving at irradiation peaks scale of activity in the common spectrum scale of activity. Computing processing of results of the measurements is applied on definition of spectrum parameters for nuclear reactor installations with thermal and close to such power spectrum of neutrons. The example of the data processing, the measurements received at carrying out at RRC KI research reactor F-1 is resulted [ru

  2. Cooperative Control of Active Power Filters in Power Systems without Mutual Communication

    Czech Academy of Sciences Publication Activity Database

    Tlustý, J.; Škramlík, Jiří; Švec, J.; Valouch, Viktor

    2010-01-01

    Roč. 2010, č. 517184 (2010), s. 1-13 ISSN 1024-123X R&D Projects: GA AV ČR IAA200760703 Institutional research plan: CEZ:AV0Z20570509 Keywords : active power filter * power system * wireless cooperation Subject RIV: JA - Electronics ; Optoelectronics, Electric al Engineering Impact factor: 0.689, year: 2010 http://www.hindawi.com/journals/mpe/2010/517184.html

  3. Exploration of submarine wake and powering performance using CFD method

    International Nuclear Information System (INIS)

    Huizhi, Y.; Hongcui, S.; Nan, Z.; Renyou, Y.; Liangmei, Y.

    2005-01-01

    In response to the needs of better design and less time, Computational Fluid Dynamic(CFD) methods have become an impartible part in the ship design, especially in the earlier design phases. In this paper FLUENT software was used to predict the wake character and powering performance of submarine at model scale. By an effective combination of the block topology, grid, turbulence model and validation, the simulation scheme was developed and applied to the predictions of multiple designs and optimizations of the earlier submarine design iterations. The incompressible RANS equations with different turbulence models were solved. To handle the block interface between the propeller and submarine stern, sliding girds in multiple blocks were employed, unstructural grids were used in the block around the propeller. Submarine with/without stator and/or propeller were studied. The flow feature, forces and powering performance at various conditions were calculated. The results were compared with experimental data, and a good agreement was obtained. (author)

  4. Determination of reactor thermal power using a more accurate method

    International Nuclear Information System (INIS)

    Papuga, J.; Madron, F.; Pliska, J.

    2005-01-01

    Reactor thermal power is an important operational parameter in many respects such as nuclear safety, reactor physics or evaluation of turbine thermal performance. Thermal power of a pressurized water reactor is determined on the basis of the steam generator thermal balance. The balance can be made in several variants differing from one another by the selection of different measuring circuits whose data are used in the balancing. In principle, no one such variant gives the true value of the thermal power. Among the variant values, the one nearest to the unknown true value of reactor thermal power is probably the value calculated with the lowest uncertainty. The determination of such uncertainty is not easy and its value can make even several percent, which has significant economic consequences. This paper presents the method of data reconciliation and its application to the data of the third of Dukovany NPP. The data reconciliation method allows to exploit all the information which process data contain. It is based on the statistical adjustment of the redundant data in such a way that the adjusted data obey generally valid laws of nature (e.g. conservation laws). Mass and energy balances based on the data not yet reconciled do not obey those laws because of measurement errors. For data reconciliation in Dukovany, a detailed model of mass and energy flows describing the 3rd unit from steam generators to alternator and condenser was set up. Laws of mass and energy conservation and phase equilibrium in water-steam systems are thus fulfilled. Moreover, the user can model momentum balances in pipelines and create other equations, which are respected during calculation. The data reconciliation is done regularly for hourly averages (Authors)

  5. Correlation expansion: a powerful alternative multiple scattering calculation method

    International Nuclear Information System (INIS)

    Zhao Haifeng; Wu Ziyu; Sebilleau, Didier

    2008-01-01

    We introduce a powerful alternative expansion method to perform multiple scattering calculations. In contrast to standard MS series expansion, where the scattering contributions are grouped in terms of scattering order and may diverge in the low energy region, this expansion, called correlation expansion, partitions the scattering process into contributions from different small atom groups and converges at all energies. It converges faster than MS series expansion when the latter is convergent. Furthermore, it takes less memory than the full MS method so it can be used in the near edge region without any divergence problem, even for large clusters. The correlation expansion framework we derive here is very general and can serve to calculate all the elements of the scattering path operator matrix. Photoelectron diffraction calculations in a cluster containing 23 atoms are presented to test the method and compare it to full MS and standard MS series expansion

  6. Regulatory control of maintenance activities in Argentine nuclear power plants

    International Nuclear Information System (INIS)

    Calvo, J.C.; Caruso, G.

    2000-01-01

    The main maintenance objective is to assure that the safety features of structures, components and systems of nuclear power plants are kept as designed. Therefore, there is a direct relationship between safety and maintenance. Owing to the above mentioned, maintenance activities are considered a relevant regulatory issue for the Argentine Nuclear Regulatory Authority (ARN). This paper describes the regulatory control to maintenance activities of Argentine nuclear power plants. It also addresses essential elements for maintenance control, routine inspections, special inspections during planned outages, audits and license conditions and requirements. (author)

  7. Methods for seismic analysis of nuclear power plants

    International Nuclear Information System (INIS)

    Gantenbein, F.

    1990-01-01

    The seismic analysis of a complex structure, such as a nuclear power plant, is done in various steps. An overview of the methods, used in each of these steps will be given in the following chapters: Seismic analysis of the buildings taking into account structures with important mass or stiffness. The input to the building analysis, called ground motion, is described by an accelerogram or a response spectra. In this step, soil structure interaction has to be taken into account. Various methods are available: Impedance, finite element. The response of the structure can be calculated by spectral method or by time history analysis; advantages and limitations of each method will be shown. Calculation of floor response spectrum which are the data for the equipment analysis. Methods to calculate this spectrum will be described. Seismic analysis of the equipments. Presentation of the methods for both monosupported and multisupported equipment will be given. In addition methods to analyse equipments which present non-linearities associated to the boundary conditions such as impacts, sliding will be presented. (author). 30 refs, 15 figs

  8. Alternative implementations of the Monte Carlo power method

    International Nuclear Information System (INIS)

    Blomquist, R.N.; Gelbard, E.M.

    2002-01-01

    We compare nominal efficiencies, i.e. variances in power shapes for equal running time, of different versions of the Monte Carlo eigenvalue computation, as applied to criticality safety analysis calculations. The two main methods considered here are ''conventional'' Monte Carlo and the superhistory method, and both are used in criticality safety codes. Within each of these major methods, different variants are available for the main steps of the basic Monte Carlo algorithm. Thus, for example, different treatments of the fission process may vary in the extent to which they follow, in analog fashion, the details of real-world fission, or may vary in details of the methods by which they choose next-generation source sites. In general the same options are available in both the superhistory method and conventional Monte Carlo, but there seems not to have been much examination of the special properties of the two major methods and their minor variants. We find, first, that the superhistory method is just as efficient as conventional Monte Carlo and, secondly, that use of different variants of the basic algorithms may, in special cases, have a surprisingly large effect on Monte Carlo computational efficiency

  9. Alternative Implementations of the Monte Carlo Power Method

    International Nuclear Information System (INIS)

    Blomquist, R.N.; Gelbard, E.M.

    2002-01-01

    We compare nominal efficiencies, i.e., variances in power shapes for equal running time, of different versions of the Monte Carlo (MC) eigenvalue computation. The two main methods considered here are 'conventional' MC and the superhistory method. Within each of these major methods, different variants are available for the main steps of the basic MC algorithm. Thus, for example, different treatments of the fission process may vary in the extent to which they follow, in analog fashion, the details of real-world fission, or they may vary in details of the methods by which they choose next-generation source sites. In general the same options are available in both the superhistory method and conventional MC, but there seems not to have been much examination of the special properties of the two major methods and their minor variants. We find, first, that the superhistory method is just as efficient as conventional MC and, second, that use of different variants of the basic algorithms may, in special cases, have a surprisingly large effect on MC computational efficiency

  10. Design and control of LCL-filter with active damping for Active Power Filter

    DEFF Research Database (Denmark)

    Zeng, Guohong; Rasmussen, Tonny Wederberg; Ma, L

    2010-01-01

    of LCL-filter for APF is introduced, which is aimed for simplified the implementation. To suppress the resonance that may be excited in the system, which brings in stability problems, an active damping control strategy using the current feed-back of the filter capacitor is adopted. By selecting two equal......In the application of shunt Active Power Filter (APF) to compensate nonlinear load's harmonic, reactive and negative sequence current, it is more effective to use a LCL-filter than an L-filter as an interface between the Voltage Source Converter (VSC) and grid. In this paper, a designing procedure...... or similar inductances, the filter designing become more simple and effective, meanwhile the capacitance requirement is minimized. A pole-zero automatic cancellation phenomenon is discussed in this paper, which can be applied to simplify the current regulator designing. The tuning method is presented, based...

  11. A Review of Human Activity Recognition Methods

    Directory of Open Access Journals (Sweden)

    Michalis eVrigkas

    2015-11-01

    Full Text Available Recognizing human activities from video sequences or still images is a challenging task due to problems such as background clutter, partial occlusion, changes in scale, viewpoint, lighting, and appearance. Many applications, including video surveillance systems, human-computer interaction, and robotics for human behavior characterization, require a multiple activity recognition system. In this work, we provide a detailed review of recent and state-of-the-art research advances in the field of human activity classification. We propose a categorization of human activity methodologies and discuss their advantages and limitations. In particular, we divide human activity classification methods into two large categories according to whether they use data from different modalities or not. Then, each of these categories is further analyzed into sub-categories, which reflect how they model human activities and what type of activities they are interested in. Moreover, we provide a comprehensive analysis of the existing, publicly available human activity classification datasets and examine the requirements for an ideal human activity recognition dataset. Finally, we report the characteristics of future research directions and present some open issues on human activity recognition.

  12. Force Feedback Control Method of Active Tuned Mass Damper

    Directory of Open Access Journals (Sweden)

    Xiuli Wang

    2017-01-01

    Full Text Available Active tuned mass dampers as vibration-control devices are widely used in many fields for their good stability and effectiveness. To improve the performance of such dampers, a control method based on force feedback is proposed. The method offers several advantages such as high-precision control and low-performance requirements for the actuator, as well as not needing additional compensators. The force feedback control strategy was designed based on direct-velocity feedback. The effectiveness of the method was verified in a single-degree-of-freedom system, and factors such as damping effect, required active force, actuator stroke, and power consumption of the damper were analyzed. Finally, a simulation study was performed by configuring a main complex elastic-vibration-damping system. The results show that the method provides effective control over modal resonances of multiple orders of the system and improves its dynamics performance.

  13. Method of operation for a nuclear power plant

    International Nuclear Information System (INIS)

    Barleon, L.; Dalle Donne, M.; Dorner, S.

    1976-01-01

    A method for the operation of a nuclear power plant is described whose primary coolant circuit contains liquid metal as coolant, and for whose secondary circuit which is coupled to the first by means of heat exchangers, one or more chemical compositions dissociating at higher temperatures and recombining at lower temperatures or associating into the original types are used as operating medium. N 2 O 4 is suggested as operating medium, and metal halogenides e.g. Al 2 Cl 6 , Al 2 Br 6 are also cited as suitable. Corrosion dangers are regarded as low. (UWI) [de

  14. Method of fabricating self-powered nuclear radiation detector assemblies

    International Nuclear Information System (INIS)

    Playfoot, K.; Bauer, R.F.; Sekella, Y.M.

    1982-01-01

    In a method of fabricating a self-powered nuclear radiation detector assembly an emitter electrode wire and signal cable center wire are connected and disposed within the collector electrode tubular sheath with compressible insulating means disposed between the wires and the tubular sheath. The above assembly is reduced in diameter while elongating the tubular sheath and the emitter wire and signal cable wire. The emitter wire is reduced to a predetermined desired diameter, and is trimmed to a predetermined length. An end cap is hermetically sealed to the tubular sheath at the extending end of the emitter with insulating means between the emitter end and the end cap. (author)

  15. Comparison of dynamic compensation methods for delayed self-powered neutron detector

    International Nuclear Information System (INIS)

    In, Wang Kee; Kim, Joon Sung; Auh, Geun Sun; Yoon, Tae Young

    1993-01-01

    Dynamic compensation methods for rhodium self-powered neutron detector have been developed by Banda and Hoppe to compensate for the time delay associated with detector signals. The time delay is due to the decay of the neutron-activated rhodium and results in delayed detector response. Two digital dynamic compensation methods, were compared for step change of neutron flux in this paper. The inverse kinetics method gave slightly better response time and noise gain. However, the inverse kinetics method also showed overshooting of neutron flux for the step change. (Author)

  16. Study on the evaluation index of active power reserve

    Science.gov (United States)

    Guo, Xiaorui; Liu, Jiantao; Wang, Ke; Min, Lu

    2018-01-01

    Based on the role of active reserve at different time scales, divides the evaluation dimension of active reserve. Analysis the calculation principle of traditional reliability index such as probability of system safety, lack of power shortage and electricity shortage expectancy, and studies the applicability of these indicators to evaluate the reserve capacity on different dimensions. Resolves the evaluation index of active reserve capacity from the dimensions of time dimension, spatial dimension, system state, risk degree and economy, then construct evaluation index of active reserve capacity.

  17. Operational experience with reactive power control methods optimized for tokamak power supplies

    International Nuclear Information System (INIS)

    Sihler, C.; Huart, M.; Kaesemann, C.-P.; Streibl, B.

    2003-01-01

    The power and energy of the ASDEX Upgrade (AUG) tokamak are provided by two separate 10.5 kV, 110-85 Hz networks based on the flywheel generators EZ3-EZ4 in addition to the generator EZ2 dedicated to the toroidal field coil. The 10.5 kV networks supply the thyristor converters allowing fast control of the DC currents in the AUG poloidal field coils. Two methods for improving the load power factor in the present experimental campaign of AUG have been investigated, namely the control of the phase-to-neutral voltage in thyristor converters fitted with neutral thyristors, such as the new 145 MVA modular thyristor converter system (Group 6), and reactive power control achieved by means of static VAr compensators (SVC). The paper shows that reliable compensation up to 90 MVAr was regularly achieved and that electrical transients in SVC modules can be kept at an acceptable level. The paper will discuss the results from the reactive power reduction by SVC and neutral thyristor control and draw a comparative conclusion

  18. Nuclear Power Plant Control and Instrumentation activities in Finland

    International Nuclear Information System (INIS)

    Haapanen, P.; Wahlstroem, B.

    1990-01-01

    Finland has achieved some remarkable achievements in nuclear power production. Existing four plants have some of the best operating records in the world - high capacity factors, low occupational doses and short refuelling outages. Although public opinion was strongly turned against nuclear power after Chernobyl accident, and no decisions for new nuclear plants can be made before next elections in 1991, the nuclear option is still open. Utility companies are maintaining readiness to start new construction immediately after a positive political decision is made. One important component of the good operation history of the Finnish nuclear power plants is connected to the continuous research, development, modification and upgrading work, which is proceeding in Finland. In the following a short description is given on recent activities related to the I and C-systems of the nuclear power plants. (author). 2 tabs

  19. Active power reserves evaluation in large scale PVPPs

    DEFF Research Database (Denmark)

    Crăciun, Bogdan-Ionut; Kerekes, Tamas; Sera, Dezso

    2013-01-01

    The present trend on investing in renewable ways of producing electricity in the detriment of conventional fossil fuel-based plants will lead to a certain point where these plants have to provide ancillary services and contribute to overall grid stability. Photovoltaic (PV) power has the fastest...... growth among all renewable energies and managed to reach high penetration levels creating instabilities which at the moment are corrected by the conventional generation. This paradigm will change in the future scenarios where most of the power is supplied by large scale renewable plants and parts...... of the ancillary services have to be shared by the renewable plants. The main focus of the proposed paper is to technically and economically analyze the possibility of having active power reserves in large scale PV power plants (PVPPs) without any auxiliary storage equipment. The provided reserves should...

  20. DISTRIBUTED ELECTRICAL POWER PRODUCTION SYSTEM AND METHOD OF CONTROL THEREOF

    DEFF Research Database (Denmark)

    2010-01-01

    The present invention relates to a distributed electrical power production system wherein two or more electrical power units comprise respective sets of power supply attributes. Each set of power supply attributes is associated with a dynamic operating state of a particular electrical power unit....

  1. Active and passive cooling methods for dwellings

    DEFF Research Database (Denmark)

    Oropeza-Perez, Ivan; Østergaard, Poul Alberg

    2018-01-01

    In this document a review of three active as well as ten passive cooling methods suitable for residential buildings is carried out. The review firstly addresses how the various technologies cool the space according to the terms of the building heat balance, under what technical conditions...... ventilation, controlled ventilation, roof coating and eco-evaporative cooling are the most suitable passive methods for an extensive use in this country....

  2. Analysis the Human and Environmental Consequences of Power Pplants Using Combined Delphi and AHP Method

    International Nuclear Information System (INIS)

    Jozi, S. A.; Saffarian, Sh.; Shafiee, M.; Akbari, A.

    2016-01-01

    Power plants, due to the nature of their processes and activities and also by producing the effluents, emitting the air pollutants and hazardous wastes, have the potential to cause negative human and environmental consequences. Given the importance of the issue, for determining the most important consequences of Abadan Gas Power Plant and also their impact on the human and natural environment, as a case study, a questionnaire was developed with Delphi method. This questionnaire was distributed within the environmentalists and experts of power plant. The human and environmental consequences of Power Plant were analyzed by Multiple Criteria Decision-Making methods including AHP and eigenvector technique. For this purpose, with applying of AHP method, the hierarchical structure of the human and environmental consequences of Abadan Gas Power Plant was constructed and then the decision making matrix was formed. The pair wise matrices were formed separately for criteria pair wise comparisons with respect to severity and occurrence probability of indoor and outdoor environment of power plant .With entering the data in EXPERT CHOICE software, criteria weights were computed with applying the eigenvector method. Then the final weights of consequences in terms of severity and occurrence probability of risk were computed. The results from the compution of Abadan Gas Power Plant consequences indicate that in human consequences, shallow wounds with a .105 weight and in environmental consequences, air pollution by weighing 0.66 are the most important consequences of power plant. Finally, the most important executable strategies and actions for mitigation of negative human and environmental consequences were presented.

  3. Active current control in wind power plants during grid faults

    DEFF Research Database (Denmark)

    Martinez, Jorge; Kjær, Phillip C.; Rodriguez, Pedro

    2010-01-01

    Modern wind power plants are required and designed to ride through faults in electrical networks, subject to fault clearing. Wind turbine fault current contribution is required from most countries with a high amount of wind power penetration. In order to comply with such grid code requirements......, wind turbines usually have solutions that enable the turbines to control the generation of reactive power during faults. This paper addresses the importance of using an optimal injection of active current during faults in order to fulfil these grid codes. This is of relevant importance for severe...... faults, causing low voltages at the point of common coupling. As a consequence, a new wind turbine current controller for operation during faults is proposed. It is shown that to achieve the maximum transfer of reactive current at the point of common coupling, a strategy for optimal setting of the active...

  4. Improved Design Methods for Robust Single- and Three-Phase ac-dc-ac Power Converters

    DEFF Research Database (Denmark)

    Qin, Zian

    . The approaches for improving their performance, in terms of the voltage stress, efficiency, power density, cost, loss distribution, and temperature, will be studied. The structure of the thesis is as follows, Chapter 1 presents the introduction and motivation of the whole project as well as the background...... becomes a emerging challenge. Accordingly, installation of sustainable power generators like wind turbines and solar panels has experienced a large increase during the last decades. Meanwhile, power electronics converters, as interfaces in electrical system, are delivering approximately 80 % electricity...... back-to-back, and meanwhile improve the harmonics, control flexibility, and thermal distribution between the switches. Afterwards, active power decoupling methods for single-phase inverters or rectifiers that are similar to the single-phase ac-dc-ac converter, are studied in Chapter 4...

  5. Public acceptance (PA) activities of nuclear power in Japan

    International Nuclear Information System (INIS)

    Yamada, Masafumi; Iguchi, Tatsuro

    1993-10-01

    At the first part of presentation present status of nuclear power development in Japan is described. Then results of poll on nuclear energy acceptance by population are analyzed. Further, current activities and future efforts directed to broad understanding by people benefits of nuclear energy are described. 6 figs

  6. Application of Discontinuous PWM Modulation in Active Power Filters

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Asiminoaei, Lucian; Rodriguez, Pedro

    2008-01-01

    Classical discontinuous pulsewidth modulations (DPWMs) may not be efficiently applied in active power filters (APFs), because it is hard to predict the peak values of the inverter current, and consequently it is difficult to calculate the position of the clamped interval, that minimizes...

  7. The management plan preparation activities nuclear power plant in Indonesia

    International Nuclear Information System (INIS)

    Utomo

    2011-01-01

    A feasibility Study that has been updated show that two nuclear power units with each unit of power up to 1000 MWe can represent decently an economical alternative energy supply. It added that the available time schedule was quite tight so that the preparation for the development must be starting first. This paper will discuss the preparation of plans of the first nuclear power plant which includes program activities, the structure of contracts, schedules of activities and funding. From the information obtained to date that in addition to a candidate site that is ready to be built in Muria peninsula is still required another potential alternative site besides to search other complete data information. This site investigation activities completed within the time schedule was passed ''critical path'', so that these activities should be carried out intensively and obey the time. This paper describes the steps that need to be prepared to welcome the first nuclear power plant, after reviewing the various input above and apply the reality in Indonesia as the initial conditions. (author)

  8. Autonomous Active and Reactive Power Distribution Strategy in Islanded Microgrids

    DEFF Research Database (Denmark)

    Wu, Dan; Tang, Fen; Guerrero, Josep M.

    2014-01-01

    This paper proposes an autonomous active and reactive power distribution strategy that can be applied directly on current control mode (CCM) inverters, being compatible as well with conventional droop-controlled voltage control mode (VCM) converters. In a microgrid, since renewable energy sources...

  9. Validation of Power Requirement Model for Active Loudspeakers

    DEFF Research Database (Denmark)

    Schneider, Henrik; Madsen, Anders Normann; Bjerregaard, Ruben

    2015-01-01

    . There are however many advantages that could be harvested from such knowledge like size, cost and efficiency improvements. In this paper a recently proposed power requirement model for active loudspeakers is experimentally validated and the model is expanded to include the closed and vented type enclosures...

  10. Active power decoupling with reduced converter stress for single ...

    Indian Academy of Sciences (India)

    SUJATA BHOWMICK

    Department of Electronic Systems Engineering, Indian Institute of Science, ... Single phase; double-frequency ripple; active power decoupling; reduced stress; ... sation of renewable energy sources (e.g., PV), potential ... In standard grid connected DC/AC H-bridge configuration, ..... solar inverter with reduced-size dc link.

  11. Disobeying Power Laws: Perils for Theory and Method

    Directory of Open Access Journals (Sweden)

    G. Christopher Crawford

    2012-08-01

    Full Text Available The “norm of normality” is a myth that organization design scholars should believe only at their peril. In contrast to the normal (bell-shaped distribution with independent observations and linear relationships assumed by Gaussian statistics, research shows that nearly every input and outcome in organizational domains is power-law (Pareto distributed. These highly skewed distributions exhibit unstable means, unlimited variance, underlying interdependence, and extreme outcomes that disproportionally influence the entire system, making Gaussian methods and assumptions largely invalid. By developing more focused research designs and using methods that assume interdependence and potentially nonlinear relationships, organization design scholars can develop theories that more closely depict empirical reality and provide more useful insights to practitioners and other stakeholders.

  12. Active sound reduction system and method

    NARCIS (Netherlands)

    2016-01-01

    The present invention refers to an active sound reduction system and method for attenuation of sound emitted by a primary sound source, especially for attenuation of snoring sounds emitted by a human being. This system comprises a primary sound source, at least one speaker as a secondary sound

  13. Monte Carlo method in neutron activation analysis

    International Nuclear Information System (INIS)

    Majerle, M.; Krasa, A.; Svoboda, O.; Wagner, V.; Adam, J.; Peetermans, S.; Slama, O.; Stegajlov, V.I.; Tsupko-Sitnikov, V.M.

    2009-01-01

    Neutron activation detectors are a useful technique for the neutron flux measurements in spallation experiments. The study of the usefulness and the accuracy of this method at similar experiments was performed with the help of Monte Carlo codes MCNPX and FLUKA

  14. Methods for using polypeptides having cellobiohydrolase activity

    Science.gov (United States)

    Morant, Marc D; Harris, Paul

    2016-08-23

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  15. Analysis of Precision of Activation Analysis Method

    DEFF Research Database (Denmark)

    Heydorn, Kaj; Nørgaard, K.

    1973-01-01

    The precision of an activation-analysis method prescribes the estimation of the precision of a single analytical result. The adequacy of these estimates to account for the observed variation between duplicate results from the analysis of different samples and materials, is tested by the statistic T...

  16. Control Strategy of Active Power Filter Based on Modular Multilevel Converter

    Science.gov (United States)

    Xie, Xifeng

    2018-03-01

    To improve the capacity, pressure resistance and the equivalent switching frequency of active power filter (APF), a control strategy of APF based on Modular Multilevel Converter (MMC) is presented. In this Control Strategy, the indirect current control method is used to achieve active current and reactive current decoupling control; Voltage Balance Control Strategy is to stabilize sub-module capacitor voltage, the predictive current control method is used to Track and control of harmonic currents. As a result, the harmonic current is restrained, and power quality is improved. Finally, the simulation model of active power filter controller based on MMC is established in Matlab/Simulink, the simulation proves that the proposed strategy is feasible and correct.

  17. Reduction Method for Active Distribution Networks

    DEFF Research Database (Denmark)

    Raboni, Pietro; Chen, Zhe

    2013-01-01

    On-line security assessment is traditionally performed by Transmission System Operators at the transmission level, ignoring the effective response of distributed generators and small loads. On the other hand the required computation time and amount of real time data for including Distribution...... Networks also would be too large. In this paper an adaptive aggregation method for subsystems with power electronic interfaced generators and voltage dependant loads is proposed. With this tool may be relatively easier including distribution networks into security assessment. The method is validated...... by comparing the results obtained in PSCAD® with the detailed network model and with the reduced one. Moreover the control schemes of a wind turbine and a photovoltaic plant included in the detailed network model are described....

  18. Voltage harmonics mitigation through hybrid active power filer

    International Nuclear Information System (INIS)

    Sahito, A.A.; Tunio, S.M.; Khizer, A.N.

    2016-01-01

    Fast dynamic response, high efficiency, low cost and small size of power electronic converters have exponentially increased their use in modern power system which resulted in harmonically distorted voltage and currents. Voltage harmonics mainly caused by current harmonics are more dangerous as performance and expected operating life of other power system equipment are affected by harmonically distorted supply voltage. Electronic filter circuits are used to improve system power quality by mitigating adverse effects of harmonics. Hybrid filters having advantages of both passive and active filters are preferred to resolve the problem of harmonics efficiently and avoiding any chance of resonance. In this paper, a three phase three wire network is considered to supply an adjustable speed drive represented by a resistive load connected across a three phase bridge rectifier. Simulation of the considered system shows THD (Total Harmonic Distortion) of 18.91 and 7.61 percentage in supply current and voltage respectively. A HAPF (Hybrid Active Power Filter) is proposed to reduce these THD values below 5 percentage as recommended by IEEE Standard-519. P-Q theorem is used to calculate required parameters for proposed filter, which is implemented through hysteresis control. Simulation results confirm the effectiveness of the designed filter as THD for both current and voltage have reduced below allowable limit of 5 percentage. (author)

  19. Voltage Harmonics Mitigation through Hybrid Active Power Filter

    Directory of Open Access Journals (Sweden)

    Anwer Ali Sahito

    2016-01-01

    Full Text Available Fast dynamic response, high efficiency, low cost and small size of power electronic converters have exponentially increased their use in modern power system which resulted in harmonically distorted voltage and currents. Voltage harmonics mainly caused by current harmonics are more dangerous as performance and expected operating life of other power system equipment are affected by harmonically distorted supply voltage. Electronic filter circuits are used to improve system power quality by mitigating adverse effects of harmonics. Hybrid filters having advantages of both passive and active filters are preferred to resolve the problem of harmonics efficiently and avoiding any chance of resonance. In this paper, a three phase three wire network is considered to supply an adjustable speed drive represented by a resistive load connected across a three phase bridge rectifier. Simulation of the considered system shows THD (Total Harmonic Distortion of 18.91 and 7.61% in supply current and voltage respectively. A HAPF (Hybrid Active Power Filter is proposed to reduce these THD values below 5% as recommended by IEEE Standard-519. P-Q theorem is used to calculate required parameters for proposed filter, which is implemented through hysteresis control. Simulation results confirm the effectiveness of the designed filter as THD for both current and voltage have reduced below allowable limit of 5%.

  20. The Control of Transmitted Power in an Active Isolation System

    DEFF Research Database (Denmark)

    Elliott, S.J.; Gardonio, P.; Pinnington, R.J.

    1997-01-01

    The isolation of vibration through a system with multiple active mounts is discussed, in which each of the mounts can transmit vibration in several degrees of freedom. Theoretical models of the various parts of this system have been developed which include a flexible receiving structure and distr......The isolation of vibration through a system with multiple active mounts is discussed, in which each of the mounts can transmit vibration in several degrees of freedom. Theoretical models of the various parts of this system have been developed which include a flexible receiving structure...... and distributed active mounts, and these models can be connected together to produce an overall theoretical description of a realistic active isolation system. Total transmitted power has been found to be an excellent criterion to quantify the effect of various control strategies in this model in which...... the contributions to the transmitted power in the various degrees of freedom can be clearly understood. It has also been found, however, that an active control system which minimises a practical estimate of transmitted power, calculated from the product of the axial forces and velocities under the mounts, can give...

  1. Application of wire sawing method to decommissioning of nuclear power plant. Cutting test with turbine pedestal of thermal power plant

    International Nuclear Information System (INIS)

    Hasegawa, Hideki; Uchiyama, Noriyuki; Sugiyama, Kazuya; Yamashita, Yoshitaka; Watanabe, Morishige

    1995-01-01

    It is very important to reduce radioactive waste volume, and to reduce radiation dose to workers and to the public during dismantling of the activated concrete in the decommissioning stage of a nuclear power plant. For the above, we studied a dismantling method which can separate activated concrete from non-activated concrete safely and effectively. Considering the state of legal regulation about radioactive waste disposal, and the state of developing of decommissioning technologies, we come to a conclusion that wire sawing method is feasible as a concrete cutting method. This study was carried out to evaluate the availability of the wire sawing method to dismantling of concrete structures of nuclear power plants. This study consists of concrete cutting rate test and concrete block cutting test. The former is to obtain data about cutting rate with various steel ratios while the latter is to obtain data about working time and man hour of the whole work with wire sawing. Thirty-six year old turbine pedestal of a thermal power plant was selected as a test piece to simulate actual decommissioning work of nuclear power plant, taking its massive concrete volume and age. Taking account of the handling in the building, the wire sawing machine with motor driven was used in this study considering that it did not produce exhaust gas. The concrete cutting rate test was performed with parameter of steel ratio in the concrete, wire tension and cutting direction. In the concrete block cutting test, imaging the actual cutting situation, cubic blocks which side was approximately 1 meter were taken out, and a large block to be cut and to be taken out is a section of 1m x 1.5m x 10m. Test results are shown below. The difference of cutting rate was mainly caused by the difference of reinforcement steel ratio. Working time data of installation, removal of machines and cutting were obtained. Data on secondary waste (dust, drainage and sludge) and environmental effect (noise and

  2. Evaluation of methods to assess physical activity

    Science.gov (United States)

    Leenders, Nicole Y. J. M.

    Epidemiological evidence has accumulated that demonstrates that the amount of physical activity-related energy expenditure during a week reduces the incidence of cardiovascular disease, diabetes, obesity, and all-cause mortality. To further understand the amount of daily physical activity and related energy expenditure that are necessary to maintain or improve the functional health status and quality of life, instruments that estimate total (TDEE) and physical activity-related energy expenditure (PAEE) under free-living conditions should be determined to be valid and reliable. Without evaluation of the various methods that estimate TDEE and PAEE with the doubly labeled water (DLW) method in females there will be eventual significant limitations on assessing the efficacy of physical activity interventions on health status in this population. A triaxial accelerometer (Tritrac-R3D, (TT)), an uniaxial (Computer Science and Applications Inc., (CSA)) activity monitor, a Yamax-Digiwalker-500sp°ler , (YX-stepcounter), by measuring heart rate responses (HR method) and a 7-d Physical Activity Recall questionnaire (7-d PAR) were compared with the "criterion method" of DLW during a 7-d period in female adults. The DLW-TDEE was underestimated on average 9, 11 and 15% using 7-d PAR, HR method and TT. The underestimation of DLW-PAEE by 7-d PAR was 21% compared to 47% and 67% for TT and YX-stepcounter. Approximately 56% of the variance in DLW-PAEE*kgsp{-1} is explained by the registration of body movement with accelerometry. A larger proportion of the variance in DLW-PAEE*kgsp{-1} was explained by jointly incorporating information from the vertical and horizontal movement measured with the CSA and Tritrac-R3D (rsp2 = 0.87). Although only a small amount of variance in DLW-PAEE*kgsp{-1} is explained by the number of steps taken per day, because of its low cost and ease of use, the Yamax-stepcounter is useful in studies promoting daily walking. Thus, studies involving the

  3. Teollisuuden Voima Oy - Industrial Power Company Ltd. Local information activity

    International Nuclear Information System (INIS)

    Engros, Taina

    1989-01-01

    There are two nuclear power producers in Finland - the state-owned power company Imatran Voima Oy which operates two 440 MW Soviet-made PWR units in southern Finland, east of Helsinki and the Teollisuuden Voima Oy - Industrial Power Company Ltd, or TVO, owned by Finnish industrial companies. TVO operates two 710 MW ABB ATOM BWR units producing about one fifth of the country's electricity consumption. Operating experiences are extremely good from all Finnish nuclear power plants. The Finns' attitude towards nuclear power has changed into a positive direction in recent times. This can probably be noted as an international trend now that the Chernobyl accident is becoming an incident of the past. The Finnish citizens and politicians are facing two questions; first, what is their attitude towards nuclear power as a source of energy, in other words, do they approve of the plants currently in operation. The second question is how they stand on the building of new plants. It is probably another universal phenomenon that the attitudes of people living in the vicinity of nuclear power plants are less critical than the attitudes of those living farther away. This does not, by any means, result in local information activity being easier or less important than nationwide information activity. On the contrary, local decision-makers, local media and inhabitants are those who can, and through whom we can, influence also wider circles. The Nuclear Energy Act, which became effective in Finland last year, defines that the final decision on whether nuclear power plants can be built inside a municipality, is made at local level. As far as TVO is concerned one factor making local information activity easier is the small size of the locality. The difficulty TVO has to face is the people's suspicion of information activity. All information is considered propaganda, regardless of its form, and only negative news are considered information. Also, a large proportion of people are passive

  4. Teollisuuden Voima Oy - Industrial Power Company Ltd. Local information activity

    Energy Technology Data Exchange (ETDEWEB)

    Engros, Taina [Department of Information, TVO, Olkiluoto FIN-27160 (Finland)

    1989-07-01

    There are two nuclear power producers in Finland - the state-owned power company Imatran Voima Oy which operates two 440 MW Soviet-made PWR units in southern Finland, east of Helsinki and the Teollisuuden Voima Oy - Industrial Power Company Ltd, or TVO, owned by Finnish industrial companies. TVO operates two 710 MW ABB ATOM BWR units producing about one fifth of the country's electricity consumption. Operating experiences are extremely good from all Finnish nuclear power plants. The Finns' attitude towards nuclear power has changed into a positive direction in recent times. This can probably be noted as an international trend now that the Chernobyl accident is becoming an incident of the past. The Finnish citizens and politicians are facing two questions; first, what is their attitude towards nuclear power as a source of energy, in other words, do they approve of the plants currently in operation. The second question is how they stand on the building of new plants. It is probably another universal phenomenon that the attitudes of people living in the vicinity of nuclear power plants are less critical than the attitudes of those living farther away. This does not, by any means, result in local information activity being easier or less important than nationwide information activity. On the contrary, local decision-makers, local media and inhabitants are those who can, and through whom we can, influence also wider circles. The Nuclear Energy Act, which became effective in Finland last year, defines that the final decision on whether nuclear power plants can be built inside a municipality, is made at local level. As far as TVO is concerned one factor making local information activity easier is the small size of the locality. The difficulty TVO has to face is the people's suspicion of information activity. All information is considered propaganda, regardless of its form, and only negative news are considered information. Also, a large proportion of people are passive

  5. Water quality control method and device for nuclear power plant and nuclear power plant

    International Nuclear Information System (INIS)

    Nagase, Makoto; Asakura, Yamato; Uetake, Naoto; Sawa, Toshio; Uchida, Shunsuke; Takeda, Renzo; Osumi, Katsumi.

    1993-01-01

    In a BWR type nuclear power plant, water quality of coolants is controlled so as to lower deposition rate of Co ions in reactor water on a fuel cladding tube. The water quality control method includes (1) decreasing an iron concentration in feedwater to less than 0.1ppb, (2) adjusting coolants weakly acidic and (3) controlling dissolved oxygen concentration in reactor water to 20ppb. This can decrease 60 Co ion concentration even if 60 Co ion concentration is increased by the change of environment for the operation in future, such as an operation with hydrogen injection and extention of fuel burnup degree. (T.M.)

  6. Method to operate power reactors with light water cooling

    International Nuclear Information System (INIS)

    Aleite, W.; Bock, H.W.

    1976-01-01

    The invention provides a possibility to 'condition' the fuel of a power plant used in base load operation, i.e. to bring it to such a high power density level that the local excesses arising with the occasional total power changes, remain below the power densities reached in normal operation (conditioning level). (orig./RW) [de

  7. A new paradigm on battery powered embedded system design based on User-Experience-Oriented method

    International Nuclear Information System (INIS)

    Wang, Zhuoran; Wu, Yue

    2014-01-01

    The battery sustainable time has been an active research topic recently for the development of battery powered embedded products such as tablets and smart phones, which are determined by the battery capacity and power consumption. Despite numerous efforts on the improvement of battery capacity in the field of material engineering, the power consumption also plays an important role and easier to ameliorate in delivering a desirable user-experience, especially considering the moderate advancement on batteries for decades. In this study, a new Top-Down modelling method, User-Experience-Oriented Battery Powered Embedded System Design Paradigm, is proposed to estimate the target average power consumption, to guide the hardware and software design, and eventually to approach the theoretical lowest power consumption that the application is still able to provide the full functionality. Starting from the 10-hour sustainable time standard, average working current is defined with battery design capacity and set as a target. Then an implementation is illustrated from both hardware perspective, which is summarized as Auto-Gating power management, and from software perspective, which introduces a new algorithm, SleepVote, to guide the system task design and scheduling

  8. A new paradigm on battery powered embedded system design based on User-Experience-Oriented method

    Science.gov (United States)

    Wang, Zhuoran; Wu, Yue

    2014-03-01

    The battery sustainable time has been an active research topic recently for the development of battery powered embedded products such as tablets and smart phones, which are determined by the battery capacity and power consumption. Despite numerous efforts on the improvement of battery capacity in the field of material engineering, the power consumption also plays an important role and easier to ameliorate in delivering a desirable user-experience, especially considering the moderate advancement on batteries for decades. In this study, a new Top-Down modelling method, User-Experience-Oriented Battery Powered Embedded System Design Paradigm, is proposed to estimate the target average power consumption, to guide the hardware and software design, and eventually to approach the theoretical lowest power consumption that the application is still able to provide the full functionality. Starting from the 10-hour sustainable time standard, average working current is defined with battery design capacity and set as a target. Then an implementation is illustrated from both hardware perspective, which is summarized as Auto-Gating power management, and from software perspective, which introduces a new algorithm, SleepVote, to guide the system task design and scheduling.

  9. Comparative study of microcontroller controlled four-wire voltage and current source shunt active power filters

    Energy Technology Data Exchange (ETDEWEB)

    Pettersson, S.

    2009-07-01

    During the past two decades, active power filters have increasingly grown their popularity as a viable method for improving electric power quality. The main reasons for this have been the advent of fast self-commutating solid-state devices, the progression of digital technology and the improved sensor technology. Four-wire active power filters provide an efficient solution for improving the quality of supply in grounded three-phase systems or three-phase systems with neutral conductors, which are commonly used for powering residential, office and public buildings. Four-wire active power filters are applicable in compensating current harmonics, reactive power, neutral current and load phase imbalance.This thesis presents a comparative study of microcontroller controlled four-wire voltage and current source shunt active power filters. The study includes two voltage source topologies and a current source topology with two different dc-link energy storage structures, which are compared on the basis of their filtering properties, filtering performance and efficiency. The obtained results are used for determining the suitability of current source technology for four-wire active power filtering and finding the most viable four-wire shunt active power filter topology. One commonly recognized disadvantage of the current source active power filter has always been the bulky dc-link inductor. To reduce the size of the dc-link inductor, an alternative dc-link structure for current source active power filters was introduced in the late 80's. The hybrid energy storage consists of both inductive and capacitive energy storage elements, two diodes and two controllable semiconductor switching devices. Since the capacitive element is used as a main storage unit, the inductance of the dc-link inductor can be considerably reduced. However, the original dc current control method proposed is not able to utilize the full potential of the hybrid energy storage and the inductance

  10. Harmonic Active Filtering and Impedance-based Stability Analysis in Offshore Wind Power Plants

    DEFF Research Database (Denmark)

    Dhua, Debasish; Yang, Guangya; Zhang, Zhe

    2017-01-01

    installation and provides effectively similar functionality as passive filters. This work is focused on harmonic propagation studies in wind power plants, power quality evaluation at the point of connection and harmonic mitigation by active filtering. Finally, an impedance-based stability analysis......Nowadays, to eliminate harmonics injected by the wind turbines in offshore wind power plants there is a need to install passive filters. Moreover, the passive filters are not adaptive to harmonic profile changes due to topology changes, grid loading etc. Therefore, active filters in wind turbines...... are proposed as a flexible harmonic mitigation measure. The motivation of this study is to explore the possibility of embedding active filtering in wind turbine grid-side converters without having to change the system electrical infrastructure. The active filtering method can prevent additional equipment...

  11. Economic Valuation Methods: The Perception of the Accountants of the Hydroeletric Power Sector in Brazil

    Directory of Open Access Journals (Sweden)

    Aracéli Cristina de S. Ferreira

    2015-12-01

    Full Text Available The aim of the present study was to verify how accountants perceive the electric power companies in Brazil, regarding the use of economic valuation methods for measuring environmental impacts on hydroelectric power generation. These methods would be used in the internalisation of impacts in compliance with accounting theory criteria of recognition, measurement and disclosure of relevant economic activities. This is an exploratory study based on the conclusion regarding the collected data from a questionnaire answered by accountants, who worked in the electric power sector and were members of the Brazilian Electric Power Sector Accountants Association (ABRACONEE. The research showed that 74% of respondents were accountants or accounting analysts, 92% of them believed that companies should account for (internalise environmental impacts caused by their activities, and 75% of them believed that this task should be based on detailed and specific norms determining what should be done and when and how to do it. Despite their high level of accounting knowledge and complete familiarity with the changes determined by the Brazilian Securities Commission, respondents adopted a conservative stance in relation to the use of estimated values or those obtained in hypothetical markets. The study revealed the existence of a vast field of research that has yet to be explored by accounting in the field of environmental accounting, especially in terms of both measurement and recognition of environmental impacts caused by diverse economic activities

  12. Metabolic Activity Interferometer: A Powerful Tool for Testing Antibiotics

    Directory of Open Access Journals (Sweden)

    Rachel R. P. Machado

    2012-01-01

    Full Text Available It is demonstrated that the efficiency of antibiotics can be tested using an interferometric method. Two antibiotics were used as models to show that an interferometric method to monitor the metabolic activity of slowly growing bacteria can be a safer method to judge antimicrobial properties of substances than conventional methods. The susceptibility of Mycobacterium bovis to hexane extract of Pterodon emarginatus and to the well-known antibiotic rifampicin was tested with the interferometric method and with the conventional microplate method. The microplate method revealed a potential activity of hexane extract against M. bovis. However, the interferometric method showed that the action of this substance is rather limited. Also in the case of rifampicin, the interferometric method was able to detect resistant bacteria.

  13. High power ring methods and accelerator driven subcritical reactor application

    Energy Technology Data Exchange (ETDEWEB)

    Tahar, Malek Haj [Univ. of Grenoble (France)

    2016-08-07

    High power proton accelerators allow providing, by spallation reaction, the neutron fluxes necessary in the synthesis of fissile material, starting from Uranium 238 or Thorium 232. This is the basis of the concept of sub-critical operation of a reactor, for energy production or nuclear waste transmutation, with the objective of achieving cleaner, safer and more efficient process than today’s technologies allow. Designing, building and operating a proton accelerator in the 500-1000 MeV energy range, CW regime, MW power class still remains a challenge nowadays. There is a limited number of installations at present achieving beam characteristics in that class, e.g., PSI in Villigen, 590 MeV CW beam from a cyclotron, SNS in Oakland, 1 GeV pulsed beam from a linear accelerator, in addition to projects as the ESS in Europe, a 5 MW beam from a linear accelerator. Furthermore, coupling an accelerator to a sub-critical nuclear reactor is a challenging proposition: some of the key issues/requirements are the design of a spallation target to withstand high power densities as well as ensure the safety of the installation. These two domains are the grounds of the PhD work: the focus is on the high power ring methods in the frame of the KURRI FFAG collaboration in Japan: upgrade of the installation towards high intensity is crucial to demonstrate the high beam power capability of FFAG. Thus, modeling of the beam dynamics and benchmarking of different codes was undertaken to validate the simulation results. Experimental results revealed some major losses that need to be understood and eventually overcome. By developing analytical models that account for the field defects, one identified major sources of imperfection in the design of scaling FFAG that explain the important tune variations resulting in the crossing of several betatron resonances. A new formula is derived to compute the tunes and properties established that characterize the effect of the field imperfections on the

  14. Optimization Methods for Supply Chain Activities

    Directory of Open Access Journals (Sweden)

    Balasescu S.

    2014-12-01

    Full Text Available This paper approach the theme of supply chain activities for medium and large companies which run many operations and need many facilities. The first goal is to analyse the influence of optimisation methods of supply chain activities on the success rate for a business. The second goal is to compare some logistic strategies applied by companies with the same profile to see which is the most effective. The final goal is to show which is the necessity of strategic optimum for a company and how can be achieved the considering the demand uncertainty.

  15. Method of remote powering and detecting multiple UWB passive tags in an RFID system

    Science.gov (United States)

    Dowla, Farid U [Castro Valley, CA; Nekoogar, Faranak [San Ramon, CA; Benzel, David M [Livermore, CA; Dallum, Gregory E [Livermore, CA; Spiridon, Alex [Palo Alto, CA

    2012-05-29

    A new Radio Frequency Identification (RFID), tracking, powering apparatus/system and method using coded Ultra-wideband (UWB) signaling is introduced. The proposed hardware and techniques disclosed herein utilize a plurality of passive UWB transponders in a field of an RFID-radar system. The radar system itself enables multiple passive tags to be remotely powered (activated) at about the same time frame via predetermined frequency UWB pulsed formats. Once such tags are in an activated state, an UWB radar transmits specific "interrogating codes" to put predetermined tags in an awakened status. Such predetermined tags can then communicate by a unique "response code" so as to be detected by an UWB system using radar methods.

  16. Methods for estimating risks to nuclear power plants from shipping

    International Nuclear Information System (INIS)

    Walker, D.H.; Hartman, M.G.; Robbins, T.R.

    1975-01-01

    Nuclear power plants sited on land near shipping lanes or offshore can be exposed to potential risks if there is nearby ship or barge traffic which involves the transport of hazardous cargo. Methods that have been developed for estimating the degree of risk are summarized. Of concern are any accidents which could lead to a release or spill of the hazardous cargo, or to an explosion. A probability of occurrence of the order of 10 -7 per year is a general guideline which has been used to judge whether or not the risk from hazards created by accidents is acceptable. This guideline has been followed in the risk assessment discussed in this paper. 19 references

  17. Discriminative power of Campylobacter phenotypic and genotypic typing methods.

    Science.gov (United States)

    Duarte, Alexandra; Seliwiorstow, Tomasz; Miller, William G; De Zutter, Lieven; Uyttendaele, Mieke; Dierick, Katelijne; Botteldoorn, Nadine

    2016-06-01

    The aim of this study was to compare different typing methods, individually and combined, for use in the monitoring of Campylobacter in food. Campylobacter jejuni (n=94) and Campylobacter coli (n=52) isolated from different broiler meat carcasses were characterized using multilocus sequence typing (MLST), flagellin gene A restriction fragment length polymorphism typing (flaA-RFLP), antimicrobial resistance profiling (AMRp), the presence/absence of 5 putative virulence genes; and, exclusively for C. jejuni, the determination of lipooligosaccharide (LOS) class. Discriminatory power was calculated by the Simpson's index of diversity (SID) and the congruence was measured by the adjusted Rand index and adjusted Wallace coefficient. MLST was individually the most discriminative typing method for both C. jejuni (SID=0.981) and C. coli (SID=0.957). The most discriminative combination with a SID of 0.992 for both C. jejuni and C. coli was obtained by combining MLST with flaA-RFLP. The combination of MLST with flaA-RFLP is an easy and feasible typing method for short-term monitoring of Campylobacter in broiler meat carcass. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. An evaluation method of power quality about electrified railways connected to power grid based on PSCAD/EMTDC

    Science.gov (United States)

    Liang, Weibin; Ouyang, Sen; Huang, Xiang; Su, Weijian

    2017-05-01

    The existing modeling process of power quality about electrified railways connected to power grid is complicated and the simulation scene is incomplete, so this paper puts forward a novel evaluation method of power quality based on PSCAD/ETMDC. Firstly, a model of power quality about electrified railways connected to power grid is established, which is based on testing report or measured data. The equivalent model of electrified locomotive contains power characteristic and harmonic characteristic, which are substituted by load and harmonic source. Secondly, in order to make evaluation more complete, an analysis scheme has been put forward. The scheme uses a combination of three-dimensions of electrified locomotive, which contains types, working conditions and quantity. At last, Shenmao Railway is taken as example to evaluate the power quality at different scenes, and the result shows electrified railways connected to power grid have significant effect on power quality.

  19. Method to produce catalytically active nanocomposite coatings

    Science.gov (United States)

    Erdemir, Ali; Eryilmaz, Osman Levent; Urgen, Mustafa; Kazmanli, Kursat

    2016-02-09

    A nanocomposite coating and method of making and using the coating. The nanocomposite coating is disposed on a base material, such as a metal or ceramic; and the nanocomposite consists essentially of a matrix of an alloy selected from the group of Cu, Ni, Pd, Pt and Re which are catalytically active for cracking of carbon bonds in oils and greases and a grain structure selected from the group of borides, carbides and nitrides.

  20. Method to produce catalytically active nanocomposite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Erdemir, Ali; Eryilmaz, Osman Levent; Urgen, Mustafa; Kazmanli, Kursat

    2017-12-19

    A nanocomposite coating and method of making and using the coating. The nanocomposite coating is disposed on a base material, such as a metal or ceramic; and the nanocomposite consists essentially of a matrix of an alloy selected from the group of Cu, Ni, Pd, Pt and Re which are catalytically active for cracking of carbon bonds in oils and greases and a grain structure selected from the group of borides, carbides and nitrides.

  1. Methods and tools for analysis and optimization of power plants

    Energy Technology Data Exchange (ETDEWEB)

    Assadi, Mohsen

    2000-09-01

    The most noticeable advantage of the introduction of the computer-aided tools in the field of power generation, has been the ability to study the plant's performance prior to the construction phase. The results of these studies have made it possible to change and adjust the plant layout to match the pre-defined requirements. Further development of computers in recent years has opened up for implementation of new features in the existing tools and also for the development of new tools for specific applications, like thermodynamic and economic optimization, prediction of the remaining component life time, and fault diagnostics, resulting in improvement of the plant's performance, availability and reliability. The most common tools for pre-design studies are heat and mass balance programs. Further thermodynamic and economic optimization of plant layouts, generated by the heat and mass balance programs, can be accomplished by using pinch programs, exergy analysis and thermoeconomics. Surveillance and fault diagnostics of existing systems can be performed by using tools like condition monitoring systems and artificial neural networks. The increased number of tools and their various construction and application areas make the choice of the most adequate tool for a certain application difficult. In this thesis the development of different categories of tools and techniques, and their application area are reviewed and presented. Case studies on both existing and theoretical power plant layouts have been performed using different commercially available tools to illuminate their advantages and shortcomings. The development of power plant technology and the requirements for new tools and measurement systems have been briefly reviewed. This thesis contains also programming techniques and calculation methods concerning part-load calculations using local linearization, which has been implemented in an inhouse heat and mass balance program developed by the author

  2. Methods of charged-particle activation analysis

    International Nuclear Information System (INIS)

    Chaudhri, M. Anwar; Chaudhri, M. Nasir; Jabbar, Q.; Nadeem, Q.

    2006-01-01

    The accuracy of Chaudhri's method for charged-particle activation analysis published in J. Radioanal. Chem. (1977) v. 37 p. 243 has been further demonstrated by extensive calculations. The nuclear reactions 12 C(d,n) 13 N, 63 Cu( 3 He,p) 65 Zn, 107 Ag(α,n) 110 In and 208 Pb(d,p) 209 Pb, the cross sections of which were easily available, have been examined for the detection of 12 C, 63 Cu, 107 Ag and 208 Pb, respectively, in matrices of Cu, Zr and Pb, at the bombarding energies of 4 - 22 MeV. The 'standard' is assumed to be in a carbon matrix. It has been clearly demonstrated that Chaudhri's method, which makes the charged particle activation analysis as simple as neutron activation analysis, provides results which are almost identical to, or only about 1-2 % different, from the results obtained using the full 'Activity Equation' involving solving complex integrals. It is valid even when the difference in the average atomic weights of matrices of the standard and the sample is large. (author)

  3. Nuclear power plant control and instrumentation activities in Finland

    International Nuclear Information System (INIS)

    Haapanen, P.; Wahlstroem, B.

    1992-01-01

    Finland has remarkable achievements in nuclear power. The existing four plants have some of the best operating records in the world - high capacity factors, low occupational doses and short refuelling outages. Public opinion was strongly turned against nuclear power after Chernobyl accident, and the previous government decided not to allow for the construction of a fifth nuclear unit during its period of reign. The opposition has however slowly been diminishing. According to the latest polls the opinion is almost balanced. Finnish power companies are going to file an application for a decision-in-principle to build a new plant to the new government appointed in April 1991. A readiness to start new construction project immediately after a positive political decision is made has been maintained during the intermediate period. Continuous research, development, modification and upgrading work provide important components of the good operational history of the Finnish nuclear power plants. Efforts have also been devoted to identifying possible new problems arising from the use of distributed digital C and I technology. The following a short description is summarizing recent activities related to the C and I-systems of the nuclear power plants. (author). 3 tab

  4. Active Power Factor Correction Using a Sliding Mode Controller

    Directory of Open Access Journals (Sweden)

    Korhan KAYIŞLI

    2008-03-01

    Full Text Available In this paper, a sliding mode controller is designed for active shaping of the input current in the boost converter. Robustness of the designed controller is tested with variable output voltage references, different loads and network voltage variations. For the simulations, MATLAB/Simulink programme is used. From simulation results, the same phase was provided between input current and input voltage and nearly unity power factor was obtained.

  5. Multi-Objective Optimization Control for the Aerospace Dual-Active Bridge Power Converter

    Directory of Open Access Journals (Sweden)

    Tao Lei

    2018-05-01

    Full Text Available With the development of More Electrical Aircraft (MEA, the electrification of secondary power systems in aircraft is becoming more and more common. As the key power conversion device, the dual active bridge (DAB converter is the power interface for the energy storage system with the high voltage direct current (HVDC bus in aircraft electrical power systems. In this paper, a DAB DC-DC converter is designed to meet aviation requirements. The extended dual phase shifted control strategy is adopted, and a multi-objective genetic algorithm is applied to optimize its operating performance. Considering the three indicators of inductance current root mean square root (RMS value, negative reverse power and direct current (DC bias component of the current for the high frequency transformer as the optimization objectives, the DAB converter’s optimization model is derived to achieve soft switching as the main constraint condition. Optimized methods of controlling quantity for the DAB based on the evolution and genetic algorithm is used to solve the model, and a number of optimal control parameters are obtained under different load conditions. The results of digital, hard-in-loop simulation and hardware prototype experiments show that the three performance indexes are all suppressed greatly, and the optimization method proposed in this paper is reasonable. The work of this paper provides a theoretical basis and researching method for the multi-objective optimization of the power converter in the aircraft electrical power system.

  6. Development of methods for evaluating active faults

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-08-15

    The HERP report for long-term evaluation of active faults and the NSC safety review guide with regard to geology and ground of site were published on Nov. 2010 and on Dec. 2010, respectively. With respect to those reports, our investigation is as follows; (1) For assessment of seismic hazard, we estimated seismic sources around NPPs based on information of tectonic geomorphology, earthquake distribution and subsurface geology. (2) For evaluation on the activity of blind fault, we calculated the slip rate on the 2008 Iwate-Miyagi Nairiku Earthquake fault, using information on late Quaternary fluvial terraces. (3) To evaluate the magnitude of earthquakes whose sources are difficult to identify, we proposed a new method for calculation of the seismogenic layer thickness. (4) To clarify the activities of active faults without superstratum, we carried out the color analysis of fault gouge and divided the activities into thousand of years and tens of thousands. (5) For improving chronology of sediments, we detected new widespread cryptotephras using mineral chemistry and developed late Quaternary cryptotephrostratigraphy around NPPs. (author)

  7. Multi-objective optimal power flow for active distribution network considering the stochastic characteristic of photovoltaic

    Science.gov (United States)

    Zhou, Bao-Rong; Liu, Si-Liang; Zhang, Yong-Jun; Yi, Ying-Qi; Lin, Xiao-Ming

    2017-05-01

    To mitigate the impact on the distribution networks caused by the stochastic characteristic and high penetration of photovoltaic, a multi-objective optimal power flow model is proposed in this paper. The regulation capability of capacitor, inverter of photovoltaic and energy storage system embedded in active distribution network are considered to minimize the expected value of active power the T loss and probability of voltage violation in this model. Firstly, a probabilistic power flow based on cumulant method is introduced to calculate the value of the objectives. Secondly, NSGA-II algorithm is adopted for optimization to obtain the Pareto optimal solutions. Finally, the best compromise solution can be achieved through fuzzy membership degree method. By the multi-objective optimization calculation of IEEE34-node distribution network, the results show that the model can effectively improve the voltage security and economy of the distribution network on different levels of photovoltaic penetration.

  8. Fast Computation and Assessment Methods in Power System Analysis

    Science.gov (United States)

    Nagata, Masaki

    Power system analysis is essential for efficient and reliable power system operation and control. Recently, online security assessment system has become of importance, as more efficient use of power networks is eagerly required. In this article, fast power system analysis techniques such as contingency screening, parallel processing and intelligent systems application are briefly surveyed from the view point of their application to online dynamic security assessment.

  9. Older people's use of powered wheelchairs for activity and participation

    DEFF Research Database (Denmark)

    Brandt, Ase; Iwarsson, Susanne; Ståhle, Agneta

    2004-01-01

    research were identified. CONCLUSION: The use of powered wheelchairs is a relevant societal intervention in relation to older people with limited walking ability in order to make activity and participation possible. It is likely that a larger proportion of older people could benefit from this intervention...... not use the wheelchair for visits, and supplementary travel modes are called for. Users who could not walk at all or who could not transfer without assistance were more likely not to be able to carry out prioritized activities. Furthermore, other risk factors for negative outcomes and need for further...

  10. Single Phase Passive Rectification Versus Active Rectification Applied to High Power Stirling Engines

    Science.gov (United States)

    Santiago, Walter; Birchenough, Arthur G.

    2006-01-01

    Stirling engine converters are being considered as potential candidates for high power energy conversion systems required by future NASA explorations missions. These types of engines typically contain two major moving parts, the displacer and the piston, in which a linear alternator is attached to the piston to produce a single phase sinusoidal waveform at a specific electric frequency. Since all Stirling engines perform at low electrical frequencies (less or equal to 100 Hz), space explorations missions that will employ these engines will be required to use DC power management and distribution (PMAD) system instead of an AC PMAD system to save on space and weight. Therefore, to supply such DC power an AC to DC converter is connected to the Stirling engine. There are two types of AC to DC converters that can be employed, a passive full bridge diode rectifier and an active switching full bridge rectifier. Due to the inherent line inductance of the Stirling Engine-Linear Alternator (SE-LA), their sinusoidal voltage and current will be phase shifted producing a power factor below 1. In order to keep power the factor close to unity, both AC to DC converters topologies will implement power factor correction. This paper discusses these power factor correction methods as well as their impact on overall mass for exploration applications. Simulation results on both AC to DC converters topologies with power factor correction as a function of output power and SE-LA line inductance impedance are presented and compared.

  11. Survey of Cyber Security Methods for the Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yoo Rark; Lee, Jae Cheol; Choi, Young Soo; Hong, Seok Boong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-10-15

    Cyber security includes the method of protecting information, computer programs, and other computer system assets. Hardware security, which is the security of computer assets and capital equipment, refers to computer location, access control, fire protection, and storage procedures. Such measures as badges, electronic identification keys, alarm systems, and physical barriers at entries are used for this purpose. Software security entails the protection of software assets such as Application Programs, the Operating System, and the Data Base Management System and stored information. Special user numbers and passwords are typically used to prevent unauthorized access to software and data. In addition to security for hardware and software, good internal control also requires that measures be taken to prevent loss or accidental destruction of data. Cyber attacks create substantial threats to large enterprises, including federal systems and digital I and C of a NPP (Nuclear Power Plant) is one of them. The cyber security policy for the digital I and C network of the NPP has been established for years by KINS, but its scope is very broad and conceptual. We will propose a cyber security method based on cryptography and authentication that is developed for the digital I and C network of the NPP.

  12. Survey of Cyber Security Methods for the Nuclear Power Plants

    International Nuclear Information System (INIS)

    Choi, Yoo Rark; Lee, Jae Cheol; Choi, Young Soo; Hong, Seok Boong

    2009-01-01

    Cyber security includes the method of protecting information, computer programs, and other computer system assets. Hardware security, which is the security of computer assets and capital equipment, refers to computer location, access control, fire protection, and storage procedures. Such measures as badges, electronic identification keys, alarm systems, and physical barriers at entries are used for this purpose. Software security entails the protection of software assets such as Application Programs, the Operating System, and the Data Base Management System and stored information. Special user numbers and passwords are typically used to prevent unauthorized access to software and data. In addition to security for hardware and software, good internal control also requires that measures be taken to prevent loss or accidental destruction of data. Cyber attacks create substantial threats to large enterprises, including federal systems and digital I and C of a NPP (Nuclear Power Plant) is one of them. The cyber security policy for the digital I and C network of the NPP has been established for years by KINS, but its scope is very broad and conceptual. We will propose a cyber security method based on cryptography and authentication that is developed for the digital I and C network of the NPP

  13. Human factors estimation methods in nuclear power plant

    International Nuclear Information System (INIS)

    Takano, Kenichi; Yoshino, Kenji; Nagasaka, Akihiko; Ishii, Keichiro; Nakasa, Hiroyasu

    1985-01-01

    To improve the operational and maintenance work reliability, it is neccessary for workers to maintain his performance always at high level, that leads to decreasing mistaken judgements and operations. This paper inuolves the development and evaluation of ''Multi-Purpose Physiological Information Measurement system'' to estimate human performance and conditions with a highly fixed quantity. The following itemes is mentioned : (1) Most suitable physiological informations are selected to measure worker' performance in nuclear power plant with none-disturbance, ambulatory, continual, and multi channel measurement. (2) Relatively important physiological informations are measured with the real-time monitoring functions. (electrocardiogram, respirometric functions and EMG (electromyogram) pulse rete). (3) It is made to optimize the measurement condition and analysing methods in the use of a noise-cut function and a D.C. drift cutting method. (4) As a example, it is clear that, when the different weight is loaded to the arm and make it strech-bend motion, the EMG signal is measured and analysed by this system, the analysed EMG pulse rate and maximum amplitude is related to the arm loaded weight. (author)

  14. Newton-Krylov Methods in Power Flow and Contingency Analysis

    NARCIS (Netherlands)

    Idema, R.

    2012-01-01

    A power system is a system that provides for the generation, transmission, and distribution of electrical energy. Power systems are considered to be the largest and most complex man-made systems. As electrical energy is vital to our society, power systems have to satisfy the highest security and

  15. A Modular Cascaded Multilevel Inverter Based Shunt Hybrid Active Power Filter for Selective Harmonic and Reactive Power Compensation Under Distorted/Unbalanced Grid Voltage Conditions

    Directory of Open Access Journals (Sweden)

    T. Demirdelen

    2016-10-01

    Full Text Available In recent years, shunt hybrid active power filters are being increasingly considered as a viable alternative to both passive filters and active power filters for compensating harmonics. In literature, their applications are restricted to balanced systems and low voltage applications and therefore not for industrial applications. This paper investigates the performance of a modular cascaded multilevel inverter based Shunt Hybrid Active Power Filter (SHAPF for reactive power compensation and selective harmonics elimination under distorted/unbalanced grid voltage conditions in medium voltage levels. In the proposed control method, reactive power compensation is achieved successfully with a perceptible amount and the performance results of harmonic compensation are satisfactory. Theoretical analysis and simulation results are obtained from an actual industrial network model in PSCAD. The simulation results are presented for a proposed system in order to demonstrate that the harmonic compensation performance meets the IEEE-519 standard.

  16. Flicker Mitigation by Active Power Control of Variable-Speed Wind Turbines With Full-Scale Back-to-Back Power Converters

    DEFF Research Database (Denmark)

    Hu, Weihao; Chen, Zhe; Wang, Zhaoan

    2009-01-01

    /EMTDC. Flicker emission of this system is investigated. Reactive power compensation is mostly adopted for flicker mitigation. However, the flicker mitigation technique shows its limits, when the grid impedance angle is low in some distribution networks. A new method of flicker mitigation by controlling active...... power is proposed. It smoothes the 3p active power oscillations from wind shear and tower shadow effects of the wind turbine by varying the dc-link voltage of the full-scale converter. Simulation results show that damping the 3p active power oscillation by using the flicker mitigation controller...... is an effective means for flicker mitigation of variable-speed wind turbines with full-scale back-to-back power converters during continuous operation....

  17. A grid-voltage-sensorless resistive active power filter with series LC-filter

    DEFF Research Database (Denmark)

    Bai, Haofeng; Wang, Xiongfei; Blaabjerg, Frede

    2017-01-01

    Voltage-sensorless control has been investigated for Voltage Source Inverters (VSIs) for many years due to the reduced system cost and potentially improved system reliability. The VSI based Resistive Active Power Filters (R-APFs) are now widely used to prevent the harmonic resonance in power...... distribution network, for which the voltage sensors are needed in order to obtain the current reference. In this paper a grid-voltage-sensorless control strategy is proposed for the R-APF with series LC-filter. Unlike the traditional resistance emulation method, this proposed control method re...

  18. A Grid-Voltage-Sensorless Resistive Active Power Filter with Series LC-Filter

    DEFF Research Database (Denmark)

    Bai, Haofeng; Wang, Xiongfei; Blaabjerg, Frede

    2018-01-01

    Voltage-sensorless control has been investigated for Voltage Source Inverters (VSIs) for many years due to the reduced system cost and potentially improved system reliability. The VSI based Resistive Active Power Filters (R-APFs) are now widely used to prevent the harmonic resonance in power...... distribution network, for which the voltage sensors are needed in order to obtain the current reference. In this paper a grid-voltage-sensorless control strategy is proposed for the R-APF with series LC-filter. Unlike the traditional resistance emulation method, this proposed control method re...

  19. Combined Active and Reactive Power Control of Wind Farms based on Model Predictive Control

    DEFF Research Database (Denmark)

    Zhao, Haoran; Wu, Qiuwei; Wang, Jianhui

    2017-01-01

    This paper proposes a combined wind farm controller based on Model Predictive Control (MPC). Compared with the conventional decoupled active and reactive power control, the proposed control scheme considers the significant impact of active power on voltage variations due to the low X=R ratio...... of wind farm collector systems. The voltage control is improved. Besides, by coordination of active and reactive power, the Var capacity is optimized to prevent potential failures due to Var shortage, especially when the wind farm operates close to its full load. An analytical method is used to calculate...... the sensitivity coefficients to improve the computation efficiency and overcome the convergence problem. Two control modes are designed for both normal and emergency conditions. A wind farm with 20 wind turbines was used to verify the proposed combined control scheme....

  20. Coincidence method for determination of radionuclides activities

    International Nuclear Information System (INIS)

    Andrukhovich, S.K.; Berestov, A.V.; Rudak, E.A.

    2004-01-01

    The radon and radium activity measurements using six-crystal gamma-gamma coincidence, 4 -spectrometer PRIPJAT and radioactivity measurements in different samples of meat and vegetation by 32-crystal spectrometer ARGUS, are described. Radiation detector with 4 -geometry provides higher efficiency, and therefore shorter counting time than a detector without such geometry. However, its application is limited by the fact that obtained spectrum contains summing peaks of all γ-quanta registered in coincidence. Multiparameter information on coincident photon emission can be obtained only by a detection system where the 4 -geometry is made by many detectors, such are both the PRIPJAT and the ARGUS - γ-coincidence spectrometer of the Crystal Ball type in the Institute of Physics, Minsk [1,2]. There are other characteristics, as background conditions, energy and time resolution, makes it ve suitable for investigation of rare decays and interactions, cascade transitions, k intensity radiations etc. We are developing a method of 2 26R a and 2 26 Rn measurement by a multidetector 4 -spectrometer. The method is based on coincidence counting of γ-rays from two step cascade transitions that follow - decay of 2 14 Bi. Its application to the PRIPL spectrometer, which has 6 Nal(Tl) detectors, is presented here, as well as the method of the determination of radionuclide activities based on the registration of the cascades intensity of γ-rays of different multiplicity using ARGUS

  1. Activities in the Dynamic Occupational Therapy Method

    Directory of Open Access Journals (Sweden)

    Jô Benetton

    2013-12-01

    Full Text Available This paper addresses the concept and use of the instrument named ‘activities’ in occupational therapy, sustained by the propositions of the Dynamic Occupational Therapy Method (DOTM. Initially, we present general aspects related to the activities in the DOTM such as the option for the name ‘activities’, its conceptual definition, use as a tool, and active participation in the dynamic of triadic relationship. Further, it approaches the character of activities: therapeutic, educational and social qualities, which distinguish this peculiar occupational therapy. Moreover, the paper highlights the use of activities as a tool, both as a central element of the processes that should underpin clinical reasoning (observation, information, association, setting up space of historicity, and construction of narrative, and as an element belonging to diagnostic procedures, to the course of clinical process, and to evaluation. Finally, we present our understanding of what we call resources in DOTM, and its intrinsic connection with the possibility of performing ‘activities’. For the creation of DOTM, occupational therapy, as a practice focused on the uniqueness of the case, was made the object of study in order to promote knowledge construction. The conceptual and instrumental framework presented in this work held this effort. We hope that this study could be useful for initial and continuing training in Occupational Therapy as well as for enriching the debate on the use of ‘activities’ in our profession.

  2. A general solution strategy of modified power method for higher mode solutions

    International Nuclear Information System (INIS)

    Zhang, Peng; Lee, Hyunsuk; Lee, Deokjung

    2016-01-01

    A general solution strategy of the modified power iteration method for calculating higher eigenmodes has been developed and applied in continuous energy Monte Carlo simulation. The new approach adopts four features: 1) the eigen decomposition of transfer matrix, 2) weight cancellation for higher modes, 3) population control with higher mode weights, and 4) stabilization technique of statistical fluctuations using multi-cycle accumulations. The numerical tests of neutron transport eigenvalue problems successfully demonstrate that the new strategy can significantly accelerate the fission source convergence with stable convergence behavior while obtaining multiple higher eigenmodes at the same time. The advantages of the new strategy can be summarized as 1) the replacement of the cumbersome solution step of high order polynomial equations required by Booth's original method with the simple matrix eigen decomposition, 2) faster fission source convergence in inactive cycles, 3) more stable behaviors in both inactive and active cycles, and 4) smaller variances in active cycles. Advantages 3 and 4 can be attributed to the lower sensitivity of the new strategy to statistical fluctuations due to the multi-cycle accumulations. The application of the modified power method to continuous energy Monte Carlo simulation and the higher eigenmodes up to 4th order are reported for the first time in this paper. -- Graphical abstract: -- Highlights: •Modified power method is applied to continuous energy Monte Carlo simulation. •Transfer matrix is introduced to generalize the modified power method. •All mode based population control is applied to get the higher eigenmodes. •Statistic fluctuation can be greatly reduced using accumulated tally results. •Fission source convergence is accelerated with higher mode solutions.

  3. Networked and Distributed Control Method with Optimal Power Dispatch for Islanded Microgrids

    DEFF Research Database (Denmark)

    Li, Qiang; Peng, Congbo; Chen, Minyou

    2017-01-01

    of controllable agents. The distributed control laws derived from the first subgraph guarantee the supply-demand balance, while further control laws from the second subgraph reassign the outputs of controllable distributed generators, which ensure active and reactive power are dispatched optimally. However...... according to our proposition. Finally, the method is evaluated over seven cases via simulation. The results show that the system performs as desired, even if environmental conditions and load demand fluctuate significantly. In summary, the method can rapidly respond to fluctuations resulting in optimal...

  4. Dual stage active magnetic regenerator and method

    Science.gov (United States)

    Pecharsky, Vitalij K.; Gschneidner, Jr., Karl A.

    1999-03-30

    A dual stage active magnetic regenerator refrigerator as well as method using the Joule-Brayton thermodynamic cycle includes a high temperature stage refrigerant comprising DyAl.sub.2 or (Dy.sub.1-x Er.sub.x)Al.sub.2 where x is selected to be greater than 0 and less than about 0.3 in combination with a low temperature stage comprising (Dy.sub.1-x Er.sub.x)Al.sub.2 where x is selected to be greater than about 0.5 and less than 1 to provide significantly improved refrigeration efficiency in the liquefaction of gaseous hydrogen.

  5. Short-Term Wind Power Forecasting Using the Enhanced Particle Swarm Optimization Based Hybrid Method

    OpenAIRE

    Wen-Yeau Chang

    2013-01-01

    High penetration of wind power in the electricity system provides many challenges to power system operators, mainly due to the unpredictability and variability of wind power generation. Although wind energy may not be dispatched, an accurate forecasting method of wind speed and power generation can help power system operators reduce the risk of an unreliable electricity supply. This paper proposes an enhanced particle swarm optimization (EPSO) based hybrid forecasting method for short-term wi...

  6. Analysis and Assessment of Operation Risk for Hybrid AC/DC Power System based on the Monte Carlo Method

    Science.gov (United States)

    Hu, Xiaojing; Li, Qiang; Zhang, Hao; Guo, Ziming; Zhao, Kun; Li, Xinpeng

    2018-06-01

    Based on the Monte Carlo method, an improved risk assessment method for hybrid AC/DC power system with VSC station considering the operation status of generators, converter stations, AC lines and DC lines is proposed. According to the sequential AC/DC power flow algorithm, node voltage and line active power are solved, and then the operation risk indices of node voltage over-limit and line active power over-limit are calculated. Finally, an improved two-area IEEE RTS-96 system is taken as a case to analyze and assessment its operation risk. The results show that the proposed model and method can intuitively and directly reflect the weak nodes and weak lines of the system, which can provide some reference for the dispatching department.

  7. Analysis and Assessment of Operation Risk for Hybrid AC/DC Power System based on the Monte Carlo Method

    Directory of Open Access Journals (Sweden)

    Hu Xiaojing

    2018-01-01

    Full Text Available Based on the Monte Carlo method, an improved risk assessment method for hybrid AC/DC power system with VSC station considering the operation status of generators, converter stations, AC lines and DC lines is proposed. According to the sequential AC/DC power flow algorithm, node voltage and line active power are solved, and then the operation risk indices of node voltage over-limit and line active power over-limit are calculated. Finally, an improved two-area IEEE RTS-96 system is taken as a case to analyze and assessment its operation risk. The results show that the proposed model and method can intuitively and directly reflect the weak nodes and weak lines of the system, which can provide some reference for the dispatching department.

  8. Coordinated Volt/Var Control in Distribution Systems with Distributed Generations Based on Joint Active and Reactive Powers Dispatch

    Directory of Open Access Journals (Sweden)

    Abouzar Samimi

    2016-01-01

    Full Text Available One of the most significant control schemes in optimal operation of distribution networks is Volt/Var control (VVC. Owing to the radial structure of distribution systems and distribution lines with a small X/R ratio, the active power scheduling affects the VVC issue. A Distribution System Operator (DSO procures its active and reactive power requirements from Distributed Generations (DGs along with the wholesale electricity market. This paper proposes a new operational scheduling method based on a joint day-ahead active/reactive power market at the distribution level. To this end, based on the capability curve, a generic reactive power cost model for DGs is developed. The joint active/reactive power dispatch model presented in this paper motivates DGs to actively participate not only in the energy markets, but also in the VVC scheme through a competitive market. The proposed method which will be performed in an offline manner aims to optimally determine (i the scheduled active and reactive power values of generation units; (ii reactive power values of switched capacitor banks; and (iii tap positions of transformers for the next day. The joint active/reactive power dispatch model for daily VVC is modeled in GAMS and solved with the DICOPT solver. Finally, the plausibility of the proposed scheduling framework is examined on a typical 22-bus distribution test network over a 24-h period.

  9. Method of reducing the radioactivity in nuclear power plants

    International Nuclear Information System (INIS)

    Ohashi, Kenya; Honda, Takashi; Furutani, Yasumasa; Kashimura, Eiji; Minato, Akira; Osumi, Katsumi.

    1986-01-01

    Purpose: To reduce the radioactivity in nuclear power plants in contact with pure water at high temperature and high pressure. Method: For suppressing the deposition of radioactive materials in nuclear reactor coolants to the structural materials, oxide layers which are relatively porous but have a sufficient layer thickness are formed as the primary treatment and then thin but dense layers are formed as the secondary treatment. Oxidization is applied by means of heated water or steams with less oxidizing property in the first treatment, while oxidizing treatment is applied with heated water and steams at high oxidizing property in the second treatment, because the effect of suppressing corrosion is insufficient only by means of the membranes in the primary treatment, while the layers formed by the secondary treatment alone are liable to be injured and degraded. Since coolants for use in BWR type reactors usually contain about 200 ppb of dissolved oxygen, it is desirably from 40 to 100 ppb for the primary treatment and from 400 ppb to 8 ppb for the secondary treatment, and non-oxidating heated gases at high purity such as Ar, N 2 , He may be used in addition to heated water and steams. (Kawakami, Y.)

  10. BWR type nuclear power plants and its operation method

    International Nuclear Information System (INIS)

    Shimura, Akira; Toshimitsu, Satoshi.

    1984-01-01

    Purpose: To improve the soundness of facilities by decreasing the dissolved oxygen density in primary coolants which causes stress corrosion crackings in pipelines or the likes upon reactor start-up. Method: After starting-up a condensate recycling pump and initiating the sealing for the gland seal portion in a turbine, the inside pressure of the main condenser is rendered negative by a condenser evacuating device. Then, recycling and agitation for the primary coolants in a pressure vessel of the nuclear reactor are started by the recycling pump, recycling and agitation for the coolants in the main condenser are further effected to promote the removal of dissolved oxygen in the primary coolants in the main condenser and the feedwater pipelines. Then, the upper space in the reactor pressure vessel is communicated with the main condenser. Then the substantial power-up is performed by the withdrawal of control rods while monitoring the dissolved oxygen density in the primary coolants within the pressure vessel, so that it may be kept as far as possible from the dangerous region for stress corrosions. (Yoshino, Y.)

  11. A Reliability-Oriented Design Method for Power Electronic Converters

    DEFF Research Database (Denmark)

    Wang, Huai; Zhou, Dao; Blaabjerg, Frede

    2013-01-01

    Reliability is a crucial performance indicator of power electronic systems in terms of availability, mission accomplishment and life cycle cost. A paradigm shift in the research on reliability of power electronics is going on from simple handbook based calculations (e.g. models in MIL-HDBK-217F h...... and reliability prediction models are provided. A case study on a 2.3 MW wind power converter is discussed with emphasis on the reliability critical component IGBT modules....

  12. Active Photonic crystal fibers for high power applications

    DEFF Research Database (Denmark)

    Olausson, Christina Bjarnal Thulin

    The photonic crystal ber technology provides means to realize bers optimized for high power operation, due to the large single-mode cores and the unique design exibility of the microstructure. The work presented in this thesis focuses on improving the properties of active photonic crystal bers...... contributed to the compounding of new and improved material compositions. The second part is an investigation of pump absorption in photonic crystal bers, demonstrating that the microstructure in photonic crystal bers improves the pump absorption by up to a factor of two compared to step-index bers....... This plays an important role in high power lasers and ampliers with respect to efficiency, packaging, and thermal handling. The third part of the work has involved developing tools for characterizing the mode quality and stability of large core bers. Stable, single-mode bers with larger cores are essential...

  13. Effect of Heat Generation of Ultrasound Transducer on Ultrasonic Power Measured by Calorimetric Method

    Science.gov (United States)

    Uchida, Takeyoshi; Kikuchi, Tsuneo

    2013-07-01

    Ultrasonic power is one of the key quantities closely related to the safety of medical ultrasonic equipment. An ultrasonic power standard is required for establishment of safety. Generally, an ultrasonic power standard below approximately 20 W is established by the radiation force balance (RFB) method as the most accurate measurement method. However, RFB is not suitable for high ultrasonic power because of thermal damage to the absorbing target. Consequently, an alternative method to RFB is required. We have been developing a measurement technique for high ultrasonic power by the calorimetric method. In this study, we examined the effect of heat generation of an ultrasound transducer on ultrasonic power measured by the calorimetric method. As a result, an excessively high ultrasonic power was measured owing to the effect of heat generation from internal loss in the transducer. A reference ultrasound transducer with low heat generation is required for a high ultrasonic power standard established by the calorimetric method.

  14. Locomotor adaptation to a powered ankle-foot orthosis depends on control method

    Directory of Open Access Journals (Sweden)

    Gordon Keith E

    2007-12-01

    Full Text Available Abstract Background We studied human locomotor adaptation to powered ankle-foot orthoses with the intent of identifying differences between two different orthosis control methods. The first orthosis control method used a footswitch to provide bang-bang control (a kinematic control and the second orthosis control method used a proportional myoelectric signal from the soleus (a physiological control. Both controllers activated an artificial pneumatic muscle providing plantar flexion torque. Methods Subjects walked on a treadmill for two thirty-minute sessions spaced three days apart under either footswitch control (n = 6 or myoelectric control (n = 6. We recorded lower limb electromyography (EMG, joint kinematics, and orthosis kinetics. We compared stance phase EMG amplitudes, correlation of joint angle patterns, and mechanical work performed by the powered orthosis between the two controllers over time. Results During steady state at the end of the second session, subjects using proportional myoelectric control had much lower soleus and gastrocnemius activation than the subjects using footswitch control. The substantial decrease in triceps surae recruitment allowed the proportional myoelectric control subjects to walk with ankle kinematics close to normal and reduce negative work performed by the orthosis. The footswitch control subjects walked with substantially perturbed ankle kinematics and performed more negative work with the orthosis. Conclusion These results provide evidence that the choice of orthosis control method can greatly alter how humans adapt to powered orthosis assistance during walking. Specifically, proportional myoelectric control results in larger reductions in muscle activation and gait kinematics more similar to normal compared to footswitch control.

  15. Method and apparatus to provide power conversion with high power factor

    Energy Technology Data Exchange (ETDEWEB)

    Perreault, David J.; Lim, Seungbum; Otten, David M.

    2017-05-23

    A power converter circuit rectifies a line voltage and applies the rectified voltage to a stack of capacitors. Voltages on the capacitors are coupled to a plurality of regulating converters to be converted to regulated output signals. The regulated output signals are combined and converted to a desired DC output voltage of the power converter. Input currents of the regulating converters are modulated in a manner that enhances the power factor of the power converter.

  16. Feedback Linearization Control of a Shunt Active Power Filter Using a Fuzzy Controller

    Directory of Open Access Journals (Sweden)

    Tianhua Li

    2013-09-01

    Full Text Available In this paper, a novel feedback linearization based sliding mode controlled parallel active power filter using a fuzzy controller is presented in a three-phase three-wire grid. A feedback linearization control with fuzzy parameter self-tuning is used to implement the DC side voltage regulation while a novel integral sliding mode controller is applied to reduce the total harmonic distortion of the supply current. Since traditional unit synchronous sinusoidal signal calculation methods are not applicable when the supply voltage contains harmonics, a novel unit synchronous sinusoidal signal computing method based on synchronous frame transforming theory is presented to overcome this disadvantage. The simulation results verify that the DC side voltage is very stable for the given value and responds quickly to the external disturbance. A comparison is also made to show the advantages of the novel unit sinusoidal signal calculating method and the super harmonic treatment property of the designed active power filter.

  17. Chicago section activities to enhance public acceptance of nuclear power

    International Nuclear Information System (INIS)

    Snyder, T.L.; Keffer, J.W.

    1992-01-01

    The Chicago section of the American Nuclear Society (ANS) is an active organization with ∼450 members. The local section territory encompasses northern Illinois and includes in its territory all six of Commonwealth Edison Company's (CECo's) nuclear generating stations as well as Argonne National Laboratory (ANL). Included in the territory are several large engineering firms - ABB Impell, Bechtel, Fluor Daniel, and Sargent ampersand Lundy. The national headquarters of the ANS is also located within the local section boundaries. All these organizations are represented in the local section membership and provide access to abundant technical resources that can be used to enhance public acceptance of nuclear power. An important attribute of any local section that enables it to perform interesting programs and be active in the community is its financial resources. The Chicago section has a strong financial base because of its ability to raise funds by participating in and sponsoring ANS topical and other meetings. For instance, in 1991, they sponsored and were actively involved in the Emergency Preparedness Topical Meeting held in Chicago. In 1992, they were actively involved in sponsoring the organizational activities of the ANS/ENS International Meeting, which will celebrate the 50th year of nuclear fission. The financial and technical resources of the Chicago section continue to contribute to a successful program of public education and public acceptance activities regarding the nuclear industry

  18. Organization and management activities in the nuclear power industry

    International Nuclear Information System (INIS)

    Evans, R.C.; Whitesel, R.N.

    1994-01-01

    The purpose of organization and management development activities in the commercial nuclear power industry is to foster high levels of power plant performance and safety through improved human performance. The NRC has been working to develop assessment tools to assay the effects of organizational factors on plant safety. The utility industry has been working on initiatives targeting individual accountability, the improvement of plant performance and the elimination of the items identified through the NRC assessment process. Organization and management activities do not focus on industry organizational charts, but on the personnel processes and dimensions (factors) that affect safety and economic performance. As individual terms these activities are often combined and referred to as organizational factors. As an area of study, organizational factors has become more prominent as the industry emphasis has switched in recent years from hardware issues related to safety and economics, to personnel-related issues. Beyond the obvious safety objectives affected by improved human performance, plant performance improvements, in areas such as capacity factors, can be achieved through improved human performance. For example, it is estimated that as many as half of the unplanned reactor scrams are caused by personnel errors. The integrated effect of these scram-initiating errors is conservatively estimated to be 100 lost capacity days per year. The financial impact of these events is estimated to be $100M per year

  19. Modular Bayesian Networks with Low-Power Wearable Sensors for Recognizing Eating Activities.

    Science.gov (United States)

    Kim, Kee-Hoon; Cho, Sung-Bae

    2017-12-11

    Recently, recognizing a user's daily activity using a smartphone and wearable sensors has become a popular issue. However, in contrast with the ideal definition of an experiment, there could be numerous complex activities in real life with respect to its various background and contexts: time, space, age, culture, and so on. Recognizing these complex activities with limited low-power sensors, considering the power and memory constraints of the wearable environment and the user's obtrusiveness at once is not an easy problem, although it is very crucial for the activity recognizer to be practically useful. In this paper, we recognize activity of eating, which is one of the most typical examples of a complex activity, using only daily low-power mobile and wearable sensors. To organize the related contexts systemically, we have constructed the context model based on activity theory and the "Five W's", and propose a Bayesian network with 88 nodes to predict uncertain contexts probabilistically. The structure of the proposed Bayesian network is designed by a modular and tree-structured approach to reduce the time complexity and increase the scalability. To evaluate the proposed method, we collected the data with 10 different activities from 25 volunteers of various ages, occupations, and jobs, and have obtained 79.71% accuracy, which outperforms other conventional classifiers by 7.54-14.4%. Analyses of the results showed that our probabilistic approach could also give approximate results even when one of contexts or sensor values has a very heterogeneous pattern or is missing.

  20. Single-Phase Single-Stage Grid Tied Solar PV System with Active Power Filtering Using Power Balance Theory

    Science.gov (United States)

    Singh, Yashi; Hussain, Ikhlaq; Singh, Bhim; Mishra, Sukumar

    2018-03-01

    In this paper, power quality features such as harmonics mitigation, power factor correction with active power filtering are addressed in a single-stage, single-phase solar photovoltaic (PV) grid tied system. The Power Balance Theory (PBT) with perturb and observe based maximum power point tracking algorithm is proposed for the mitigation of power quality problems in a solar PV grid tied system. The solar PV array is interfaced to a single phase AC grid through a Voltage Source Converter (VSC), which provides active power flow from a solar PV array to the grid as well as to the load and it performs harmonics mitigation using PBT based control. The solar PV array power varies with sunlight and due to this, the solar PV grid tied VSC works only 8-10 h per day. At night, when PV power is zero, the VSC works as an active power filter for power quality improvement, and the load active power is delivered by the grid to the load connected at the point of common coupling. This increases the effective utilization of a VSC. The system is modelled and simulated using MATLAB and simulated responses of the system at nonlinear loads and varying environmental conditions are also validated experimentally on a prototype developed in the laboratory.

  1. Active power control strategies for inverter-based distributed power generation adapted to grid-fault ride-through requirements

    NARCIS (Netherlands)

    Wang, F.; Duarte, J.L.; Hendrix, M.A.M.

    2009-01-01

    Distributed power generation is expected to deliver power into the grid without interruption during voltage dips. To improve system ride-through capabilities, a generalized active power control strategy is proposed for grid-interfacing inverters. Specifically, a current reference generation strategy

  2. Methods of marketing and advertising activity evaluation

    Directory of Open Access Journals (Sweden)

    A.I. Yakovlev

    2016-09-01

    Full Text Available The result of the business entities’ activities is associated with the development of instruments of the economic processes efficiency determination, including marketing activities. It has determined the purpose of the article. The methodological principles in this area are developed. It is proved that the increase in sales of the profit margin is only partly dependent on the implementation of advertising measures. The methodical approaches for estimation of exhibition and advertising activity and promotion of its employees are specified. The results of work involve evaluation of the advertising effect value on the basis of share of the advertising impact on the increase of sales and revenue from the sale of products. The corresponding proportion of such impact is determined based on the consumer inquiry. The index of trade fair works, its calculation based on two components: how many times a specific company participated in such events; and how well the company was presented at relevant trade fairs. The indices of the cost on advertising and promotion of certain products manufacturer are provided. The scientific innovation of the research is as follows. It is proved that the sales increase effect should not be assigned to advertising only. The compositions that influence the consumer preferences and their share in the total value effect are determined. The new is the proposed index of influence of the trade fair work results depending on the selected factors. The practical importance of the research results involve more accurate calculation of the effect of the activities made and, consequently, increase efficiency of the business entities.

  3. Active Participation of Air Conditioners in Power System Frequency Control Considering Users’ Thermal Comfort

    Directory of Open Access Journals (Sweden)

    Rongxiang Zhang

    2015-09-01

    Full Text Available Air conditioners have great potential to participate in power system frequency control. This paper proposes a control strategy to facilitate the active participation of air conditioners. For each air conditioner, a decentralized control law is designed to adjust its temperature set point in response to the system frequency deviation. The decentralized control law accounts for the user’s thermal comfort that is evaluated by a fuzzy algorithm. The aggregation of air conditioners’ response is conducted by using the Monte Carlo simulation method. A structure preserving model is applied to the multi-bus power system, in which air conditioners are aggregated at certain load buses. An inner-outer iteration scheme is adopted to solve power system dynamics. An experiment is conducted on a test air conditioner to examine the performance of the proposed decentralized control law. Simulation results on a test power system verify the effectiveness of the proposed strategy for air conditioners participating in frequency control.

  4. PULSE MODULATION POWER AMPLIFIER WITH ENHANCED CASCADE CONTROL METHOD

    DEFF Research Database (Denmark)

    1998-01-01

    a single local feedback path A (7) with a lowpass characteristic and local forward blocks B¿1? or B (3, 4). The leads to a much improved system with a very low sensitivity to errors in the switching power stage. In the second preferred embodiment of the invention the control structure is extended...... and feedback path A to determine stable self-oscillating conditions. An implemented 250W example MECC digital power amplifier has proven superior performance in terms of audio performance (0.005 % distortion, 115 dB dynamic range) and efficiency (92 %).......A digital switching power amplifier with Multivariable Enhanced Cascade Controlled (MECC) includes a modulator, a switching power stage and a low pass filter. In the first preferred embodiment an enhanced cascade control structure local to the switching power stage is added, characterised by having...

  5. Removing radio-active wastes from nuclear power stations by the STEAG system

    International Nuclear Information System (INIS)

    Baatz, H.

    1978-01-01

    The mobile STEAG System for conditioning radio-active wastes from nuclear power stations represents a particularly safe and economic method of removing them in present day conditions. Cementation by the FAFNIR System is used for the greater part of the waste, the liquid concentrate (evaporator concentrate and filter slurry). For the special case of the medium active resin balls from the primary circuits, embedding in plastic by the FAMA process has proved to be the only available successful process so far. The highly active solid waste from the reactor core is decomposed by the MOSAIK System, is packed in transportable and storable containers and is removed from the fuel element storage pond. The systems are so safe that faults or interruptions of power station operation due to faults in removing radio-active wastes can be excluded. (orig.) [de

  6. Power Cycling Test Method for Reliability Assessment of Power Device Modules in Respect to Temperature Stress

    DEFF Research Database (Denmark)

    Choi, Ui-Min; Blaabjerg, Frede; Jørgensen, Søren

    2018-01-01

    Power cycling test is one of the important tasks to investigate the reliability performance of power device modules in respect to temperature stress. From this, it is able to predict the lifetime of a component in power converters. In this paper, representative power cycling test circuits......, measurement circuits of wear-out failure indicators as well as measurement strategies for different power cycling test circuits are discussed in order to provide the current state of knowledge of this topic by organizing and evaluating current literature. In the first section of this paper, the structure...... of a conventional power device module and its related wear-out failure mechanisms with degradation indicators are discussed. Then, representative power cycling test circuits are introduced. Furthermore, on-state collector-emitter voltage (VCE ON) and forward voltage (VF) measurement circuits for wear-out condition...

  7. The King's Return: The Mutation In Classical Division Of Powers By Judicialization Of Social Relations And Judicial Activism

    Directory of Open Access Journals (Sweden)

    Kelly de Souza Barbosa

    2017-02-01

    Full Text Available Separation of powers is one of strongest aspects of contemporary constitutionalism, mostly to rationalize the exercise of state power. In Brazil, the 1988 Constitution provides as entrenchment clause to tripartition of powers. However, there is a change in paradigms, especially at the level of constitutional jurisdiction, through the phenomena of judicialization and judicial activism because the intervention of the Judiciary in the primary functions of other powers. Using deductive and descriptive method, bibliographical and documentary research, we tried to point out the harms that the invasive action of the Judiciary causes to the functional balance between the powers and democracy.

  8. A method for analysis of nuclear power plant operators' decision making in simulated disturbance situations

    International Nuclear Information System (INIS)

    1995-01-01

    An analysis method has been developed for analysis of nuclear power plant operators' decision making in simulated disturbance situations. The aim of the analysis is to investigate operators' orientation which is expected to manifest itself as collective strategies in utilization of resources of decision making. Resources analyzed here are different information sources and, in addition, collaborative resources like communication and participation. The cognitive approach on the basis of the method considers decision making as collective construction of common interpretation of available information. Utilization of information is evaluated with respect to operative context. This is made with help of conceptualization of the disturbance situation from the decision making point of view and by construction of operative reference for activity. The latter means conceptualization of the situation from the safety point of view and also consideration of other boundary constraints of decision making, i.e. economical and technical aspects. The analysis method is intended to be used in routine simulator training in nuclear power plants. By virtue of its contextual and dynamical approach it makes the developing nature of activity visible. Cumulation and distribution of knowledge of decision making as developing activity, controlled by orientation and boundary constraints of process control, is expected to improve operational culture of a plant organization. (author). 2 refs, 1 fig

  9. Tooth Whitening And Temperature Rise With Two Bleaching Activation Methods

    International Nuclear Information System (INIS)

    Abu-ElMagd, D. M.; El-Sayad, I. I.; Abd El-Gawad, L. M.

    2009-01-01

    To measure the tooth whitening and the surface and Intrapulpal temperature increase in vitro on freshly extracted upper human central incisors after chemical, Zoom AP light and diode laser activated bleaching. Thirty caries-free upper human incisors were selected. Teeth were divided into three equal groups according to the methods of activation of the bleaching agent (n = 10). A whitening gel containing hydrogen peroxide was applied to the buccal surface of all teeth. Group I was bleached using chemically activated hydrogen peroxide gel, for three applications of 15 min each. Group II was bleached with high intensity advanced power Zoom activation light (Zoom AP), for three applications of 15 min each. Group III was bleached with diode laser activation technique, where the teeth were irradiated with 2 Watt diode laser for three applications of 30 sec each. The whitening degree was assessed using an image analysis system, while temperature rise was recorded using a thermocouple on the external tooth surface and Intrapulpal. The degree of whitening increased significantly in all groups. However, the percentage of whitening was not statistically significantly different between the three groups. In addition, group II showed statistically significant higher mean rise in both surface and pulp temperatures than group I and group III. Chemical bleaching produces the same whitening effect as Zoom AP light and laser, with no surface or pulpal temperature rise. Laser application is faster and produces less surface and pulp temperature increase than Zoom AP light. Diode laser used to activate bleaching gels is not considered dangerous to the vitality of dental pulp using power settings of 2 W.

  10. SMART core power control method by coolant temperature variation

    International Nuclear Information System (INIS)

    Lee, Chung Chan; Cho, Byung Oh

    2001-08-01

    SMART is a soluble boron-free integral type pressurized water reactor. Its moderator temperature coefficient (MTC) is strongly negative throughout the cycle. The purpose of this report is how to utilize the primary coolant temperature as a second reactivity control system using the strong negative MTC. The reactivity components associated with reactor power change are Doppler reactivity due to fuel temperature change, moderator temperature reactivity and xenon reactivity. Doppler reactivity and moderator temperature reactivity take effects almost as soon as reactor power changes. On the other hand, xenon reactivity change takes more than several hours to reach an equilibrium state. Therefore, coolant temperature at equilibrium state is chosen as the reference temperature. The power dependent reference temperature line is limited above 50% power not to affect adversely in reactor safety. To compensate transient xenon reactivity, coolant temperature operating range is expanded. The suggested coolant temperature operation range requires minimum control rod motion for 50% power change. For smaller power changes such as 25% power change, it is not necessary to move control rods to assure that fuel design limits are not exceeded

  11. Active Power Control with Undead-Band Voltage & Frequency Droop for HVDC Converters in Large Meshed DC Grids

    DEFF Research Database (Denmark)

    Vrana, Til Kristian; Zeni, Lorenzo; Fosso, Olav Bjarte

    A new control method for large meshed HVDC grids has been developed, which helps to keep the active power balance at the AC and the DC side. The method definition is kept wide, leaving the possibility for control parameter optimisation. Other known control methods can be seen as specific examples...

  12. ACTIVE AND PARTICIPATORY METHODS IN BIOLOGY: MODELING

    Directory of Open Access Journals (Sweden)

    Brînduşa-Antonela SBÎRCEA

    2011-01-01

    Full Text Available By using active and participatory methods it is hoped that pupils will not only come to a deeper understanding of the issues involved, but also that their motivation will be heightened. Pupil involvement in their learning is essential. Moreover, by using a variety of teaching techniques, we can help students make sense of the world in different ways, increasing the likelihood that they will develop a conceptual understanding. The teacher must be a good facilitator, monitoring and supporting group dynamics. Modeling is an instructional strategy in which the teacher demonstrates a new concept or approach to learning and pupils learn by observing. In the teaching of biology the didactic materials are fundamental tools in the teaching-learning process. Reading about scientific concepts or having a teacher explain them is not enough. Research has shown that modeling can be used across disciplines and in all grade and ability level classrooms. Using this type of instruction, teachers encourage learning.

  13. A simplified method of estimating noise power spectra

    International Nuclear Information System (INIS)

    Hanson, K.M.

    1998-01-01

    A technique to estimate the radial dependence of the noise power spectrum of images is proposed in which the calculations are conducted solely in the spatial domain of the noise image. The noise power spectrum averaged over a radial spatial-frequency interval is obtained form the variance of a noise image that has been convolved with a small kernel that approximates a Laplacian operator. Recursive consolidation of the image by factors of two in each dimension yields estimates of the noise power spectrum over that full range of spatial frequencies

  14. Methodology and conclusions of activation calculations of WWER-440 type nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Babcsány, Boglárka, E-mail: boglarka.babcsany@reak.bme.hu; Czifrus, Szabolcs; Fehér, Sándor

    2015-04-01

    Highlights: • Activation calculation of two WWER-440 type nuclear power plants. • Detailed description of the applied activation calculation methodology. • Graphical results for total activity and waste index categorization. • General conclusions for activation applicable in the case of PWR reactors. - Abstract: Activation calculations for two nuclear power plants of WWER-440 type have been performed by the authors in order to assist the decommissioning planning by assessing the radioactive inventory present at the time of and at different times after the final shutdown. According to related international literature and studies performed earlier by the authors, considering the activity more than 99% of this inventory is concentrated in the materials directly surrounding the reactor core, where the predominant evolution of radionuclides is generated by neutron induced nuclear reactions. In order to obtain the highest possible accuracy in modelling, three-dimensional Monte Carlo neutron transport calculations were performed. Besides the methods and models applied to these analyses, the paper also summarizes the results that can be generally applied to such nuclear power plant types. At the time of shutdown, the total activity of the stainless steel components is about 6 × 10{sup 16} Bq and 1.3 × 10{sup 17} Bq for the two NPPs considered. The biological shielding concrete constitutes approximately 7 × 10{sup 13} Bq and 1.1 × 10{sup 14} Bq.

  15. Basic study on dynamic reactive-power control method with PV output prediction for solar inverter

    Directory of Open Access Journals (Sweden)

    Ryunosuke Miyoshi

    2016-01-01

    Full Text Available To effectively utilize a photovoltaic (PV system, reactive-power control methods for solar inverters have been considered. Among the various methods, the constant-voltage control outputs less reactive power compared with the other methods. We have developed a constant-voltage control to reduce the reactive-power output. However, the developed constant-voltage control still outputs unnecessary reactive power because the control parameter is constant in every waveform of the PV output. To reduce the reactive-power output, we propose a dynamic reactive-power control method with a PV output prediction. In the proposed method, the control parameter is varied according to the properties of the predicted PV waveform. In this study, we performed numerical simulations using a distribution system model, and we confirmed that the proposed method reduces the reactive-power output within the voltage constraint.

  16. Safe operation of nuclear power plants - Is safety culture an adequate management method?

    International Nuclear Information System (INIS)

    Piirto, A.

    2012-01-01

    One of the characteristics of a good safety culture is a definable commitment to the improvement of safety behaviours and attitudes at all organisational levels. A second characteristic of an organisation with excellent safety culture is free and open communication. The general understanding has been that safety culture is a part of organisation culture. In addition to safety culture thinking, proactive programmes and displays of proactive work to improve safety are required. This work needs to include, qt a minimum, actions aiming at reducing human errors, the development of human error prevention tools, improvements in training, and the development of working methods and the organisation's activities. Safety depends not only on the technical systems, but also on the organisation. There is a need for better methods and tools for organisational assessment and development. Today there is universal acceptance of the significant impact that management and organisational factors have over the safety significance of complex industrial installations such as nuclear power plants. Many events with significant economic and public impact had causes that have been traced to management deficiencies. The objective of this study is development of new methods to increase safety of nuclear power plant operation. The research has been limited to commercial nuclear power plants that are intended for electrical power generation in Finland. Their production activities, especially operation and maintenance, are primarily reviewed from a safety point of view, as well as human performance and organisational factors perspective. This defines the scope and focus of the study. The research includes studies related to knowledge management and tacit knowledge in the project management context and specific studies related to transfer of tacit knowledge in the maintenance organization and transfer of tacit knowledge between workers of old generation and young generation. The empirical results

  17. Safe operation of nuclear power plants - Is safety culture an adequate management method?

    Energy Technology Data Exchange (ETDEWEB)

    Piirto, A.

    2012-07-01

    One of the characteristics of a good safety culture is a definable commitment to the improvement of safety behaviours and attitudes at all organisational levels. A second characteristic of an organisation with excellent safety culture is free and open communication. The general understanding has been that safety culture is a part of organisation culture. In addition to safety culture thinking, proactive programmes and displays of proactive work to improve safety are required. This work needs to include, qt a minimum, actions aiming at reducing human errors, the development of human error prevention tools, improvements in training, and the development of working methods and the organisation's activities. Safety depends not only on the technical systems, but also on the organisation. There is a need for better methods and tools for organisational assessment and development. Today there is universal acceptance of the significant impact that management and organisational factors have over the safety significance of complex industrial installations such as nuclear power plants. Many events with significant economic and public impact had causes that have been traced to management deficiencies. The objective of this study is development of new methods to increase safety of nuclear power plant operation. The research has been limited to commercial nuclear power plants that are intended for electrical power generation in Finland. Their production activities, especially operation and maintenance, are primarily reviewed from a safety point of view, as well as human performance and organisational factors perspective. This defines the scope and focus of the study. The research includes studies related to knowledge management and tacit knowledge in the project management context and specific studies related to transfer of tacit knowledge in the maintenance organization and transfer of tacit knowledge between workers of old generation and young generation. The empirical

  18. Total gamma activity measurements for determining the radioactivity of residual materials from nuclear power stations

    International Nuclear Information System (INIS)

    Auler, I.; Meyer, M.; Stickelmann, J.

    1995-01-01

    Large amounts of residual materials from retrofitting measures and from decommissioning of nuclear power stations shows such a weak level of radioactivity that they could be released after decision measurements. Expenses incurred with complex geometry cannot be taken with common methods. NIS developed a Release Measurement Facility (RMF) based on total gamma activity measurements especially for these kind of residual materials. The RMF has been applied for decision measurements in different nuclear power plants. Altogether about 2,000 Mg of various types of materials have been measured up to now. More than 90 % of these materials could be released 0 without any restriction after decision measurements

  19. New digital reference current generation for shunt active power filter under distorted voltage conditions

    Energy Technology Data Exchange (ETDEWEB)

    Abdusalam, Mohamed; Karimi, Shahram; Saadate, Shahrokh [Groupe de Recherche en Electrotechnique et Electronique de Nancy (GREEN), CNRS UMR 7037 (France); Poure, Philippe [Laboratoire d' Instrumentation Electronique de Nancy (LIEN), EA 3440, Universite Henri Poincare - Nancy Universite, B.P. 239, 54506 Vandoeuvre les Nancy Cedex (France)

    2009-05-15

    In this paper, a new reference current computation method suitable for shunt active power filter control under distorted voltage conditions is proposed. The active power filter control is based on the use of self-tuning filters (STF) for the reference current generation and on a modulated hysteresis current controller. This active filter is intended for harmonic compensation of a diode rectifier feeding a RL load under distorted voltage conditions. The study of the active filter control is divided in two parts. The first one deals with the harmonic isolator which generates the harmonic reference currents and is experimentally implemented in a DS1104 card of a DSPACE prototyping system. The second part focuses on the generation of the switching pattern of the inverter by using a modulated hysteresis current controller, implemented in an analogue card. The use of STF instead of classical extraction filters allows extracting directly the voltage and current fundamental components in the {alpha}-{beta} axis without phase locked loop (PLL). The performances are good even under distorted voltage conditions. First, the effectiveness of the new proposed method is mathematically studied and verified by computer simulation. Then, experimental results are presented using a DSPACE system associated with the analogue current controller for a real shunt active power filter. (author)

  20. Experiment of Power Supply Method for WLAN Sensor Using Both Energy Harvesting and Microwave Power Transmission

    International Nuclear Information System (INIS)

    Sakaguchi, K; Yamashita, S; Yamamoto, K; Nishio, T; Morikura, M; Huang, Y; Shinohara, N

    2014-01-01

    This paper proposes to improve effectiveness of supplying a sensor with energy using microwave power transmission (MPT) and energy harvesting (EH). The MPT duration should be as short as possible to avoid serious interference between the MPT and wireless local area network data transmission when co-channel operation of both microwave power transmission (MPT) and wireless data transmissions is performed. To shorten the MPT duration, we use multiple power sources such as an MPT source and an EH source to supply a sensor with power. Here, an overcharge or an energy shortage could occur at the sensor if the power supplied by both the MPT and EH sources is not adjusted appropriately. To solve this problem, the power supplied by multiple sources should be estimated precisely. In this paper, we propose a scheme for estimating the power supplied by multiple sources on the basis of an existing MPT scheduling system and then conducted an experiment using the scheme. From the experimental results, it is confirmed to estimate the power supplied by multiple sources successfully. In addition, the required MPT duration when the EH source is used is reduced compared to that when it is not used. Moreover, it is confirmed that the sensor station successfully estimates the power supplied by an MPT source and that by an EH source and adequately configures the MPT duration

  1. Current measurement method for characterization of fast switching power semiconductors with Silicon Steel Current Transformer

    DEFF Research Database (Denmark)

    Li, Helong; Beczkowski, Szymon; Munk-Nielsen, Stig

    2015-01-01

    This paper proposes a novel current measurement method with Silicon Steel Current Transformer (SSCT) for the characterization of fast switching power semiconductors. First, the existing current sensors for characterization of fast switching power semiconductors are experimentally evaluated...

  2. An innovative method for on-power radiometry of end-shields of nuclear power plants

    International Nuclear Information System (INIS)

    Kumar, Gaurav; Gupta, Pankaj; Nawal, Shriram; Gautam, Mahesh; Kakkar, Aman Deep; Yadav, Umed

    2012-01-01

    rise on retraction of roll-on-shield). The software is then configured to collect important radiological data viz. dose, dose rate, maximum and minimum dose rates, etc. for a specific period before auto-resetting of the system to collect another such data set. These data sets are recorded in a database on the laptop and are later used to map radiological information on the end-shields. To start-with, the main control room master clock and the laptop clocks were synchronized and the fuelling machine was moved to various identified locations on end-face. Simultaneously, the main control room master clock timings were noted w.r.t. locations of fuelling machine on end-face. Subsequently, the detailed sequential database collected from laptop was correlated with the recorded timing and locations. This information was then plotted in 2D/3D to visualize a precise radiation dose rate profile on end-face. These measurements were conducted effectively at low, moderate and full power of the reactor on several occasions to obtain baseline information. As a result of these exercises, a shielding weakness in the upper portion of one of the end-shield could be timely detected; its location was precisely identified and was addressed with negligible dose consumption. Such timely on-power measurements not only provide us with the confidence on effective implementation of equipment/systems, but also allow an early detection and addressal of a problem with almost no dose impact for the future. This setup can be integrated with robotic arms, manipulating devices, etc. for radiation dose rate profile measurement of highly active equipment/components. (author)

  3. Power conversion and control methods for renewable energy sources

    Science.gov (United States)

    Yu, Dachuan

    2005-07-01

    In recent years, there has been an increase in the use of renewable energy due to the growing concern over the pollution caused by fossil-fuel-based energy. Renewable energy sources, such as photovoltaic (PV) and fuel cell, can be used to enhance the safety, reliability, sustainability, and transmission efficiency of a power system. This dissertation focuses on the power conversion and control for two major renewable-energy sources: PV and fuel cell. Firstly, a current-based, maximum power-point tracking (MPPT) algorithm is proposed for PV energy. An economical converter system using the above scheme for converting the output from PV panels into 60 Hz AC voltage is developed and built. Secondly, a novel circuit model for the Proton Exchange Membrane (PEM) fuel-cell stack that is useful in the design and analysis of fuel-cell-based power systems is proposed. This Pspice-based model uses elements available in the Pspice library with some modifications to represent both the static and dynamic responses of a PEM fuel-cell module. The accuracy of the model is verified by comparing the simulation and experimental results. Thirdly, a DSP-controlled three-phase induction-motor drive using constant voltage over frequency is built and can be used in a fuel-cell automobile. A hydrogen sensor is used in the drive to both sound an alarm and shut down the inverter trigger pulses through the DSP. Finally, a hybrid power system consisting of PV panels and fuel cell is proposed and built. In the proposed system, PV panels can supply most of the power when the sunlight is available, and the excess power required by the load is supplied by a fuel cell. Load sharing between a fuel cell (FC) and the PV panel is investigated by both simulation and experiments.

  4. A novel maximum power point tracking method for PV systems using fuzzy cognitive networks (FCN)

    Energy Technology Data Exchange (ETDEWEB)

    Karlis, A.D. [Electrical Machines Laboratory, Department of Electrical & amp; Computer Engineering, Democritus University of Thrace, V. Sofias 12, 67100 Xanthi (Greece); Kottas, T.L.; Boutalis, Y.S. [Automatic Control Systems Laboratory, Department of Electrical & amp; Computer Engineering, Democritus University of Thrace, V. Sofias 12, 67100 Xanthi (Greece)

    2007-03-15

    Maximum power point trackers (MPPTs) play an important role in photovoltaic (PV) power systems because they maximize the power output from a PV system for a given set of conditions, and therefore maximize the array efficiency. This paper presents a novel MPPT method based on fuzzy cognitive networks (FCN). The new method gives a good maximum power operation of any PV array under different conditions such as changing insolation and temperature. The numerical results show the effectiveness of the proposed algorithm. (author)

  5. Method of determining remedial control actions for a power system in an insecure state

    DEFF Research Database (Denmark)

    2013-01-01

    A method of determining remedial control actions for a power system in an insecure and unstable operating condition is provided. The power system has a plurality of generators injecting power into a network and each generator has a generator injection impedance and a stability boundary in the inj......A method of determining remedial control actions for a power system in an insecure and unstable operating condition is provided. The power system has a plurality of generators injecting power into a network and each generator has a generator injection impedance and a stability boundary...

  6. Wind Farm Active Power Dispatch for Output Power Maximizing Based on a Wind Turbine Control Strategy for Load Minimizing

    DEFF Research Database (Denmark)

    Zhang, Baohua; Hu, Weihao; Hou, Peng

    2015-01-01

    Inclusion of the wake effect in the wind farm control design (WF) can increase the total captured power by wind turbines (WTs), which is usually implemented by derating upwind WTs. However, derating the WT without a proper control strategy will increase the structural loads, caused by operation...... in stall mode. Therefore, the WT control strategy for derating operation should be considered in the attempt at maximizing the total captured power while reducing structural loads. Moreover, electrical power loss on the transmission system inside a WF is also not negligible for maximizing the total output...... power of the WF. In this paper, an optimal active power dispatch strategy based on a WT derating strategy and considering the transmission loss is proposed for maximizing the total output power. The active power reference of each WT is chosen as the optimization variable. A partial swarm optimizing...

  7. Scaling factors for the activity determination of radioactive waste from nuclear power reactors

    International Nuclear Information System (INIS)

    Medici, Marcela A.; Piumetti, Elsa H.

    2007-01-01

    Specific information of the total activity and activity concentration of the radionuclides contained is required for conditioning, transporting and final disposal of radioactive waste. Due to the complexity associated to alpha and beta measurements for these emitters it is worldwide used, particularly in the case of heterogeneous radioactive waste, the Scaling Factor Method. As in other cases, inputs of the results of the analysis of waste samples taking from waste streams are necessary. The Scaling Factor Method is based on the determination of averaged correlations between the activity concentrations of Difficult to Measure (DTM) nuclides (i.e. alpha and beta emitters) and the activity concentration of easy to measure nuclides (i.e. strong gamma emitters) called Key Nuclides (KN). In the application of this method two phases may be identified: in the first one the degree of correlation between averaged activities of DTM and a given KN is verified, and specific Scaling Factors are derived for every DTM radionuclide. In the second stage the total activity and the activity concentration of the selected KN is determined in each waste item and, by applying the SFs obtained previously, the activities of DTM nuclides are calculated. It is concluded that this method is appropriate and cost-effective and it is stressed that it is only applicable while the Nuclear Power Reactor is in operation. (author)

  8. Ventricular activity cancellation in electrograms during atrial fibrillation with constraints on residuals' power.

    Science.gov (United States)

    Corino, Valentina D A; Rivolta, Massimo W; Sassi, Roberto; Lombardi, Federico; Mainardi, Luca T

    2013-12-01

    During atrial fibrillation (AF), cancellation of ventricular activity from atrial electrograms (AEG) is commonly performed by template matching and subtraction (TMS): a running template, built in correspondence of QRSs, is subtracted from the AEG to uncover atrial activity (AA). However, TMS can produce poor cancellation, leaving high-power residues. In this study, we propose to modulate the templates before subtraction, in order to make the residuals as similar as possible to the nearby atrial activity, avoiding high-power ones. The coefficients used to modulate the template are estimated by maximizing, via Multi-swarm Particle Swarm Optimization, a fitness function. The modulated TMS method (mTMS) was tested on synthetic and real AEGs. Cancellation performances were assessed using: normalized mean squared error (NMSE, computed on simulated data only), reduction of ventricular activity (VDR), and percentage of segments (PP) whose power was outside the standard range of the atrial power. All testings suggested that mTMS is an improvement over TMS alone, being, on simulated data, NMSE and PP significantly decreased while VDR significantly increased. Similar results were obtained on real electrograms (median values of CS1 recordings PP: 2.44 vs. 0.38 p < 0.001; VDR: 6.71 vs. 8.15 p < 0.001). Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

  9. Intelligent Electric Power Systems with Active-Adaptive Electric Networks: Challenges for Simulation Tools

    Directory of Open Access Journals (Sweden)

    Ufa Ruslan A.

    2015-01-01

    Full Text Available The motivation of the presented research is based on the needs for development of new methods and tools for adequate simulation of intelligent electric power systems with active-adaptive electric networks (IES including Flexible Alternating Current Transmission System (FACTS devices. The key requirements for the simulation were formed. The presented analysis of simulation results of IES confirms the need to use a hybrid modelling approach.

  10. Seismic qualification method of equipment for nuclear power plant

    International Nuclear Information System (INIS)

    Kim, J.S.; Choi, T.H.; Sulaimana, R.A.

    1995-01-01

    Safety related equipment installed in Korean Nuclear Power Plants are required to perform a safety function during and after a seismic event. To accomplish this safety function, they must be seismically qualified in accordance with the intent and requirements of the USNRC Reg. Guide 1.100 Rev. 02 and IEEE Std. 344-1987. This paper defines and summarizes acceptable criteria and procedures, based on the Korean experience, for seismic qualification of purchased equipment to be installed in a nuclear power plant. As such the paper is intended to be a concise reference by equipment designers, architectural engineering company and plant owners in uniform implementation of commitments to nuclear regulatory agencies such as the USNRC or Korea Institute of Nuclear Safety (KINS) relating to adequacy of seismic Category 1 equipment. Thus, the paper provides the methodologies which can be used for qualifying equipment for safely related service in Nuclear Power Plants in a cost effective manner

  11. Whole core calculations of power reactors by Monte Carlo method

    International Nuclear Information System (INIS)

    Nakagawa, Masayuki; Mori, Takamasa

    1993-01-01

    Whole core calculations have been performed for a commercial size PWR and a prototype LMFBR by using vectorized Monte Carlo codes. Geometries of cores were precisely represented in a pin by pin model. The calculated parameters were k eff , control rod worth, power distribution and so on. Both multigroup and continuous energy models were used and the accuracy of multigroup approximation was evaluated through the comparison of both results. One million neutron histories were tracked to considerably reduce variances. It was demonstrated that the high speed vectorized codes could calculate k eff , assembly power and some reactivity worths within practical computation time. For pin power and small reactivity worth calculations, the order of 10 million histories would be necessary. Required number of histories to achieve target design accuracy were estimated for those neutronic parameters. (orig.)

  12. Decentralized Method for Load Sharing and Power Management in a PV/Battery Hybrid Source Islanded Microgrid

    DEFF Research Database (Denmark)

    Karimi, Yaser; Oraee, Hashem; Golsorkhi, Mohammad

    2017-01-01

    This paper proposes a new decentralized power management and load sharing method for a photovoltaic based islanded microgrid consisting of various PV units, battery units and hybrid PV/battery units. Unlike the previous methods in the literature, there is no need to communication among the units......, the operation of each unit is divided into five states and modified active power-frequency droop functions are used according to operating states. The frequency level is used as trigger for switching between the states. Efficacy of the proposed method in different load, PV generation and battery conditions...... and the proposed method is not limited to the systems with separate PV and battery units or systems with only one hybrid unit. The proposed method takes into account the available PV power and battery conditions of the units to share the load among them. To cover all possible conditions of the microgrid...

  13. Combined-cycle power plant. 500 MW on a single shaft. Active stability improvement of the compressor - methods of analysis. Final report; GuD-Kraftwerk, 500 MW auf einer Welle. Aktive Stabilitaetsverbesserung am Verdichter - Analyseverfahren. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Stoff, H.; Methling, F.O.

    2002-07-01

    Various analysis techniques are tested as possible stall and surge avoidance monitoring systems on high-speed axial compressors. Measurements were taken in a 4-stage transonic compressor with igv in the region of stable operation as well as approaching and crossing the surge line with fully developed rotating stall. The measurements contain the static wall pressure in front of each blade row. Artificial neural networks, Fourier techniques and cepstral analysis are investigated. The different methods are checked on a single sensor signal to reduce the instrumentational effort. Using the cepstral analysis a characteristic parameter is calculated which is valid in all investigated regions of operation of the compressor. This characteristic parameter is based on the blade passing frequency, i.e. in the terms of cepstral analysis it is the intensity of the fundamental component as well as the intensities of all its higher harmonics which are covered by the sensor signal. (orig.)

  14. PA activity by using nuclear power plant safety demonstration and analysis

    International Nuclear Information System (INIS)

    Tsuchiya, Mitsuo; Kamimae, Rie

    1999-01-01

    INS/NUPEC presents one of Public acceptance (PA) methods for nuclear power in Japan, 'PA activity by using Nuclear Power Plant Safety Demonstration and Analysis', by using one of videos which is explained and analyzed accident events (Loss of Coolant Accident). Safety regulations of The National Government are strictly implemented in licensing at each of basic design and detailed design. To support safety regulation activities conducted by the National Government, INS/NLTPEC continuously implement Safety demonstration and analysis. With safety demonstration and analysis, made by assuming some abnormal conditions, what impacts could be produced by the assumed conditions are forecast based on specific design data on a given nuclear power plants. When analysis results compared with relevant decision criteria, the safety of nuclear power plants is confirmed. The decision criteria are designed to help judge if or not safety design of nuclear power plants is properly made. The decision criteria are set in the safety examination guidelines by taking sufficient safety allowance based on the latest technical knowledge obtained from a wide range of tests and safety studies. Safety demonstration and analysis is made by taking the procedure which are summarized in this presentation. In Japan, various PA (Public Acceptance) pamphlets and videos on nuclear energy have been published. But many of them focused on such topics as necessity or importance of nuclear energy, basic principles of nuclear power generation, etc., and a few described safety evaluation particularly of abnormal and accident events in accordance with the regulatory requirements. In this background, INS/NUPEC has been making efforts to prepare PA pamphlets and videos to explain the safety of nuclear power plants, to be simple and concrete enough, using various analytical computations for abnormal and accident events. In results, PA activity of INS/NUPEC is evaluated highly by the people

  15. Advanced construction methods for new nuclear power plants

    International Nuclear Information System (INIS)

    Bilbao y Leon, Sama; Cleveland, John; Moon, Seong-Gyun; Tyobeka, Bismark

    2009-01-01

    The length of the construction and commissioning phases of nuclear power plants have historically been longer than for conventional fossil fuelled plants, often having a record of delays and cost overruns as a result from several factors including legal interventions and revisions of safety regulations. Recent nuclear construction projects however, have shown that long construction periods for nuclear power plants are no longer the norm. While there are several inter-related factors that influence the construction time, the use of advanced construction techniques has contributed significantly to reducing the construction length of recent nuclear projects. (author)

  16. Application of modern SHM methods in electric power industry

    Energy Technology Data Exchange (ETDEWEB)

    Gasior, Pawel; Kaleta, Jerzy [Wroclaw Univ. of Technolgy (Poland); Przygoda, Aleksander [RAFAKO S.A., Raciborz (Poland)

    2012-07-01

    In this paper an application of up-to-date Structural Health Monitoring systems based mainly on optical fibre sensors for various applications in power plants is presented. Real working solutions and ideas of the SHM systems were applied to fluid power boilers, installations of environmental protection (the so called desulphurisation systems) and main frames of construction (130m high). The measured values were compared with the design ones, as well as with the calculated values. It enabled evaluation of the inhomogeneous loads distribution and increased safety of the construction during its repair and operation. (orig.)

  17. Radioactive waste processing method for a nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Y; Kuriyama, O

    1976-06-04

    Object is to subject radioactive liquid waste in a nuclear power plant to reverse permeation process after which it is vaporized and concentrated thereby decreasing the quantity of foam to be used to achieve effective concentration of the liquid waste. Liquid waste containing a radioactive material produced from a nuclear power plant is first applied with pressure in excess of osmotic pressure by a reverse permeation device and is separated into clean water and concentrated liquid by semi-permeable membrane. Next, the thus reverse-permeated and concentrated waste is fed to an evaporator which control foaming by the foam and then further reconcentrated for purification of the liquid waste.

  18. Development of a New Safety Culture Assessment Method for Nuclear Power Plants (NPPs) (A study to suggest a new safety culture assessment method in nuclear power plants)

    Energy Technology Data Exchange (ETDEWEB)

    Han, Sang Min; Seong, Poong Hyun [KAIST, Daejeon (Korea, Republic of)

    2014-08-15

    This study is conducted to suggest a new safety culture assessment method in nuclear power plants. Criteria with various existing safety culture analysis methods are united, and reliability analysis methods are applied. The concept of the most representative methods, Fault Tree Analysis (FTA) and Failure Mode and Effect Analysis (FMEA), are adopted to assess safety culture. Through this application, it is expected that the suggested method will bring results with convenience and objectiveness.

  19. Development of a New Safety Culture Assessment Method for Nuclear Power Plants (NPPs) (A study to suggest a new safety culture assessment method in nuclear power plants)

    International Nuclear Information System (INIS)

    Han, Sang Min; Seong, Poong Hyun

    2014-01-01

    This study is conducted to suggest a new safety culture assessment method in nuclear power plants. Criteria with various existing safety culture analysis methods are united, and reliability analysis methods are applied. The concept of the most representative methods, Fault Tree Analysis (FTA) and Failure Mode and Effect Analysis (FMEA), are adopted to assess safety culture. Through this application, it is expected that the suggested method will bring results with convenience and objectiveness

  20. A New Control Method to Mitigate Power Fluctuations for Grid Integrated PV/Wind Hybrid Power System Using Ultracapacitors

    Science.gov (United States)

    Jayalakshmi, N. S.; Gaonkar, D. N.

    2016-08-01

    The output power obtained from solar-wind hybrid system fluctuates with changes in weather conditions. These power fluctuations cause adverse effects on the voltage, frequency and transient stability of the utility grid. In this paper, a control method is presented for power smoothing of grid integrated PV/wind hybrid system using ultracapacitors in a DC coupled structure. The power fluctuations of hybrid system are mitigated and smoothed power is supplied to the utility grid. In this work both photovoltaic (PV) panels and the wind generator are controlled to operate at their maximum power point. The grid side inverter control strategy presented in this paper maintains DC link voltage constant while injecting power to the grid at unity power factor considering different operating conditions. Actual solar irradiation and wind speed data are used in this study to evaluate the performance of the developed system using MATLAB/Simulink software. The simulation results show that output power fluctuations of solar-wind hybrid system can be significantly mitigated using the ultracapacitor based storage system.

  1. Scalable power selection method for wireless mesh networks

    CSIR Research Space (South Africa)

    Olwal, TO

    2009-01-01

    Full Text Available This paper addresses the problem of a scalable dynamic power control (SDPC) for wireless mesh networks (WMNs) based on IEEE 802.11 standards. An SDPC model that accounts for architectural complexities witnessed in multiple radios and hops...

  2. Probabilistic methods in nuclear power plant component ageing analysis

    International Nuclear Information System (INIS)

    Simola, K.

    1992-03-01

    The nuclear power plant ageing research is aimed to ensure that the plant safety and reliability are maintained at a desired level through the designed, and possibly extended lifetime. In ageing studies, the reliability of components, systems and structures is evaluated taking into account the possible time- dependent decrease in reliability. The results of analyses can be used in the evaluation of the remaining lifetime of components and in the development of preventive maintenance, testing and replacement programmes. The report discusses the use of probabilistic models in the evaluations of the ageing of nuclear power plant components. The principles of nuclear power plant ageing studies are described and examples of ageing management programmes in foreign countries are given. The use of time-dependent probabilistic models to evaluate the ageing of various components and structures is described and the application of models is demonstrated with two case studies. In the case study of motor- operated closing valves the analysis are based on failure data obtained from a power plant. In the second example, the environmentally assisted crack growth is modelled with a computer code developed in United States, and the applicability of the model is evaluated on the basis of operating experience

  3. Method of disposing of shut-down nuclear power plants

    International Nuclear Information System (INIS)

    Gaiser, H.

    1984-01-01

    A shut-down atomic power plant or a section thereof, particularly the nuclear reactor, is disposed of by sinking it to below ground level by constructing a caisson with cutting edges from the foundations of said plant or section or by excavating a pit therebelow

  4. Power-dependent photocatalytic activity of ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Chun, So Yeon; Han, Noh Soo; Jeong, Seong Hyun; Park, Seung Min; Song, Jae Kyu [Dept. of Chemistry, Kyung Hee University, Seoul (Korea, Republic of); Moon, Cheol Joo; Choi, Myong Yong [Dept. of Chemistry (BK21) and Research Institute of Natural Science, Gyeongsang NationalUniversity, Jinju (Korea, Republic of)

    2017-03-15

    the power-dependent photocatalytic activity of ZnO was examined for the photoreduction processes of Rh101 and AN in the presence of hole scavengers, where the fluorescence spectra were measured as a function of irradiation time and excitation intensity. The concentration of the reactants decreased, while the concentration of the products increased accordingly, which indicated the single-electron reduction process by electrons supplied from the conduction band of ZnO. Despite the single-electron process, the efficiency of the photoreaction depended nonlinearly on the excitation intensity, which was explained by the saturation of defect states in ZnO. The enhanced ratio of available electrons in ZnO led to a superlinear increase in the photoreduction efficiency, while the single-electron process linearly reflected the electrons available in ZnO.

  5. Advanced nonlinear control of three phase series active power filter

    Directory of Open Access Journals (Sweden)

    Abouelmahjoub Y.

    2014-01-01

    Full Text Available The problem of controlling three-phase series active power filter (TPSAPF is addressed in this paper in presence of the perturbations in the voltages of the electrical supply network. The control objective of the TPSAPF is twofold: (i compensation of all voltage perturbations (voltage harmonics, voltage unbalance and voltage sags, (ii regulation of the DC bus voltage of the inverter. A controller formed by two nonlinear regulators is designed, using the Backstepping technique, to provide the above compensation. The regulation of the DC bus voltage of the inverter is ensured by the use of a diode bridge rectifier which its output is in parallel with the DC bus capacitor. The Analysis of controller performances is illustrated by numerical simulation in Matlab/Simulink environment.

  6. Adaptive Power Saving Method for Mobile Walking Guidance Device Using Motion Context

    Directory of Open Access Journals (Sweden)

    Jin-Hee Lee

    2015-01-01

    Full Text Available It is important to recognize the motion of the user and the surrounding environment with multiple sensors. We developed a guidance system based on mobile device for visually impaired person that helps the user to walk safely to the destination in the previous study. However, a mobile device having multiple sensors spends more power when the sensors are activated simultaneously and continuously. We propose a method for reducing the power consumption of a mobile device by considering the motion context of the user. We analyze and classify the user’s motion accurately by means of a decision tree and HMM (Hidden Markov Model that exploit the data from a triaxial accelerometer sensor and a tilt sensor. We can reduce battery power consumption by controlling the number of active ultrasonic sensors and the frame rate of the camera used to acquire spatial context around the user. This helps us to extend the operating time of the device and reduce the weight of the device’s built-in battery.

  7. A simple method for estimating the entropy of neural activity

    International Nuclear Information System (INIS)

    Berry II, Michael J; Tkačik, Gašper; Dubuis, Julien; Marre, Olivier; Da Silveira, Rava Azeredo

    2013-01-01

    The number of possible activity patterns in a population of neurons grows exponentially with the size of the population. Typical experiments explore only a tiny fraction of the large space of possible activity patterns in the case of populations with more than 10 or 20 neurons. It is thus impossible, in this undersampled regime, to estimate the probabilities with which most of the activity patterns occur. As a result, the corresponding entropy—which is a measure of the computational power of the neural population—cannot be estimated directly. We propose a simple scheme for estimating the entropy in the undersampled regime, which bounds its value from both below and above. The lower bound is the usual ‘naive’ entropy of the experimental frequencies. The upper bound results from a hybrid approximation of the entropy which makes use of the naive estimate, a maximum entropy fit, and a coverage adjustment. We apply our simple scheme to artificial data, in order to check their accuracy; we also compare its performance to those of several previously defined entropy estimators. We then apply it to actual measurements of neural activity in populations with up to 100 cells. Finally, we discuss the similarities and differences between the proposed simple estimation scheme and various earlier methods. (paper)

  8. Applying formal method to design of nuclear power plant embedded protection system

    International Nuclear Information System (INIS)

    Kim, Jin Hyun; Kim, Il Gon; Sung, Chang Hoon; Choi, Jin Young; Lee, Na Young

    2001-01-01

    Nuclear power embedded protection systems is a typical safety-critical system, which detects its failure and shutdowns its operation of nuclear reactor. These systems are very dangerous so that it absolutely requires safety and reliability. Therefore nuclear power embedded protection system should fulfill verification and validation completely from the design stage. To develop embedded system, various V and V method have been provided and especially its design using Formal Method is studied in other advanced country. In this paper, we introduce design method of nuclear power embedded protection systems using various Formal-Method in various respect following nuclear power plant software development guideline

  9. A Hybrid Estimator for Active/Reactive Power Control of Single-Phase Distributed Generation Systems with Energy Storage

    DEFF Research Database (Denmark)

    Pahlevani, Majid; Eren, Suzan; Guerrero, Josep M.

    2016-01-01

    This paper presents a new active/reactive power closed-loop control system for a hybrid renewable energy generation system used for single-phase residential/commercial applications. The proposed active/reactive control method includes a hybrid estimator, which is able to quickly and accurately es...

  10. Active Power Filter DC Bus Voltage Piecewise Reaching Law Variable Structure Control

    Directory of Open Access Journals (Sweden)

    Baolian Liu

    2014-01-01

    Full Text Available The DC bus voltage stability control is one key technology to ensure that Active Power Filter (APF operates stably. The external disturbances such as power grid and load fluctuation and the system parameters changing may affect the stability of APF DC bus voltage and the normal operation of APF. The mathematical model of DC bus voltage is established according to power balance principle and a DC bus voltage piecewise reaching law variable structure control algorithm is proposed to solve the above problem, and the design method is given. The simulation and experiment results proved that the proposed variable structure control algorithm can eliminate the chattering problem existing in traditional variable structure control effectively, is insensitive to system disturbance, and has good robustness and fast dynamic response speed and stable DC bus voltage with small fluctuation. The above advantages ensure the compensation effect of APF.

  11. Evolution in controls methods for the SPS power converters

    CERN Document Server

    Dinius, A H; Brazier, J C L

    1995-01-01

    In common with much accelerator specific material, there is a constant need to improve both hardware and software for power converter control. Maintenance and performance improvements of older systems have become extremely tedious and in some areas impossible. By using modern real-time software and the latest high-performance processors, such problems should be substantially reduced. This paper describes the software concepts and the hardware chosen for the upgrade of the existing facilities. Using the UNIX compatible LynxOS real time kernel, running on a PowerPC 603 in a VME environment, this new approach provides excellent performance while retaining the desired flexibility for future enhancements. The 64 channel system is implemented as a set of cooperating processes, several of which are multi-threaded. Processes include analogue function generation, analogue measurement and digital I/O, all of which are accurately scheduled by the accelerator timing system. This generalised structure, which performs comp...

  12. Method of nuclear power plant transition to partial loa

    International Nuclear Information System (INIS)

    Ilyunin, V.G.; Kuznetsov, I.A.; Murogov, V.M.; Shmelev, A.N.

    1977-01-01

    Five variants are proposed of a nuclear power plant with two reactors, of which one a breeder reactor, suitable for work under partial electrical load. Both reactors have a common secondary coolant circuit with a turbine, the breeder reactor operates at a lower coolant temperature in the primary coolant circuit than the other. In the transition of the power plant to the partial electrical load mode, the coolants of both reactors mix at a certain ratio. Heating of the turbine working medium is controlled so that the breeder reactor output increases rather than decreases. The breeding ratio is thereby also increased. Excess heat in the breeder reactor primary circuit is removed via a separate coolant circuit provided with a heat consumer. (Z.M.)

  13. Method of controlling power of a heavy water reactor

    International Nuclear Information System (INIS)

    Masuda, Hiroyuki.

    1975-01-01

    Object: To adjust a level of heavy water in a region of reflection body to control power in a heavy water reactor. Structure: The interior of a core tank filled with heavy water is divided by a partition into a core heavy water region and a reflection body region formed by surrounding the core heavy water region, and a level of heavy water within the reflection body region is adjusted to control power. Preferably, it is desirable to communicate the core heavy water region with the reflection body heavy water region at their lower portion, and gas pressure applied to an upper portion within at least one of said regions is adjusted to adjust the level of heavy water within the reflection body heavy water region. Thereby, the heavy water within the reflection body heavy water region may be introduced into the core region, thus requiring no tank which stores heavy water within the reflection body region. (Kamimura, M.)

  14. New methods of building WWER 1000 nuclear power plants

    International Nuclear Information System (INIS)

    Tadzher, O.

    1983-01-01

    The shortening of construction time needed for building the 5th unit of the Kozloduj nuclear power plant in Bulgaria is discussed. In the 2nd to 4th stages of construction the builders are expected to use the large CC-4000 mobile crane with high lifting power (Demag, FRG) for construction and assembly work. This work may be done by ''open'' assembly, i.e., the assembly of equipment in an unfinished building. By using the said crane it is possible to increase the weight of the individual units and thereby to reduce their number. The advantages of ''open'' assembly is that there is no need for a opecial transport corridor for the lifting and assembly of heavy handling units. A preliminary evaluation of the new technology has shown that assembly of the reactor hall equipment can be started 6 to 8 months ahead of schedule. (E.S.)

  15. Fast and precise method of contingency ranking in modern power system

    DEFF Research Database (Denmark)

    Rather, Zakir Hussain; Chen, Zhe; Thøgersen, Paul

    2011-01-01

    Contingency Analysis is one of the most important aspect of Power System Security Analysis. This paper presents a fast and precise method of contingency ranking for effective power system security analysis. The method proposed in this research work takes due consideration of both apparent power o...... is based on realistic approach taking practical situations into account. Besides taking real situations into consideration the proposed method is fast enough to be considered for on-line security analysis.......Contingency Analysis is one of the most important aspect of Power System Security Analysis. This paper presents a fast and precise method of contingency ranking for effective power system security analysis. The method proposed in this research work takes due consideration of both apparent power...

  16. Progressive building methods in nuclear power plant construction

    International Nuclear Information System (INIS)

    Sikura, V.

    1980-01-01

    A detailed description is given of the new prospective technologies used in the construction of the Bohunice V-1 nuclear power plant. They include the use of steel and large-area forms, the use of profile sheets as a substitute for forms, assembled raw partitions, wall shells consisting of clamped porous concrete slabs, assembled roof shells, special finish of concrete walls, bearing wall deep foundation, the use of modern building machinery for concreting, reinforcing and welding works. (M.S.)

  17. Optimal sizing method for stand-alone photovoltaic power systems

    Energy Technology Data Exchange (ETDEWEB)

    Groumpos, P P; Papageorgiou, G

    1987-01-01

    The total life-cycle cost of stand-alone photovoltaic (SAPV) power systems is mathematically formulated. A new optimal sizing algorithm for the solar array and battery capacity is developed. The optimum value of a balancing parameter, M, for the optimal sizing of SAPV system components is derived. The proposed optimal sizing algorithm is used in an illustrative example, where a more economical life-cycle cost has bene obtained. The question of cost versus reliability is briefly discussed.

  18. Method of calculating heat transfer in furnaces of small power

    Directory of Open Access Journals (Sweden)

    Khavanov Pavel

    2016-01-01

    Full Text Available This publication presents the experiences and results of generalization criterion equation of importance in the analysis of the processes of heat transfer and thermal calculations of low-power heat generators cooled combustion chambers. With generalizing depending estimated contribution of radiation and convective heat transfer component in the complex for the combustion chambers of small capacity boilers. Determined qualitative and quantitative dependence of the integrated radiative-convective heat transfer from the main factors working combustion chambers of small volume.

  19. Method for removing radioactive waste from a nuclear power plant

    International Nuclear Information System (INIS)

    1978-01-01

    By using the existing safety and auxiliary systems in a nuclear power plant a bunker-type building is to be linked up with the region of the main airlock, in which the radioactive material to be disposed of may pass through the necessary mechanical and chemical process while being handled in mobile containers. The constructional and engineering measures are described by a design example. (TK) [de

  20. Risk assessment of power systems models, methods, and applications

    CERN Document Server

    Li, Wenyuan

    2014-01-01

    Risk Assessment of Power Systems addresses the regulations and functions of risk assessment with regard to its relevance in system planning, maintenance, and asset management. Brimming with practical examples, this edition introduces the latest risk information on renewable resources, the smart grid, voltage stability assessment, and fuzzy risk evaluation. It is a comprehensive reference of a highly pertinent topic for engineers, managers, and upper-level students who seek examples of risk theory applications in the workplace.

  1. Transmutation and activation analysis of fusion power plants

    International Nuclear Information System (INIS)

    White, A.M.

    1985-01-01

    There are three principal objectives of this research: (1) development of an activation computer code that insures no important isotopes are neglected: (2) development of a linear chain code that enables one to compute the stable isotope inventory at all times; and (3) revision of the DCDLIB library using ACTL data. DKR is a computer code that uses the linear chain method to determine the activity, biological hazards potential, afterheat, and dose that will be present should a fusion reactor be constructed and operated. Unfortunately, this code terminates the chains with a strategy that can allow important chains to be neglected or not produced. To remedy this situation, the adjoint method of chain construction was developed. In this study, the adjoint operator is derived and the adjoint nuclide density equations are solved. The validity of using this method for the construction of chains is also demonstrated. A computer code, ANDYKAY, was developed that employs the adjoint method. The structure of this code is described and results obtained running this code in various configurations are given. The DKR and ANDYKAY codes are only capable of computing the radioactive isotope inventory. The code DKR-STABLE, which has been written to calculate the stable isotope inventory, is described. The results of a sample calculation performed using this code are given

  2. Equivalent Method of Integrated Power Generation System of Wind, Photovoltaic and Energy Storage in Power Flow Calculation and Transient Simulation

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The integrated power generation system of wind, photovoltaic (PV) and energy storage is composed of several wind turbines, PV units and energy storage units. The detailed model of integrated generation is not suitable for the large-scale powe.r system simulation because of the model's complexity and long computation time. An equivalent method for power flow calculation and transient simulation of the integrated generation system is proposed based on actual projects, so as to establish the foundation of such integrated system simulation and analysis.

  3. Comparison of different methods of calculating pinwise power

    International Nuclear Information System (INIS)

    Powers, M.A.

    1987-01-01

    One objective of a nuclear utility is the capability to predict the peak rod power in reload core design accurately and efficiently. This capability can be utilized in the verification of vendor results and the development of utility reload methodology. The MBS code solves the diffusion equation in x-y geometry by the finite different technique. The MBS code utilizes coarser meshes but reaches the same level of accuracy as a pin-by-pin model. The CASMO code utilizes pin profiles at specified core conditions, which are superimposed on the MBS diffusion theory results for pin power predictions. Placement of the burnable poison rods in the loading pattern are crucial to minimizing peak pin power. Westinghouse utilizes a code called TURTLE, licensed by the US Nuclear Regulatory Commission and proprietary to Westinghouse. The MBS code, with macroscopic cross sections from CASMO, can be run with coarser meshes and macroscopic depletion and still reach the same level of accuracy as a pin-by-pin code such as PDQ-7 or TURTLE. The MBS input preparation is simpler than PDQ-7 or TURTLE-type input preparation

  4. Hybrid Active Filter with Variable Conductance for Harmonic Resonance Suppression in Industrial Power Systems

    DEFF Research Database (Denmark)

    Lee, Tzung-Lin; Wang, Yen-Ching; Li, Jian-Cheng

    2015-01-01

    Unintentional series and/or parallel resonances, due to the tuned passive filter and the line inductance, may result in severe harmonic distortion in the industrial power system. This paper presents a hybrid active filter to suppress harmonic resonance and reduce harmonic distortion as well...... expensive. A reasonable trade-off between filtering performances and cost is to use the hybrid active filter. Design consideration are presented and experimental results are provided to validate effectiveness of the proposed method. Furthermore, this paper discusses filtering performances on line impedance...

  5. Fuzzy-predictive direct power control implementation of a grid connected photovoltaic system, associated with an active power filter

    International Nuclear Information System (INIS)

    Ouchen, Sabir; Betka, Achour; Abdeddaim, Sabrina; Menadi, Abdelkrim

    2016-01-01

    Highlights: • An implementation on dSPACE 1104 of a double stage grid connected photovoltaic system, associated with an active power filter. • A fuzzy logic controller for maximum power point tracking of photovoltaic generator using a boost converter. • Predictive direct power control almost eliminates the effect of harmonics under a unite power factor. • The robustness of control strategies was examined in different irradiance level conditions. - Abstract: The present paper proposes a real time implementation of an optimal operation of a double stage grid connected photovoltaic system, associated with a shunt active power filter. On the photovoltaic side, a fuzzy logic based maximum power point taking control is proposed to track permanently the optimum point through an adequate tuning of a boost converter regardless the solar irradiance variations; whereas, on the grid side, a model predictive direct power control is applied, to ensure both supplying a part of the load demand with the extracted photovoltaic power, and a compensation of undesirable harmonic contents of the grid current, under a unity power factor operation. The implementation of the control strategies is conducted on a small scale photovoltaic system, controlled via a dSPACE 1104 single card. The obtained experimental results show on one hand, that the proposed Fuzzy logic based maximum power taking point technique provides fast and high performances under different irradiance levels while compared with a sliding mode control, and ensures 1.57% more in efficiency. On the other hand, the predictive power control ensures a flexible settlement of active power amounts exchanges with the grid, under a unity power functioning. Furthermore, the grid current presents a sinusoidal shape with a tolerable total harmonic distortion coefficient 4.71%.

  6. Activities in the field of small nuclear power reactors

    Energy Technology Data Exchange (ETDEWEB)

    Baranaev, Yu.D.; Dolgov, V.V.; Sergeev, Yu.A. [Physics and Power Eng. Inst., Obninsk (Russian Federation). State Res. Centre

    1997-10-01

    Considerable efforts have been undertaken for development, design, construction and operation of small nuclear power plants (SNPP) in Russia. Systematic work in this area was started in the mid-1950s. The driving force for this activity was the awareness that the use of nuclear fuel would practically solve the problem of fuel transportation. As far as the remote northern regions are concerned, this provides the key advantage of nuclear over conventional energy sources. The activity in the field of SNPP has included pre-design analytical feasibility studies and experimental research including large-scale experiments on critical assemblies, thermal and hydraulic test facilities, research and development work, construction and operation of pilot and demonstration SNPPs, and finally, construction and more than 20 years of operation of the commercial SNPP, namely Bilibino nuclear co-generation plant (NCGP) located in Chukotka autonomous district, which is one of the most remote regions in the far north-east of Russia. In recent years, studies have been carried out on the development of several new SNPP designs using advanced reactors of the new generation. Among these are the second stage of Bilibino NCGP, floating NCGP VOLNOLOM-3, designated for siting in the Arctic sea coast area, and a nuclear district heating plant for the town of Apatity, in the Murmansk region. In this paper, the background and current status of the SNPPs are given, and the problems as well as prospects of small nuclear reactors development and implementation are considered. (orig.) 20 refs.

  7. Transient Control of Synchronous Machine Active and Reactive Power in Micro-grid Power Systems

    Science.gov (United States)

    Weber, Luke G.

    There are two main topics associated with this dissertation. The first is to investigate phase-to-neutral fault current magnitude occurring in generators with multiple zero-sequence current sources. The second is to design, model, and tune a linear control system for operating a micro-grid in the event of a separation from the electric power system. In the former case, detailed generator, AC8B excitation system, and four-wire electric power system models are constructed. Where available, manufacturers data is used to validate the generator and exciter models. A gain-delay with frequency droop control is used to model an internal combustion engine and governor. The four wire system is connected through a transformer impedance to an infinite bus. Phase-to-neutral faults are imposed on the system, and fault magnitudes analyzed against three-phase faults to gauge their severity. In the latter case, a balanced three-phase system is assumed. The model structure from the former case - but using data for a different generator - is incorporated with a model for an energy storage device and a net load model to form a micro-grid. The primary control model for the energy storage device has a high level of detail, as does the energy storage device plant model in describing the LC filter and transformer. A gain-delay battery and inverter model is used at the front end. The net load model is intended to be the difference between renewable energy sources and load within a micro-grid system that has separated from the grid. Given the variability of both renewable generation and load, frequency and voltage stability are not guaranteed. This work is an attempt to model components of a proposed micro-grid system at the University of Wisconsin Milwaukee, and design, model, and tune a linear control system for operation in the event of a separation from the electric power system. The control module is responsible for management of frequency and active power, and voltage and reactive

  8. Reliability research to nuclear power plant operators based on several methods

    International Nuclear Information System (INIS)

    Fang Xiang; Li Fu; Zhao Bingquan

    2009-01-01

    The paper utilizes many kinds of international reliability research methods, and summarizes the review of reliability research of Chinese nuclear power plant operators in past over ten years based on the simulator platform of nuclear power plant. The paper shows the necessity and feasibility of the research to nuclear power plant operators from many angles including human cognition reliability, fuzzy mathematics model and psychological research model, etc. It will be good to the safe operation of nuclear power plant based on many kinds of research methods to the reliability research of nuclear power plant operators. (authors)

  9. Teaching Power Electronics with a Design-Oriented and Project-Based Learning Method at the Technical University of Denmark

    DEFF Research Database (Denmark)

    Zhang, Zhe; Hansen, Claus Thorp; Andersen, Michael A. E.

    2016-01-01

    Power electronics is a fast developing technology within the electrical engineering field. This paper presents the results and experiences gained from DesignOriented Project Based Learning of switch-mode power supply design within a power electronics course at the Technical University of Denmark...... (DTU). Project-based learning (PBL) is known to be a motivating and problem-centered teaching method that not only places students at the core of the teaching and learning activities but also gives students the ability to transfer their acquired scientific knowledge into industrial practices. Students...... are asked to choose a specification from different power converter applications such as a fuel cell power conditioning converter, a light-emitting diode (LED) driver or a battery charger. Based upon their choice, the students select topology, design magnetic components, calculate input/output filters...

  10. A peaking-regulation-balance-based method for wind & PV power integrated accommodation

    Science.gov (United States)

    Zhang, Jinfang; Li, Nan; Liu, Jun

    2018-02-01

    Rapid development of China’s new energy in current and future should be focused on cooperation of wind and PV power. Based on the analysis of system peaking balance, combined with the statistical features of wind and PV power output characteristics, a method of comprehensive integrated accommodation analysis of wind and PV power is put forward. By the electric power balance during night peaking load period in typical day, wind power installed capacity is determined firstly; then PV power installed capacity could be figured out by midday peak load hours, which effectively solves the problem of uncertainty when traditional method hard determines the combination of the wind and solar power simultaneously. The simulation results have validated the effectiveness of the proposed method.

  11. On Advanced Control Methods toward Power Capture and Load Mitigation in Wind Turbines

    Institute of Scientific and Technical Information of China (English)

    Yuan Yuan; Jiong Tang

    2017-01-01

    This article provides a survey of recently emerged methods for wind turbine control.Multivariate control approaches to the optimization of power capture and the reduction of loads in components under time-varying turbulent wind fields have been under extensive investigation in recent years.We divide the related research activities into three categories:modeling and dynamics of wind turbines,active control of wind turbines,and passive control of wind turbines.Regarding turbine dynamics,we discuss the physical fundamentals and present the aeroelastic analysis tools.Regarding active control,we review pitch control,torque control,and yaw control strategies encompassing mathematical formulations as well as their applications toward different objectives.Our survey mostly focuses on blade pitch control,which is considered one of the key elements in facilitating load reduction while maintaining power capture performance.Regarding passive control,we review techniques such as tuned mass dampers,smart rotors,and microtabs.Possible future directions are suggested.

  12. Risk Evaluation on UHV Power Transmission Construction Project Based on AHP and FCE Method

    OpenAIRE

    Huiru Zhao; Sen Guo

    2014-01-01

    Ultra high voltage (UHV) power transmission construction project is a high-tech power grid construction project which faces many risks and uncertainty. Identifying the risk of UHV power transmission construction project can help mitigate the risk loss and promote the smooth construction. The risk evaluation on “Zhejiang-Fuzhou” UHV power transmission construction project was performed based on analytic hierarchy process (AHP) and fuzzy comprehensive evaluation (FCE) method in this paper. Afte...

  13. Method and apparatus for optimizing operation of a power generating plant using artificial intelligence techniques

    Science.gov (United States)

    Wroblewski, David [Mentor, OH; Katrompas, Alexander M [Concord, OH; Parikh, Neel J [Richmond Heights, OH

    2009-09-01

    A method and apparatus for optimizing the operation of a power generating plant using artificial intelligence techniques. One or more decisions D are determined for at least one consecutive time increment, where at least one of the decisions D is associated with a discrete variable for the operation of a power plant device in the power generating plant. In an illustrated embodiment, the power plant device is a soot cleaning device associated with a boiler.

  14. Power Company No 2. Activity Report 1992 - 1994

    International Nuclear Information System (INIS)

    1995-01-01

    The Power Company No.2 is in charge of power generation and distribution for the southern area of Vietnam. Status and development plans of the Company is presented in the report. (NHA). 10 figs, 2 tabs, 17 photos, 2 maps

  15. Methods of computing steady-state voltage stability margins of power systems

    Science.gov (United States)

    Chow, Joe Hong; Ghiocel, Scott Gordon

    2018-03-20

    In steady-state voltage stability analysis, as load increases toward a maximum, conventional Newton-Raphson power flow Jacobian matrix becomes increasingly ill-conditioned so power flow fails to converge before reaching maximum loading. A method to directly eliminate this singularity reformulates the power flow problem by introducing an AQ bus with specified bus angle and reactive power consumption of a load bus. For steady-state voltage stability analysis, the angle separation between the swing bus and AQ bus can be varied to control power transfer to the load, rather than specifying the load power itself. For an AQ bus, the power flow formulation is only made up of a reactive power equation, thus reducing the size of the Jacobian matrix by one. This reduced Jacobian matrix is nonsingular at the critical voltage point, eliminating a major difficulty in voltage stability analysis for power system operations.

  16. Method in the Madness: Hysteria and the Will to Power

    Directory of Open Access Journals (Sweden)

    Matthew Gildersleeve

    2016-07-01

    Full Text Available At the very start of a chapter on hysteria in her book From Mastery to Analysis: Theories of Gender in Psychoanalytic Feminism, Patricia Elliot cites Nietzsche’s “truths are illusions of which one has forgotten that they are illusions”. This paper follows this connection between hysteria and the work of Nietzsche. This paper will highlight how a Lacanian interpretation of hysteria can elucidate Heidegger’s reading of Nietzsche’s Will to Power and how this interpretation of the Will to Power can better explain the value and importance of hysteria for psychoanalysis and philosophy. I will show that the hysteric’s discourse has a “higher value” than the master’s discourse because it meets Nietzsche’s definition of art, which aims at life’s enhancement rather than the master’s knowledge or truth which aims at the preservation of life. My work will explain how the hysteric’s discourse can transform the master’s discourse into the analyst’s discourse through the Will to Power. This is important, as this is the ultimate aim of psychoanalysis where “At the end of analysis the subject passes to the position of analyst”. This is the ultimate aim of psychoanalysis because “For Lacan, the Discourse of the Analyst is revolutionary because it articulates the truth of the (unconscious subject”. Fundamentally, the objective of this article is to demonstrate that “hysteria is to be understood not as an ‘abnormal’ condition but as one possible manifestation of the subject’s uncanny relationship to itself”.

  17. Efficiency optimization of wireless power transmission systems for active capsule endoscopes.

    Science.gov (United States)

    Zhiwei, Jia; Guozheng, Yan; Jiangpingping; Zhiwu, Wang; Hua, Liu

    2011-10-01

    Multipurpose active capsule endoscopes have drawn considerable attention in recent years, but these devices continue to suffer from energy limitations. A wireless power supply system is regarded as a practical way to overcome the power shortage problem in such devices. This paper focuses on the efficiency optimization of a wireless energy supply system with size and safety constraints. A mathematical programming model in which these constraints are considered is proposed for transmission efficiency, optimal frequency and current, and overall system effectiveness. To verify the feasibility of the proposed method, we use a wireless active capsule endoscope as an illustrative example. The achieved efficiency can be regarded as an index for evaluating the system, and the proposed approach can be used to direct the design of transmitting and receiving coils.

  18. Efficiency optimization of wireless power transmission systems for active capsule endoscopes

    International Nuclear Information System (INIS)

    Zhiwei, Jia; Guozheng, Yan; Jiangpingping; Zhiwu, Wang; Hua, Liu

    2011-01-01

    Multipurpose active capsule endoscopes have drawn considerable attention in recent years, but these devices continue to suffer from energy limitations. A wireless power supply system is regarded as a practical way to overcome the power shortage problem in such devices. This paper focuses on the efficiency optimization of a wireless energy supply system with size and safety constraints. A mathematical programming model in which these constraints are considered is proposed for transmission efficiency, optimal frequency and current, and overall system effectiveness. To verify the feasibility of the proposed method, we use a wireless active capsule endoscope as an illustrative example. The achieved efficiency can be regarded as an index for evaluating the system, and the proposed approach can be used to direct the design of transmitting and receiving coils

  19. Nuclear power plant training simulator system and method

    International Nuclear Information System (INIS)

    Ferguson, R.W.; Converse, R.E. Jr.

    1975-01-01

    A system is described for simulating the real-time dynamic operation of a full scope nuclear powered electrical generating plant for operator training utilizing apparatus that includes a control console with plant component control devices and indicating devices for monitoring plant operation. A general purpose digital computer calculates the dynamic simulation data for operating the indicating devices in accordance with the operation of the control devices. The functions for synchronization and calculation are arranged in a priority structure so as to insure an execution order that provides a maximum overlap of data exchange and simulation calculations. (Official Gazette)

  20. Bi-Level Decentralized Active Power Control for Large-Scale Wind Farm Cluster

    DEFF Research Database (Denmark)

    Huang, Shengli; Wu, Qiuwei; Guo, Yifei

    2018-01-01

    This paper presents a bi-level decentralized active power control (DAPC) for a large-scale wind farm cluster, consisting of several wind farms for better active power dispatch. In the upper level, a distributed active power control scheme based on the distributed consensus is designed to achieve...... fair active power sharing among multiple wind farms, which generates the power reference for each wind farm. A distributed estimator is used to estimate the total available power of all wind farms. In the lower level, a centralized control scheme based on the Model Predictive Control (MPC) is proposed...... to regulate active power outputs of all wind turbines (WTs) within a wind farm, which reduces the fatigue loads of WTs while tracking the power reference obtained from the upper level control. A wind farm cluster with 8 wind farms and totally 160 WTs, was used to test the control performance of the proposed...

  1. Human factors estimation methods in nuclear power plant

    International Nuclear Information System (INIS)

    Takano, Kenichi; Yoshino, Kenji; Nagasaka, Akihiko

    1986-01-01

    The diffinitions and models of mental work-loads are investigated, consequently the most simple and reasonable one is the single channel model, and the channel has limited capacity. The capacity depends on the time related to the brain information processings, like as the recognizations by eyes or ears etc., and the judgements by memory or experience etc., and the actions. In this paper the mental work load is diffined by the relative needed time of such information processing compared to total capacity. Based on the above diffinitions, the model experiment is carried out, the main task is simple additional task of the two digits displayed on a CRT and varying the additional speed from 10 cycle/min. - 60 cycle/min. Four techniques to measure the mental work-load, (1) the task time analysis method, (2) the physiological method, (3) the secondary task method, (4) the subjective method, are examined in the respects of the sensitivity and validity. The measured values gained by the physiological method and the secondary task method and subjective method are compared to those of the task time analysis results, because the task time analysis method is most faithfull to the diffinitions. (author)

  2. A Review of Frequency Response Analysis Methods for Power Transformer Diagnostics

    Directory of Open Access Journals (Sweden)

    Saleh Alsuhaibani

    2016-10-01

    Full Text Available Power transformers play a critical role in electric power networks. Such transformers can suffer failures due to multiple stresses and aging. Thus, assessment of condition and diagnostic techniques are of great importance for improving power network reliability and service continuity. Several techniques are available to diagnose the faults within the power transformer. Frequency response analysis (FRA method is a powerful technique for diagnosing transformer winding deformation and several other types of problems that are caused during manufacture, transportation, installation and/or service life. This paper provides a comprehensive review on FRA methods and their applications in diagnostics and fault identification for power transformers. The paper discusses theory and applications of FRA methods as well as various issues and challenges faced in the application of this method.

  3. Optimal Active Power Control of A Wind Farm Equipped with Energy Storage System based on Distributed Model Predictive Control

    DEFF Research Database (Denmark)

    Zhao, Haoran; Wu, Qiuwei; Guo, Qinglai

    2016-01-01

    This paper presents the Distributed Model Predictive Control (D-MPC) of a wind farm equipped with fast and short-term Energy Storage System (ESS) for optimal active power control using the fast gradient method via dual decomposition. The primary objective of the D-MPC control of the wind farm...... is power reference tracking from system operators. Besides, by optimal distribution of the power references to individual wind turbines and the ESS unit, the wind turbine mechanical loads are alleviated. With the fast gradient method, the convergence rate of the DMPC is significantly improved which leads...

  4. ESTIMATION OF THERMAL PARAMETERS OF POWER BIPOLAR TRANSISTORS BY THE METHOD OF THERMAL RELAXATION DIFFERENTIAL SPECTROMETRY

    Directory of Open Access Journals (Sweden)

    V. S. Niss

    2015-01-01

    Full Text Available Thermal performance of electronic devices determines the stability and reliability of the equipment. This leads to the need for a detailed thermal analysis of semiconductor devices. The goal of the work is evaluation of thermal parameters of high-power bipolar transistors in plastic packages TO-252 and TO-126 by a method of thermal relaxation differential spectrometry. Thermal constants of device elements and distribution structure of thermal resistance defined as discrete and continuous spectra using previously developed relaxation impedance spectrometer. Continuous spectrum, based on higher-order derivatives of the dynamic thermal impedance, follows the model of Foster, and discrete to model of Cauer. The structure of sample thermal resistance is presented in the form of siх-chain electro-thermal RC model. Analysis of the heat flow spreading in the studied structures is carried out on the basis of the concept of thermal diffusivity. For transistor structures the area and distribution of the heat flow cross-section are determined. On the basis of the measurements the thermal parameters of high-power bipolar transistors is evaluated, in particular, the structure of their thermal resistance. For all of the measured samples is obtained that the thermal resistance of the layer planting crystal makes a defining contribution to the internal thermal resistance of transistors. In the transition layer at the border of semiconductor-solder the thermal resistance increases due to changes in the mechanism of heat transfer. Defects in this area in the form of delamination of solder, voids and cracks lead to additional growth of thermal resistance caused by the reduction of the active square of the transition layer. Method of thermal relaxation differential spectrometry allows effectively control the distribution of heat flow in high-power semiconductor devices, which is important for improving the design, improve the quality of landing crystals of power

  5. GROUNDING THE REDUCTION OF POWER OF THE HYDRAULIC DRIVE ELECTRIC MOTOR BY EQUIVALENT POWER METHOD

    Directory of Open Access Journals (Sweden)

    O. Hrygorov

    2017-06-01

    Full Text Available The authors have analyzed the power consumption by a hydraulic drive and wound rotor motor of crane mechanisms at all stages of the operational cycle: acceleration, movement at nominal or intermediate speed and deceleration. The decrease of the rated capacity of electric motors is justified.

  6. Method for enhancing amidohydrolase activity of fatty acid amide hydrolase

    Science.gov (United States)

    John, George; Nagarajan, Subbiah; Chapman, Kent; Faure, Lionel; Koulen, Peter

    2016-10-25

    A method for enhancing amidohydrolase activity of Fatty Acid Amide Hydrolase (FAAH) is disclosed. The method comprising administering a phenoxyacylethanolamide that causes the enhanced activity. The enhanced activity can have numerous effects on biological organisms including, for example, enhancing the growth of certain seedlings. The subject matter disclosed herein relates to enhancers of amidohydrolase activity.

  7. A NEW 3D DESIGN METHOD FOR FOOTWEAR SOLES USING DELCAM PowerSHAPE-e SYSTEM

    Directory of Open Access Journals (Sweden)

    IONESCU Cozmin

    2016-05-01

    Full Text Available Design methods of soles and soles injection moulds must be accurate, timely and at the same time, accessible to a wide category of soles and injection moulds designers and manufacturers. For designing soles and injection moulds for soles, various dedicated CAD/CAM systems have been developed, such as: Delcam Shoe Solution (3D, Delcam PowerSHAPE-e (2D and 3D, Padsy II (2D and Padsy III (3D, Shoemaster System (2D and 3D, Lectra System (2D and 3D, Parmel System (2D and ATOS II System (3D. These systems are equipped with colour displays, plotters, digitizers, terminals and other equipment dedicated for computer aided design activities. Designing 3D soles models using computer systems enables the prevention of ambiguities inherited from 2D drawings, thus reducing errors and remanufacturing. Depending on the design complexity of soles, the technical means available for copying shoe soles and the technologies at the disposal of the soles manufacturers, soles and injection moulds designers adopt various design methods. Not all CAD/CAM systems are accessible for all users, because often their purchasing costs are high. Design method developed and presented in this paper, uses Delcam PowerSHAPE software program, which has the advantage that it can be accessed free of charge from the manufacturer's website. At the same time, this software program provides the user with all the necessary tools and instruments needed to design the most complex injection moulds and footwear sole.

  8. Numerical simulation methods of fires in nuclear power plants

    International Nuclear Information System (INIS)

    Keski-Rahkonen, O.; Bjoerkman, J.; Heikkilae, L.

    1992-01-01

    Fire is a significant hazard to the safety of nuclear power plants (NPP). Fire may be serious accident as such, but even small fire at a critical point in a NPP may cause an accident much more serious than fire itself. According to risk assessments a fire may be an initial cause or a contributing factor in a large part of reactor accidents. At the Fire Technology and the the Nuclear Engineering Laboratory of the Technical Research Centre of Finland (VTT) fire safety research for NPPs has been carried out in a large extent since 1985. During years 1988-92 a project Advanced Numerical Modelling in Nuclear Power Plants (PALOME) was carried out. In the project the level of numerical modelling for fire research in Finland was improved by acquiring, preparing for use and developing numerical fire simulation programs. Large scale test data of the German experimental program (PHDR Sicherheitsprogramm in Kernforschungscentral Karlsruhe) has been as reference. The large scale tests were simulated by numerical codes and results were compared to calculations carried out by others. Scientific interaction with outstanding foreign laboratories and scientists has been an important part of the project. This report describes the work of PALOME-project carried out at the Fire Technology Laboratory only. A report on the work at the Nuclear Engineering Laboratory will be published separatively. (au)

  9. Skill forecasting from different wind power ensemble prediction methods

    International Nuclear Information System (INIS)

    Pinson, Pierre; Nielsen, Henrik A; Madsen, Henrik; Kariniotakis, George

    2007-01-01

    This paper presents an investigation on alternative approaches to the providing of uncertainty estimates associated to point predictions of wind generation. Focus is given to skill forecasts in the form of prediction risk indices, aiming at giving a comprehensive signal on the expected level of forecast uncertainty. Ensemble predictions of wind generation are used as input. A proposal for the definition of prediction risk indices is given. Such skill forecasts are based on the dispersion of ensemble members for a single prediction horizon, or over a set of successive look-ahead times. It is shown on the test case of a Danish offshore wind farm how prediction risk indices may be related to several levels of forecast uncertainty (and energy imbalances). Wind power ensemble predictions are derived from the transformation of ECMWF and NCEP ensembles of meteorological variables to power, as well as by a lagged average approach alternative. The ability of risk indices calculated from the various types of ensembles forecasts to resolve among situations with different levels of uncertainty is discussed

  10. Entropy method combined with extreme learning machine method for the short-term photovoltaic power generation forecasting

    International Nuclear Information System (INIS)

    Tang, Pingzhou; Chen, Di; Hou, Yushuo

    2016-01-01

    As the world’s energy problem becomes more severe day by day, photovoltaic power generation has opened a new door for us with no doubt. It will provide an effective solution for this severe energy problem and meet human’s needs for energy if we can apply photovoltaic power generation in real life, Similar to wind power generation, photovoltaic power generation is uncertain. Therefore, the forecast of photovoltaic power generation is very crucial. In this paper, entropy method and extreme learning machine (ELM) method were combined to forecast a short-term photovoltaic power generation. First, entropy method is used to process initial data, train the network through the data after unification, and then forecast electricity generation. Finally, the data results obtained through the entropy method with ELM were compared with that generated through generalized regression neural network (GRNN) and radial basis function neural network (RBF) method. We found that entropy method combining with ELM method possesses higher accuracy and the calculation is faster.

  11. Modular Bayesian Networks with Low-Power Wearable Sensors for Recognizing Eating Activities

    Directory of Open Access Journals (Sweden)

    Kee-Hoon Kim

    2017-12-01

    Full Text Available Recently, recognizing a user’s daily activity using a smartphone and wearable sensors has become a popular issue. However, in contrast with the ideal definition of an experiment, there could be numerous complex activities in real life with respect to its various background and contexts: time, space, age, culture, and so on. Recognizing these complex activities with limited low-power sensors, considering the power and memory constraints of the wearable environment and the user’s obtrusiveness at once is not an easy problem, although it is very crucial for the activity recognizer to be practically useful. In this paper, we recognize activity of eating, which is one of the most typical examples of a complex activity, using only daily low-power mobile and wearable sensors. To organize the related contexts systemically, we have constructed the context model based on activity theory and the “Five W’s”, and propose a Bayesian network with 88 nodes to predict uncertain contexts probabilistically. The structure of the proposed Bayesian network is designed by a modular and tree-structured approach to reduce the time complexity and increase the scalability. To evaluate the proposed method, we collected the data with 10 different activities from 25 volunteers of various ages, occupations, and jobs, and have obtained 79.71% accuracy, which outperforms other conventional classifiers by 7.54–14.4%. Analyses of the results showed that our probabilistic approach could also give approximate results even when one of contexts or sensor values has a very heterogeneous pattern or is missing.

  12. Modular Bayesian Networks with Low-Power Wearable Sensors for Recognizing Eating Activities

    Science.gov (United States)

    Kim, Kee-Hoon

    2017-01-01

    Recently, recognizing a user’s daily activity using a smartphone and wearable sensors has become a popular issue. However, in contrast with the ideal definition of an experiment, there could be numerous complex activities in real life with respect to its various background and contexts: time, space, age, culture, and so on. Recognizing these complex activities with limited low-power sensors, considering the power and memory constraints of the wearable environment and the user’s obtrusiveness at once is not an easy problem, although it is very crucial for the activity recognizer to be practically useful. In this paper, we recognize activity of eating, which is one of the most typical examples of a complex activity, using only daily low-power mobile and wearable sensors. To organize the related contexts systemically, we have constructed the context model based on activity theory and the “Five W’s”, and propose a Bayesian network with 88 nodes to predict uncertain contexts probabilistically. The structure of the proposed Bayesian network is designed by a modular and tree-structured approach to reduce the time complexity and increase the scalability. To evaluate the proposed method, we collected the data with 10 different activities from 25 volunteers of various ages, occupations, and jobs, and have obtained 79.71% accuracy, which outperforms other conventional classifiers by 7.54–14.4%. Analyses of the results showed that our probabilistic approach could also give approximate results even when one of contexts or sensor values has a very heterogeneous pattern or is missing. PMID:29232937

  13. Reliability Evaluation of a Single-phase H-bridge Inverter with Integrated Active Power Decoupling

    DEFF Research Database (Denmark)

    Tang, Junchaojie; Wang, Haoran; Ma, Siyuan

    2016-01-01

    it with the traditional passive DC-link solution. The converter level reliability is obtained by component level electro-thermal stress modeling, lifetime model, Weibull distribution, and Reliability Block Diagram (RBD) method. The results are demonstrated by a 2 kW single-phase inverter application.......Various power decoupling methods have been proposed recently to replace the DC-link Electrolytic Capacitors (E-caps) in single-phase conversion system, in order to extend the lifetime and improve the reliability of the DC-link. However, it is still an open question whether the converter level...... reliability becomes better or not, since additional components are introduced and the loading of the existing components may be changed. This paper aims to study the converter level reliability of a single-phase full-bridge inverter with two kinds of active power decoupling module and to compare...

  14. Design and analysis of active power control strategies for distributed generation inverters under unbalanced grid faults

    NARCIS (Netherlands)

    Wang, F.; Duarte, J.L.; Hendrix, M.A.M.

    2010-01-01

    Distributed power generation systems are expected to deliver active power into the grid and support it without interruption during unbalanced grid faults. Aiming to provide grid-interfacing inverters the flexibility to adapt to the coming change of grid requirements, an optimised active power

  15. Low activation structural material candidates for fusion power plants

    International Nuclear Information System (INIS)

    Forty, C.B.A.; Cook, I.

    1997-06-01

    Under the SEAL Programme of the European Long-Term Fusion Safety Programme, an assessment was performed of a number of possible blanket structural materials. These included the steels then under consideration in the European Blanket Programme, as well as materials being considered for investigation in the Advanced Materials Programme. Calculations were performed, using SEAFP methods, of the activation properties of the materials, and these were related, based on the SEAFP experience, to assessments of S and E performance. The materials investigated were the SEAFP low-activation martensitic steel (LA12TaLC); a Japanese low-activation martensitic steel (F-82H), a range of compositional variants about this steel; the vanadium-titanium-chromium alloy which was the original proposal of the ITER JCT for the ITER in-vessel components; a titanium-aluminium intermetallic (Ti-Al) which is under investigation in Japan; and silicon carbide composite (SiC). Assessed impurities were included in the compositions of these materials, and they have very important impacts on the activation properties. Lack of sufficiently detailed data on the composition of chromium alloys precluded their inclusion in the study. (UK)

  16. Analysis of Power Transfer Efficiency of Standard Integrated Circuit Immunity Test Methods

    Directory of Open Access Journals (Sweden)

    Hai Au Huynh

    2015-01-01

    Full Text Available Direct power injection (DPI and bulk current injection (BCI methods are defined in IEC 62132-3 and IEC 62132-4 as the electromagnetic immunity test method of integrated circuits (IC. The forward power measured at the RF noise generator when the IC malfunctions is used as the measure of immunity level of the IC. However, the actual power that causes failure in ICs is different from forward power measured at the noise source. Power transfer efficiency is used as a measure of power loss of the noise injection path. In this paper, the power transfer efficiencies of DPI and BCI methods are derived and validated experimentally with immunity test setup of a clock divider IC. Power transfer efficiency varies significantly over the frequency range as a function of the test method used and the IC input impedance. For the frequency range of 15 kHz to 1 GHz, power transfer efficiency of the BCI test was constantly higher than that of the DPI test. In the DPI test, power transfer efficiency is particularly low in the lower test frequency range up to 10 MHz. When performing the IC immunity tests following the standards, these characteristics of the test methods need to be considered.

  17. Assessing different parameters estimation methods of Weibull distribution to compute wind power density

    International Nuclear Information System (INIS)

    Mohammadi, Kasra; Alavi, Omid; Mostafaeipour, Ali; Goudarzi, Navid; Jalilvand, Mahdi

    2016-01-01

    Highlights: • Effectiveness of six numerical methods is evaluated to determine wind power density. • More appropriate method for computing the daily wind power density is estimated. • Four windy stations located in the south part of Alberta, Canada namely is investigated. • The more appropriate parameters estimation method was not identical among all examined stations. - Abstract: In this study, the effectiveness of six numerical methods is evaluated to determine the shape (k) and scale (c) parameters of Weibull distribution function for the purpose of calculating the wind power density. The selected methods are graphical method (GP), empirical method of Justus (EMJ), empirical method of Lysen (EML), energy pattern factor method (EPF), maximum likelihood method (ML) and modified maximum likelihood method (MML). The purpose of this study is to identify the more appropriate method for computing the wind power density in four stations distributed in Alberta province of Canada namely Edmonton City Center Awos, Grande Prairie A, Lethbridge A and Waterton Park Gate. To provide a complete analysis, the evaluations are performed on both daily and monthly scales. The results indicate that the precision of computed wind power density values change when different parameters estimation methods are used to determine the k and c parameters. Four methods of EMJ, EML, EPF and ML present very favorable efficiency while the GP method shows weak ability for all stations. However, it is found that the more effective method is not similar among stations owing to the difference in the wind characteristics.

  18. State-space model predictive control method for core power control in pressurized water reactor nuclear power stations

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Guo Xu; Wu, Jie; Zeng, Bifan; Wu, Wangqiang; Ma, Xiao Qian [School of Electric Power, South China University of Technology, Guangzhou (China); Xu, Zhibin [Electric Power Research Institute of Guangdong Power Grid Corporation, Guangzhou (China)

    2017-02-15

    A well-performed core power control to track load changes is crucial in pressurized water reactor (PWR) nuclear power stations. It is challenging to keep the core power stable at the desired value within acceptable error bands for the safety demands of the PWR due to the sensitivity of nuclear reactors. In this paper, a state-space model predictive control (MPC) method was applied to the control of the core power. The model for core power control was based on mathematical models of the reactor core, the MPC model, and quadratic programming (QP). The mathematical models of the reactor core were based on neutron dynamic models, thermal hydraulic models, and reactivity models. The MPC model was presented in state-space model form, and QP was introduced for optimization solution under system constraints. Simulations of the proposed state-space MPC control system in PWR were designed for control performance analysis, and the simulation results manifest the effectiveness and the good performance of the proposed control method for core power control.

  19. 42 CFR 84.146 - Method of measuring the power and torque required to operate blowers.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Method of measuring the power and torque required... RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.146 Method of measuring the power and torque.... These are used to facilitate timing. To determine the torque or horsepower required to operate the...

  20. Newton Power Flow Methods for Unbalanced Three-Phase Distribution Networks

    NARCIS (Netherlands)

    Sereeter, B.; Vuik, C.; Witteveen, C.

    2017-01-01

    Two mismatch functions (power or current) and three coordinates (polar, Cartesian andcomplex form) result in six versions of the Newton–Raphson method for the solution of powerflow problems. In this paper, five new versions of the Newton power flow method developed forsingle-phase problems in our