WorldWideScience

Sample records for voltage converter modulators

  1. Novel zero voltage transition pulse width modulation flyback converter

    Science.gov (United States)

    Adib, Ehsan; Farzanehfard, Hosein

    2010-09-01

    In this article, a new zero voltage (ZV) transition flyback converter is introduced which uses a simple auxiliary circuit. In this converter, ZV switching condition is achieved for the converter switch while zero current switching condition is attained for the auxiliary switch. There is no additional voltage and current stress on the main switch. Main diode, auxiliary circuit voltage and current ratings are low. The proposed converter is analysed and design procedure is discussed. The presented experimental results of a prototype converter justify the theoretical analysis.

  2. Zero-Sequence Voltage Modulation Strategy for Multiparallel Converters Circulating Current Suppression

    DEFF Research Database (Denmark)

    Zhu, Rongwu; Liserre, Marco; Chen, Zhe

    2017-01-01

    A zero-sequence circulating current (ZSCC) is typically generated among the multiparallel converters that share the common dc link and ac side without isolated transformers under the space vector modulation (SVM), due to the injected third-order zero-sequence voltage (ZSV). This paper analyzes SVM...... references and filter inductances. The simulation and experimental results based on the parallel converters clearly verify the effectiveness of the proposed control....

  3. Constant Common Mode Voltage Modulation Strategy for the FB10 power converter

    DEFF Research Database (Denmark)

    Rodriguez, Pedro; Vázquez, Gerardo; Teodorescu, Remus

    2011-01-01

    In this paper a modulation strategy based on the classical space vector modulation is applied to the FB10 converter, a new converter topology for PV applications. Firstly, the FB10 converter is presented and the natural modulation is computed. Secondly, the simulation and experimental results...

  4. Influence of modulation method on using LC-traps with single-phase voltage source converters

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Min, Huang; Bai, Haofeng

    2015-01-01

    The switching-frequency LC-trap filter has recently been employed with high-order passive filters for Voltage Source Inverters (VSIs). This paper investigates the influence of modulation method on using the LC-traps with single-phase VSIs. Two-level (bipolar) and three-level (unipolar) modulations...... that include phase distortion and alternative phase opposition distortion methods are analyzed. Harmonic filtering performances of four LC-trap-based filters with different locations of LC-traps are compared. It is shown that the use of parallel-LC-traps in series with filter inductors, either grid...... or converter side, has a worse harmonic filtering performance than using series-LC-trap in the shunt branch. Simulations and experimental results are presented for verifications....

  5. Compact high voltage, high peak power, high frequency transformer for converter type modulator applications.

    Science.gov (United States)

    Reghu, T; Mandloi, V; Shrivastava, Purushottam

    2016-04-01

    The design and development of a compact high voltage, high peak power, high frequency transformer for a converter type modulator of klystron amplifiers is presented. The transformer has been designed to operate at a frequency of 20 kHz and at a flux swing of ±0.6 T. Iron (Fe) based nanocrystalline material has been selected as a core for the construction of the transformer. The transformer employs a specially designed solid Teflon bobbin having 120 kV insulation for winding the high voltage secondary windings. The flux swing of the core has been experimentally found by plotting the hysteresis loop at actual operating conditions. Based on the design, a prototype transformer has been built which is per se a unique combination of high voltage, high frequency, and peak power specifications. The transformer was able to provide 58 kV (pk-pk) at the secondary with a peak power handling capability of 700 kVA. The transformation ratio was 1:17. The performance of the transformer is also presented and discussed.

  6. Zero-voltage DC/DC converter with asymmetric pulse-width modulation for DC micro-grid system

    Science.gov (United States)

    Lin, Bor-Ren

    2018-04-01

    This paper presents a zero-voltage switching DC/DC converter for DC micro-grid system applications. The proposed circuit includes three half-bridge circuit cells connected in primary-series and secondary-parallel in order to lessen the voltage rating of power switches and current rating of rectifier diodes. Thus, low voltage stress of power MOSFETs can be adopted for high-voltage input applications with high switching frequency operation. In order to achieve low switching losses and high circuit efficiency, asymmetric pulse-width modulation is used to turn on power switches at zero voltage. Flying capacitors are used between each circuit cell to automatically balance input split voltages. Therefore, the voltage stress of each power switch is limited at Vin/3. Finally, a prototype is constructed and experiments are provided to demonstrate the circuit performance.

  7. Sigma-Delta Voltage to Frequency Converter With Phase Modulation Possibility

    OpenAIRE

    STORK, Milan

    2014-01-01

    Voltage to frequency converter (VFC) is an oscillator whose frequency is linearly proportional to control voltage. There are two common VFC architectures: the current steering multivibrator and the charge-balance VFC. For higher linearity, the charge-balancing method is preferred. The charge balanced VFC may be made in asynchronous or synchronous (clocked) forms. The synchronous charge balanced VFC or "sigma delta" (S-D) VFC is used when output pulses are synchroni...

  8. DC-bus voltage control of grid-connected voltage source converter by using space vector modulated direct power control under unbalanced network conditions

    DEFF Research Database (Denmark)

    Xiao, Lei; Huang, Shoudao; Lu, Kaiyuan

    2013-01-01

    Unbalanced grid voltage will cause large dc-bus voltage ripple and introduce high harmonic current components on the grid side. This will severely threaten the safety of the grid-connected voltage source converter (VSC) and consequently, affect the healthy operation condition of the load. In this......Unbalanced grid voltage will cause large dc-bus voltage ripple and introduce high harmonic current components on the grid side. This will severely threaten the safety of the grid-connected voltage source converter (VSC) and consequently, affect the healthy operation condition of the load....... In this study, a new proportional-integral-resonant (PI-RES) controller-based, space vector modulated direct power control topology is proposed to suppress the dc-bus voltage ripple and in the same time, controlling effectively the instantaneous power of the VSC. A special ac reactive power reference component...... is introduced in the controller, which is necessary in order to reduce the dc-bus voltage ripple and active power harmonics at the same time. The proposed control topology is implemented in the lab. Simulation and experimental results are provided to validate its performance and the analysis presented...

  9. Stability Analysis of a Matrix Converter Drive: Effects of Input Filter Type and the Voltage Fed to the Modulation Algorithm

    Directory of Open Access Journals (Sweden)

    M. Hosseini Abardeh

    2015-03-01

    Full Text Available The matrix converter instability can cause a substantial distortion in the input currents and voltages which leads to the malfunction of the converter. This paper deals with the effects of input filter type, grid inductance, voltage fed to the modulation algorithm and the synchronous rotating digital filter time constant on the stability and performance of the matrix converter. The studies are carried out using eigenvalues of the linearized system and simulations. Two most common schemes for the input filter (LC and RLC are analyzed. It is shown that by a proper choice of voltage input to the modulation algorithm, structure of the input filter and its parameters, the need for the digital filter for ensuring the stability can be resolved. Moreover, a detailed model of the system considering the switching effects is simulated and the results are used to validate the analytical outcomes. The agreement between simulation and analytical results implies that the system performance is not deteriorated by neglecting the nonlinear switching behavior of the converter. Hence, the eigenvalue analysis of the linearized system can be a proper indicator of the system stability.

  10. A Novel Modulation Function-Based Control of Modular Multilevel Converters for High Voltage Direct Current Transmission Systems

    Directory of Open Access Journals (Sweden)

    Majid Mehrasa

    2016-10-01

    Full Text Available In this paper, a novel modulation function-based method including analyses of the modulation index and phase is proposed for operation of modular multilevel converters (MMCs in high voltage direct current (HVDC transmission systems. The proposed modulation function-based control technique is developed based on thorough and precise analyses of all MMC voltages and currents in the a-b-c reference frame in which the alternating current (AC-side voltage is the first target to be obtained. Using the AC-side voltage, the combination of the MMC upper and lower arm voltages is achieved as the main structure of the proposed modulation function. The main contribution of this paper is to obtain two very simple new modulation functions to control MMC performance in different operating conditions. The features of the modulation function-based control technique are as follows: (1 this control technique is very simple and can be easily achieved in a-b-c reference frame without the need of using Park transformation; and (2 in addition, the inherent properties of the MMC model are considered in the proposed control technique. Considering these properties leads to constructing a control technique that is robust against MMC parameters changes and also is a very good tracking method for the components of MMC input currents. These features lead to improving the operation of MMC significantly, which can act as a rectifier in the HVDC structure. The simulation studies are conducted through MATLAB/SIMULINK software, and the results obtained verify the effectiveness of the proposed modulation function-based control technique.

  11. Charge-pump voltage converter

    Science.gov (United States)

    Brainard, John P [Albuquerque, NM; Christenson, Todd R [Albuquerque, NM

    2009-11-03

    A charge-pump voltage converter for converting a low voltage provided by a low-voltage source to a higher voltage. Charge is inductively generated on a transfer rotor electrode during its transit past an inductor stator electrode and subsequently transferred by the rotating rotor to a collector stator electrode for storage or use. Repetition of the charge transfer process leads to a build-up of voltage on a charge-receiving device. Connection of multiple charge-pump voltage converters in series can generate higher voltages, and connection of multiple charge-pump voltage converters in parallel can generate higher currents. Microelectromechanical (MEMS) embodiments of this invention provide a small and compact high-voltage (several hundred V) voltage source starting with a few-V initial voltage source. The microscale size of many embodiments of this invention make it ideally suited for MEMS- and other micro-applications where integration of the voltage or charge source in a small package is highly desirable.

  12. Common-Mode Voltage Reduction of Three-to-Five Phase Indirect Matrix Converters with Zero-Current Vector Modulation

    DEFF Research Database (Denmark)

    Zhang, Guanguan; Yang, Jian; Yang, Yongheng

    2017-01-01

    In order to reduce the Common-Mode Voltage (CMV) in three-to-five phase indirect matrix converters, three improved Space Vector Pulse Width Modulation (SVPWM) methods are proposed and discussed. The improved modulation schemes are achieved by reorganizing zero vectors from the inversion stage......) in the inversion stage, which results in a large amount of third-order harmonics in output currents. In addition, the method that utilizes two adjacent active current vectors (ACVs) and the method that uses two non-adjacent ACVs in the rectification stage have the same CMV peak value. By contrast, the latter...... achieves a lower Total Harmonic Distortion (THD) level of the output currents. Simulation results verify the effectiveness of the proposed methods....

  13. Development of modulation strategies for NPC converter addressing DC link voltage balancing and CMV reduction

    DEFF Research Database (Denmark)

    Boian, D.; Biris, C.; Teodorescu, Remus

    2012-01-01

    3L-NPC inverters are more popular due to their superior performance compared with two level inverters. One of the most optimal applications for multilevel inverter is the Adjustable Speed Drives (ASD). The industry reported numerous ASD failures due to high frequency PWM. Those failures consist i...... strategies is to reduce the Common Mode Voltage (CMV) and balance the DC Link Voltage....

  14. Voltage-Balancing Method for Modular Multilevel Converters Under Phase-Shifted Carrier-Based Pulsewidth Modulation

    DEFF Research Database (Denmark)

    Deng, Fujin; Chen, Zhe

    2015-01-01

    The modular multilevel converter (MMC) becomes attractive for medium- or high-power applications because of the advantages of high modularity, availability, and power quality. One of the technical challenges associated with an MMC is the balancing of the capacitors' voltages. In this paper...

  15. Spectrum analysis of a voltage source converter due to semiconductor voltage drops

    DEFF Research Database (Denmark)

    Rasmussen, Tonny Wederberg; Eltouki, Mustafa

    2017-01-01

    It is known that power electronic voltage source converters are non-ideal. This paper presents a state-of-the-art review on the effect of semiconductor voltage drop on the output voltage spectrum, using single-phase H-bridge two-level converter topology with natural sampled pulse width modulation....... The paper describes the analysis of output voltage spectrum, when the semiconductor voltage drop is added. The results of the analysis of the spectral contribution including and excluding semiconductor voltage drop reveal a good agreement between the theoretical results, simulations and laboratory...

  16. Energy Efficiency of Induction Motors Running Off Frequency Converters with Pulse-Width Voltage Modulation{sup 1}

    Energy Technology Data Exchange (ETDEWEB)

    Shvetsov, N. K., E-mail: elmash@em.ispu.ru [V. I. Lenin Ivanovo State Power University (Russian Federation)

    2016-11-15

    The results of calculations of the increase in losses in an induction motor with frequency control and different forms of the supply voltage are presented. The calculations were performed by an analytic method based on harmonic analysis of the supply voltage as well as numerical calculation of the electromagnetic processes by the finite-element method.

  17. A Bidirectional Multi-Port DC-DC Converter Integrating Voltage Equalizer

    DEFF Research Database (Denmark)

    Chen, Jianfei; Hou, Shiying; Deng, Fujin

    2015-01-01

    A novel bidirectional multi-port dc-dc converter integrating voltage equalizer based on switched-capacitor voltage accumulator (SCVA) is proposed. It has two operating modes of charging and discharging for battery modules. All battery modules are connected in series indirectly and can be equalize...... battery modules with different voltages. Simulation results has shown the feasibility of the proposed converter.......A novel bidirectional multi-port dc-dc converter integrating voltage equalizer based on switched-capacitor voltage accumulator (SCVA) is proposed. It has two operating modes of charging and discharging for battery modules. All battery modules are connected in series indirectly and can be equalized...

  18. Harmonic elimination technique for a single-phase multilevel converter with unequal DC link voltage levels

    DEFF Research Database (Denmark)

    Ghasemi, N.; Zare, F.; Boora, A.A.

    2012-01-01

    Multilevel converters, because of the benefits they attract in generating high quality output voltage, are used in several applications. Various modulation and control techniques are introduced by several researchers to control the output voltage of the multilevel converters like space vector...... modulation and harmonic elimination (HE) methods. Multilevel converters may have a DC link with equal or unequal DC voltages. In this study a new HE technique based on the HE method is proposed for multilevel converters with unequal DC link voltage. The DC link voltage levels are considered as additional...

  19. Triple voltage dc-to-dc converter and method

    Science.gov (United States)

    Su, Gui-Jia

    2008-08-05

    A circuit and method of providing three dc voltage buses and transforming power between a low voltage dc converter and a high voltage dc converter, by coupling a primary dc power circuit and a secondary dc power circuit through an isolation transformer; providing the gating signals to power semiconductor switches in the primary and secondary circuits to control power flow between the primary and secondary circuits and by controlling a phase shift between the primary voltage and the secondary voltage. The primary dc power circuit and the secondary dc power circuit each further comprising at least two tank capacitances arranged in series as a tank leg, at least two resonant switching devices arranged in series with each other and arranged in parallel with the tank leg, and at least one voltage source arranged in parallel with the tank leg and the resonant switching devices, said resonant switching devices including power semiconductor switches that are operated by gating signals. Additional embodiments having a center-tapped battery on the low voltage side and a plurality of modules on both the low voltage side and the high voltage side are also disclosed for the purpose of reducing ripple current and for reducing the size of the components.

  20. A novel loss reduced modulation strategy for matrix converters

    DEFF Research Database (Denmark)

    Helle, Lars; Munk-Nielsen, Stig

    2001-01-01

    This paper presents a new modulation strategy for three-phase to three-phase matrix converters. The new modulation strategy is applicable whenever the output voltage reference is below half the input voltage. By applying this new modulation method, the switching losses are reduced by 15-35% compa...

  1. Triple Line-Voltage Cascaded VIENNA Converter Applied as the Medium-Voltage AC Drive

    Directory of Open Access Journals (Sweden)

    Jia Zou

    2018-04-01

    Full Text Available A novel rectifier based on a triple line-voltage cascaded VIENNA converter (LVC-VC was proposed. Compared to the conventional cascaded H-bridge converters, the switch voltage stress is lower, and the numbers of switches and dc capacitors are fewer under similar operating conditions in the proposed new multilevel converter. The modeling and control for the LVC-VC ware presented. Based on the analysis of the operation principle of the new converter, the power factor correction of the proposed converter was realized by employing a traditional one-cycle control strategy. The minimum average value and maximum harmonic components of the dc-link voltages of the three VIENNA rectifier modules ware calculated. Three VIENNA dc-link voltages were unbalanced under the unbalanced load conditions, so the zero sequence current was injected to the three inner currents for balancing three VIENNA dc-link voltages. Simulation and the results of the experiment verified the availability of the new proposed multilevel converter and the effectiveness of the corresponding control strategy applied.

  2. Triphase Cascaded Converters with Direct Synchronous Pulswidth Modulation

    DEFF Research Database (Denmark)

    Oleschuk, V.; Blaabjerg, Frede; Bose, B. K.

    2002-01-01

    A novel method of direct synchronous pulse-width modulation (PWM) is applied for control of modular multilevel converters consisting from three standard triphase inverter modules along with an 0.33 p.u. output transformer. The proposed method provides synchronisation of the voltage waveforms...... for both each module and the composed voltage at the output of the converter. Multilevel output voltage of the converter has quarter-wave symmetry during the whole range including the zone of overmodulation. Both continuous and discontinuous versions of synchronous PWM, based on a vector approach...

  3. Test setup for accelerated test of high power IGBT modules with online monitoring of Vce and Vf voltage during converter operation

    DEFF Research Database (Denmark)

    de Vega, Angel Ruiz; Ghimire, Pramod; Pedersen, Kristian Bonderup

    2014-01-01

    Several accelerated test methods exist in order to study the failures mechanisms of the high power IGBT modules like temperature cycling test or power cycles based on DC current pulses. The main drawback is that the test conditions do not represent the real performance and stress conditions...... of the device in real application. The hypothesis is that ageing of power modules closer to real environment including cooling system, full dc-link voltage and continuous PWM operation could lead to more accurate study of failure mechanism. A new type of test setup is proposed, which can create different real...... load conditions like in the field. Furthermore, collector-emitter voltage (Vce) has been used as indicator of the wear-out of the high power IGBT module. The innovative monitoring system implemented in the test setup is capable of measure the Vce and forward voltage of the antiparallel diode (Vf...

  4. AC Voltage Control of DC/DC Converters Based on Modular Multilevel Converters in Multi-Terminal High-Voltage Direct Current Transmission Systems

    Directory of Open Access Journals (Sweden)

    Rui Li

    2016-12-01

    Full Text Available The AC voltage control of a DC/DC converter based on the modular multilevel converter (MMC is considered under normal operation and during a local DC fault. By actively setting the AC voltage according to the two DC voltages of the DC/DC converter, the modulation index can be near unity, and the DC voltage is effectively utilized to output higher AC voltage. This significantly decreases submodule (SM capacitance and conduction losses of the DC/DC converter, yielding reduced capital cost, volume, and higher efficiency. Additionally, the AC voltage is limited in the controllable range of both the MMCs in the DC/DC converter; thus, over-modulation and uncontrolled currents are actively avoided. The AC voltage control of the DC/DC converter during local DC faults, i.e., standby operation, is also proposed, where only the MMC connected on the faulty cable is blocked, while the other MMC remains operational with zero AC voltage output. Thus, the capacitor voltages can be regulated at the rated value and the decrease of the SM capacitor voltages after the blocking of the DC/DC converter is avoided. Moreover, the fault can still be isolated as quickly as the conventional approach, where both MMCs are blocked and the DC/DC converter is not exposed to the risk of overcurrent. The proposed AC voltage control strategy is assessed in a three-terminal high-voltage direct current (HVDC system incorporating a DC/DC converter, and the simulation results confirm its feasibility.

  5. Power converters for medium voltage networks

    CERN Document Server

    Islam, Md Rabiul; Zhu, Jianguo

    2014-01-01

    This book examines a number of topics, mainly in connection with advances in semiconductor devices and magnetic materials and developments in medium and large-scale renewable power plant technologies, grid integration techniques and new converter topologies, including advanced digital control systems for medium-voltage networks. The book's individual chapters provide an extensive compilation of fundamental theories and in-depth information on current research and development trends, while also exploring new approaches to overcoming some critical limitations of conventional grid integration te

  6. Bi-directional power control system for voltage converter

    Science.gov (United States)

    Garrigan, Neil Richard; King, Robert Dean; Schwartz, James Edward

    1999-01-01

    A control system for a voltage converter includes: a power comparator for comparing a power signal on input terminals of the converter with a commanded power signal and producing a power comparison signal; a power regulator for transforming the power comparison signal to a commanded current signal; a current comparator for comparing the commanded current signal with a measured current signal on output terminals of the converter and producing a current comparison signal; a current regulator for transforming the current comparison signal to a pulse width modulator (PWM) duty cycle command signal; and a PWM for using the PWM duty cycle command signal to control electrical switches of the converter. The control system may further include: a command multiplier for converting a voltage signal across the output terminals of the converter to a gain signal having a value between zero (0) and unity (1), and a power multiplier for multiplying the commanded power signal by the gain signal to provide a limited commanded power signal, wherein power comparator compares the limited commanded power signal with the power signal on the input terminals.

  7. Pulse-width modulated DC-DC power converters

    CERN Document Server

    Kazimierczuk, Marian K

    2008-01-01

    This book studies switch-mode power supplies (SMPS) in great detail. This type of converter changes an unregulated DC voltage into a high-frequency pulse-width modulated (PWM) voltage controlled by varying the duty cycle, then changes the PWM AC voltage to a regulated DC voltage at a high efficiency by rectification and filtering. Used to supply electronic circuits, this converter saves energy and space in the overall system. With concept-orientated explanations, this book offers state-of-the-art SMPS technology and promotes an understanding of the principle operations of PWM converters,

  8. Modulation Methods for Neutral-Point-Clamped Wind Power Converter Achieving Loss and Thermal Redistribution Under Low-Voltage Ride-Through

    DEFF Research Database (Denmark)

    Ma, Ke; Blaabjerg, Frede

    2014-01-01

    The three-level neutral-point (NP)-clamped (3L-NPC) converter is a promising multilevel topology in the application of megawatt wind power generation systems. However, the growing requirements by grid codes may impose high stress and even give reliability problem to this converter topology......, with the proposed modulation methods, the thermal distribution in the 3L-NPC wind power inverter undergoing LVRT becomes more equal, and the junction temperature of the most stressed devices can be also relieved. Also, the control ability of the dc-bus NP potential, which is one of the crucial considerations...

  9. A New Asymmetrical Current-fed Converter with Voltage Lifting

    Directory of Open Access Journals (Sweden)

    DELSHAD, M.

    2011-05-01

    Full Text Available This paper presents a new zero voltage switching current-fed DC-DC converter with high voltage gain. In this converter all switches (main and auxiliary turn on under zero voltage switching and turn off under almost zero voltage switching due to snubber capacitor. Furthermore, the voltage spike across the main switch due to leakage inductance of forward transformer is absorbed. The flyback transformer which is connected to the output in series causes to high voltage gain and less voltage stress on the power devices. Considering high efficiency and voltage gain of this converter, it is suitable for green generated systems such as fuel cells or photovoltaic systems. The presented experimental results verify the integrity of the proposed converter.

  10. Multilevel Converter by Cascading Two-Level Three-Phase Voltage Source Converter

    Directory of Open Access Journals (Sweden)

    Abdullrahman A. Al-Shamma’a

    2018-04-01

    Full Text Available This paper proposes a topology using isolated, cascaded multilevel voltage source converters (VSCs and employing two-winding magnetic elements for high-power applications. The proposed topology synthesizes 6 two-level, three-phase VSCs, so the power capability of the presented converter is six times the capability of each VSC module. The characteristics of the proposed topology are demonstrated through analyzing its current relationships, voltage relationships and power capability in detail. The power rating is equally shared among the VSC modules without the need for a sharing algorithm; thus, the converter operates as a single three-phase VSC. The comparative analysis with classical neutral-point clamped, flying capacitor and cascaded H-bridge exhibits the superior features of fewer insulated gate bipolar transistors (IGBTs, capacitor requirement and fewer diodes. To validate the theoretical performance of the proposed converter, it is simulated in a MATLAB/Simulink environment and the results are experimentally demonstrated using a laboratory prototype.

  11. High Current, Low Voltage Power Converter [20kA, 6V] LHC Converter Prototype

    CERN Document Server

    Jørgensen, H E; Dupaquier, A; Fernqvist, G

    1998-01-01

    The superconducting LHC accelerator requires high currents (~12.5kA) and relatively low voltages (~10 V) for its magnets. The need to install the power converters underground is the driving force for reduced volume and high efficiency. Moreover, the LHC machine will require a very high level of performance from the power converters, particularly in terms of DC stability, dynamic response and also in matters of EMC. To meet these requirements soft-switching techniques will be used. This paper describes the development of a [20kA,6V] power converter intended as a stable high-current source for D CCT calibration and an evaluation prototype for the future LHC converters. The converter is made with a modular concept with five current sources [4kA,6V] in parallel. The 4kA sources are built as plu g-in modules: a diode rectifier on the AC mains with a damped L-C passive filter, a Zero Voltage Switching inverter working at 20 kHz and an output stage (high frequency transformers, Schottky rectifi ers and output filter...

  12. Modulation and control of matrix converter for aerospace application

    Science.gov (United States)

    Kobravi, Keyhan

    In the context of modern aircraft systems, a major challenge is power conversion to supply the aircraft's electrical instruments. These instruments are energized through a fixed-frequency internal power grid. In an aircraft, the available sources of energy are a set of variable-speed generators which provide variable-frequency ac voltages. Therefore, to energize the internal power grid of an aircraft, the variable-frequency ac voltages should be converted to a fixed-frequency ac voltage. As a result, an ac to ac power conversion is required within an aircraft's power system. This thesis develops a Matrix Converter to energize the aircraft's internal power grid. The Matrix Converter provides a direct ac to ac power conversion. A major challenge of designing Matrix Converters for aerospace applications is to minimize the volume and weight of the converter. These parameters are minimized by increasing the switching frequency of the converter. To design a Matrix Converter operating at a high switching frequency, this thesis (i) develops a scheme to integrate fast semiconductor switches within the current available Matrix Converter topologies, i.e., MOSFET-based Matrix Converter, and (ii) develops a new modulation strategy for the Matrix Converter. This Matrix Converter and the new modulation strategy enables the operation of the converter at a switching-frequency of 40kHz. To provide a reliable source of energy, this thesis also develops a new methodology for robust control of Matrix Converter. To verify the performance of the proposed MOSFET-based Matrix Converter, modulation strategy, and control design methodology, various simulation and experimental results are presented. The experimental results are obtained under operating condition present in an aircraft. The experimental results verify the proposed Matrix Converter provides a reliable power conversion in an aircraft under extreme operating conditions. The results prove the superiority of the proposed Matrix

  13. PV source based high voltage gain current fed converter

    Science.gov (United States)

    Saha, Soumya; Poddar, Sahityika; Chimonyo, Kudzai B.; Arunkumar, G.; Elangovan, D.

    2017-11-01

    This work involves designing and simulation of a PV source based high voltage gain, current fed converter. It deals with an isolated DC-DC converter which utilizes boost converter topology. The proposed converter is capable of high voltage gain and above all have very high efficiency levels as proved by the simulation results. The project intends to produce an output of 800 V dc from a 48 V dc input. The simulation results obtained from PSIM application interface were used to analyze the performance of the proposed converter. Transformer used in the circuit steps up the voltage as well as to provide electrical isolation between the low voltage and high voltage side. Since the converter involves high switching frequency of 100 kHz, ultrafast recovery diodes are employed in the circuitry. The major application of the project is for future modeling of solar powered electric hybrid cars.

  14. Five-Level Active-Neutral-Point-Clamped DC/DC Converter for Medium-Voltage DC Grids

    DEFF Research Database (Denmark)

    Liu, Dong; Deng, Fujin; Chen, Zhe

    2017-01-01

    This paper proposes a five-level active-neutralpoint- clamped (5L-ANPC) dc/dc converter for applications in medium voltage dc (MVDC) grids. A modulation strategy is proposed for the 5L-ANPC dc/dc converter to generate multilevel voltage waveforms, which can effectively reduce voltage change rate dv...... effectively eliminate high voltage leaps caused by the dead time effect. In addition, a capacitor voltage control strategy is proposed for the 5L-ANPC dc/dc converter to ensure the balanced flying capacitor voltage and desired five-level voltage waveforms. Finally, simulation and experimental studies...

  15. High Efficiency Power Converter for Low Voltage High Power Applications

    DEFF Research Database (Denmark)

    Nymand, Morten

    The topic of this thesis is the design of high efficiency power electronic dc-to-dc converters for high-power, low-input-voltage to high-output-voltage applications. These converters are increasingly required for emerging sustainable energy systems such as fuel cell, battery or photo voltaic based...

  16. Communication between a Matrix Converter Modulator and a Superset Regulator

    Directory of Open Access Journals (Sweden)

    P. Pošta

    2008-01-01

    Full Text Available This work deals with the modulator of a matrix converter and its communication with the superset regulator. A switching algorithm is briefly introduced. The input voltage measurement method is presented. In the last part of the paper, the testing of communication between the superset regulator and the modulator in FPGA technology are also presented. 

  17. Three-level boost converter with zero voltage transition

    Directory of Open Access Journals (Sweden)

    Kuo-Ing Hwu

    2017-06-01

    Full Text Available As compared with the traditional boost converter, the three-level boost converter possesses several advantages, such as lower switch voltage stresses and lower inductor current ripple. To improve the efficiency, this paper proposes a zero voltage transition (ZVT three-level boost converter. With the proposed ZVT circuit, the switches can achieve soft switching. Moreover, by using the voltage balance control, the output voltage can be equally across the output capacitors. In this study, the effectiveness of the proposed topology is verified by the experimental results based on the field-programmable gate array control.

  18. Cavity Voltage Phase Modulation MD

    CERN Document Server

    Mastoridis, Themistoklis; Molendijk, John; Timko, Helga; CERN. Geneva. ATS Department

    2016-01-01

    The LHC RF/LLRF system is currently configured for extremely stable RF voltage to minimize transient beam loading effects. The present scheme cannot be extended beyond nominal beam current since the demanded power would exceed the peak klystron power and lead to saturation. A new scheme has therefore been proposed: for beam currents above nominal (and possibly earlier), the cavity phase modulation by the beam will not be corrected (transient beam loading), but the strong RF feedback and One-Turn Delay feedback will still be active for loop and beam stability in physics. To achieve this, the voltage set point will be adapted for each bunch. The goal of this MD was to test a new algorithm that would adjust the voltage set point to achieve the cavity phase modulation that would minimize klystron forward power.

  19. Capacitor Voltages Measurement and Balancing in Flying Capacitor Multilevel Converters Utilizing a Single Voltage Sensor

    DEFF Research Database (Denmark)

    Farivar, Glen; Ghias, Amer M. Y. M.; Hredzak, Branislav

    2017-01-01

    This paper proposes a new method for measuring capacitor voltages in multilevel flying capacitor (FC) converters that requires only one voltage sensor per phase leg. Multiple dc voltage sensors traditionally used to measure the capacitor voltages are replaced with a single voltage sensor at the ac...... side of the phase leg. The proposed method is subsequently used to balance the capacitor voltages using only the measured ac voltage. The operation of the proposed measurement and balancing method is independent of the number of the converter levels. Experimental results presented for a five-level FC...

  20. A Voltage Doubler Circuit to Extend the Soft-switching Range of Dual Active Bridge Converters

    DEFF Research Database (Denmark)

    Qin, Zian; Shen, Yanfeng; Wang, Huai

    2017-01-01

    A voltage doubler circuit is realized to extend the soft-switching range of Dual Active Bridge (DAB) converters. No extra hardware is added to the DAB to form this circuit, since it is composed of the dc blocking capacitor and the low side full bridge converter, which already exist in DAB....... With the voltage doubler, the DAB converter can achieve soft switching and high efficiency when the low side dc voltage is close to 2 pu (1 pu is the high side dc voltage divided by the transformer turn ratio), which can be realized only when the low side dc voltage is close to 1 pu by using the conventional phase...... shift modulation in DAB. Thus the soft switching range is extended. The soft switching boundary conditions are derived. A map to show the soft switching or hard switching in the full load and voltage range is obtained. The feasibility and effectiveness of the proposed method is finally verified...

  1. A soft switching with reduced voltage stress ZVT-PWM full-bridge converter

    Science.gov (United States)

    Sahin, Yakup; Ting, Naim Suleyman; Acar, Fatih

    2018-04-01

    This paper introduces a novel active snubber cell for soft switching pulse width modulation DC-DC converters. In the proposed converter, the main switch is turned on under zero voltage transition and turned off under zero voltage switching (ZVS). The auxiliary switch is turned on under zero current switching (ZCS) and turned off under zero current transition. The main diode is turned on under ZVS and turned off under ZCS. All of the other semiconductors in the converter are turned on and off with soft switching. There is no extra voltage stress on the semiconductor devices. Besides, the proposed converter has simple structure and ease of control due to common ground. The detailed theoretical analysis of the proposed converter is presented and also verified with both simulation and experimental study at 100 kHz switching frequency and 600 W output power. Furthermore, the efficiency of the proposed converter is 95.7% at nominal power.

  2. High Efficiency Power Converter for Low Voltage High Power Applications

    DEFF Research Database (Denmark)

    Nymand, Morten

    The topic of this thesis is the design of high efficiency power electronic dc-to-dc converters for high-power, low-input-voltage to high-output-voltage applications. These converters are increasingly required for emerging sustainable energy systems such as fuel cell, battery or photo voltaic based......, and remote power generation for light towers, camper vans, boats, beacons, and buoys etc. A review of current state-of-the-art is presented. The best performing converters achieve moderately high peak efficiencies at high input voltage and medium power level. However, system dimensioning and cost are often...

  3. Number-to-voltage converter on commutated condensers

    International Nuclear Information System (INIS)

    Grekhov, Yu.N.

    1975-01-01

    A code-voltage converter using precision voltage dividers based on commutated capacitors [1] is described which is distinguished by the absence of precision elements. Each digit includes eight field-effect transistors in two 1KT682 microcircuit assemblies and three microcapacitors with a conventional unstable capacitance 6200 pF +- 50%. The converter has a speed of response that is not inferior to that of converters based on R-2R matrices, while in time stability of the characteristics, low interference level, and low output impedance it is superior to such converters

  4. PLL strategies of grid connected converters under distorted input voltages

    Czech Academy of Sciences Publication Activity Database

    Šimek, Petr; Škramlík, Jiří; Valouch, Viktor

    2014-01-01

    Roč. 59, č. 1 (2014), s. 1-12 ISSN 0001-7043 Institutional support: RVO:61388998 Keywords : voltage source converter * grid - connected applications * phase locked loop Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  5. Multi-Port High Voltage Gain Modular Power Converter for Offshore Wind Farms

    Directory of Open Access Journals (Sweden)

    Sen Song

    2018-06-01

    Full Text Available In high voltage direct current (HVDC power transmission of offshore wind power systems, DC/DC converters are applied to transfer power from wind generators to HVDC terminals, and they play a crucial role in providing a high voltage gain, high efficiency, and high fault tolerance. This paper introduces an innovative multi-port DC/DC converter with multiple modules connected in a scalable matrix configuration, presenting an ultra-high voltage step-up ratio and low voltage/current rating of components simultaneously. Additionally, thanks to the adoption of active clamping current-fed push–pull (CFPP converters as sub-modules (SMs, soft-switching is obtained for all power switches, and the currents of series-connected CFPP converters are auto-balanced, which significantly reduce switching losses and control complexity. Furthermore, owing to the expandable matrix structure, the output voltage and power of a modular converter can be controlled by those of a single SM, or by adjusting the column and row numbers of the matrix. High control flexibility improves fault tolerance. Moreover, due to the flexible control, the proposed converter can transfer power directly from multiple ports to HVDC terminals without bus cable. In this paper, the design of the proposed converter is introduced, and its functions are illustrated by simulation results.

  6. High voltage dc-dc converter with dynamic voltage regulation and decoupling during load-generated arcs

    Science.gov (United States)

    Shimer, Daniel W.; Lange, Arnold C.

    1995-01-01

    A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules.

  7. High voltage dc--dc converter with dynamic voltage regulation and decoupling during load-generated arcs

    Science.gov (United States)

    Shimer, D.W.; Lange, A.C.

    1995-05-23

    A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules. 5 Figs.

  8. SVPWM Technique with Varying DC-Link Voltage for Common Mode Voltage Reduction in a Matrix Converter and Analytical Estimation of its Output Voltage Distortion

    Science.gov (United States)

    Padhee, Varsha

    Common Mode Voltage (CMV) in any power converter has been the major contributor to premature motor failures, bearing deterioration, shaft voltage build up and electromagnetic interference. Intelligent control methods like Space Vector Pulse Width Modulation (SVPWM) techniques provide immense potential and flexibility to reduce CMV, thereby targeting all the afore mentioned problems. Other solutions like passive filters, shielded cables and EMI filters add to the volume and cost metrics of the entire system. Smart SVPWM techniques therefore, come with a very important advantage of being an economical solution. This thesis discusses a modified space vector technique applied to an Indirect Matrix Converter (IMC) which results in the reduction of common mode voltages and other advanced features. The conventional indirect space vector pulse-width modulation (SVPWM) method of controlling matrix converters involves the usage of two adjacent active vectors and one zero vector for both rectifying and inverting stages of the converter. By suitable selection of space vectors, the rectifying stage of the matrix converter can generate different levels of virtual DC-link voltage. This capability can be exploited for operation of the converter in different ranges of modulation indices for varying machine speeds. This results in lower common mode voltage and improves the harmonic spectrum of the output voltage, without increasing the number of switching transitions as compared to conventional modulation. To summarize it can be said that the responsibility of formulating output voltages with a particular magnitude and frequency has been transferred solely to the rectifying stage of the IMC. Estimation of degree of distortion in the three phase output voltage is another facet discussed in this thesis. An understanding of the SVPWM technique and the switching sequence of the space vectors in detail gives the potential to estimate the RMS value of the switched output voltage of any

  9. Converter topologies for common mode voltage reduction

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Fernando

    2017-11-21

    An inverter includes a three-winding transformer, a DC-AC inverter electrically coupled to the first winding of the transformer, a cycloconverter electrically coupled to the second winding of the transformer, and an active filter electrically coupled to the third winding of the transformer. The DC-AC inverter is adapted to convert the input DC waveform to an AC waveform delivered to the transformer at the first winding. The cycloconverter is adapted to convert an AC waveform received at the second winding of the transformer to the output AC waveform having a grid frequency of the AC grid. The active filter is adapted to sink and source power with one or more energy storage devices based on a mismatch in power between the DC source and the AC grid. At least two of the DC-AC inverter, the cycloconverter, or the active filter are electrically coupled via a common reference electrical interconnect.

  10. Wide-range voltage modulation

    International Nuclear Information System (INIS)

    Rust, K.R.; Wilson, J.M.

    1992-06-01

    The Superconducting Super Collider's Medium Energy Booster Abort (MEBA) kicker modulator will supply a current pulse to the abort magnets which deflect the proton beam from the MEB ring into a designated beam stop. The abort kicker will be used extensively during testing of the Low Energy Booster (LEB) and the MEB rings. When the Collider is in full operation, the MEBA kicker modulator will abort the MEB beam in the event of a malfunction during the filling process. The modulator must generate a 14-μs wide pulse with a rise time of less than 1 μs, including the delay and jitter times. It must also be able to deliver a current pulse to the magnet proportional to the beam energy at any time during ramp-up of the accelerator. Tracking the beam energy, which increases from 12 GeV at injection to 200 GeV at extraction, requires the modulator to operate over a wide range of voltages (4 kV to 80 kV). A vacuum spark gap and a thyratron have been chosen for test and evaluation as candidate switches for the abort modulator. Modulator design, switching time delay, jitter and pre-fire data are presented

  11. Influence of current limitation on voltage stability with voltage sourced converter HVDC

    DEFF Research Database (Denmark)

    Zeni, Lorenzo; Jóhannsson, Hjörtur; Hansen, Anca Daniela

    2013-01-01

    A first study of voltage stability with relevant amount of Voltage Sourced Converter based High Voltage Direct Current (VSC-HVDC) transmission is presented, with particular focus on the converters’ behaviour when reaching their rated current. The detrimental effect of entering the current...

  12. Frequency to Voltage Converter Analog Front-End Prototype

    Science.gov (United States)

    Mata, Carlos; Raines, Matthew

    2012-01-01

    The frequency to voltage converter analog front end evaluation prototype (F2V AFE) is an evaluation board designed for comparison of different methods of accurately extracting the frequency of a sinusoidal input signal. A configurable input stage is routed to one or several of five separate, configurable filtering circuits, and then to a configurable output stage. Amplifier selection and gain, filter corner frequencies, and comparator hysteresis and voltage reference are all easily configurable through the use of jumpers and potentiometers.

  13. New series half-bridge converters with the balance input split capacitor voltages

    Science.gov (United States)

    Lin, Bor-Ren; Chiang, Huann-Keng; Wang, Shang-Lun

    2016-03-01

    This article presents a new dc/dc converter to perform the main functions of zero voltage switching (ZWS), low converter size, high switching frequency and low-voltage stress. Metal-oxide-semiconductor field-effect transistors (MOSFETs) with high switching frequency are used to reduce the converter size and increase circuit efficiency. To overcome low-voltage stress and high turn-on resistance of MOSFETs, the series half-bridge topology is adopted in the proposed converter. Hence, the low-voltage stress MOSFETs can be used for medium-input voltage applications. The asymmetric pulse-width modulation is used to generate the gating signals and achieve the ZWS. On the secondary side, the parallel connection of two diode rectifiers is adopted to reduce the current rating of passive components. On the primary side, the series connection of two transformers is used to balance two output inductor currents. Two flying capacitors are used to automatically balance the input split capacitor voltages. Finally, experiments with 1000 W rated power are performed to verify the theoretical analysis and the effectiveness of proposed converter.

  14. Angle Stability Analysis for Voltage-Controlled Converters

    DEFF Research Database (Denmark)

    Lin, Hengwei; Jia, Chenxi; Guerrero, Josep M.

    2017-01-01

    a criterion to analyze the quasi-steady angle stability and the direct current (DC) side stability for VSCs. The operating limit and the angle instability mechanism are revealed, which is generally applicable to the voltage-controlled converters. During the analysis, the influence of the parameters on angle...... stability is studied. Further, the difference on instability mechanism between power electronic converters and synchronous generators are explained in detail. Finally, experiment results with corrective actions verify the analysis....

  15. Thyristor voltage converter in induction electric drives with microprocessor control

    Energy Technology Data Exchange (ETDEWEB)

    Braslavsky, I.; Zuzev, A.; Shilin, S. [Electric Drive Department, Urals State Technical University, Ekaterinburg (Russian Federation)

    1997-12-31

    The paper consists of some results on developed pulse model of thyristor voltage converter which is one of the most mathematically complicated unit of electric drive. The model structure and model parameter calculating method are represented. The application of the model allows to analyse stability in `locally` by the linear pulse system theory methods with talking into consideration quantise processes within the converter. Such application provides the obtaining higher accurate results comparing with the non-linear system theory approximate methods. Logarithmic frequency characteristics are used to analyse converter dynamic features and they are represented too. (orig.) 4 refs.

  16. High Voltage Bi-directional Flyback Converter for Capacitive Actuator

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Zhang, Zhe; Andersen, Michael A. E.

    2013-01-01

    in the converter, including the most dominating parameters of the high voltage transformer viz., self-capacitance and leakage inductance. The specific capacitive load for this converter is a dielectric electro active polymer (DEAP) actuator, which can be used as an effective replacement for conventional actuators...... in a number of applications. In this paper, the discharging energy efficiency definition is introduced. The proposed converter has been experimentally tested with the film capacitive load and the DEAP actuator, and the experimental results are shown together with the efficiency measurements....

  17. Primary Paralleled Isolated Boost Converter with Extended Operating Voltage Range

    DEFF Research Database (Denmark)

    Hernandez Botella, Juan Carlos; Sen, Gökhan; Mira Albert, Maria del Carmen

    2012-01-01

    Applications requiring wide input and output voltage range cannot often be satisfied by using buck or boost derived topologies. Primary paralleled isolated boost converter (PPIBC) [1]-[2] is a high efficiency boost derived topology. This paper proposes a new operation mode for extending the input...

  18. Double input converters for different voltage sources with isolated charger

    Directory of Open Access Journals (Sweden)

    Chalash Sattayarak

    2014-09-01

    Full Text Available This paper presents the double input converters for different voltage input sources with isolated charger coils. This research aims to increase the performance of the battery charger circuit. In the circuit, there are the different voltage levels of input source. The operating modes of the switch in the circuit use the microcontroller to control the battery charge and to control discharge mode automatically when the input voltage sources are lost from the system. The experimental result of this research shows better performance for charging at any time period of the switch, while the voltage input sources work together. Therefore, this research can use and develop to battery charger for present or future.

  19. A Zero-Voltage Switching Control Strategy for Dual Half-Bridge Cascaded Three-Level DC/DC Converter with Balanced Capacitor Voltages

    DEFF Research Database (Denmark)

    Liu, Dong; Wang, Yanbo; Chen, Zhe

    2017-01-01

    The input capacitor's voltages are unbalanced under the conventional control strategy in a dual half-bridge cascaded three-level (TL) DC/DC converter, which would affect the high voltage stresses on the capacitors. This paper proposes a pulse-wide modulation (PWM) strategy with two working modes...... for the dual half-bridge cascaded TL DC/DC converter, which can realize the zero-voltage switching (ZVS). More significantly, a capacitor voltage balance control is proposed by alternating the two working modes of the proposed ZVS PWM strategy, which can eliminate the voltage unbalance on the four input...... capacitors. Therefore, the proposed control strategy can improve the converter's performances in: 1) reducing the switching losses and noises of the power switches; and 2) reducing the voltage stresses on the input capacitors. Finally, the simulation results are conducted to verify the proposed control...

  20. Parallel operation of voltage-source converters: issues and applications

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, F.C.B.; Silva, D.S. [Federal University of Juiz de Fora (UFJF), MG (Brazil)], Emails: felipe.brum@engenharia.ufjf.br, salomaoime@yahoo.com.br; Ribeiro, P.F. [Calvin College, Grand Rapids, MI (United States); Federal University of Juiz de Fora (UFJF), MG (Brazil)], E-mail: pfribeiro@ieee.org

    2009-07-01

    Technological advancements in power electronics have prompted the development of advanced AC/DC conversion systems with high efficiency and flexible performance. Among these devices, the Voltage-Source Converter (VSC) has become an essential building block. This paper considers the parallel operation of VSCs under different system conditions and how they can assist the operation of highly complex power networks. A multi-terminal VSC-based High Voltage Direct Current (M-VSC-HVDC) system is chosen to be modeled, simulated and then analyzed as an example of VSCs operating in parallel. (author)

  1. Current integrator using the voltage to frequency converter

    International Nuclear Information System (INIS)

    Ukai, K.; Gomi, K.

    1975-01-01

    A current integrator using the Voltage to Frequency Converter has been constructed to measure the beam intensity of the 1.3 GeV Electron Synchrotron at the INS. This integrator ranges the current 10 -7 to 10 -11 amperes and has been calibrated by the extracted electron beam and constant current sources. The accuracy of this integrator agrees with the previous integrator within 1%. (auth.)

  2. Programmable differential capacitance-to-voltage converter for MEMS accelerometers

    Science.gov (United States)

    Royo, G.; Sánchez-Azqueta, C.; Gimeno, C.; Aldea, C.; Celma, S.

    2017-05-01

    Capacitive MEMS sensors exhibit an excellent noise performance, high sensitivity and low power consumption. They offer a huge range of applications, being the accelerometer one of its main uses. In this work, we present the design of a capacitance-to-voltage converter in CMOS technology to measure the acceleration from the capacitance variations. It is based on a low-power, fully-differential transimpedance amplifier with low input impedance and a very low input noise.

  3. A voltage to frequency converter for astronomical photometry

    Science.gov (United States)

    Dunham, E.; Elliot, J. L.

    1978-01-01

    A voltage to frequency converter (VFC) for general use with photomultipliers is described. For high light levels, when the dead-time corrections for a photon counter would be excessive, the VFC maintains a linear response and allows the recording of data at high time resolution. Results of laboratory tests are given for the signal-to-noise characteristics, linearity, stability, and transient response of the VFC when used in conjunction with EMI 9658 and RCA C31034 photomultipliers.

  4. Fast response double series resonant high-voltage DC-DC converter

    International Nuclear Information System (INIS)

    Lee, S S; Iqbal, S; Kamarol, M

    2012-01-01

    In this paper, a novel double series resonant high-voltage dc-dc converter with dual-mode pulse frequency modulation (PFM) control scheme is proposed. The proposed topology consists of two series resonant tanks and hence two resonant currents flow in each switching period. Moreover, it consists of two high-voltage transformer with the leakage inductances are absorbed as resonant inductor in the series resonant tanks. The secondary output of both transformers are rectified and mixed before supplying to load. In the resonant mode operation, the series resonant tanks are energized alternately by controlling two Insulated Gate Bipolar Transistor (IGBT) switches with pulse frequency modulation (PFM). This topology operates in discontinuous conduction mode (DCM) with all IGBT switches operating in zero current switching (ZCS) condition and hence no switching loss occurs. To achieve fast rise in output voltage, a dual-mode PFM control during start-up of the converter is proposed. In this operation, the inverter is started at a high switching frequency and as the output voltage reaches 90% of the target value, the switching frequency is reduced to a value which corresponds to the target output voltage. This can effectively reduce the rise time of the output voltage and prevent overshoot. Experimental results collected from a 100-W laboratory prototype are presented to verify the effectiveness of the proposed system.

  5. An inductor-based converter with EMI reduction for low-voltage thermoelectric energy harvesting

    Science.gov (United States)

    Wang, Chuang; Zhao, Kai; Li, Zunchao

    2017-07-01

    This paper presents a self-powered inductor-based converter which harvests thermoelectric energy and boosts extremely low voltage to a typical voltage level for supplying body sensor nodes. Electromagnetic interference (EMI) of the converter is reduced by spreading spectrum of fundamental frequency and harmonics via pseudo-random modulation, which is obtained via combining the linear feedback shift register and digitally controlled oscillator. Besides, the methods, namely extracting energy near MPP and reducing the power dissipation, are employed to improve the power efficiency. The presented inductor-based converter is designed and verified in CSMC CMOS 0.18-µm 1P6M process. The results reveal that it achieves the high efficiency and EMI reduction at the same time.

  6. Investigation and improvement of high step- up converters for pv module applications

    Directory of Open Access Journals (Sweden)

    Hamed moradmand jazi

    2017-01-01

    Full Text Available sun is of the clean and cheapest sources of energy. Charging slight energy to electricity is carried out by PV modules. Since most electric consumers need Ac input voltage, the PV modules output voltage should be changed into Ac form. But, the voltage level of PV modules is much lower than the voltage needed in input stage of inverters. Because of large voltage level. Difference it is not possible to use the basic boost and buck-boost converters. The basic boost and buck-boost converters definitely can not be used in this applications, for, they will face extreme drop in efficiency in duty cycles closer to unity. In this paper The proposed converter is presented in order to decrease the voltage stress of coupled inductors based high step-up converters. The voltage stress in the proposed converter is lower than the high step-up boost converter with coupled inductors in identical condition. Also, soft switching condition for switches and diodes is realized by active clamp circuit, and with this technique and proper selection of duty cycle, large gain and high efficiency could be achieved ultimately. . In this paper theoretical analysis is used for analyzing the performance of the proposed converters, and in order to verify the theoretical analysis, simulated results from pspice software is provides.

  7. Light-weight DC to very high voltage DC converter

    Science.gov (United States)

    Druce, R.L.; Kirbie, H.C.; Newton, M.A.

    1998-06-30

    A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current. 1 fig.

  8. Light-weight DC to very high voltage DC converter

    Energy Technology Data Exchange (ETDEWEB)

    Druce, Robert L. (Union City, CA); Kirbie, Hugh C. (Dublin, CA); Newton, Mark A. (Livermore, CA)

    1998-01-01

    A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current.

  9. A high voltage ratio and low ripple interleaved DC-DC converter for fuel cell applications.

    Science.gov (United States)

    Chang, Long-Yi; Chao, Kuei-Hsiang; Chang, Tsang-Chih

    2012-01-01

    This paper proposes a high voltage ratio and low ripple interleaved boost DC-DC converter, which can be used to reduce the output voltage ripple. This converter transfers the low DC voltage of fuel cell to high DC voltage in DC link. The structure of the converter is parallel with two voltage-doubler boost converters by interleaving their output voltages to reduce the voltage ripple ratio. Besides, it can lower the current stress for the switches and inductors in the system. First, the PSIM software was used to establish a proton exchange membrane fuel cell and a converter circuit model. The simulated and measured results of the fuel cell output characteristic curve are made to verify the correctness of the established simulation model. In addition, some experimental results are made to validate the effectiveness in improving output voltage ripple of the proposed high voltage ratio interleaved boost DC-DC converters.

  10. Current source converter based D-STATCOM for voltage sag mitigation

    Directory of Open Access Journals (Sweden)

    Singh Moirangthem Deben

    2015-01-01

    Full Text Available This paper presents a novel method of realizing one of the custom power controllers, the distribution static synchronous compensator (D-STATCOM using current source converter (CSC topology. Almost all the custom power controllers such as dynamic voltage restorer (DVR, unified power quality conditioner (UPQC including D-STATCOM are generally designed and implemented by using voltage source converters (VSC and not much research publications with CSC based approach has been reported over the last one decade. Since the D-STATCOM is a current injection device, its performance can be improved when realized by a current-source converter which can generate a controllable current directly at its output terminals and offers many advantageous features. In this paper, an attempt has been made to study the performance of a CSC based D-STATCOM suitable for use in the power distribution system in order to mitigate voltage sag and improve power quality. The proposed model uses a three leg CSC whose switching strategy is based on sinusoidal pulse width modulation (SPWM. The model has been simulated in the Matlab/Simulink environment. The results of the simulation runs under steady state and dynamic load perturbation provide excellent voltage and current waveforms that support the justification of the proposed model.

  11. Novel composite resonance DC-DC converter with voltage doubler rectifier

    OpenAIRE

    Kato, Hisatsugu; Matsuo, Hirohumi; Eguchi, Masaki; Sakamoto, Yukitaka; Nakaishi, Masaki

    2009-01-01

    This paper deals with a novel composite resonance DC-DC converter with the voltage doubler rectifier, which is developed to be applied to the power conditioner of the photovoltaic generation system. The proposed DC-DC converter has the current and voltage resonance functions. Therefore, the output voltage regulation can be achieved for the large variations of the input voltage and load. Also, this converter has the high power efficiency. The maximum power efficiency 96.1% can be realized.

  12. Solid-state high voltage modulator and its application to rf source high voltage power supplies

    International Nuclear Information System (INIS)

    Tooker, J.F.; Huynh, P.; Street, R.W.

    2009-01-01

    A solid-state high voltage modulator is described in which series-connected insulated-gate bipolar transistors (IGBTs) are switched at a fixed frequency by a pulse width modulation (PWM) regulator, that adjusts the pulse width to control the voltage out of an inductor-capacitor filter network. General Atomics proposed the HV power supply (HVPS) topology of multiple IGBT modulators connected to a common HVdc source for the large number of 1 MW klystrons in the linear accelerator of the Accelerator Production of Tritium project. The switching of 24 IGBTs to obtain 20 kVdc at 20 A for short pulses was successfully demonstrated. This effort was incorporated into the design of a -70 kV, 80 A, IGBT modulator, and in a short-pulse test 12 IGBTs regulated -5 kV at 50 A under PWM control. These two tests confirm the practicality of solid-state IGBT modulators to regulate high voltage at reasonable currents. Tokamaks such as ITER require large rf heating and current drive systems with multiple rf sources. A HVPS topology is presented that readily adapts to the three rf heating systems on ITER. To take advantage of the known economy of scale for power conversion equipment, a single HVdc source feeds multiple rf sources. The large power conversion equipment, which is located outside, converts the incoming utility line voltage directly to the HVdc needed for the class of rf sources connected to it, to further reduce cost. The HVdc feeds a set of IGBT modulators, one for each rf source, to independently control the voltage applied to each source, maximizing operational flexibility. Only the modulators are indoors, close to the rf sources, minimizing the use of costly near-tokamak floor space.

  13. An Algebraic Method of Synchronous Pulsewidth Modulation for Converters for Adjustable Speed Drives

    DEFF Research Database (Denmark)

    Oleschuk, Valentin; Blaabjerg, Frede

    2002-01-01

    This paper describes the basic peculiarities of a new method of feedforward synchronous pulsewidth modulation (PWM) of the output voltage of converters, based on one-stage closed-form strategy of PWM with pure algebraic control dependencies. It is applied to voltage source inverters with a contin......This paper describes the basic peculiarities of a new method of feedforward synchronous pulsewidth modulation (PWM) of the output voltage of converters, based on one-stage closed-form strategy of PWM with pure algebraic control dependencies. It is applied to voltage source inverters...... with a continuous scheme of conventional voltage space vector modulation and with two basic variants of symmetrical discontinuous PWM. Simulations give the behaviour of the proposed method and show the advantage of algebraic synchronous PWM compared with the typical asynchronous, for low indices of the frequency...

  14. Generic inertia emulation controller for multi-terminal voltage-source-converter high voltage direct current systems

    DEFF Research Database (Denmark)

    Zhu, Jiebei; Guerrero, Josep M.; Hung, William

    2014-01-01

    A generic Inertia Emulation Controller (INEC) scheme for Multi-Terminal Voltage-Source-Converter based HVDC (VSC-MTDC) systems is proposed and presented in this paper. The proposed INEC can be incorporated in any Grid-side Voltage-Source-Converter (GVSC) station, allowing the MTDC terminal...

  15. A Fixed-Frequency Bidirectional Resonant DC-DC Converter Suitable for Wide Voltage Gain Range

    DEFF Research Database (Denmark)

    Shen, Yanfeng; Wang, Huai; Blaabjerg, Frede

    2017-01-01

    This paper proposes a new bidirectional resonant dc-dc converter suitable for wide voltage gain range applications (e.g., energy storage systems). The proposed converter overcomes the narrow voltage gain range of conventional resonant DC-DC converters, and meanwhile achieves high efficiency...... and characteristics of the proposed converter are analyzed. Finally, a 1-kW converter prototype is built and the experimental results verify the theoretical analyses....

  16. Voltage-to-frequency converters CMOS design and implementation

    CERN Document Server

    Azcona Murillo, Cristina; Pueyo, Santiago Celma

    2013-01-01

    This book develops voltage-to-frequency converter (VFC) solutions integrated in standard CMOS technology to be used as a part of a microcontroller-based, multisensor interface in the environment of portable applications, particularly within a WSN node.  Coverage includes the total design flow of monolithic VFCs, according to the target application, as well as the analysis, design and implementation of the main VFC blocks, revealing the main challenges and solutions encountered during the design of such high performance cells. Four complete VFCs, each temperature compensated, are fully designed and evaluated: a programmable VFC that includes an offset frequency and a sleep/mode enable terminal; a low power rail-to-rail VFC; and two rail-to-rail differential VFCs.

  17. Gas tube-switched high voltage DC power converter

    Science.gov (United States)

    She, Xu; Bray, James William; Sommerer, Timothy John; Chokhawala, Rahul

    2018-05-15

    A direct current (DC)-DC converter includes a transformer and a gas tube-switched inverter circuit. The transformer includes a primary winding and a secondary winding. The gas tube-switched inverter circuit includes first and second inverter load terminals and first and second inverter input terminals. The first and second inverter load terminals are coupled to the primary winding. The first and second inverter input terminals are couplable to a DC node. The gas tube-switched inverter circuit further includes a plurality of gas tube switches respectively coupled between the first and second inverter load terminals and the first and second inverter input terminals. The plurality of gas tube switches is configured to operate to generate an alternating current (AC) voltage at the primary winding.

  18. Five-Level Converter with Low Switching Frequency Applied as DC Voltage Supply

    DEFF Research Database (Denmark)

    Rasmussen, Tonny Wederberg

    1999-01-01

    This paper describes the use of a multi-level converter as a DC supply. Equations for the converter will be deduced in the nondissipative case. The equations provide solutions to DC voltage and the angle of converter voltage. In addition the spectrum for the harmonics after the elimination of sel...

  19. The harmonic composition of the output voltage of a rectifier unit with a PWM voltage booster converter.

    OpenAIRE

    ПАНЧЕНКО, В В

    2015-01-01

    The author investigates a rectifier unit constructed on the basis of cascade connection of the main non-controlled m-pulse rectifier and PWM voltage booster converter. The research presents the analysis of the harmonic composition of the output voltage of a rectifier unit with a PWM voltage booster converter on completely controlled keys. The dependence of the relative harmonic amplitude on the commutation corner is defined. The estimation of a rectifier unit electromagnetic compatibility wit...

  20. Modified High Voltage Conversion Inverting Cuk DC-DC Converter for Renewable Energy Application

    DEFF Research Database (Denmark)

    Maroti, Pandav Kiran; Padmanaban, Sanjeevikumar; Wheeler, Patrick

    2017-01-01

    controlled device DC-DC topology. The voltage conversion ratio of proposed converter has increased by ten times of the conventional Cuk converterat a duty ratio of 90%. The detailed analysis of the voltage conversion ratio and losses occur due to internal resistance of components is done in the paper......The proposed exertion represents the modified high voltage conversion Cuk converter for renewable energy application. The proposed Cuk converter is a combination of the conventional boost converter and Cuk converter. The arrangement of the proposed converter make, such as, it becomes the single...

  1. Space Vector Modulation for an Indirect Matrix Converter with Improved Input Power Factor

    Directory of Open Access Journals (Sweden)

    Nguyen Dinh Tuyen

    2017-04-01

    Full Text Available Pulse width modulation strategies have been developed for indirect matrix converters (IMCs in order to improve their performance. In indirect matrix converters, the LC input filter is used to remove input current harmonics and electromagnetic interference problems. Unfortunately, due to the existence of the input filter, the input power factor is diminished, especially during operation at low voltage outputs. In this paper, a new space vector modulation (SVM is proposed to compensate for the input power factor of the indirect matrix converter. Both computer simulation and experimental studies through hardware implementation were performed to verify the effectiveness of the proposed modulation strategy.

  2. Cross Voltage Control with Inner Hysteresis Current Control for Multi-output Boost Converter

    DEFF Research Database (Denmark)

    Nami, Alireza; Zare, Firuz; Blaabjerg, Frede

    2009-01-01

    Multi-output boost (MOB) converter is a novel DC-DC converter unlike the regular boost converter, has the ability to share its total output voltage and to have different series output voltage from a given duty cycle for low and high power applications. In this paper, discrete voltage control...... with inner hysteresis current control loop has been proposed to keep the simplicity of the control law for the double-output MOB converter, which can be implemented by a combination of analogue and logical ICs or simple microcontroller to constrain the output voltages of MOB converter at their reference...... voltages against variation in load or input voltage. The salient features of the proposed control strategy are simplicity of implementation and ease to extend to multiple outputs in the MOB converter. Simulation and experimental results are presented to show the validity of control strategy....

  3. Modeling generalized interline power-flow controller (GIPFC using 48-pulse voltage source converters

    Directory of Open Access Journals (Sweden)

    Amir Ghorbani

    2018-05-01

    Full Text Available Generalized interline power-flow controller (GIPFC is one of the voltage-source controller (VSC-based flexible AC transmission system (FACTS controllers that can independently regulate the power-flow over each transmission line of a multiline system. This paper presents the modeling and performance analysis of GIPFC based on 48-pulsed voltage-source converters. This paper deals with a cascaded multilevel converter model, which is a 48-pulse (three levels voltage source converter. The voltage source converter described in this paper is a harmonic neutralized, 48-pulse GTO converter. The GIPFC controller is based on d-q orthogonal coordinates. The algorithm is verified using simulations in MATLAB/Simulink environment. Comparisons between unified power flow controller (UPFC and GIPFC are also included. Keywords: Generalized interline power-flow controller (GIPFC, Voltage source converter (VCS, 48-pulse GTO converter

  4. A Review of Passive Filters for Grid-Connected Voltage Source Converters

    DEFF Research Database (Denmark)

    Beres, Remus Narcis; Wang, Xiongfei; Blaabjerg, Frede

    2014-01-01

    LCL filter is the common interface between the Pulse Width Modulated Voltage Source Converter (PWM VSC) and the utility grid due to high harmonic attenuation capability and reduced size of the passive elements. The present paper investigates the most promising passive damping methods for the LCL...... topology but also propose an overview of high order filters capable to offer even more attenuation than the LCL filter at a reduced size. This is the case of more recently introduced LCL topology with tuned traps. However, it is shown that by decreasing the size of the passive elements the robustness...

  5. Low start-up voltage dc–dc converter with negative voltage control for thermoelectric energy harvesting

    Directory of Open Access Journals (Sweden)

    Pui-Sun Lei

    2015-01-01

    Full Text Available This Letter presents a low start-up voltage dc–dc converter for low-power thermoelectric systems which uses a native n-type MOS transistor as the start-up switch. The start-up voltage of the proposed converter is 300 mV and the converter does not need batteries to start up. The negative voltage control is proposed to reduce the leakage current caused by native n-type transistor and increase the efficiency. The proposed converter was designed using standard 0.18 µm CMOS process with chip size of 0.388 mm^2. The peak efficiency is 63% at load current of 1.5 mA. The proposed converter provides output voltage >1 V at maximum load current of 3.2 mA.

  6. Performance and scalability of isolated DC-DC converter topologies in low voltage, high current applications

    Energy Technology Data Exchange (ETDEWEB)

    Vaisanen, V.

    2012-07-01

    Fuel cells are a promising alternative for clean and efficient energy production. A fuel cell is probably the most demanding of all distributed generation power sources. It resembles a solar cell in many ways, but sets strict limits to current ripple, common mode voltages and load variations. The typically low output voltage from the fuel cell stack needs to be boosted to a higher voltage level for grid interfacing. Due to the high electrical efficiency of the fuel cell, there is a need for high efficiency power converters, and in the case of low voltage, high current and galvanic isolation, the implementation of such converters is not a trivial task. This thesis presents galvanically isolated DC-DC converter topologies that have favorable characteristics for fuel cell usage and reviews the topologies from the viewpoint of electrical efficiency and cost efficiency. The focus is on evaluating the design issues when considering a single converter module having large current stresses. The dominating loss mechanism in low voltage, high current applications is conduction losses. In the case of MOSFETs, the conduction losses can be efficiently reduced by paralleling, but in the case of diodes, the effectiveness of paralleling depends strongly on the semiconductor material, diode parameters and output configuration. The transformer winding losses can be a major source of losses if the windings are not optimized according to the topology and the operating conditions. Transformer prototyping can be expensive and time consuming, and thus it is preferable to utilize various calculation methods during the design process in order to evaluate the performance of the transformer. This thesis reviews calculation methods for solid wire, litz wire and copper foil winding losses, and in order to evaluate the applicability of the methods, the calculations are compared against measurements and FEM simulations. By selecting a proper calculation method for each winding type, the winding

  7. High-frequency high-voltage high-power DC-to-DC converters

    Science.gov (United States)

    Wilson, T. G.; Owen, H. A.; Wilson, P. M.

    1982-09-01

    A simple analysis of the current and voltage waveshapes associated with the power transistor and the power diode in an example current-or-voltage step-up (buck-boost) converter is presented. The purpose of the analysis is to provide an overview of the problems and design trade-offs which must be addressed as high-power high-voltage converters are operated at switching frequencies in the range of 100 kHz and beyond. Although the analysis focuses on the current-or-voltage step-up converter as the vehicle for discussion, the basic principles presented are applicable to other converter topologies as well.

  8. A Bidirectional Resonant DC-DC Converter Suitable for Wide Voltage Gain Range

    DEFF Research Database (Denmark)

    Shen, Yanfeng; Wang, Huai; Al-Durra, Ahmed

    2018-01-01

    This paper proposes a new bidirectional resonant dc-dc converter suitable for wide voltage gain range applications (e.g., energy storage systems). The proposed converter overcomes the narrow voltage gain range of conventional resonant dc-dc converters, and meanwhile achieves high efficiency...... losses. The operation principles and characteristics of the proposed converter are firstly analyzed in this paper. Then the analytical solutions for the voltage gain, soft-switching, and rms currents are derived, which facilitates the parameters design and optimization. Finally, the proposed topology...... and analysis are verified with experimental results obtained from a 1-kW converter prototype....

  9. A zero-voltage-switched three-phase interleaved buck converter

    Science.gov (United States)

    Hsieh, Yao-Ching; Huang, Bing-Siang; Lin, Jing-Yuan; Pham, Phu Hieu; Chen, Po-Hao; Chiu, Huang-Jen

    2018-04-01

    This paper proposes a three-phase interleaved buck converter which is composed of three identical paralleled buck converters. The proposed solution has three shunt inductors connected between each other of three basic buck conversion units. With the help of the shunt inductors, the MOSFET parasitic capacitances will resonate to achieve zero-voltage-switching. Furthermore, the decreasing rate of the current through the free-wheeling diodes is limited, and therefore, their reverse-recovery losses can be minimised. The active power switches are controlled by interleaved pulse-width modulation signals to reduce the input and output current ripples. Therefore, the filtering capacitances on the input and output sides can be reduced. The power efficiency is measured to be as high as 98% in experiment with a prototype circuit.

  10. A Component-Reduced Zero-Voltage Switching Three-Level DC-DC Converter

    DEFF Research Database (Denmark)

    Qin, Zian; Pang, Ying; Wang, Huai

    2016-01-01

    The basic Zero-Voltage Switching (ZVS) three-level DC-DC converter has one clamping capacitor to realize the ZVS of the switches, and two clamping diodes to clamp the voltage of the clamping capacitor. In order to reduce the reverse recovery loss of the diode as well as its cost, this paper...... proposes to remove one of the clamping diodes in basic ZVS three-level DC-DC converter. With less components, the proposed converter can still have a stable clamping capacitor voltage, which is clamped at half of the dc link voltage. Moreover, the ZVS performance will be influenced by removing the clamping...

  11. DC-Voltage Fluctuation Elimination Through a DC-Capacitor Current Control for DFIG Converters Under Unbalanced Grid Voltage Conditions

    DEFF Research Database (Denmark)

    Liu, Changjin; Xu, Dehong; Zhu, Nan

    2013-01-01

    Unbalanced grid voltage causes a large second-order harmonic current in the dc-link capacitors as well as dc-voltage fluctuation, which potentially will degrade the lifespan and reliability of the capacitors in voltage source converters. This paper proposes a novel dc-capacitor current control...... method for a grid-side converter (GSC) to eliminate the negative impact of unbalanced grid voltage on the dc-capacitors. In this method, a dc-capacitor current control loop, where a negative-sequence resonant controller is used to increase the loop gain, is added to the conventional GSC current control...... loop. The rejection capability to the unbalanced grid voltage and the stability of the proposed control system are discussed. The second-order harmonic current in the dc capacitor as well as dc-voltage fluctuation is very well eliminated. Hence, the dc capacitors will be more reliable under unbalanced...

  12. A Novel Quasi-SEPIC High-Voltage Boost DC-DC Converter

    DEFF Research Database (Denmark)

    Siwakoti, Yam Prasad; N. Soltani, Mohsen; Blaabjerg, Frede

    2017-01-01

    This paper proposes a modified coupled-inductor SEPIC dc-dc converter for low power and high voltage gain applications such as for piezoelectric drive systems. The converter uses the same components as of SEPIC converter with an additional diode. Compared to conventional topologies with similar...... voltage gain expression, the proposed topology uses less components to achieve same or even higher voltage gain. This helps to design a very compact and light weight converter with higher power density at lower cost. Due to brevity, the principle of operation, theoretical analysis and comparison supported...

  13. Voltage-Balancing Method for Modular Multilevel Converters Switched at Grid Frequency

    DEFF Research Database (Denmark)

    Deng, Fujin; Chen, Zhe

    2015-01-01

    The modular multilevel converter (MMC) becomes attractive for high-voltage and high-power applications due to its high modularity, availability, and power quality. The voltage balance issue of capacitors is very important in the MMC, and the balancing of the capacitor voltage is increasingly...

  14. Distributed Low Voltage Ride-Through Operation of Power Converters in Grid-Connected Microgrids under Voltage Sags

    DEFF Research Database (Denmark)

    Zhao, Xin; Meng, Lexuan; Dragicevic, Tomislav

    2015-01-01

    it can make the MG a contributor in smooth ride through the faults. In this paper, a reactive power support strategy using droop controlled converters is proposed to aid MG riding through three phase symmetrical voltage sags. In such a case, the MGs should inject reactive power to the grid to boost...... the voltage in all phases at AC common bus. However, since the line admittances from each converter to point of common coupling (PCC) are not identical, the injected reactive power may not be equally shared. In order to achieve low voltage ride through (LVRT) capability along with a good power sharing...

  15. Analysis of high voltage step-up nonisolated DC-DC boost converters

    Science.gov (United States)

    Alisson Alencar Freitas, Antônio; Lessa Tofoli, Fernando; Junior, Edilson Mineiro Sá; Daher, Sergio; Antunes, Fernando Luiz Marcelo

    2016-05-01

    A high voltage step-up nonisolated DC-DC converter based on coupled inductors suitable to photovoltaic (PV) systems applications is proposed in this paper. Considering that numerous approaches exist to extend the voltage conversion ratio of DC-DC converters that do not use transformers, a detailed comparison is also presented among the proposed converter and other popular topologies such as the conventional boost converter and the quadratic boost converter. The qualitative analysis of the coupled-inductor-based topology is developed so that a design procedure can be obtained, from which an experimental prototype is implemented to validate the theoretical assumptions.

  16. High-voltage transistor converter for pulsed x-ray sources

    International Nuclear Information System (INIS)

    Krasil'nikov, S.B.; Kristalinskii, A.L.; Lozovoi, L.N.; Markov, S.N.; Sindalovskii, E.I.

    1986-01-01

    A 24-V/12-kV converter for MIRA-2D and NORA pulsed x-ray sources is described. When the low-voltage supply varies within 20-26 V, the frequency stability of the x-ray pulses is higher by a factor of 3 ≅ 3 than when the PRIMA converter is used. For 14-24 V, the average output power of the converter is independent of the load impedance and increases linearly with an increase in supply voltage. The efficiency of the converter reaches 60%. The converter operates in the temperature range of -40 to +60 0 C

  17. 1 GHz GaAs Buck Converter for High Power Amplifier Modulation Applications

    NARCIS (Netherlands)

    Busking, E.B.; Hek, A.P. de; Vliet, F.E. van

    2012-01-01

    A fully integrated 1 GHz buck converter output stage, including on-chip inductor and DC output filtering has been realized, in a standard high-voltage breakdown GaAs MMIC technology. This is a significant step forward in designing highspeed power control of supply-modulated HPAs (high power

  18. Double-Carrier Phase-Disposition Pulse Width Modulation Method for Modular Multilevel Converters

    DEFF Research Database (Denmark)

    Zhou, Fayun; Luo, An; Li, Yan

    2017-01-01

    Modular multilevel converters (MMCs) have become one of the most attractive topologies for high-voltage and high-power applications. A double-carrier phase disposition pulse width modulation (DCPDPWM) method for MMCs is proposed in this paper. Only double triangular carriers with displacement ang......, the proposed method and theoretical analysis are verified by simulation and experimental results. View Full-Text...

  19. A Comprehensive Analysis and Hardware Implementation of Control Strategies for High Output Voltage DC-DC Boost Power Converter

    Directory of Open Access Journals (Sweden)

    Sanjeevikumar Padmanaban

    2017-01-01

    Full Text Available Classical DC-DC converters used in high voltage direct current (HVDC power transmission systems, lack in terms of efficiency, reduced transfer gain and increased cost with sensor (voltage/current numbers. Besides, the internal self-parasitic behavior of the power components reduces the output voltage and efficiency of classical HV converters. This paper deals with extra high-voltage (EHV dc-dc boost converter by the application of voltage-lift technique to overcome the aforementioned deficiencies. The control strategy is based on classical proportional-integral (P-I and fuzzy logic closed-loop controller to get high and stable output voltage. Complete hardware prototype of EHV is implemented and experimental tasks are carried out with digital signal processor (DSP TMS320F2812. The control algorithms P-I, fuzzy logic and the pulse-width modulation (PWM signals for N-channel MOSFET device are performed by the DSP. The experimental results provided show good conformity with developed hypothetical predictions. Additionally, the presented study confirms that the fuzzy logic controller provides better performance than classical P-I controller under different perturbation conditions.

  20. Pulsewidth Modulation of Neutral-Point-Clamped Indirect Matrix Converter

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Poh Chiang, Loh; Gao, Feng

    2008-01-01

    An indirect matrix converter is an alternative "all-semiconductor" energy processor proposed recently for converting an ac source with fixed magnitude and frequency to a variable voltage and frequency supply that can meet the requirements of a particular industry application. In principle...

  1. Investigation of Efficiency and Thermal Performance of The Y-source Converters for a Wide Voltage Range

    Directory of Open Access Journals (Sweden)

    Brwene Salah Gadalla

    2015-12-01

    Full Text Available The Y-source topology has a unique advantage of having high voltages gain with small shoot through duty cycles. Furthermore, having the advantage of high modulation index which increase the power density and improve the performance of the converter. In this paper, a collective thermal and efficiency investigation has been performed in order to improve the reliability of the converter. Evaluation of relevant losses as ( switching, conduction, capacitor ESR, core and winding losses , and evaluation of the junction temperature of the devices under 25C ambient temperature. The analysis is done for different voltage gain factors (2, 3, and 4, and different winding factor (4, and 5 using PLECS toolbox. The results shows that the higher the voltage gain and winding factor, the higher power losses and rising in the junction temperature of the device.

  2. A Predictive-Control-Based Over-Modulation Method for Conventional Matrix Converters

    DEFF Research Database (Denmark)

    Zhang, Guanguan; Yang, Jian; Sun, Yao

    2018-01-01

    To increase the voltage transfer ratio of the matrix converter and improve the input/output current performance simultaneously, an over-modulation method based on predictive control is proposed in this paper, where the weighting factor is selected by an automatic adjusting mechanism, which is able...... to further enhance the system performance promptly. This method has advantages like the maximum voltage transfer ratio can reach 0.987 in the experiments; the total harmonic distortion of the input and output current are reduced, and the losses in the matrix converter are decreased. Moreover, the specific...

  3. Multi-stage LLC resonant converters designed for wide output voltage ranges

    OpenAIRE

    Tsang, C.-W.; Bingham, C. M.; Foster, M. P.; Stone, D. A.; Leech, J. M.

    2016-01-01

    The paper describes a novel multi-stage LLC resonant converter topology for facilitating wide output voltage ranges. This is achieved by combining the gain range of a capacitor-diode clamped LLC resonant converter with that of a traditional LLC resonant converter. A prototype converter is designed and commissioned to illustrate the design procedure and demonstrate resulting operational characteristics. Experimental results are used to show operational characteristics of the proposed conver...

  4. A high voltage gain quasi Z-source isolated DC/DC converter

    DEFF Research Database (Denmark)

    Siwakoti, Yam P.; Blaabjerg, Frede; Loh, Poh Chiang

    2014-01-01

    A compact quasi-Z-source DC/DC converter is presented with high voltage gain, isolated output, and improved efficiency. The improvements in size and performance were achieved by using a square wave inverter with only two output switches driving an isolating transformer in push-pull mode, followed...... by a voltage doubling output rectifier. The converter is well-suited to applications requiring a high voltage gain, especially renewable energy sources such as photovoltaic and fuel-cell power supplies. To demonstrate the converter's performance a prototype designed to output 400 V at 500 W was constructed...

  5. dc analysis and design of zero-voltage-switched multi-resonant converters

    Science.gov (United States)

    Tabisz, Wojciech A.; Lee, Fred C.

    Recently introduced multiresonant converters (MRCs) provide zero-voltage switching (ZVS) of both active and passive switches and offer a substantial reduction of transistor voltage stress and an increase of load range, compared to their quasi-resonant converter counterparts. Using the resonant switch concept, a simple, generalized analysis of ZVS MRCs is presented. The conversion ratio and voltage stress characteristics are derived for basic ZVS MRCs, including buck, boost, and buck/boost converters. Based on the analysis, a design procedure that optimizes the selection of resonant elements for maximum conversion efficiency is proposed.

  6. Flexible operation of parallel grid-connecting converters under unbalanced grid voltage

    DEFF Research Database (Denmark)

    Lu, Jinghang; Savaghebi, Mehdi; Guerrero, Josep M.

    2017-01-01

    -link voltage ripple, and overloading. Moreover, under grid voltage unbalance, the active power delivery ability is decreased due to the converter's current rating limitation. In this paper, a thorough study on the current limitation of the grid-connecting converter under grid voltage unbalance is conducted....... In addition, based on the principle that total output active power should be oscillation free, a coordinated control strategy is proposed for the parallel grid-connecting converters. The case study has been conducted to demonstrate the effectiveness of this proposed control strategy....

  7. A Four-Phase High Voltage Conversion Ratio Bidirectional DC-DC Converter for Battery Applications

    Directory of Open Access Journals (Sweden)

    Li-Kun Xue

    2015-06-01

    Full Text Available This study presents a four-phase interleaved high voltage conversion ratio bidirectional DC-DC converter circuit based on coupled inductors and switched capacitors, which can eliminate the defects of conventional high voltage conversion ratio bidirectional DC-DC converters in terms of high-voltage/current stress, less efficiency and low-power limitation. Parallel channels are used to reduce current stress at the low-voltage side and series connected switched capacitors are used to enlarge voltage conversion ratio, reduce voltage stress and achieve auto current sharing. This paper proposes the operation principle, feature analysis and optimization design considerations. On this basis the objectives of high voltage conversion ratio, low voltage/current stress, high power density, high efficiency and high-power applications can be achieved. Some experimental results based on a 500 W prototype converter (24 V to 48 V at low-voltage side, 400 V at high-voltage side are given to verify the theoretical analysis and the effectiveness of the proposed converter.

  8. A current to voltage converter for cryogenics using a CMOS operational amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, K; Saitoh, K; Shibayama, Y; Shirahama, K [Department of Physics, Keio University, Yokohama 223-8522 (Japan)], E-mail: khayashi@a2.keio.jp

    2009-02-01

    We have constructed a versatile current to voltage (I-V) converter operating at liquid helium temperature, using a commercially available all-CMOS OPamp. It is valuable for cryogenic measurements of electrical current of nano-pico amperes, for example, in scanning probe microscopy. The I-V converter is thermally linked to liquid helium bath and self-heated up to 10.7 K. We have confirmed its capability of a transimpedance gain of 10{sup 6} V/A and a bandwidth from DC to 200 kHz. In order to test the practical use for a frequency-modulation atomic force microscope, we have measured the resonance frequency shift of a quartz tuning fork at 32 kHz. In the operation of the I-V converter close to the sensor at liquid helium temperature, the signal-to-noise ratio has been improved to a factor of 13.6 compared to the operation at room temperature.

  9. A current to voltage converter for cryogenics using a CMOS operational amplifier

    International Nuclear Information System (INIS)

    Hayashi, K; Saitoh, K; Shibayama, Y; Shirahama, K

    2009-01-01

    We have constructed a versatile current to voltage (I-V) converter operating at liquid helium temperature, using a commercially available all-CMOS OPamp. It is valuable for cryogenic measurements of electrical current of nano-pico amperes, for example, in scanning probe microscopy. The I-V converter is thermally linked to liquid helium bath and self-heated up to 10.7 K. We have confirmed its capability of a transimpedance gain of 10 6 V/A and a bandwidth from DC to 200 kHz. In order to test the practical use for a frequency-modulation atomic force microscope, we have measured the resonance frequency shift of a quartz tuning fork at 32 kHz. In the operation of the I-V converter close to the sensor at liquid helium temperature, the signal-to-noise ratio has been improved to a factor of 13.6 compared to the operation at room temperature.

  10. High-Voltage DC-DC Converter Topology for PV Energy Utilization - Investigation and Implementation

    DEFF Research Database (Denmark)

    Sanjeevikumar, Padmanaban; Blaabjerg, Frede; Wheeler, Patrick

    2017-01-01

    This paper exploited the utilization of photovoltaic (PV) energy system with high-voltage (HV) output DC-DC converter. Classical boost converters are used for both renewable energy integration and HV applications, but limited by reducing output/efficiency in performance. Moreover, as parasitic...... elements suppress the power transfer ratio, converter needs to maximize the PV energy utilization. This investigation study focused to include additional parasitic elements (voltage-lift technique) to a standard DC-DC buck converter and to overcome all the above drawbacks to maximize the PV power...

  11. High Input Voltage Hall Thruster Discharge Converter, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall scope of this Phase I/II effort is the development of a high efficiency 15kW (nominal) Hall thruster discharge converter. In Phase I, Busek Co. Inc. will...

  12. A real time measurement of junction temperature variation in high power IGBT modules for wind power converter application

    DEFF Research Database (Denmark)

    Ghimire, Pramod; Pedersen, Kristian Bonderup; de Vega, Angel Ruiz

    2014-01-01

    This paper presents a real time measurement of on-state forward voltage and estimating the junction temperature for a high power IGBT module during a power converter operation. The power converter is realized as it can be used for a wind turbine system. The peak of the junction temperature is dec...

  13. A Review of Passive Power Filters for Three-Phase Grid-Connected Voltage-Source Converters

    DEFF Research Database (Denmark)

    Beres, Remus Narcis; Wang, Xiongfei; Liserre, Marco

    2016-01-01

    and source impedances. Furthermore, the stabilizing effect is more difficult to be guaranteed for cost-optimized filters, which are characterized by low inductance and high capacitance passive components. In this paper, several passive filter topologies used to interface voltage source converters......In order to reduce size and cost, high-order passive filters are generally preferred in power converters to cancel out high frequency harmonics caused by pulse width modulation. However, the filter resonance peaks may require the use of passive dampers to stabilize the interactions between the load...

  14. A comprehensive analysis and hardware implementation of control strategies for high output voltage DC-DC boost power converter

    OpenAIRE

    Padmanaban, Sanjeevikumar; Grandi, Gabriele; Blaabjerg, Frede; Wheeler, Patrick; Siano, Pierluigi; Hammami, Manel

    2017-01-01

    Classical DC-DC converters used in high voltage direct current (HVDC) power transmission systems, lack in terms of efficiency, reduced transfer gain and increased cost with sensor (voltage/current) numbers. Besides, the internal self-parasitic behavior of the power components reduces the output voltage and efficiency of classical HV converters. This paper deals with extra high-voltage (EHV) dc-dc boost converter by the application of voltage-lift technique to overcome the aforementioned defic...

  15. Design of High-Voltage Switch-Mode Power Amplifier Based on Digital-Controlled Hybrid Multilevel Converter

    Directory of Open Access Journals (Sweden)

    Yanbin Hou

    2016-01-01

    Full Text Available Compared with conventional Class-A, Class-B, and Class-AB amplifiers, Class-D amplifier, also known as switching amplifier, employs pulse width modulation (PWM technology and solid-state switching devices, capable of achieving much higher efficiency. However, PWM-based switching amplifier is usually designed for low-voltage application, offering a maximum output voltage of several hundred Volts. Therefore, a step-up transformer is indispensably adopted in PWM-based Class-D amplifier to produce high-voltage output. In this paper, a switching amplifier without step-up transformer is developed based on digital pulse step modulation (PSM and hybrid multilevel converter. Under the control of input signal, cascaded power converters with separate DC sources operate in PSM switch mode to directly generate high-voltage and high-power output. The relevant topological structure, operating principle, and design scheme are introduced. Finally, a prototype system is built, which can provide power up to 1400 Watts and peak voltage up to ±1700 Volts. And the performance, including efficiency, linearity, and distortion, is evaluated by experimental tests.

  16. An Integrated Inductor For Parallel Interleaved Three-Phase Voltage Source Converters

    DEFF Research Database (Denmark)

    Gohil, Ghanshyamsinh Vijaysinh; Bede, Lorand; Teodorescu, Remus

    2016-01-01

    Three phase Voltage Source Converters (VSCs) are often connected in parallel to realize high current output converter system. The harmonic quality of the resultant switched output voltage can be improved by interleaving the carrier signals of these parallel connected VSCs. As a result, the line...... of the state-of-the-art filtering solution. The performance of the integrated inductor is also verified by the experimental measurements....

  17. High voltage direct current transmission converters, systems and DC grids

    CERN Document Server

    Jovcic, Dragan

    2015-01-01

    This comprehensive reference guides the reader through all HVDC technologies, including LCC (Line Commutated Converter), 2-level VSC and VSC HVDC based on modular multilevel converters (MMC) for an in-depth understanding of converters, system level design, operating principles and modeling. Written in a tutorial style, the book also describes the key principles of design, control, protection and operation of DC transmission grids, which will be substantially different from the practice with AC transmission grids. The first dedicated reference to the latest HVDC technologies and DC grid developments; this is an essential resource for graduate students and researchers as well as engineers and professionals working on the design, modeling and operation of DC grids and HVDC.

  18. Space vector modulation strategy for neutral-point voltage balancing in three-level inverter systems

    DEFF Research Database (Denmark)

    Choi, Uimin; Lee, Kyo Beum

    2013-01-01

    This study proposes a space vector modulation (SVM) strategy to balance the neutral-point voltage of three-level inverter systems. The proposed method is implemented by combining conventional symmetric SVM with nearest three-vector (NTV) modulation. The conventional SVM is converted to NTV...... modulation by properly adding or subtracting a minimum gate-on time. In addition, using this method, the switching frequency is reduced and a decrease of switching loss would be yielded. The neutral-point voltage is balanced by the proposed SVM strategy without additional hardware or complex calculations....... Simulation and experimental results are shown to verify the validity and feasibility of the proposed SVM strategy....

  19. Dynamics of voltage source converter in a grid connected solar photovoltaic system

    DEFF Research Database (Denmark)

    Haribabu, Divyanagalakshmi; Vangari, Adithya; Sakamuri, Jayachandra N.

    2015-01-01

    This paper emphasises the modelling and control of a voltage source converter (VSC) for three phase grid connected PV system. The transfer functions for inner current control and outer DC link voltage control for VSC are derived. The controllers for VSC are designed based on PI and K factor contr...

  20. Multi-cell DC-DC converter with high step-down voltage ratio

    NARCIS (Netherlands)

    Tibola, G.; Duarte, J.L.; Blinov, A.

    2015-01-01

    The use of high voltage allows a power processing system to operate with low currents, improving efficiency. Nevertheless, final applications usually require low voltage inlet, which can be provided using modular multilevel converters submodules, for instance. However, every submodule's gate-unit

  1. Bidirectional current-voltage converters based on magnetostrictive/piezoelectric composites

    NARCIS (Netherlands)

    Jia, Y.; Or, S.W.; Chan, H.L.W.; Jiao, J.; Luo, H.; Van der Zwaag, S.

    2009-01-01

    We report a power supply-free, bidirectional electric current-voltage converter based on a coil-wound laminated composite of magnetostrictive alloy and piezoelectric crystal. An electric current applied to the coil induces a magnetic field, resulting in an electric voltage from the composite due to

  2. Investigating Enhancement Mode Gallium Nitride Power FETs in High Voltage, High Frequency Soft Switching Converters

    DEFF Research Database (Denmark)

    Nour, Yasser; Knott, Arnold; Jørgensen, Ivan Harald Holger

    2016-01-01

    An increased attention has been detected to develop smaller and lighter high voltage power converters in the range of 50V to 400V domain. The main applications for these converters are mainly focused for Power over Ethernet (PoE), LED lighting and AC adapters. This work will discuss a study...

  3. A Unified Voltage Harmonic Control Strategy for Coordinated Compensation with VCM and CCM Converters

    DEFF Research Database (Denmark)

    Zhao, Xin; Meng, Lexuan; Xie, Chuan

    2018-01-01

    -controlled mode (VCM) and current-controlled mode (CCM), need to cooperatively provide the compensation function. Aiming at this objective, this paper proposes a unified voltage harmonic mitigation strategy for VCM and CCM converters with high harmonic current sharing accuracy. Another advantage of the proposal......Harmonics have been considered as one of the major issues in modern power grids. Considering the high penetration level of power electronic converter interfaced distributed generators (DGs), it is of interest to provide ancillary services through DG interfacing converters, such as harmonic...... compensation. In case of that, multiple DG interfacing converters are utilized to compensate harmonics, and the compensation effort should be properly shared among these converters. However, it is rarely considered in existing literatures that converters operating in different modes, such as voltage...

  4. Novel Step-Up DC/DC Converter with No Right Half Plane Zero and Reduced Switched Voltage Stress Characteristics

    DEFF Research Database (Denmark)

    Mostaan, Ali; Alizadeh, Ebrahim; Soltani, Mohsen

    2014-01-01

    and the voltage transfer gain is obtained. It is also demonstrated that the voltage stress on all semiconductor devices is restricted to input voltage which allows the utilization of a power switch with lower drain source resistance. In order to further increase the voltage gain another switched capacitor voltage......Novel step-up DC/DC converter is introduced in this paper. This converter is realized with adding the switched capacitor voltage multiplier cell to the three switch step-down DC/DC converter that has been proposed in the literature. The proposed converter is analyzed in the steady state...

  5. DC-link Voltage Coordinative-Proportional Control in Cascaded Converter Systems

    DEFF Research Database (Denmark)

    Tian, Yanjun; Loh, Poh Chiang; Deng, Fujin

    2015-01-01

    PI controllers are frequently implemented in cascaded converter system to control the DC-link voltage, because they can achieve zero steady state error. However the PI controller adds a pole at the origin point and a zero on the left half plane, and it increases the control system type number......, and then the system is more difficult to control. This paper proposed a DC-link control method for the two stages cascaded converter, and it uses proportional controller for the DC-link voltage control. This control method can achieve zero steady state error on the DC-link voltage; reduce the control system type...

  6. Generalized modular multilevel converter and modulation

    DEFF Research Database (Denmark)

    Liu, Hui; Loh, Poh Chiang; Blaabjerg, Frede

    2014-01-01

    converters regulating a power grid. The generalized topology derived and notated as GMMC can then be altered to create various types of MMC, including the traditional topology that is presently well-known. This effort has not been previously discussed, and may smoothen the understanding of MMC operation...

  7. Elimination of output voltage oscillations in DC-DC converter using PWM with PI controller

    Directory of Open Access Journals (Sweden)

    Sreenivasappa Veeranna Bhupasandra

    2010-01-01

    Full Text Available In this paper the SIMULINK model of a PWM controlled DC-DC converter is modeled using switching function concept to control the speed of the DC motor. The presence of the voltage oscillation cycles due to higher switching frequency in the DC-DC converter is identified. The effect of these oscillations on the output voltage of the converter, Armature current, Developed torque and Speed of the DC motor is analyzed. In order to minimize the oscillation cycles the PI controller is proposed in the PWM controller.

  8. High Voltage Gain Dual Active Bridge Converter with an Extended Operation Range for Renewable Energy Systems

    DEFF Research Database (Denmark)

    Zhang, Zhe; Tomas Manez, Kevin; Yudi, Xiao

    2018-01-01

    Bridge (P2DAB) converter, i.e. low-voltage (LV) side parallel and high-voltage (HV) side series, is proposed to achieve high voltage gain and low current stress over switching devices and transformer windings. Given the unmodified P2DAB power stage, by regulating the phase-shift angle between......Developing bidirectional dc-dc converters has become a critical research topic and gains more and more attention in recent years due to the extensive applications of smart grids with energy storages, hybrid and electrical vehicles and dc microgrids. In this paper, a Partial Parallel Dual Active...... the paralleled active bridges, the power equations and voltage gain are then modified, and therefore the operation range can be extended effectively. The operating principles of the proposed converter and its power characteristics under various operation modes are studied, and the design constraints...

  9. Power angle control of grid-connected voltage source converter in a wind energy application

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Jan [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Electric Power Engineering

    1996-12-31

    In this thesis, the connection of a voltage source converter to the grid in a wind energy application is examined. The possibility of using a cheap control system without grid current measurements, is investigated. The control method is based on controlling the voltage angle of the inverter, which governs the active power flow. The highest frequency of the power variation, coming from wind turbine, is approx. 5 Hz. Since the proposed control method easily can handle such power variations it is very well suited for wind turbine applications. The characteristics of the system depend on the DC-link capacitor, the grid filter inductance and resistance. Large values of the resistance damp the system well but increase the energy losses. A high inductance leads to a reduced harmonic level on the grid but makes the system slower. By using feed-forward of the generator/rectifier current signal, the performance is increased compared to an ordinary PI-control. Combining the Linear Quadratic (LQ) control method with Kalman filtered input signals, a robust control method with a good performance is obtained. The LQ controller controls both the phase displacement angle and the modulation index, resulting in higher bandwidth, and the typical power angle resonance at the grid frequency disappears. 22 refs, 109 figs, 14 tabs

  10. High Voltage Coil Current Sensor for DC-DC Converters Employing DDCC

    Directory of Open Access Journals (Sweden)

    M. Drinovsky

    2015-12-01

    Full Text Available Current sensor is an integral part of every switching converter. It is used for over-current protection, regulation and in case of multiphase converters for balancing. A new high voltage current sensor for coil-based current sensing in DC-DC converters is presented. The sensor employs DDCC with high voltage input stage and gain trimming. The circuit has been simulated and implemented in 0.35 um BCD technology as part of a multiphase DC-DC converter where its function has been verified. The circuit is able to sustain common mode voltage on the input up to 40 V, it occupies 0.387*0.345 mm2 and consumes 3.2 mW typically.

  11. Novel Interleaved Converter with Extra-High Voltage Gain to Process Low-Voltage Renewable-Energy Generation

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2016-10-01

    Full Text Available This paper presents a novel interleaved converter (NIC with extra-high voltage gain to process the power of low-voltage renewable-energy generators such as photovoltaic (PV panel, wind turbine, and fuel cells. The NIC can boost a low input voltage to a much higher voltage level to inject renewable energy to DC bus for grid applications. Since the NIC has two circuit branches in parallel at frond end to share input current, it is suitable for high power applications. In addition, the NIC is controlled in an interleaving pattern, which has the advantages that the NIC has lower input current ripple, and the frequency of the ripple is twice the switching frequency. Two coupled inductors and two switched capacitors are incorporated to achieve a much higher voltage gain than conventional high step-up converters. The proposed NIC has intrinsic features such as leakage energy totally recycling and low voltage stress on power semiconductor. Thorough theoretical analysis and key parameter design are presented in this paper. A prototype is built for practical measurements to validate the proposed NIC.

  12. A high-voltage resonant converter for pulsed magnets

    International Nuclear Information System (INIS)

    Rafael, F.S.; Lira, A.C.; Apfelbaum, J.; Pomilio, J.A.

    1992-01-01

    A 500-W, 25-kV, parallel-loaded resonant converter has been built in order to feed the LNLS ring kicker magnets. The use of high frequency permits reduction of the transformer and filter sizes. The tank components are the transformer leakage inductance and winding capacitance. The switching frequency is 20 kHz, limited by the tank circuit characteristic. The load is an LC Pulse-Forming Network, which is discharged on the load by a thyratron tube. The current pulse rise and fall times are about 100 ns and the flat top is 200 ns, at 800 A. (author) 3 refs.; 7 figs

  13. High-Speed Fuses in IGBT based Voltage Source Converters

    DEFF Research Database (Denmark)

    Iov, Florin; Blaabjerg, Frede; Rasmussen, Henrik

    2005-01-01

    The demand for protection of power electronic applications has during the last couple of years increased regarding the high-power IGBT modules. Even with an active protection, a high power IGBT still has a risk of exhibiting a violent rupture in the case of a fault if IGBT fuses do not protect it...... protection. First, the problem of adding inductance in the DC-link circuit is treated, second a short discussion of the protection of the IGBT module is done, and finally, the impact of the high frequency loading on the current carrying capability of the fuses is presented....

  14. Low-Voltage, Low-Power, and Wide-Tuning-Range Ring-VCO for Frequency ΔΣ Modulator

    DEFF Research Database (Denmark)

    Tuan Vu, Cao; Wisland, Dag T.; Lande, Tor Sverre

    A low-voltage, low-power, and wide-tuning-range VCO which converts an analog input voltage to phase information for a frequency ΔΣ modulator is proposed in this paper. The VCO is based on a differential ring oscillator, which is improved with modified symmetric load and a positive feedback...

  15. An isolated bridgeless AC-DC PFC converter using a LC resonant voltage doubler rectifier

    Science.gov (United States)

    Lee, Sin-woo; Do, Hyun-Lark

    2016-12-01

    This paper proposed an isolated bridgeless AC-DC power factor correction (PFC) converter using a LC resonant voltage doubler rectifier. The proposed converter is based on isolated conventional single-ended primary inductance converter (SEPIC) PFC converter. The conduction loss of rectification is reduced than a conventional one because the proposed converter is designed to eliminate a full-bridge rectifier at an input stage. Moreover, for zero-current switching (ZCS) operation and low voltage stresses of output diodes, the secondary of the proposed converter is designed as voltage doubler with a LC resonant tank. Additionally, an input-output electrical isolation is provided for safety standard. In conclusion, high power factor is achieved and efficiency is improved. The operational principles, steady-state analysis and design equations of the proposed converter are described in detail. Experimental results from a 60 W prototype at a constant switching frequency 100 kHz are presented to verify the performance of the proposed converter.

  16. State-plane analysis of zero-voltage-switching resonant dc/dc power converters

    Science.gov (United States)

    Kazimierczuk, Marian K.; Morse, William D.

    The state-plane analysis technique for the zero-voltage-switching resonant dc/dc power converter family of topologies, namely the buck, boost, buck-boost, and Cuk converters is established. The state plane provides a compression of information that allows the designer to uniquely examine the nonlinear dynamics of resonant converter operation. Utilizing the state plane, resonant converter modes of operation are examined and the switching frequencies are derived for the boundaries between these modes, including the boundary of energy conversion.

  17. Auxiliary controller for time-to-digital converter module readout

    International Nuclear Information System (INIS)

    Ermolin, Yu.V.

    1992-01-01

    The KD-225 auxiliary controller for time-to-digital converter module readout in the SUMMA crate is described. After readout and preliminary processing the data are written in the P-140 buffer memory module. The controller is used in the FODS-2 experimental setup data acquisition system. 12 refs.; 1 fig

  18. A high efficiency photovoltaic module integrated converter with the asymmetrical half-bridge flyback converter

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Heeje; Kim, Jongrak; Shin, Dongsul [Department of Electrical Engineering, Pusan National University, Jangjeon, Geumjeong, Busan 609-735 (Korea); Kim, Hosung; Lee, Kyungjun [Department of Electrical Engineering, Pusan National University, Jangjeon, Geumjeong, Busan 609-735 (Korea); New and Renewable Energy System Research Center, Korea Electro-technology Research Institute, 28-1, Sungju-dong Changwon-si, Kyungsannam-do, 641-120 (Korea); Kim, Jonghyun; Yoo, Dongwook [New and Renewable Energy System Research Center, Korea Electro-technology Research Institute, 28-1, Sungju-dong Changwon-si, Kyungsannam-do, 641-120 (Korea)

    2010-08-15

    A module integrated converter (MIC) for a photovoltaic (PV) cell is important part of power conditioning system (PCS). It performs maximum power point tracking of a PV cell to generate the power as much as possible from solar energy. There are several methods for connection between the PV modules and the MICs. In order to avoid partial shading effects, converter-per-module approach was proposed. The MIC that performs maximum power point tracking (MPPT), if it is low efficiency, is no use. The MIC whose output is connected to the output of PV module was proposed for high efficiency. However, there are some problems. In this study, an asymmetrical half-bridge flyback converter is proposed instead of the original flyback converter with same method to solve the problems. The proposed MIC was built to verify the performance. The new topology using soft switching technique showed good performance for the efficiency. At the higher power, the efficiency of the proposed converter is higher than existing converter. (author)

  19. Long Lifetime DC-Link Voltage Stabilization Module for Smart Grid Application

    DEFF Research Database (Denmark)

    Wang, Huai; Chung, Henry; Liu, Wenchao

    2012-01-01

    Power converters enable efficient and flexible control and conversion of electric energy among different smart grid players (i.e. producers, energy storage systems, and loads). One of the expected features of smart grid is that it will be more reliable compared to conventional grid. However, power...... converters are one kind of the lifetime limiting components applied in smart grid. One of the major causes is the malfunction of electrolytic capacitors (E-Caps) which are widely used for stabilizing the dc-link voltage in various types of power converters applied in smart grid. A dc-link module is therefore...

  20. Junction temperature estimation method for a 600 V, 30A IGBT module during converter operation

    DEFF Research Database (Denmark)

    Choi, U. M.; Blaabjerg, F.; Iannuzzo, F.

    2015-01-01

    This paper proposes an accurate method to estimate the junction temperature using the on-state collector-emitter voltage at high current. By means of the proposed method, the estimation error which comes from the different temperatures of the interconnection materials in the module is compensated....... Finally, it leads to satisfactory estimated results. The proposed method has been verified by means of an IR (Infra-Red) camera during power converter operations when the loading current is sinusoidal....

  1. Short-circuit protection of LLC resonant converter using voltages across resonant tank elements

    Directory of Open Access Journals (Sweden)

    Denys Igorovych Zaikin

    2015-06-01

    Full Text Available This paper describes two methods for the short-circuit protection of the LLC resonant converter. One of them uses the voltage across the capacitor and the other uses the voltage across the inductor of the resonant tank. These voltages can be processed (integrated or differentiated to recover the resonant tank current. The two circuits illustrated in the described methods make it possible to develop a robust LLC converter design and to avoid using lossy current measurement elements, such as a shunt resistor or current transformer. The methods also allow measuring resonant tank current without breaking high-current paths and connecting the measuring circuit in parallel with the inductor or capacitor of the resonant tank. Practical implementations of these indirect current measurements have been experimentally tested for the short-circuit protection of the 1600 W LLC converter.

  2. High Efficiency Single Output ZVS-ZCS Voltage Doubled Flyback Converter

    Science.gov (United States)

    Kaliyaperumal, Deepa; Saju, Hridya Merin; Kumar, M. Vijaya

    2016-06-01

    A switch operating at high switching frequency increases the switching losses of the converter resulting in lesser efficiency. Hence this paper proposes a new topology which has resonant switches [zero voltage switching (ZVS)] in the primary circuit to eliminate the above said disadvantages, and voltage doubler zero current switching (ZCS) circuit in the secondary to double the output voltage, and hence the output power, power density and efficiency. The design aspects of the proposed topology for a single output of 5 V at 50 kHz, its simulation and hardware results are discussed in detail. The analysis of the results obtained from a 2.5 W converter reveals the superiority of the proposed converter.

  3. Enhanced DC-Link Capacitor Voltage Balancing Control of DC–AC Multilevel Multileg Converters

    DEFF Research Database (Denmark)

    Busquets-Monge, Sergio; Maheshwari, Ram Krishan; Nicolas-Apruzzese, Joan

    2015-01-01

    This paper presents a capacitor voltage balancing control applicable to any multilevel dc–ac converter formed by a single set of series-connected capacitors implementing the dc link and semiconductor devices, such as the diode-clamped topology. The control is defined for any number of dc-link vol......This paper presents a capacitor voltage balancing control applicable to any multilevel dc–ac converter formed by a single set of series-connected capacitors implementing the dc link and semiconductor devices, such as the diode-clamped topology. The control is defined for any number of dc...

  4. Investigation of Grid-connected Voltage Source Converter Performance under Unbalanced Faults

    DEFF Research Database (Denmark)

    Jia, Jundi; Yang, Guangya; Nielsen, Arne Hejde

    2016-01-01

    Renewable energy sources (RES) and HVDC links are typically interfaced with the grid by power converters, whose performance during grid faults is significantly different from that of traditional synchronous generators. This paper investigates the performance of grid-connected voltage source...... that the performance of VSCs varies with their control strategies. Negative-sequence current control is necessary to restrict converter current in each phase under unbalanced faults. Among presented control strategies, the balanced current control strategy complies with the present voltage support requirement best...

  5. Nonlinear control of voltage source converters in AC-DC power system.

    Science.gov (United States)

    Dash, P K; Nayak, N

    2014-07-01

    This paper presents the design of a robust nonlinear controller for a parallel AC-DC power system using a Lyapunov function-based sliding mode control (LYPSMC) strategy. The inputs for the proposed control scheme are the DC voltage and reactive power errors at the converter station and the active and reactive power errors at the inverter station of the voltage-source converter-based high voltage direct current transmission (VSC-HVDC) link. The stability and robust tracking of the system parameters are ensured by applying the Lyapunov direct method. Also the gains of the sliding mode control (SMC) are made adaptive using the stability conditions of the Lyapunov function. The proposed control strategy offers invariant stability to a class of systems having modeling uncertainties due to parameter changes and exogenous inputs. Comprehensive computer simulations are carried out to verify the proposed control scheme under several system disturbances like changes in short-circuit ratio, converter parametric changes, and faults on the converter and inverter buses for single generating system connected to the power grid in a single machine infinite-bus AC-DC network and also for a 3-machine two-area power system. Furthermore, a second order super twisting sliding mode control scheme has been presented in this paper that provides a higher degree of nonlinearity than the LYPSMC and damps faster the converter and inverter voltage and power oscillations. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  6. Zero-Voltage Switching PWM Strategy Based Capacitor Current-Balancing Control for Half-Bridge Three-Level DC/DC Converter

    DEFF Research Database (Denmark)

    Liu, Dong; Deng, Fujin; Zhang, Qi

    2018-01-01

    The current imbalance among the two input capacitors is one of the important issues of the half-bridge threelevel (HBTL) DC/DC converter, which would affect system performance and reliability. In this paper, a zero-voltage switching (ZVS) pulse-wide modulation (PWM) strategy including two operation...

  7. Voltage Impact of a Wave Energy Converter on an Unbalanced Distribution Grid and Corrective Actions

    Directory of Open Access Journals (Sweden)

    Hugo Mendonça

    2017-10-01

    Full Text Available Renewable energy is steadily increasing its penetration level in electric power systems. Wind and solar energy have reached a high degree of maturity, and their impacts on the grid are well known. However, this is not the case for emerging sources like wave energy. This work explores the impact of the fluctuating power injected by a wave energy converter on the distribution grid voltage and proposes a strategy for mitigating the induced voltage fluctuations. The paper describes the mechanics of how a fluctuating active power injection leads to grid voltage fluctuations and presents an unbalanced three-phase power flow tool that allows one to quantitatively analyze the voltage evolution at every phase and bus of a distribution grid driven by this power injection. The paper also proposes a corrective action for mitigating the voltage fluctuations that makes use of the hardware resources already available in the wave energy converter, by means of a control strategy on the reactive capability of the grid-side inverter. The use of a STATCOM as additional reactive compensation equipment is also explored. The effectiveness of the proposal is assessed in the IEEE 13-bus test feeder showing that, in some cases, the wave energy converter by itself is able to mitigate the voltage fluctuations that it causes. If not, a STATCOM can provide the extra reactive capability needed.

  8. Topology and Technology Survey on Medium Voltage Power Converters for Large Wind Turbines

    DEFF Research Database (Denmark)

    Sztykiel, Michal; Teodorescu, Remus; Munk-Nielsen, Stig

    2011-01-01

    Based on state-of-the-art within generator and power converter designs, this paper presents and justifies the most promising converter circuitries and concepts for future 10 MW wind turbines. In order to reduce losses and increase efficiency of the turbine, it is assumed that the bulky step...... by various circuit configurations of previously defined power modules....

  9. Optimized Controller Design for a 12-Pulse Voltage Source Converter Based HVDC System

    Science.gov (United States)

    Agarwal, Ruchi; Singh, Sanjeev

    2017-12-01

    The paper proposes an optimized controller design scheme for power quality improvement in 12-pulse voltage source converter based high voltage direct current system. The proposed scheme is hybrid combination of golden section search and successive linear search method. The paper aims at reduction of current sensor and optimization of controller. The voltage and current controller parameters are selected for optimization due to its impact on power quality. The proposed algorithm for controller optimizes the objective function which is composed of current harmonic distortion, power factor, and DC voltage ripples. The detailed designs and modeling of the complete system are discussed and its simulation is carried out in MATLAB-Simulink environment. The obtained results are presented to demonstrate the effectiveness of the proposed scheme under different transient conditions such as load perturbation, non-linear load condition, voltage sag condition, and tapped load fault under one phase open condition at both points-of-common coupling.

  10. Comparison of the converter systems for a high-voltage variable-frequency AC drive

    Directory of Open Access Journals (Sweden)

    G.G. Zhemerov

    2013-12-01

    Full Text Available Matlab-models of two converter systems of an 8 MW AC drive are developed, one based on a self-contained current inverter with cut-off diodes, the other based on a multilevel cascade voltage inverter. By applying virtual simulation, qualitative characteristics of these systems are compared.

  11. Input-current-shaper based on a modified SEPIC converter with low voltage stress

    DEFF Research Database (Denmark)

    Petersen, Lars

    2001-01-01

    The boost topology is often the designer's first choice when dealing with PFC front-ends. This topology is well documented in the literature and has obvious advantages like continuous input current and low voltage- and current-stress compared to other PFC topologies. The PFC SEPIC converter also...

  12. Grid-interfacing converter systems with enhanced voltage quality for microgrid application : concept and implementation

    NARCIS (Netherlands)

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

    2011-01-01

    Grid-interfacing converter systems with enhanced voltage quality are proposed for microgrid application in this paper. By adapting the conventional series-parallel structure, a group of grid-interfacing system topologies are proposed for the purpose of interfacing local generation/microgrid to the

  13. Method and apparatus for controlling LCL converters using asymmetric voltage cancellation techniques

    Science.gov (United States)

    Wu, Hunter; Sealy, Kylee Devro; Sharp, Bryan Thomas; Gilchrist, Aaron

    2016-01-26

    A method and apparatus for LCL resonant converter control utilizing Asymmetric Voltage Cancellation is described. The methods to determine the optimal trajectory of the control variables are discussed. Practical implementations of sensing load parameters are included. Simple PI, PID and fuzzy logic controllers are included with AVC for achieving good transient response characteristics with output current regulation.

  14. Analysis and Design of Symmetrical Capacitor Diode Voltage Multiplier Driven by LCL-T Resonant Converter

    Science.gov (United States)

    Malviya, Devesh; Borage, Mangesh Balkrishna; Tiwari, Sunil

    2017-12-01

    This paper investigates the possibility of application of Resonant Immittance Converters (RICs) as a current source for the current-fed symmetrical Capacitor-Diode Voltage Multiplier (CDVM) with LCL-T Resonant Converter (RC) as an example. Firstly, detailed characterization of the current-fed symmetrical CDVM is carried out using repeated simulations followed by the normalization of the simulation results in order to derive the closed-form curve fit equations to predict the operating modes, output voltage and ripple in terms of operating parameters. RICs, due to their ability to convert voltage source into a current source, become a possible candidate for the realization of current source for the current-fed symmetrical CDVM. Detailed analysis, optimization and design of LCL-T RC with CDVM is performed in this paper. A step by step design procedure for the design of CDVM and the converter is proposed. A 5-stage prototype symmetrical CDVM driven by LCL-T RC to produce 2.5 kV, 50 mA dc output voltage is designed, built and tested to validate the findings of the analysis and simulation.

  15. A Voltage and Frequency Control Strategy for Stand-Alone Full Converter Wind Energy Conversion Systems

    Directory of Open Access Journals (Sweden)

    Andrés Peña Asensio

    2018-02-01

    Full Text Available This paper addresses the design and analysis of a voltage and frequency control (VFC strategy for full converter (FC-based wind energy conversion systems (WECSs and its applicability for the supply of an isolated load. When supplying an isolated load, the role of the back-to-back converters in the FC must change with respect to a grid-connected application. Voltage and frequency are established by the FC line side converter (LSC, while the generator side converter (GSC is responsible for maintaining constant voltage in the DC link. Thus, the roles of the converters in the WECS are inverted. Under such control strategies, the LSC will automatically supply the load power and hence, in order to maintain a stable operation of the WECS, the wind turbine (WT power must also be controlled in a load-following strategy. The proposed VFC is fully modelled and a stability analysis is performed. Then, the operation of the WECS under the proposed VFC is simulated and tested on a real-time test bench, demonstrating the performance of the VFC for the isolated operation of the WECS.

  16. A 1 MEGAWATT POLYPHASE BOOST CONVERTER-MODULATOR FOR KLYSTRON PULSE APPLICATION

    International Nuclear Information System (INIS)

    Reass, W.A.; Doss, J.D.; Gribble, R.F.

    2001-01-01

    This paper describes electrical design criteria and first operational results a 140 kV, 1 MW average, 11 MW peak, zero-voltage-switching 20 kHz polyphase bridge, boost converter/modulator for klystron pulse application. The DC-DC converter derives the buss voltages from a standard 13.8 kV to 2300 Y substation cast-core transformer. Energy storage and filtering is provided by self-clearing metallized hazy polypropylene traction capacitors. Three ''H-Bridge'' Insulated Gate Bipolar Transistor (IGBT) switching networks are used to generate the polyphase 20 kHz transformer primary drive waveforms. The 20 kHz drive waveforms are chirped the appropriate duration to generate the desired klystron pulse width. PWM (pulse width modulation) of the individual 20 kHz pulses is utilized to provide regulated output waveforms with adaptive feedforward and feedback techniques. The boost transformer design utilizes amorphous nanocrystalline material that provides the required low core loss at design flux levels and switching frequencies. Resonant shunt-peaking is used on the transformer secondary to boost output voltage and resonate transformer leakage inductance. With the appropriate transformer leakage inductance and peaking capacitance, zero-voltage-switching of the IGBT's is attained, minimizing switching losses. A review of these design parameters and the first results of the performance characteristics will be presented

  17. PI and Fuzzy Control Strategies for High Voltage Output DC-DC Boost Power Converter - Hardware Implementation and Analysis

    DEFF Research Database (Denmark)

    Padmanaban, Sanjeevi Kumar; Blaabjerg, Frede; Siano, Pierluigi

    2016-01-01

    This paper presents the control strategies by Proportional-Integral (P-I) and Fuzzy Logic (FL) for a DC-DC boost power converter for high output voltage configuration. Standard DC-DC converters are traditionally used for high voltage direct current (HVDC) power transmission systems. But, lack its...... converter with inbuilt voltage-lift technique and overcome the aforementioned deficiencies. Further, the control strategy is adapted based on proportional-integral (P-I) and fuzzy logic, closed-loop controller to regulate the outputs and ensure the performances. Complete hardware prototype of EHV converter...... performances in terms of efficiency, reduced transfer gain and increased cost with sensor units. Moreover, the internal self-parasitic components reduce the output voltage and efficiency of classical high voltage converters (HVC). This investigation focused on extra high-voltage (EHV) DC-DC boost power...

  18. Interconnected High-Voltage Pulsed-Power Converters System Design for H− Ion Sources

    CERN Document Server

    Aguglia, D

    2014-01-01

    This paper presents the design and experimental validations of a system of three new high-voltage (HV) pulsedpower converters for the H− sources. The system requires three pulsed voltages (50, 40, and 25 kV to ground) at 2-Hz repetition rate, for 700 μs of usable flat-top. The solution presents ripplefree output voltages and minimal stored energy to protect the ion source from the consequences of arc events. Experimental results on the final full-scale prototype are presented. In case of short-circuit events, the maximal energy delivered to the source is in the Joule range. HV flat-top stability of 1% is experimentally achieved with a simple Proportional-Integral- Derivative regulation and preliminary tuned H− source (e.g., radio frequency control, gas injection, and so forth). The system is running since more than a year with no power converter failures and damage to the source.

  19. SSP Technology Investigation of a High-Voltage DC-DC Converter

    Science.gov (United States)

    Pappas, J. A.; Grady, W. M.; George, Patrick J. (Technical Monitor)

    2002-01-01

    The goal of this project was to establish the feasibility of a high-voltage DC-DC converter based on a rod-array triggered vacuum switch (RATVS) for the Space Solar Power system. The RATVS has many advantages over silicon and silicon-carbide devices. The RATVS is attractive for this application because it is a high-voltage device that has already been demonstrated at currents in excess of the requirement for an SSP device and at much higher per-device voltages than existing or near-term solid state switching devices. The RATVS packs a much higher specific power rating than any solid-state device and it is likely to be more tolerant of its surroundings in space. In addition, pursuit of an RATVS-based system would provide NASA with a nearer-term and less expensive power converter option for the SSP.

  20. Analysis of a Multilevel Dual Active Bridge (ML-DAB DC-DC Converter Using Symmetric Modulation

    Directory of Open Access Journals (Sweden)

    M. A. Moonem

    2015-04-01

    Full Text Available Dual active bridge (DAB converters have been popular in high voltage, low and medium power DC-DC applications, as well as an intermediate high frequency link in solid state transformers. In this paper, a multilevel DAB (ML-DAB has been proposed in which two active bridges produce two-level (2L-5L, 5L-2L and 3L-5L voltage waveforms across the high frequency transformer. The proposed ML-DAB has the advantage of being used in high step-up/down converters, which deal with higher voltages, as compared to conventional two-level DABs. A three-level neutral point diode clamped (NPC topology has been used in the high voltage bridge, which enables the semiconductor switches to be operated within a higher voltage range without the need for cascaded bridges or multiple two-level DAB converters. A symmetric modulation scheme, based on the least number of angular parameters rather than the duty-ratio, has been proposed for a different combination of bridge voltages. This ML-DAB is also suitable for maximum power point tracking (MPPT control in photovoltaic applications. Steady-state analysis of the converter with symmetric phase-shift modulation is presented and verified using simulation and hardware experiments.

  1. High power operation of the polyphase resonant converter modulator system for the spallation neutron source linear accelerator

    CERN Document Server

    Reass, W A; Baca, D M; Doss, J D; Gonzáles, J M; Gribble, R F; Trujillo, P G

    2003-01-01

    The spallation neutron source (SNS) is a new 1.4 MW average power beam, 1 GeV accelerator being built at Oak Ridge national laboratory. The accelerator requires 15 "long-pulse" converter-modulator stations each providing a maximum of 11 MW pulses with a 1.1 MW average power. Two variants of the converter-modulator are utilized, an 80 kV and a 140 kV design, the voltage dependant on the type of klystron load. The converter-modulator can be described as a resonant zero-voltage- switching polyphase boost inverter. As noted in Figure 1, each converter modulator derives its buss voltage from a standard 13.8 kV to 2100 Y (1.5 MVA) substation cast-core transformer. The substation also contains harmonic traps and filters to accommodate IEEE 519 and 141 regulations. Each substation is followed by an SCR preregulator to accommodate system voltage changes from no load to full load, in addition to providing a soft-start function. Energy storage and filtering is provided by special low inductance self-clearing metallized ...

  2. Push-pull with recovery stage high-voltage DC converter for PV solar generator

    Science.gov (United States)

    Nguyen, The Vinh; Aillerie, Michel; Petit, Pierre; Pham, Hong Thang; Vo, Thành Vinh

    2017-02-01

    A lot of systems are basically developed on DC-DC or DC-AC converters including electronic switches such as MOS or bipolar transistors. The limits of efficiency are quickly reached when high output voltages and high input currents are needed. This work presents a new high-efficiency-high-step-up based on push-pull DC-DC converter integrating recovery stages dedicated to smart HVDC distributed architecture in PV solar energy production systems. Appropriate duty cycle ratio assumes that the recovery stage work with parallel charge and discharge to achieve high step-up voltage gain. Besides, the voltage stress on the main switch is reduced with a passive clamp circuit and thus, low on-state resistance Rdson of the main switch can be adopted to reduce conduction losses. Thus, the efficiency of a basic DC-HVDC converter dedicated to renewable energy production can be further improved with such topology. A prototype converter is developed, and experimentally tested for validation.

  3. Optimization of Modulation Waveforms for Improved EMI Attenuation in Switching Frequency Modulated Power Converters

    Directory of Open Access Journals (Sweden)

    Deniss Stepins

    2015-01-01

    Full Text Available Electromagnetic interference (EMI is one of the major problems of switching power converters. This paper is devoted to switching frequency modulation used for conducted EMI suppression in switching power converters. Comprehensive theoretical analysis of switching power converter conducted EMI spectrum and EMI attenuation due the use of traditional ramp and multislope ramp modulation waveforms is presented. Expressions to calculate EMI spectrum and attenuation are derived. Optimization procedure of the multislope ramp modulation waveform is proposed to get maximum benefits from switching frequency modulation for EMI reduction. Experimental verification is also performed to prove that the optimized multislope ramp modulation waveform is very useful solution for effective EMI reduction in switching power converters.

  4. High-voltage boost quasi-Z-source isolated DC/DC converter

    DEFF Research Database (Denmark)

    Siwakoti, Yam P.; Blaabjerg, Frede; Loh, Poh Chiang

    2014-01-01

    converter uses less switches, a smaller common duty cycle and less turns for the transformer when compared with existing topologies. Its size and weight are therefore smaller, whereas its efficiency is higher. It is therefore well-suited for applications, where a wide range of voltage gain is required like...... renewable energy systems, DC power supplies found in telecom, aerospace and electric vehicles. To demonstrate the performance of the proposed converter, a 400 V, 500 W prototype has been implemented in the laboratory. Efficiency of the prototype measured is found to vary from 89.0 to 97.4% when its input...

  5. Characterization of diode valve in medium voltage dc/dc converter for wind turbines

    DEFF Research Database (Denmark)

    Dincan, Catalin Gabriel; Kjær, Philip Carne

    2016-01-01

    This paper proposes a methodology for characterization of medium voltage (MV), medium frequency (MF) rectifier diode valve. The intended application is for 10MW dc/dc converters used in DC offshore wind turbines. Sensitivity to semiconductor component parameter variation, snubber component tolera...... tolerance, influence of temperature and stray capacitance are analyzed. It is concluded that the largest impact on sensitivity is given by reverse recovery charge variation and differences of temperature between adjacent devices....

  6. Performance Analysis of a Voltage Source Converter (VSC based HVDC Transmission System under Faulted Conditions

    Directory of Open Access Journals (Sweden)

    Amiri RABIE

    2009-12-01

    Full Text Available Voltage Source Converter (VSC based HVDC transmission technology hasbeen selected as the basis for several recent projects due to its controllability,compact modular design, ease of system interface, and low environmentalimpact. This paper investigates the dynamic performance of a 200MW,±100kV VSC-HVDC transmission system under some faulted conditionsusing MATLAB/Simulink. Simulation results confirm the satisfactoryperformance of the proposed system under active and reactive powervariations and fault conditions.

  7. Circuit for automatic load sharing in parallel converter modules

    Science.gov (United States)

    Nagano, S. (Inventor)

    1979-01-01

    A nondissipative circuit for automatic load sharing in parallel converter modules having push-pull power transistors is presented. Each transistor has a separate current-sensing transformer and an impedance-adjusting transformer in series with its collector. The impedance-adjusting transformer functions as a current-controlled variable impedance that is responsive to the difference between the peak collector current of the transistor and the average peak current of all collector currents of power transistors in all modules, thereby to control the collector currents of all power transistors with reference to the average peak collector current.

  8. Grid Voltage Modulated Control of Grid-Connected Voltage Source Inverters under Unbalanced Grid Conditions

    DEFF Research Database (Denmark)

    Li, Mingshen; Gui, Yonghao; Quintero, Juan Carlos Vasquez

    2017-01-01

    In this paper, an improved grid voltage modulated control (GVM) with power compensation is proposed for grid-connected voltage inverters when the grid voltage is unbalanced. The objective of the proposed control is to remove the power ripple and to improve current quality. Three power compensation...... objectives are selected to eliminate the negative sequence components of currents. The modified GVM method is designed to obtain two separate second-order systems for not only the fast convergence rate of the instantaneous active and reactive powers but also the robust performance. In addition, this method...

  9. Voltage Control Scheme with Distributed Generation and Grid Connected Converter in a DC Microgrid

    Directory of Open Access Journals (Sweden)

    Jong-Chan Choi

    2014-10-01

    Full Text Available Direct Current (DC microgrids are expected to become larger due to the rapid growth of DC energy sources and power loads. As the scale of the system expends, the importance of voltage control will be increased to operate power systems stably. Many studies have been performed on voltage control methods in a DC microgrid, but most of them focused only on a small scale microgrid, such as a building microgrid. Therefore, a new control method is needed for a middle or large scale DC microgrid. This paper analyzes voltage drop problems in a large DC microgrid and proposes a cooperative voltage control scheme with a distributed generator (DG and a grid connected converter (GCC. For the voltage control with DGs, their location and capacity should be considered for economic operation in the systems. Accordingly, an optimal DG allocation algorithm is proposed to minimize the capacity of a DG for voltage control in DC microgrids. The proposed methods are verified with typical load types by a simulation using MATLAB and PSCAD/EMTDC.

  10. Optimal Constant DC Link Voltage Operation of aWave Energy Converter

    Directory of Open Access Journals (Sweden)

    Mats Leijon

    2013-04-01

    Full Text Available This article proposes a simple and reliable damping strategy for wave powerfarm operation of small-scale point-absorber converters. The strategy is based on passiverectification onto a constant DC-link, making it very suitable for grid integration of the farm.A complete model of the system has been developed in Matlab Simulink, and uses real sitedata as input. The optimal constant DC-voltage is evaluated as a function of the significantwave height and energy period of the waves. The total energy output of the WEC is derivedfor one year of experimental site data. The energy output is compared for two cases, onewhere the optimal DC-voltage is determined and held constant at half-hour basis throughoutthe year, and one where a selected value of the DC-voltage is kept constant throughout theyear regardless of sea state.

  11. A Method for the Realization of an Interruption Generator Based on Voltage Source Converters

    Directory of Open Access Journals (Sweden)

    Junhui Li

    2017-10-01

    Full Text Available In this paper we described the structure and working principle of an interruption generator based on voltage source converters (VSCs. The main circuit parameters of the VSCs are determined according to the target of power transfer capability, harmonic suppression, and dynamic response capability. A state feedback linearization method in nonlinear differential geometry theory was used for dq axis current decoupling, based on the mathematical model used in the dq coordinate system of VSCs. The direct current control strategy was adopted to achieve the independent regulation of active power and reactive power. The proportional integral (PI link was used to optimize the dynamic performance of the controller, and PI parameters were adjusted. Disturbance voltage waves were generated by the regular sampling method. PSCAD/EMTDC simulation results and physical prototype experiments showed that the device could generate various disturbance voltage waveforms steadily, and had good dynamic and steady-state performance.

  12. A sensorless control method for capacitor voltage balance and circulating current suppression of modular multilevel converter

    DEFF Research Database (Denmark)

    Liu, Hui; Ma, Ke; Loh, Poh Chiang

    2015-01-01

    There are several problems in the Modular Multilevel Converter (MMC), such as the appearance of circulating current, capacitor voltage unbalance and the requirement for a high number of sensors. All these problems will decrease the reliability and raise the cost/uncertainty of using MMC solutions....... As a result, a sensorless control method is proposed in this paper, which targets to improve the performances of MMC in respect to the above mentioned disadvantages: To decrease the cost and simplify the physical implementation, a state observer is proposed and designed to estimate both the capacitor voltages...... and the circulating currents in order to replace the high numbers of sensors. Furthermore, a control method combining the circulating current suppression and the capacitor voltage balancing is conducted based on the proposed state observer. It is concluded that the proposed state observer and control method can...

  13. Impact of the Converter Control Strategies on the Drive Train of Wind Turbine during Voltage Dips

    Directory of Open Access Journals (Sweden)

    Fenglin Miao

    2015-10-01

    Full Text Available The impact of converter control strategies on the drive train of wind turbines during voltage dips is investigated in this paper using a full electromechanical model. Aerodynamics and tower vibration are taken into consideration by means of a simulation program, named FAST. Detailed gearbox and electrical subsystems are represented in MATLAB. The dynamic response of electromagnetic torque and its impact on the mechanical variables are the concern in this paper and the response of electrical variables is less discussed. From the mechanical aspects, the effect of rising power recovery speed and unsymmetrical voltage dips are analyzed on the basis of the dynamic response of the high-speed shaft (HSS. A comparison of the impact on the drive train is made for two converter control strategies during small voltage dips. Through the analysis of torque, speed and tower vibration, the results indicate that both power recovery speed and the sudden torque sag have a significant impact on drive trains, and the effects depend on the different control strategies. Moreover, resonance might be excited on the drive train by an unbalanced voltage.

  14. Hybrid HVDC (H2VDC System Using Current and Voltage Source Converters

    Directory of Open Access Journals (Sweden)

    José Rafael Lebre

    2018-05-01

    Full Text Available This paper presents an analysis of a new high voltage DC (HVDC transmission system, which is based on current and voltage source converters (CSC and VSC in the same circuit. This proposed topology is composed of one CSC (rectifier and one or more VSCs (inverters connected through an overhead transmission line in a multiterminal configuration. The main purpose of this Hybrid HVDC (H2VDC, as it was designed, is putting together the best benefits of both types of converters in the same circuit: no commutation failure and system’s black start capability in the VSC side, high power converter capability and low cost at the rectifier side, etc. A monopole of the H2VDC system with one CSC and two VSCs—here, the VSC is the Modular Multilevel Converter (MMC considered with full-bridge submodules—in multiterminal configuration is studied. The study includes theoretical analyses, development of the CSC and VSCs control philosophies and simulations. The H2VDC system’s behavior is analyzed by computational simulations considering steady-state operation and short-circuit conditions at the AC and DC side. The obtained results and conclusions show a promising system for very high-power multiterminal HVDC transmission.

  15. A hierarchical model predictive voltage control for NPC/H-bridge converters with a reduced computational burden

    DEFF Research Database (Denmark)

    Gong, Zheng; Dai, Peng; Wu, Xiaojie

    2017-01-01

    In recent years, voltage source multilevel converters are very popular in medium/high-voltage industrial applications, among which the NPC/H-Bridge converter is a popular solution to the medium/high-voltage drive systems. The conventional finite control set model predictive control (FCS-MPC) stra......In recent years, voltage source multilevel converters are very popular in medium/high-voltage industrial applications, among which the NPC/H-Bridge converter is a popular solution to the medium/high-voltage drive systems. The conventional finite control set model predictive control (FCS......-MPC) strategy is not practical for multilevel converters due to their substantial calculation requirements, especially under high number of voltage levels. To solve this problem, a hierarchical model predictive voltage control (HMPVC) strategy with referring to the implementation of g-h coordinate space vector...... and experiments with a down-scaled NPC/H-Bridge converter prototype under various conditions, which validate the proposed HMPVC strategy....

  16. Analysis of a PWM Resonant Buck Chopper for Use as a Ship Service Converter Module

    National Research Council Canada - National Science Library

    Ciezki, John

    1999-01-01

    .... This study provides a background analysis into resonant converters which utilize zero-voltage-switching and zero-current-switching techniques to mitigate the aforementioned concerns and facilitate...

  17. New non-linear control strategy for non-isolated DC/DC converter with high voltage ratio

    International Nuclear Information System (INIS)

    Shahin, A.; Huang, B.; Martin, J.P.; Pierfederici, S.; Davat, B.

    2010-01-01

    In this paper, a non-isolated DC/DC converter with high voltage ratio is proposed to allow the interface between a low voltage power source like fuel cell and a high voltage DC bus. To take into account the low voltage-high density characteristics of power sources, a cascaded structure composed of two sub-converters has been chosen and allows obtaining a high voltage ratio. The choice of each sub-converter is based on the requirements of the source and its performances. Consequently, we have chosen a three-interleaved boost converter as the 1st sub-converter whereas the 2nd sub-converter is a three-level boost converter. The control of the whole system is realized thanks to energetic trajectories planning based on flatness properties of the system. The control of both the current and the balance of voltage across the output serial capacitors of the three-level boost converter is ensured by non-linear controllers based on a new non-linear model. Experimental results allow validating the proposed power architecture and its associated control.

  18. New non-linear control strategy for non-isolated DC/DC converter with high voltage ratio

    Energy Technology Data Exchange (ETDEWEB)

    Shahin, A.; Huang, B.; Martin, J.P.; Pierfederici, S.; Davat, B. [Groupe de Recherche en Electronique et en Electrotechnique de Nancy - INPL - Nancy Universite, 2, Avenue de la Foret de Haye, 54516 Vandoeuvre-les-Nancy Cedex (France)

    2010-01-15

    In this paper, a non-isolated DC/DC converter with high voltage ratio is proposed to allow the interface between a low voltage power source like fuel cell and a high voltage DC bus. To take into account the low voltage-high density characteristics of power sources, a cascaded structure composed of two sub-converters has been chosen and allows obtaining a high voltage ratio. The choice of each sub-converter is based on the requirements of the source and its performances. Consequently, we have chosen a three-interleaved boost converter as the 1st sub-converter whereas the 2nd sub-converter is a three-level boost converter. The control of the whole system is realized thanks to energetic trajectories planning based on flatness properties of the system. The control of both the current and the balance of voltage across the output serial capacitors of the three-level boost converter is ensured by non-linear controllers based on a new non-linear model. Experimental results allow validating the proposed power architecture and its associated control. (author)

  19. Design, status and first operations of the spallation neutron source polyphase resonant converter modulator system

    Energy Technology Data Exchange (ETDEWEB)

    Reass, W. A. (William A.); Apgar, S. E. (Sean E.); Baca, D. M. (David M.); Doss, James D.; Gonzales, J. (Jacqueline); Gribble, R. F. (Robert F.); Hardek, T. W. (Thomas W.); Lynch, M. T. (Michael T.); Rees, D. E. (Daniel E.); Tallerico, P. J. (Paul J.); Trujillo, P. B. (Pete B.); Anderson, D. E. (David E.); Heidenreich, D. A. (Dale A.); Hicks, J. D. (Jim D.); Leontiev, V. N.

    2003-01-01

    The Spallation Neutron Source (SNS) is a new 1.4 MW average power beam, 1 GeV accelerator being built at Oak Ridge National Laboratory. The accelerator requires 15 converter-modulator stations each providing between 9 and 11 MW pulses with up to a 1 .I MW average power. The converter-modulator can be described as a resonant 20 kHz polyphase boost inverter. Each converter modulator derives its buss voltage from a standard substation cast-core transformer. Each substation is followed by an SCR pre-regulator to accommodate voltage changes from no load to full load, in addition to providing a soft-start function. Energy storage is provided by self-clearing metallized hazy polypropylene traction capacitors. These capacitors do not fail short, but clear any internal anomaly. Three 'H-Bridge' IGBT transistor networks are used to generate the polyphase 20 kHz transformer primary drive waveforms. The 20 kHz drive waveforms are time-gated to generate the desired klystron pulse width. Pulse width modulation of the individual 20 lcHz pulses is utilized to provide regulated output waveforms with DSP based adaptive feedforward and feedback techniques. The boost transformer design utilizes nanocrystalline alloy that provides low core loss at design flux levels and switching frequencies. Capacitors are used on the transformer secondary networks to resonate the leakage inductance. The transformers are wound for a specific leakage inductance, not turns ratio. This design technique generates multiple secondary volts per turn as compared to the primary. With the appropriate tuning conditions, switching losses are minimized. The resonant topology has the added benefit of being deQed in a klystron fault condition, with little energy deposited in the arc. This obviates the need of crowbars or other related networks. A review of these design parameters, operational performance, production status, and OWL installation and performance to date will be presented.

  20. Design, status and first operations of the spallation neutron source polyphase resonant converter modulator system

    International Nuclear Information System (INIS)

    Reass, W.A.; Apgar, S.E.; Baca, D.M.; Doss, James D.; Gonzales, J.; Gribble, R.F.; Hardek, T.W.; Lynch, M.T.; Rees, D.E.; Tallerico, P.J.; Trujillo, P.B.; Anderson, D.E.; Heidenreich, D.A.; Hicks, J.D.; Leontiev, V.N.

    2003-01-01

    The Spallation Neutron Source (SNS) is a new 1.4 MW average power beam, 1 GeV accelerator being built at Oak Ridge National Laboratory. The accelerator requires 15 converter-modulator stations each providing between 9 and 11 MW pulses with up to a 1 .I MW average power. The converter-modulator can be described as a resonant 20 kHz polyphase boost inverter. Each converter modulator derives its buss voltage from a standard substation cast-core transformer. Each substation is followed by an SCR pre-regulator to accommodate voltage changes from no load to full load, in addition to providing a soft-start function. Energy storage is provided by self-clearing metallized hazy polypropylene traction capacitors. These capacitors do not fail short, but clear any internal anomaly. Three 'H-Bridge' IGBT transistor networks are used to generate the polyphase 20 kHz transformer primary drive waveforms. The 20 kHz drive waveforms are time-gated to generate the desired klystron pulse width. Pulse width modulation of the individual 20 lcHz pulses is utilized to provide regulated output waveforms with DSP based adaptive feedforward and feedback techniques. The boost transformer design utilizes nanocrystalline alloy that provides low core loss at design flux levels and switching frequencies. Capacitors are used on the transformer secondary networks to resonate the leakage inductance. The transformers are wound for a specific leakage inductance, not turns ratio. This design technique generates multiple secondary volts per turn as compared to the primary. With the appropriate tuning conditions, switching losses are minimized. The resonant topology has the added benefit of being deQed in a klystron fault condition, with little energy deposited in the arc. This obviates the need of crowbars or other related networks. A review of these design parameters, operational performance, production status, and OWL installation and performance to date will be presented.

  1. Cost Effectiveness Analysis of Converting a Classroom Course to a Network Based Instruction Module

    National Research Council Canada - National Science Library

    green, Samantha

    1997-01-01

    ...) classes into NBL modules. This thesis performs a cost effectiveness analysis on converting the two modules and discusses the intangible costs and benefits associated with converting traditional classroom courses...

  2. Modulation Strategy of a 3 × 5 Modular Multilevel Matrix Converter

    Directory of Open Access Journals (Sweden)

    Rutian Wang

    2018-02-01

    Full Text Available In this paper, a modulation strategy of a 3 × 5 modular multilevel matrix converter (M3C is proposed. The circuit of 3 × 5 M3C is firstly introduced. Then, operation rules of 3 × 5 M3C are illustrated, and a connection pattern of branches is determined based on these rules. Different voltage states in the input and output side can be achieved by different connection patterns. These voltage states are represented in the form of vector. It is hard to synthesize five-phase output with the three-level synthesis method. Therefore, the five-level synthesis method is adopted in this paper; i.e., is the branch states have been increased. Ten effective vectors and a zero vector are selected based on the five-level synthesis method. With this modulation strategy, we achieve output line-to-line voltages that are in line with the trend of a sine wave. The segment division and duty cycle calculation are very simple, and the modulation strategy can be implemented easily. The simulation model of 3 × 5 M3C is constructed based on Matlab/Simulink, and the corresponding experimental platform is set up. The results of simulation and experiment show that the proposed method is reasonable and correct.

  3. High voltage photo switch package module

    Science.gov (United States)

    Sullivan, James S; Sanders, David M; Hawkins, Steven A; Sampayan, Stephen E

    2014-02-18

    A photo-conductive switch package module having a photo-conductive substrate or wafer with opposing electrode-interface surfaces, and at least one light-input surface. First metallic layers are formed on the electrode-interface surfaces, and one or more optical waveguides having input and output ends are bonded to the substrate so that the output end of each waveguide is bonded to a corresponding one of the light-input surfaces of the photo-conductive substrate. This forms a waveguide-substrate interface for coupling light into the photo-conductive wafer. A dielectric material such as epoxy is then used to encapsulate the photo-conductive substrate and optical waveguide so that only the metallic layers and the input end of the optical waveguide are exposed. Second metallic layers are then formed on the first metallic layers so that the waveguide-substrate interface is positioned under the second metallic layers.

  4. Cavity Voltage Phase Modulation MD blocks 3 and 4

    CERN Document Server

    Mastoridis, T; Butterworth, A; Molendijk, J; Tuckmantel, J

    2013-01-01

    The LHC RF/LLRF system is currently setup for extremely stable RF voltage to minimize transient beam loading effects. The present scheme cannot be extended beyond nominal beam current since the demanded power would push the klystrons to saturation. For beam currents above nominal (and possibly earlier), the cavity phase modulation by the beam (transient beam loading) will not be corrected, but the strong RF feedback and One-Turn Delay feedback will still be active for RF loop and beam stability in physics. To achieve this, the voltage set point should be adapted for each bunch. The goal of these MDs was to test thefirmware version of an iterative algorithm that adjusts the voltage set point to achieve the optimal phase modulation for klystron forward power considerations.

  5. Utility Interfaced Pulse-Width Modulation of Solar Fed Voltage ...

    African Journals Online (AJOL)

    Utility Interfaced Pulse-Width Modulation of Solar Fed Voltage Source Inverter Using Fixed-Band Hysteresis Current Controller Method. ... with the conversion of solar energy into electrical energy; boosting the dc power; inversion of the dc to ac and then synchronization of the inverter output with the utility, and consequently, ...

  6. Loading Analysis of Modular Multi-level Converter for Offshore High-voltage DC Application under Various Grid Faults

    DEFF Research Database (Denmark)

    Liu, Hui; Ma, Ke; Loh, Poh Chiang

    2016-01-01

    challenges but may also result in overstressed components for the modular multi-level converter. However, the thermal loading of the modular multi-level converter under various grid faults has not yet been clarified. In this article, the power loss and thermal performance of the modular multi-level converter...... low-voltage ride-through strongly depend on the types and severity values of grid voltage dips. The thermal distribution among the three phases of the modular multi-level converter may be quite uneven, and some devices are much more stressed than the normal operating condition, which may...

  7. Back-to-back converter control of grid-connected wind turbine to mitigate voltage drop caused by faults

    DEFF Research Database (Denmark)

    Hassanzadeh, Fattah; Sangrody, Hossein; Hajizadeh, Amin

    2017-01-01

    Power electronic converters enable wind turbines, operating at variable speed, to generate electricity more efficiently. Among variable speed operating turbine generators, permanent magnetic synchronous generator (PMSG) has got more attentions due to low cost and maintenance requirements...... side converter is designed to improve voltage drop caused by the fault in the grid while maximum available active power of wind turbine system is injected to the grid and the DC link voltage in the converter is regulated. The methodology of the converter control is elaborated in details and its...

  8. Analysis of bi-directional piezoelectric-based converters for zero-voltage switching operation

    DEFF Research Database (Denmark)

    Ekhtiari, Marzieh; Zhang, Zhe; Andersen, Michael A. E.

    2016-01-01

    This paper deals with a thorough analysis of zerovoltage switching especially for bi-directional, inductorless, piezoelectric transformer-based switch-mode power supplies with a half-bridge topology. Practically, obtaining zero-voltage switching for all of the switches in a bi-directional piezoel......This paper deals with a thorough analysis of zerovoltage switching especially for bi-directional, inductorless, piezoelectric transformer-based switch-mode power supplies with a half-bridge topology. Practically, obtaining zero-voltage switching for all of the switches in a bi......-directional piezoelectric power converter is a difficult task. However, the analysis in this work will be convenient for overcoming this challenge. The analysis defines the zero-voltage region indicating the operating points whether or not soft switching can be met over the switching frequency and load range. For the first...... time, a comprehensive analysis is provided, which can be used as a design guideline for applying control techniques in order to drive switches in piezoelectric transformer-based converters. This study further conveys the proposed method to the region where all the switches can obtain soft switching...

  9. Model Based Optimization of Integrated Low Voltage DC-DC Converter for Energy Harvesting Applications

    Science.gov (United States)

    Jayaweera, H. M. P. C.; Muhtaroğlu, Ali

    2016-11-01

    A novel model based methodology is presented to determine optimal device parameters for the fully integrated ultra low voltage DC-DC converter for energy harvesting applications. The proposed model feasibly contributes to determine the maximum efficient number of charge pump stages to fulfill the voltage requirement of the energy harvester application. The proposed DC-DC converter based power consumption model enables the analytical derivation of the charge pump efficiency when utilized simultaneously with the known LC tank oscillator behavior under resonant conditions, and voltage step up characteristics of the cross-coupled charge pump topology. The verification of the model has been done using a circuit simulator. The optimized system through the established model achieves more than 40% maximum efficiency yielding 0.45 V output with single stage, 0.75 V output with two stages, and 0.9 V with three stages for 2.5 kΩ, 3.5 kΩ and 5 kΩ loads respectively using 0.2 V input.

  10. Improved Passive-Damped LCL Filter to Enhance Stability in Grid-Connected Voltage-Source Converters

    DEFF Research Database (Denmark)

    Beres, Remus Narcis; Wang, Xiongfei; Blaabjerg, Frede

    2015-01-01

    This paper proposes an improved passive-damped LCL filter to be used as interface between the grid-connected voltage-source converters and the utility grid. The proposed filter replaces the LCL filter capacitor with a traditional C-type filter with the resonant circuit tuned in such a way...... passive-damped LCL filter. To verify the benefits of the proposed filter, a comparison with the conventional filter is made in terms of losses and ratings when both the filters are designed under the same condition....... that switching harmonics due to pulse width modulation are to be cancelled. Since the tuned circuit of the C-type filter suppresses the switching harmonics more effectively, the total inductance of the filter can be reduced. Additionally, the rating of the damping resistor is lower, compared with conventional...

  11. Analysis of transistor and snubber turn-off dynamics in high-frequency high-voltage high-power converters

    Science.gov (United States)

    Wilson, P. M.; Wilson, T. G.; Owen, H. A., Jr.

    Dc to dc converters which operate reliably and efficiently at switching frequencies high enough to effect substantial reductions in the size and weight of converter energy storage elements are studied. A two winding current or voltage stepup (buck boost) dc-to-dc converter power stage submodule designed to operate in the 2.5-kW range, with an input voltage range of 110 to 180 V dc, and an output voltage of 250 V dc is emphasized. In order to assess the limitations of present day component and circuit technologies, a design goal switching frequency of 10 kHz was maintained. The converter design requirements represent a unique combination of high frequency, high voltage, and high power operation. The turn off dynamics of the primary circuit power switching transistor and its associated turn off snubber circuitry are investigated.

  12. Thermal Stress Analysis of Medium-Voltage Converters for Smart Transformers

    DEFF Research Database (Denmark)

    Andresen, Markus; Ma, Ke; De Carne, Giovanni

    2017-01-01

    . To address this concern, this work conducts thermal stress analysis for a modular multilevel converter (MMC), which is a promising solution for the medium voltage stage of the ST. The focus is put on the mission profiles of the transformer and the impact on the thermal stress of power semiconductor devices......A smart transformer (ST) can take over an important managing role in the future electrical distribution grid system and can provide many advanced grid services compared to the traditional transformer. However, the risk is that the advanced functionality is balanced out by a lower reliability....... Normal operation at different power levels and medium voltage grid faults in a feeder fed by a traditional transformer are considered as well as the electrical and the thermal stress of the disconnection and the reconnection procedures. For the validation, the thermal stress of one MMC cell is reproduced...

  13. Grid Integration of Single Stage Solar PV System using Three-level Voltage Source Converter

    Science.gov (United States)

    Hussain, Ikhlaq; Kandpal, Maulik; Singh, Bhim

    2016-08-01

    This paper presents a single stage solar PV (photovoltaic) grid integrated power generating system using a three level voltage source converter (VSC) operating at low switching frequency of 900 Hz with robust synchronizing phase locked loop (RS-PLL) based control algorithm. To track the maximum power from solar PV array, an incremental conductance algorithm is used and this maximum power is fed to the grid via three-level VSC. The use of single stage system with three level VSC offers the advantage of low switching losses and the operation at high voltages and high power which results in enhancement of power quality in the proposed system. Simulated results validate the design and control algorithm under steady state and dynamic conditions.

  14. A Novel Programmable CMOS Fuzzifiers Using Voltage-to-Current Converter Circuit

    Directory of Open Access Journals (Sweden)

    K. P. Abdulla

    2012-01-01

    Full Text Available This paper presents a new voltage-input, current-output programmable membership function generator circuit (MFC using CMOS technology. It employs a voltage-to-current converter to provide the required current bias for the membership function circuit. The proposed MFC has several advantageous features. This MFC can be reconfigured to perform triangular, trapezoidal, S-shape, Z-Shape, and Gaussian membership forms. This membership function can be programmed in terms of its width, slope, and its center locations in its universe of discourses. The easily adjustable characteristics of the proposed circuit and its accuracy make it suitable for embedded system and industrial control applications. The proposed MFC is designed using the spice software, and simulation results are obtained.

  15. A CMOS integrated voltage and power efficient AC/DC converter for energy harvesting applications

    International Nuclear Information System (INIS)

    Peters, Christian; Ortmanns, Maurits; Manoli, Yiannos; Spreemann, Dirk

    2008-01-01

    In this paper, a fully CMOS integrated active AC/DC converter for energy harvesting applications is presented. The rectifier is realized in a standard 0.35 µm CMOS process without special process options. It works as a full wave rectifier and can be separated into two stages—one passive and one active. The active part is powered from the storage capacitor and consumes about 600 nA at 2 V supply. The input voltage amplitude range is between 1.25 and 3.75 V, and the operating frequency range is from 1 Hz to as much as several 100 kHz. The series voltage drop over the rectifier is less than 20 mV. Measurements in combination with an electromagnetic harvester show a significant increase in the achievable output voltage and power compared to a common, discrete Schottky diode rectifier. The measured efficiency of the rectifier is over 95%. Measurements show a negligible temperature influence on the output voltage between −40 °C and +125 °C

  16. Low-Power, Low-Voltage Resistance-to-Digital Converter for Sensing Applications

    Directory of Open Access Journals (Sweden)

    Sergey Y. YURISH

    2016-09-01

    Full Text Available IC (ASIP of Universal Sensors and Transducers Interface (USTI-MOB with low power consumption, working in the resistive measurement mode (one of 26 possible measuring modes is described in the article. The proposed IC has 20 W to 4.5 M W range of measurement, relative error< ±0.04 %, 0.85 mA supply current and 1.2 V supply voltage. The worst-case error of about< ±1.54 % is observed. IC has three popular serial interfaces: I2C, SPI and RS232/USB. Due to high metrological performance and technical characteristics the USTI- MOB is well suitable for such application as: sensor systems for IoT, wearable and mobile devices, and digital multimeters. The ICs can also work with any quasi-digital resistive converters, in which the resistance is converted to frequency, period, duty-cycle or pulse width.

  17. Estimation of the Plant Time Constant of Current-Controlled Voltage Source Converters

    DEFF Research Database (Denmark)

    Vidal, Ana; Yepes, Alejandro G.; Malvar, Jano

    2014-01-01

    Precise knowledge of the plant time constant is essential to perform a thorough analysis of the current control loop in voltage source converters (VSCs). As the loop behavior can be significantly influenced by the VSC working conditions, the effects associated to converter losses should be included...... in the model, through an equivalent series resistance. In a recent work, an algorithm to identify this parameter was developed, considering the inductance value as known and practically constant. Nevertheless, the plant inductance can also present important uncertainties with respect to the inductance...... of the VSC interface filter measured at rated conditions. This paper extends that method so that both parameters of the plant time constant (resistance and inductance) are estimated. Such enhancement is achieved through the evaluation of the closed-loop transient responses of both axes of the synchronous...

  18. Passivity-based design of robust passive damping for LCL-filtered voltage source converters

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Loh, Poh Chiang

    2015-01-01

    Passive damping is proven as a robust stabilizing technique for LCL-filtered voltage source converters. However, conventional design methods of passive dampers are based on the passive components only, while the inherent damping effect of time delay in the digital control system is overlooked....... In this paper, a frequency-domain passivity-based design approach is proposed, where the passive dampers are designed to eliminate the negative real part of the converter output admittance with closed-loop current control, rather than shaping the LCL-filter itself. Thus, the influence of time delay...... in the current control is included, which allows a relaxed design of the passive damper with the reduced power loss and improved stability robustness against grid parameters variations. Design procedures of two commonly used passive dampers with LCL-filtered VSCs are illustrated. Experimental results validate...

  19. Virtual RC Damping of LCL-Filtered Voltage Source Converters with Extended Selective Harmonic Compensation

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Loh, Poh Chiang

    2015-01-01

    Active damping and harmonic compensation are two common challenges faced by LCL-filtered voltage source converters. To manage them holistically, this paper begins by proposing a virtual RC damper in parallel with the passive filter capacitor. The virtual damper is actively inserted by feeding back...... the passive capacitor current through a high-pass filter, which indirectly, furnishes two superior features. They are the mitigation of phase lag experienced by a conventional damper and the avoidance of instability caused by the negative resistance inserted unintentionally. Moreover, with the virtual RC...

  20. Unified Impedance Model of Grid-Connected Voltage-Source Converters

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Harnefors, Lennart; Blaabjerg, Frede

    2018-01-01

    This paper proposes a unified impedance model of grid-connected voltage-source converters for analyzing dynamic influences of the Phase-Locked Loop (PLL) and current control. The mathematical relations between the impedance models in the different domains are first explicitly revealed by means...... of complex transfer functions and complex space vectors. A stationary (αβ-) frame impedance model is then proposed, which not only predicts the stability impact of the PLL, but reveals also its frequency coupling effect explicitly. Furthermore, the impedance shaping effect of the PLL on the current control...... results and theoretical analysis confirm the effectiveness of the stationary-frame impedance model....

  1. Integrated Three-Voltage-Booster DC-DC Converter to Achieve High Voltage Gain with Leakage-Energy Recycling for PV or Fuel-Cell Power Systems

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2015-09-01

    Full Text Available In this paper, an integrated three-voltage-booster DC-DC (direct current to direct current converter is proposed to achieve high voltage gain for renewable-energy generation systems. The proposed converter integrates three voltage-boosters into one power stage, which is composed of an active switch, a coupled-inductor, five diodes, and five capacitors. As compared with conventional high step-up converters, it has a lower component count. In addition, the features of leakage-energy recycling and switching loss reduction can be accomplished for conversion efficiency improvement. While the active switch is turned off, the converter can inherently clamp the voltage across power switch and suppress voltage spikes. Moreover, the reverse-recovery currents of all diodes can be alleviated by leakage inductance. A 200 W prototype operating at 100 kHz switching frequency with 36 V input and 400 V output is implemented to verify the theoretical analysis and to demonstrate the feasibility of the proposed high step-up DC-DC converter.

  2. Control of a Two-Stage Direct Power Converter with a Single Voltage Sensor Mounted in the Intermediary Circuit

    DEFF Research Database (Denmark)

    Klumpner, Christian; Wheeler, P.; Blaabjerg, Frede

    2004-01-01

    Controlling a converter requires not only a powerful processors but also accurate voltage and current sensors and fast and precise analogue-digital converters, which increase the cost per kW of the assembly, especially in the low power range. A matrix converter requires less transducers than a back...... converters but in two stages (AC/DC/AC) without using energy storage in the intermediary circuit. They also offer the possibility to reduce the number of switches compared to the standard single-stage matrix converter. This paper presents a new method to control a two-stage DPC providing sine-wave in sine...

  3. Design and implementation of a bidirectional current-controlled voltage-regulated DC-DC switched-mode converter

    CSIR Research Space (South Africa)

    Coetzer, A

    2016-01-01

    Full Text Available The design and implementation of a bidirectional current-controlled voltage-regulated DC-DC converter is presented. The converter is required to connect a battery of electrochemical cells (the battery) to an asynchronous motor-drive unit via a...

  4. Passivity-Based Control by Series/Parallel Damping of Single-Phase PWM Voltage Source Converter

    NARCIS (Netherlands)

    del Puerto Flores, Dunstano; Scherpen, Jacqueline; Liserre, Marco; de Vries, Martijn M. J.; Kransse, Marco J.; Monopoli, Vito Giuseppe

    This paper describes a detailed design procedure for passivity-based controllers developed using the Brayton-Moser (BM) framework. Several passivity-based feedback designs are presented for the voltage-source converter, specifically for the H-bridge converter, since nowadays it is one of the

  5. Synchronised Voltage Space Vector Modulation for Three-level Inverters with Common-mode Voltage Elimination

    DEFF Research Database (Denmark)

    Oleschuk, Valentin; Blaabjerg, Frede

    2002-01-01

    A novel method of direct synchronous pulse-width modulation (PWM) is disseminated to three-level voltage source inverters with control algorithms with elimination of the common-mode voltages in three-phase drive systems with PWM. It provides smooth pulses-ratio changing and a quarter-wave symmetry...... of the voltage waveforms during the whole control range including overmodulation. Continuous, discontinuous and "direct-direct" schemes of synchronous PWM with both algebraic and trigonometric control functions have been analysed and compared. Simulations give the behaviour of the proposed methods and show some...... advantages of synchronous PWM in comparison with asynchronous at low ratios between the switching frequency and fundamental frequency....

  6. Digital measurement system for the LHC klystron high voltage modulator.

    CERN Document Server

    Mikkelsen, Anders

    Accelerating voltage in the Large Hadron Collider (LHC) is created by a means of 16 superconducting standing wave RF cavities, each fed by a 400MHz/300kW continuous wave klystron amplifier. Part of the upgrade program for the LHC long shutdown one is to replace the obsolete analogue current and voltage measurement circuitry located in the high voltage bunkers by a new, digital system, using ADCs and optical fibres. A digital measurement card is implemented and integrated into the current HV modulator oil tank (floating at -58kV) and interfaced to the existing digital VME boards collecting the data for several klystrons at the ground potential. Measured signals are stored for the logging, diagnostics and post-mortem analysis purposes.

  7. A comprehensive analysis and hardware implementation of control strategies for high output voltage DC-DC boost power converter

    DEFF Research Database (Denmark)

    Padmanaban, Sanjeevikumar; Grandi, Gabriele; Blaabjerg, Frede

    2017-01-01

    voltage and efficiency of classical HV converters. This paper deals with extra high-voltage (EHV) dc-dc boost converter by the application of voltage-lift technique to overcome the aforementioned deficiencies. The control strategy is based on classical proportional-integral (P-I) and fuzzy logic closed...... are performed by the DSP. The experimental results provided show good conformity with developed hypothetical predictions. Additionally, the presented study confirms that the fuzzy logic controller provides better performance than classical P-I controller under different perturbation conditions....

  8. Boost Half-Bridge DC-DC Converter with Reconfigurable Rectifier for Ultra-Wide Input Voltage Range Applications

    DEFF Research Database (Denmark)

    Vinnikov, Dmitri; Chub, Andrii; Liivik, Elizaveta

    2018-01-01

    This paper introduces a novel galvanically isolated boost half-bridge dc-dc converter intended for modern power electronic applications where ultra-wide input voltage regulation range is needed. A reconfigurable output rectifier stage performs a transition between the voltage doubler and the full......-bridge diode rectifiers and, by this means, extends the regulation range significantly. The converter features a low number of components and resonant soft switching of semiconductors, which result in high power conversion efficiency over a wide input voltage and load range. The paper presents the operating...

  9. Contrast distortion induced by modulation voltage in scanning capacitance microscopy

    Science.gov (United States)

    Chang, M. N.; Hu, C. W.; Chou, T. H.; Lee, Y. J.

    2012-08-01

    With a dark-mode scanning capacitance microscopy (SCM), we directly observed the influence of SCM modulation voltage (MV) on image contrasts. For electrical junctions, an extensive modulated area induced by MV may lead to noticeable changes in the SCM signal phase and intensity, resulting in a narrowed junction image and a broadened carrier concentration profile. This contrast distortion in SCM images may occur even if the peak-to-peak MV is down to 0.3 V. In addition, MV may shift the measured electrical junction depth. The balance of SCM signals components explain these MV-induced contrast distortions.

  10. Experimental Results of a DC Bus Voltage Level Control for a Load-Controlled Marine Current Energy Converter

    Directory of Open Access Journals (Sweden)

    Johan Forslund

    2015-05-01

    Full Text Available This paper investigates three load control methods for a  marine current energy converter using a vertical axis current  turbine (VACT mounted on a permanent magnet synchronous generator  (PMSG. The three cases are; a fixed AC load, a fixed pulse width  modulated (PWM DC load and DC bus voltage control of a DC  load. Experimental results show that the DC bus voltage control  reduces the variations of rotational speed by a factor of 3.5 at the cost  of slightly increased losses in the generator and transmission lines.  For all three cases, the tip speed ratio \\(\\lambda\\ can be kept close to  the expected \\(\\lambda_{opt}\\. The power coefficient is estimated to be  0.36 at \\(\\lambda_{opt}\\; however, for all three cases, the average  extracted power was about \\(\\sim 19\\\\%. A maximum power point  tracking (MPPT system, with or without water velocity measurement,  could increase the average extracted power.

  11. A New Topology for Interline Dynamic Voltage Restorer Based on Direct Three-Phase Converter

    Directory of Open Access Journals (Sweden)

    E. Babaei

    2016-03-01

    Full Text Available In this paper, a new topology for Interline Dynamic Voltage Restorer (IDVR is proposed. This topology contains two direct three-phase converters which have been connected together by a common fictitious dc-link. According to the kind of the disturbances, both of the converters can be employed as a rectifier or inverter. The converters receive the required compensation energy from the gird through the direct link which is provided by the dual-proposed switches. Due to the lack of the huge storage elements, the practical prototype of the proposed topology is more economical in comparison with the traditional structure. Moreover, compensating for long time duration is possible due to the unlimited eternal energy which is provided from the grids. The low volume, cost and weight are the additional features of the proposed topology in comparison with traditional types. This topology is capable to compensate both of the balanced and unbalanced disturbances. Furthermore, restoring the deep sags and power outages will be possible with the support from the other grid. Unlike the conventional topologies, the capability of compensation is independent from the power flow and the power factor of each grid. The performance of the proposed IDVR topology is validated by computer simulation with PSCAD/EMTDC software.

  12. Phase-lock loop of Grid-connected Voltage Source Converter under non-ideal grid condition

    DEFF Research Database (Denmark)

    Wang, Haojie; Sun, Hai; Han, Minxiao

    2015-01-01

    It is a normal practice that the DC micro-grid is connected to AC main grid through Grid-connected Voltage Source Converter (G-VSC) for voltage support. Accurate control of DC micro-grid voltage is difficult for G-VSC under unbalanced grid condition as the fundamental positive-sequence component...... and distorted system voltage the proposed PLL can accurately detect the fundamental positive-sequence component of grid voltage thus accurate control of DC micro-grid voltage can be realized....... phase information cannot be accurately tracked. Based on analysis of the cause of double-frequency ripple when unbalance exists in main grid, a phase-locked loop (PLL) detection technique is proposed. Under the conditions of unsymmetrical system voltage, varying system frequency, single-phase system...

  13. Design and Implementation of a High Efficiency, Low Component Voltage Stress, Single-Switch High Step-Up Voltage Converter for Vehicular Green Energy Systems

    Directory of Open Access Journals (Sweden)

    Yu-En Wu

    2016-09-01

    Full Text Available In this study, a novel, non-isolated, cascade-type, single-switch, high step-up DC/DC converter was developed for green energy systems. An integrated coupled inductor and voltage lift circuit were applied to simplify the converter structure and satisfy the requirements of high efficiency and high voltage gain ratios. In addition, the proposed structure is controllable with a single switch, which effectively reduces the circuit cost and simplifies the control circuit. With the leakage inductor energy recovery function and active voltage clamp characteristics being present, the circuit yields optimizable conversion efficiency and low component voltage stress. After the operating principles of the proposed structure and characteristics of a steady-state circuit were analyzed, a converter prototype with 450 W, 40 V of input voltage, 400 V of output voltage, and 95% operating efficiency was fabricated. The Renesas MCU RX62T was employed to control the circuits. Experimental results were analyzed to validate the feasibility and effectiveness of the proposed system.

  14. Fast Self-Synchronization between LowVoltage Microgrid and Inverter using Virtual Synchronous Converter

    Directory of Open Access Journals (Sweden)

    Md Ruhul Amin

    2017-12-01

    Full Text Available In this paper, a fast self-synchronization known as virtual synchronous converter (VSCon between single-phase microgrid and inverter in low-voltage microgrid, has been developed in Matlab/Simulink. The idea is to any phase locked loop (PLL circuit for inverter-microgrid synchronization in order to improve the synchronization time. As known, it is difficult and lengthy process to tune the PLL gain parameters to reach suitable performance for synchronizing among the voltage, phase-angle and frequency between them. Due to this problem, a fast self synchronization technique is needed in order to minimize the time losses at the microgrid connection. Therefore, the VSCon has been developed which is based on the synchronous generator mathematical model but in virtual environment representation. It has been applied in the inverter control for generating switching pattern to the inverter switches in order to respond to the grid voltage for improve the synchronization. For a prove of concept, several simulation tests in MATLAB models have been conducted, in order to see the effectiveness of this VSCon. First test has been conducted, when a 240V, 50Hz frequency grid source is used for observing the self-synchronization the system with the power flows output. Furthermore, the next test is conducted when the grid frequency is changed from the rated frequency at 50Hz to 51Hz and the result shows the VSCon in inverter control takes nearly 40ms to synchronize to this new frequency value. The test on grid phase-angle delay also been tested when ac grid voltage has 150 phase delay. As from all the results, the improved inverter control with VSCon structure is able to have fast and self-synchronized between the invertergrid connection before the power from the inverter can be transferred.

  15. Medium voltage three-level converters for the grid connection of a multi-MW wind turbine

    DEFF Research Database (Denmark)

    Senturk, Osman Selcuk; Helle, Lars; Munk-Nielsen, Stig

    2009-01-01

    Three-level (3L) neutral point clamped (NPC), flying capacitor (FC), and H-bridge (HB) voltage source converters (VSCs) as a grid-side full-scale medium voltage (MV) converter are modeled, controlled, and simulated for the grid connection of a hypothetical 6MW wind turbine. Via the converter...... topological features and the simulation results demonstrating the converter performance, these three 3L-VSCs are discussed and compared in terms of power density and reliability, which can be considered as two of the most important criteria for the converters placed in wind turbine nacelles. Given the grid...... connection circuit (without capacitive switching ripple filters), the 3L-HB-VSC is expected to be superior with respect to power density and reliability over the 3L-NPC- and -FC-VSCs....

  16. Medium Voltage Three-level Converters for the Grid Connection of aMulti-MW Wind Turbine

    DEFF Research Database (Denmark)

    Senturk, Osman Selcuk; Helle, Lars; Munk-Nielsen, Stig

    2009-01-01

    Three-level (3L) neutral point clamped (NPC), flying capacitor (FC), and H-bridge (HB) voltage source converters (VSCs) as a grid-side full-scale medium voltage (MV) converter are modeled, controlled, and simulated for the grid connection of a hypothetical 6MW wind turbine. Via the converter...... topological features and the simulation results demonstrating the converter performance, these three 3L-VSCs are discussed and compared in terms of power density and reliability, which can be considered as two of the most important criteria for the converters placed in wind turbine nacelles. Given the grid...... connection circuit (without capacitive switching ripple filters), the 3L-HB-VSC is expected to be superior with respect to power density and reliability over the 3L-NPC- and -FC-VSCs....

  17. High Step-Up DC—DC Converter for AC Photovoltaic Module with MPPT Control

    Science.gov (United States)

    Sundar, Govindasamy; Karthick, Narashiman; Rama Reddy, Sasi

    2014-08-01

    This paper presents the high gain step-up BOOST converter which is essential to step up the low output voltage from PV panel to the high voltage according to the requirement of the application. In this paper a high gain BOOST converter with coupled inductor technique is proposed with the MPPT control. Without extreme duty ratios and the numerous turns-ratios of a coupled inductor this converter achieves a high step-up voltage-conversion ratio and the leakage energy of the coupled inductor is efficiently recycled to the load. MPPT control used to extract the maximum power from PV panel by controlling the Duty ratio of the converter. The PV panel, BOOST converter and the MPPT are modeled using Sim Power System blocks in MATLAB/SIMULINK environment. The prototype model of the proposed converter has been implemented with the maximum measured efficiency is up to 95.4% and full-load efficiency is 93.1%.

  18. A DC-Link Voltage Self-Balance Method for a Diode-Clamped Modular Multilevel Converter With Minimum Number of Voltage Sensors

    DEFF Research Database (Denmark)

    Gao, Congzhe; Jiang, Xinjian; Li, Yongdong

    2013-01-01

    Voltage balance issue of dc-link capacitors is very important for applications of a cascade multilevel converter or a modular multilevel converter. In this paper, a novel diode-clamped modular multilevel converter (DCM2C) topology is proposed and a power feedback control method is developed...... used traditional method; therefore, the system performance improvement and cost reduction are expected. Based on the proposed DCM2C, a novel N +1-level cascade multilevel topology is proposed for a cascade active power filter (CS-APF). The simulation and experimental results from the CS-APF have...

  19. Performance Improvement of DFIG Wind Turbine Using Series Grid-Side Converter under Unbalanced Grid Voltage and Voltage Sag Conditions

    DEFF Research Database (Denmark)

    Shokri, Yunes; Ebrahimzadeh, Esmaeil; Lesani, Hamid

    2014-01-01

    under unbalanced grid voltage and small voltage sag conditions without needing additional DC link capacitor or energy storage unlike other methods. The control system includes negative and positive sequence controllers which make the stator voltage balanced and keep it constant at the nominal value...

  20. 10-bit rapid single flux quantum digital-to-analog converter for ac voltage standard

    International Nuclear Information System (INIS)

    Maezawa, M; Hirayama, F

    2008-01-01

    Digital-to-analog (D/A) converters based on rapid single flux quantum (RSFQ) technology are under development for ac voltage standard applications. We present design and test results on a prototype 10-bit version integrated on a single chip. The 10-bit chip includes over 6000 Josephson junctions and consumes a bias current exceeding 1 A. To reduce the effects of the high bias current on circuit operation, a custom design method was employed in part and large circuit blocks were divided into smaller ones. The 10-bit chips were fabricated and tested at low speed. The test results suggested that our design approach could manage large bias currents on the order of 1 A per chip

  1. Utilization of the voltage frequency converter or digital representation and documentation of transient reactor operation

    International Nuclear Information System (INIS)

    Doane, Harry J.

    1986-01-01

    The ease and speed of handling transient data is enhanced by the use of a voltage to frequency converter (VFC). This analogue to digital semiconductor device provides an inexpensive and portable alternative to electro-mechanical recorders and hand entry of data into computer codes. The VFC used at The University of Arizona is a Teledyne Philbrick 4705/01. A zero to positive ten volt input signal provides a zero to one megahertz output signal which is TTL/DTL compatible. VFC is used at the University of Arizona to collect data for super prompt critical TRIGA excursions. The VFC provides a low cost, convenient method of transient data storage and retrieval for experimentation and laboratory demonstration

  2. Parameterized Analysis of Zero Voltage Switching in Resonant Converters for Optimal Electrode Layout of Piezoelectric Transformers

    DEFF Research Database (Denmark)

    Meyer, Kaspar Sinding; Andersen, Michael Andreas E.; Jensen, Flemming

    2008-01-01

    Ring shaped PTs (Piezoelectric Transformers) are an attractive alternative to magnetics in power converters. The achievable energy efficiency is 98% and the power density is up to 30W/cm3. Additionally power supplies based on PTs display low levels of conducted and radiated EMI due to power...... conversion based on the piezoelectric effect. Rooted in the physics of this effect, both the in- and output terminal of a PT has a noticeable parasitic capacitance. In a common half-bridge power stage without any supporting magnetic components, the input parasitic capacitance can lead to hard switching...... losses that are in the range of the actual power rating of a specific PT. In this paper it is demonstrated how the electrode layout of a PT can be designed to enable ZVS (Zero Voltage Switching). This optimization is made simple with a novel set of accurate and simple symbolic equations which relates ZVS...

  3. A time to voltage converter and analog memory unit for straw tracking detectors

    International Nuclear Information System (INIS)

    Callewaert, L.; Eyckmans, W.; Sansen, W.; Stevens, A.; Van der Spiegel, J.; Van Berg, R.; Williams, H.H.; Yau, T.Y.

    1990-01-01

    In a high precision drift tube or straw tracking system, one measures the time of arrival of the first electron at the anode. While many possible schemes exist, the authors initial judgment was that an analog time measurement would offer both lower power and greater resolution than an equally complex digital system. In addition, they believe that it will be necessary to incorporate all of the system features such as connection to the trigger and DAQ systems in any usable design in order to keep the power, mass and complexity of the final system under control. A low power, sub-nanosecond accuracy, quick recovery, data-driven, multiple sample Time to Voltage Converter suitable for use on high rate straw tracking detectors is described. The described TVC includes virtual storage of analog data in both Level 1 and Level 2 queues and an on board ADC with first order correction for capacitance variations and non-linearities

  4. A Unified Impedance Model of Voltage-Source Converters with Phase-Locked Loop Effect

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Harnefors, Lennart; Blaabjerg, Frede

    2016-01-01

    This paper proposes a unified impedance model for analyzing the effect of Phase-Locked Loop (PLL) on the stability of grid-connected voltage-source converters. In the approach, the dq-frame impedance model is transformed into the stationary αβ-frame by means of complex transfer functions...... and complex space vectors, which not only predicts the stability impact of the PLL, but reveals also its frequency coupling effect in the phase domain. Thus, the impedance models previously developed in the different domains can be unified. Moreover, the impedance shaping effects of PLL are structurally...... characterized for the current control in the rotating dq-frame and the stationary αβ-frame. Case studies based on the unified impedance model are presented, which are then verified in the time-domain simulations and experiments. The results closely correlate with the impedance-based analysis....

  5. Programmable Low-Power Low-Noise Capacitance to Voltage Converter for MEMS Accelerometers.

    Science.gov (United States)

    Royo, Guillermo; Sánchez-Azqueta, Carlos; Gimeno, Cecilia; Aldea, Concepción; Celma, Santiago

    2016-12-30

    In this work, we present a capacitance-to-voltage converter (CVC) for capacitive accelerometers based on microelectromechanical systems (MEMS). Based on a fully-differential transimpedance amplifier (TIA), it features a 34-dB transimpedance gain control and over one decade programmable bandwidth, from 75 kHz to 1.2 MHz. The TIA is aimed for low-cost low-power capacitive sensor applications. It has been designed in a standard 0.18-μm CMOS technology and its power consumption is only 54 μW. At the maximum transimpedance configuration, the TIA shows an equivalent input noise of 42 fA/ Hz at 50 kHz, which corresponds to 100 μg/ Hz .

  6. Programmable Low-Power Low-Noise Capacitance to Voltage Converter for MEMS Accelerometers

    Directory of Open Access Journals (Sweden)

    Guillermo Royo

    2016-12-01

    Full Text Available In this work, we present a capacitance-to-voltage converter (CVC for capacitive accelerometers based on microelectromechanical systems (MEMS. Based on a fully-differential transimpedance amplifier (TIA, it features a 34-dB transimpedance gain control and over one decade programmable bandwidth, from 75 kHz to 1.2 MHz. The TIA is aimed for low-cost low-power capacitive sensor applications. It has been designed in a standard 0.18-μm CMOS technology and its power consumption is only 54 μW. At the maximum transimpedance configuration, the TIA shows an equivalent input noise of 42 fA/ Hz at 50 kHz, which corresponds to 100 μg/ Hz .

  7. High-performance feedback-type active damping of LCL-filtered voltage source converters

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Loh, Poh Chiang

    2015-01-01

    a generalized impedance-based model of grid current control with feedback-type active damping. Then, a controller design method based on the z-domain root contours and frequency-domain passivity theorem is proposed. It not only allows a co-design of the grid current controller and damping controller......Active damping of LCL-filter resonance based on single-state feedback control is widely used with voltage source converters. Its robustness against grid impedance variation has always been a major concern with its controller design. To deal with this issue, this paper begins by developing......, but ensures also a robust stabilization against the grid parameters variations. For illustration, the approach is applied to design three single-state feedback-damping schemes, and their damping robustness are compared under both inductive and resonant grid impedances. Experimental results validate...

  8. Improvement of Shade Resilience in Photovoltaic Modules Using Buck Converters in a Smart Module Architecture

    Directory of Open Access Journals (Sweden)

    S. Zahra Mirbagheri Golroodbari

    2018-01-01

    Full Text Available Partial shading has a nonlinear effect on the performance of photovoltaic (PV modules. Different methods of optimizing energy harvesting under partial shading conditions have been suggested to mitigate this issue. In this paper, a smart PV module architecture is proposed for improvement of shade resilience in a PV module consisting of 60 silicon solar cells, which compensates the current drops caused by partial shading. The architecture consists of groups of series-connected solar cells in parallel to a DC-DC buck converter. The number of cell groups is optimized with respect to cell and converter specifications using a least-squares support vector machine method. A generic model is developed to simulate the behavior of the smart architecture under different shading patterns, using high time resolution irradiance data. In this research the shading patterns are a combination of random and pole shadows. To investigate the shade resilience, results for the smart architecture are compared with an ideal module, and also ordinary series and parallel connected architectures. Although the annual yield for the smart architecture is 79.5% of the yield of an ideal module, we show that the smart architecture outperforms a standard series connected module by 47%, and a parallel architecture by 13.4%.

  9. A Reconfigurable Series Resonant DC-DC Converter for Wide-Input and Wide-Output Voltages

    DEFF Research Database (Denmark)

    Shen, Yanfeng; Wang, Huai; Qin, Zian

    2017-01-01

    This paper proposes a dual-bridge based LC series resonant dc-dc converter. The input inverter unit incorporates two bridge structures, i.e., a full-bridge inverter and a half-bridge inverter. For the output rectifier, it can be a full-bridge rectifier or an asymmetric half-bridge rectifier....... Different from the conventional resonant converter, a fixed-frequency PWM control is employed which makes the optimization of magnetic components easier. The primary-side switches can achieve ZVS and the secondary-side diodes turn off with ZCS. In addition, the root-mean-square (RMS) values...... of the transformer currents do not significantly vary with respect to the voltage variation. Therefore, this converter can maintain high efficiency over a wide voltage range. The topology and operating principle are firstly described. Then the dc voltage gain and the RMS current characteristics are detailed. Finally...

  10. A New Approach to High Efficincy in Isolated Boost Converters for High-Power Low-Voltage Fuel Cell Apllications

    DEFF Research Database (Denmark)

    Nymand, Morten; Andersen, Michael A. E.

    2008-01-01

    A new low-leakage-inductance low-resistance design approach to low-voltage high-power isolated boost converters is presented. Very low levels of parasitic circuit inductances are achieved by optimizing transformer design and circuit lay-out. Primary side voltage clamp circuits can be eliminated...... by the use of power MOSFETs fully rated for repetitive avalanche. Voltage rating of primary switches can now be reduced, significantly reducing switch on-state losses. Finally, silicon carbide rectifying diodes allow fast diode turn-off, further reducing losses. Test results from a 1.5 kW full-bridge boost...... converter verify theoretical analysis and demonstrate very high efficiency. Worst case efficiency, at minimum input voltage maximum power, is 96.8 percent and maximum efficiency reaches 98 percent....

  11. Simulation of rectifier voltage malfunction on OWECS, four-level converter, HVDC light link: Smart grid context tool

    International Nuclear Information System (INIS)

    Seixas, M.; Melício, R.; Mendes, V.M.F.

    2015-01-01

    Highlights: • Floating offshore wind turbine in deep water. • DC link and voltage malfunction. • Converter topology considered is four-level. • Controllers are based on fractional-order. • Smart grid context. - Abstract: This paper presents a model for the simulation of an offshore wind system having a rectifier input voltage malfunction at one phase. The offshore wind system model comprises a variable-speed wind turbine supported on a floating platform, equipped with a permanent magnet synchronous generator using full-power four-level neutral point clamped converter. The link from the offshore floating platform to the onshore electrical grid is done through a light high voltage direct current submarine cable. The drive train is modeled by a three-mass model. Considerations about the smart grid context are offered for the use of the model in such a context. The rectifier voltage malfunction domino effect is presented as a case study to show capabilities of the model

  12. Instability of Wind Turbine Converters during Current Injection to Low Voltage Grid Faults and PLL Frequency Based Stability Solution

    DEFF Research Database (Denmark)

    Göksu, Ömer; Teodorescu, Remus; Bak, Claus Leth

    2014-01-01

    In recent grid codes for wind power integration, wind turbines are required to stay connected during grid faults even when the grid voltage drops down to zero; and also to inject reactive current in proportion to the voltage drop. However, a physical fact, instability of grid-connected converters...... during current injection to very low (close to zero) voltage faults, has been omitted, i.e., failed to be noticed in the previous wind power studies and grid code revisions. In this paper, the instability of grid side converters of wind turbines defined as loss of synchronism (LOS), where the wind...... turbines lose synchronism with the grid fundamental frequency (e.g., 50 Hz) during very deep voltage sags, is explored with its theory, analyzed and a novel stability solution based on PLL frequency is proposed; and both are verified with power system simulations and by experiments on a grid...

  13. Modulation linearization of a frequency-modulated voltage controlled oscillator, part 3

    Science.gov (United States)

    Honnell, M. A.

    1975-01-01

    An analysis is presented for the voltage versus frequency characteristics of a varactor modulated VHF voltage controlled oscillator in which the frequency deviation is linearized by using the nonlinear characteristics of a field effect transistor as a signal amplifier. The equations developed are used to calculate the oscillator output frequency in terms of pertinent circuit parameters. It is shown that the nonlinearity exponent of the FET has a pronounced influence on frequency deviation linearity, whereas the junction exponent of the varactor controls total frequency deviation for a given input signal. A design example for a 250 MHz frequency modulated oscillator is presented.

  14. Voltage-sensing phosphatase modulation by a C2 domain

    Directory of Open Access Journals (Sweden)

    Paul M. Castle

    2015-04-01

    Full Text Available The voltage-sensing phosphatase (VSP is the first example of an enzyme controlled by changes in membrane potential. VSP has four distinct regions: the transmembrane voltage-sensing domain (VSD, the inter-domain linker, the cytosolic catalytic domain and the C2 domain. The VSD transmits the changes in membrane potential through the inter-domain linker activating the catalytic domain which then dephosphorylates phosphatidylinositol phosphate lipids. The role of the C2, however, has not been established. In this study, we explore two possible roles for the C2: catalysis and membrane-binding. The Ci-VSP crystal structures show that the C2 residue Y522 lines the active site suggesting a contribution to catalysis. When we mutated Y522 to phenylalanine, we found a shift in the voltage dependence of activity. This suggests hydrogen bonding as a mechanism of action. Going one step further, when we deleted the entire C2 domain, we found voltage-dependent enzyme activity was no longer detectable. This result clearly indicates the entire C2 is necessary for catalysis as well as for modulating activity. As C2s are known membrane-binding domains, we tested whether the VSP C2 interacts with the membrane. We probed a cluster of four positively charged residues lining the top of the C2 and suggested by previous studies to interact with phosphatidylinositol 4,5-bisphosphate (PI(4,5P2 (Kalli et al., 2014. Neutralizing those positive charges significantly shifted the voltage dependence of activity to higher voltages. We tested membrane binding by depleting PI(4,5P2 from the membrane using the 5HT2C receptor and found that the VSD motions as measured by voltage clamp fluorometry were not changed. These results suggest that if the C2 domain interacts with the membrane to influence VSP function it may not occur exclusively through PI(4,5P2. Together, this data advances our understanding of the VSP C2 by demonstrating a necessary and critical role for the C2 domain in

  15. Voltage-sensing phosphatase modulation by a C2 domain.

    Science.gov (United States)

    Castle, Paul M; Zolman, Kevin D; Kohout, Susy C

    2015-01-01

    The voltage-sensing phosphatase (VSP) is the first example of an enzyme controlled by changes in membrane potential. VSP has four distinct regions: the transmembrane voltage-sensing domain (VSD), the inter-domain linker, the cytosolic catalytic domain, and the C2 domain. The VSD transmits the changes in membrane potential through the inter-domain linker activating the catalytic domain which then dephosphorylates phosphatidylinositol phosphate (PIP) lipids. The role of the C2, however, has not been established. In this study, we explore two possible roles for the C2: catalysis and membrane-binding. The Ci-VSP crystal structures show that the C2 residue Y522 lines the active site suggesting a contribution to catalysis. When we mutated Y522 to phenylalanine, we found a shift in the voltage dependence of activity. This suggests hydrogen bonding as a mechanism of action. Going one step further, when we deleted the entire C2 domain, we found voltage-dependent enzyme activity was no longer detectable. This result clearly indicates the entire C2 is necessary for catalysis as well as for modulating activity. As C2s are known membrane-binding domains, we tested whether the VSP C2 interacts with the membrane. We probed a cluster of four positively charged residues lining the top of the C2 and suggested by previous studies to interact with phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] (Kalli et al., 2014). Neutralizing those positive charges significantly shifted the voltage dependence of activity to higher voltages. We tested membrane binding by depleting PI(4,5)P2 from the membrane using the 5HT2C receptor and found that the VSD motions as measured by voltage clamp fluorometry (VCF) were not changed. These results suggest that if the C2 domain interacts with the membrane to influence VSP function it may not occur exclusively through PI(4,5)P2. Together, this data advances our understanding of the VSP C2 by demonstrating a necessary and critical role for the C2 domain in

  16. Design-Oriented Analysis of Resonance Damping and Harmonic Compensation for LCL-Filtered Voltage Source Converters

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Loh, Poh Chiang

    2014-01-01

    This paper addresses the interaction between harmonic resonant controllers and active damping of LCL resonance in voltage source converters. A virtual series R-C damper in parallel with the filter capacitor is proposed with the capacitor current feedback loop. The phase lag resulting from...... crossover frequency defined by the proportional gain of current controller. This is of particular interest for high-performance active harmonic filtering applications and low-pulse-ratio converters. Case studies in experiments validate the theoretical analysis....

  17. SYNTHESIS OF AUTOMATIC CONTROL SYSTEM FOR STEPPING-UP CONVERTER OF DC VOLTAGE AT ACTIVE LOAD OPERATION

    Directory of Open Access Journals (Sweden)

    A. V. Мironovich

    2005-01-01

    Full Text Available Investigation of a nontransformer stepping-up converter of dc voltage has been carried out. A non-linear structural circuit of the converter has been developed with the help of the controlled current injection method. A linearization of an object and an automation control system synthesis have been conducted applying method of successive optimization of the circuits. The paper contains results of transient process simulation in the linear computer model and in the power electronics computer model. 

  18. Sub-module Short Circuit Fault Diagnosis in Modular Multilevel Converter Based on Wavelet Transform and Adaptive Neuro Fuzzy Inference System

    DEFF Research Database (Denmark)

    Liu, Hui; Loh, Poh Chiang; Blaabjerg, Frede

    2015-01-01

    for continuous operation and post-fault maintenance. In this article, a fault diagnosis technique is proposed for the short circuit fault in a modular multi-level converter sub-module using the wavelet transform and adaptive neuro fuzzy inference system. The fault features are extracted from output phase voltage...

  19. Module Seven: Combination Circuits and Voltage Dividers; Basic Electricity and Electronics Individualized Learning System.

    Science.gov (United States)

    Bureau of Naval Personnel, Washington, DC.

    In this module the student will learn to apply the rules previously learned for series and parallel circuits to more complex circuits called series-parallel circuits, discover the utility of a common reference when making reference to voltage values, and learn how to obtain a required voltage from a voltage divider network. The module is divided…

  20. Isolated PWM DC-AC SICAM with an active capacitive voltage clamp[Pulse Density Modulated; Pulse Width Modulation

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.

    2004-03-15

    In this report an isolated PWM DC-AC SICAM with an active capacitive voltage clamp is presented. AC-DC power supply is implemented in its simplest form: diode rectifier followed by a medium-size charge-storage capacitors and possibly with an EMC filter on the mains entrance. Isolation from the AC mains is achieved using a high frequency (HF) transformer, whose voltages are not audio-modulated. The latter simplifies the design and is expected to have many advantages over the approach where the transformer voltages are modulated in regards to the audio signal reference. Input stage is built as a DC-AC inverter (push-pull, half-bridge or a full-bridge) and operated with 50% duty cycle, with all the challenges to avoid transformer saturation and obtain symmetrical operation. On the secondary side the output section is implemented as rectifier+inverter AC-AC stage, i.e. a true bidirectional bridge, which operation is aimed towards amplification of the audio signal. In order to solve the problem with the commutation of the load current, a dead time between the incoming and outgoing bidirectional switch is implemented, while a capacitive voltage clamp is used to keep the induced overvoltage to reasonable levels. The energy stored in the clamping capacitor is not wasted as in the dissipative clamps, but is rather transferred back to the primary side for further processing using an auxiliary isolated single-switch converter, i.e. an active clamping technique is used. (au)

  1. High-Voltage, Multiphasic, Nanosecond Pulses to Modulate Cellular Responses.

    Science.gov (United States)

    Ryan, Hollie A; Hirakawa, Shinji; Yang, Enbo; Zhou, Chunrong; Xiao, Shu

    2018-04-01

    Nanosecond electric pulses are an effective power source in plasma medicine and biological stimulation, in which biophysical responses are governed by peak power and not energy. While uniphasic nanosecond pulse generators are widely available, the recent discovery that biological effects can be uniquely modulated by reversing the polarity of nanosecond duration pulses calls for the development of a multimodal pulse generator. This paper describes a method to generate nanosecond multiphasic pulses for biomedical use, and specifically demonstrates its ability to cancel or enhance cell swelling and blebbing. The generator consists of a series of the fundamental module, which includes a capacitor and a MOSFET switch. A positive or a negative phase pulse module can be produced based on how the switch is connected. Stacking the modules in series can increase the voltage up to 5 kV. Multiple stacks in parallel can create multiphase outputs. As each stack is independently controlled and charged, multiphasic pulses can be created to produce flexible and versatile pulse waveforms. The circuit topology can be used for high-frequency uniphasic or biphasic nanosecond burst pulse production, creating numerous opportunities for the generator in electroporation applications, tissue ablation, wound healing, and nonthermal plasma generation.

  2. Using variable DC sources in order to improve the voltage quality of a multilevel STATCOM with low frequency modulation

    DEFF Research Database (Denmark)

    Dowlatabadi, Mohammadkazem Bakhshizadeh; Najjar, Mohammad; Blaabjerg, Frede

    2016-01-01

    In this paper, a Selective Harmonic Elimination Pulse Width Modulation (SHE-PWM) method, which utilizes adjustable dc links, is presented for a Static Synchronous Compensator (STATCOM) based on Cascaded H-Bridge (CHB) multilevel converter. The proposed switching algorithm is able to fix the capac......In this paper, a Selective Harmonic Elimination Pulse Width Modulation (SHE-PWM) method, which utilizes adjustable dc links, is presented for a Static Synchronous Compensator (STATCOM) based on Cascaded H-Bridge (CHB) multilevel converter. The proposed switching algorithm is able to fix...... unequal dc link voltages more levels at the output is achievable compared to the symmetrical multilevel converters that could be used in enhancing the power quality, while keeping the switching frequency near the fundamental (the maximum switching frequency can be kept below 150 Hz). The validity...

  3. Unifying and generating of space vector modulation sequences for multilevel converter

    DEFF Research Database (Denmark)

    Ma, Ke; Blaabjerg, Frede

    2014-01-01

    Space Vector Modulation (SVM) is a powerful method which enables some freedom to generate the modulation sequences and modify the performances of converter. However, in the multi-level converter structures, the number of switching state redundancies significantly increases, and the determination...

  4. Optimal Design of a High Efficiency LLC Resonant Converter with a Narrow Frequency Range for Voltage Regulation

    Directory of Open Access Journals (Sweden)

    Junhao Luo

    2018-05-01

    Full Text Available As a key factor in the design of a voltage-adjustable LLC resonant converter, frequency regulation range is very important to the optimization of magnetic components and efficiency improvement. This paper presents a novel optimal design method for LLC resonant converters, which can narrow the frequency variation range and ensure high efficiency under the premise of a required gain achievement. A simplified gain model was utilized to simplify the calculation and the expected efficiency was initially set as 96.5%. The restricted area of parameter optimization design can be obtained by taking the intersection of the gain requirement, the efficiency requirement, and three restrictions of ZVS (Zero Voltage Switch. The proposed method was verified by simulation and experiments of a 150 W prototype. The results show that the proposed method can achieve ZVS from full-load to no-load conditions and can reach 1.6 times the normalized voltage gain in the frequency variation range of 18 kHz with a peak efficiency of up to 96.3%. Moreover, the expected efficiency is adjustable, which means a converter with a higher efficiency can be designed. The proposed method can also be used for the design of large-power LLC resonant converters to obtain a wide output voltage range and higher efficiency.

  5. New 2LC-Y DC-DC converter topologies for high-voltage/low-current renewable applications

    DEFF Research Database (Denmark)

    Bhaskar, Mahajan Sagar; Padmanaban, Sanjeevikumar; Maroti, Pandav Kiran

    2017-01-01

    (2LC-LVD, 2LC-2LVD, 2LC-2LCVD and 2LC-2LCmVD) converters are presented in this treatise which offer an effective solution for renewable applications requiring a very high voltage conversion ratio such as a Photovoltaic Multilevel Inverter (PV-MLI) system, hybrid electrical drives and automotive...

  6. A Dual Active Bridge Converter with an Extended High-Efficiency Range by DC Blocking Capacitor Voltage Control

    DEFF Research Database (Denmark)

    Qin, Zian; Shen, Yanfeng; Loh, Poh Chiang

    2018-01-01

    of hard switching and high circulating power. Thus, a new modulation scheme has been proposed, whose main idea is to introduce a voltage offset across the dc blocking capacitor connected in series with the transformer. Operational principle of the proposed modulation has been introduced, before analyzing...

  7. Optimal Design of a Push-Pull-Forward Half-Bridge (PPFHB) Bidirectional DC–DC Converter With Variable Input Voltage

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2012-01-01

    This paper presents a low-cost bidirectional isolated dc–dc converte, derived from dual-active-bridge converter for the power sources with variable output voltage like supercapacitors. The proposed converter consists of push-pull-forward circuit half-bridge circuit (PPFHB) and a high-frequency tr......This paper presents a low-cost bidirectional isolated dc–dc converte, derived from dual-active-bridge converter for the power sources with variable output voltage like supercapacitors. The proposed converter consists of push-pull-forward circuit half-bridge circuit (PPFHB) and a high...

  8. Improving Power Converter Reliability

    DEFF Research Database (Denmark)

    Ghimire, Pramod; de Vega, Angel Ruiz; Beczkowski, Szymon

    2014-01-01

    of a high-power IGBT module during converter operation, which may play a vital role in improving the reliability of the power converters. The measured voltage is used to estimate the module average junction temperature of the high and low-voltage side of a half-bridge IGBT separately in every fundamental......The real-time junction temperature monitoring of a high-power insulated-gate bipolar transistor (IGBT) module is important to increase the overall reliability of power converters for industrial applications. This article proposes a new method to measure the on-state collector?emitter voltage...... is measured in a wind power converter at a low fundamental frequency. To illustrate more, the test method as well as the performance of the measurement circuit are also presented. This measurement is also useful to indicate failure mechanisms such as bond wire lift-off and solder layer degradation...

  9. SOGI-based capacitor voltage feedback active damping in LCL-filtered grid converters

    DEFF Research Database (Denmark)

    Xin, Zhen; Wang, Xiongfei; Loh, Poh Chiang

    2015-01-01

    The capacitor voltage feedback active damping control is an attractive way to suppress LCL-filter resonance especially for the systems where the capacitor voltage is used for grid synchronization, since no extra sensors are added. The derivative is the core of the capacitor voltage feedback active...... derivative is more suited for capacitor voltage feedback active damping control. Experimental results validate the effectiveness of the proposed method....

  10. Module-Integrated Power Converters Based on Universal Dock

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, Patrick; Rodriguez, Fernando

    2015-03-13

    Solar power installations using alternating current photovoltaic (ACPV) modules have significant cost and performance advantages over systems using conventional solar modules and string inverters. ACPV modules have improved energy harvest due to module-level power point tracking and redundancy. More importantly, ACPV modules are easier and cheaper to install, lowering the total installed cost, indirect costs, and barriers to market entry. Furthermore, ACPV modules have communications and data logging capability, yielding module-level telemetry data that is useful in site diagnostics and other data applications. The products of these efforts were threefold. First, an advanced microinverter power topology was developed, modeled, simulated, and tested. Second, new microinverter enclosure concepts were developed and tested. Third, a new ACPV module prototype was constructed, combining the power topology and the enclosure concepts. SolarBridge filed for patents in each of these areas and is transitioning the project from a concept phase to full development.

  11. Space Charge Modulated Electrical Breakdown of Oil Impregnated Paper Insulation Subjected to AC-DC Combined Voltages

    Directory of Open Access Journals (Sweden)

    Yuanwei Zhu

    2018-06-01

    Full Text Available Based on the existing acknowledgment that space charge modulates AC and DC breakdown of insulating materials, this investigation promotes the related investigation into the situations of more complex electrical stress, i.e., AC-DC combined voltages. Experimentally, the AC-DC breakdown characteristics of oil impregnated paper insulation were systematically investigated. The effects of pre-applied voltage waveform, AC component ratio, and sample thickness on AC-DC breakdown characteristics were analyzed. After that, based on an improved bipolar charge transport model, the space charge profiles and the space charge induced electric field distortion during AC-DC breakdown were numerically simulated to explain the differences in breakdown characteristics between the pre-applied AC and pre-applied DC methods under AC-DC combined voltages. It is concluded that large amounts of homo-charges are accumulated during AC-DC breakdown, which results in significantly distorted inner electric field, leading to variations of breakdown characteristics of oil impregnated paper insulation. Therefore, space charges under AC-DC combined voltages must be considered in the design of converter transformers. In addition, this investigation could provide supporting breakdown data for insulation design of converter transformers and could promote better understanding on the breakdown mechanism of insulating materials subjected to AC-DC combined voltages.

  12. Digital Control of a High Voltage (2.5 kV) Bidirectional Flyback DC-DC Converter for Driving a Capacitive Incremental Actuator

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Maksimovic, Dragan; Zhang, Zhe

    2016-01-01

    This paper presents a digital control technique to achieve valley switching in a bidirectional flyback converter used to drive a dielectric electro-active polymer based capacitive incremental actuator. The paper also provides the design of a low input voltage (24 V) and variable high output voltage...... on the output high-voltage (HV) side. Experimental results verifying the bidirectional operation of a high voltage flyback converter are presented, using a 3 kV polypropylene film capacitor as the load. The energy loss distributions of the converter when 4 kV and 4.5 kV HV MOSFETs are used on HV side...

  13. Weighting Function Integrated in Grid-interfacing Converters for Unbalanced Voltage Correction

    NARCIS (Netherlands)

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

    2008-01-01

    In this paper a weighting function for voltage unbalance correction is proposed to be integrated into the control of distributed grid-interfacing systems. The correction action can help decrease the negative-sequence voltage at the point of connection with the grid. Based on the voltage unbalance

  14. Voltage and Current Regulators Design of Power Converters in Islanded Microgrids based on State Feedback Decoupling

    DEFF Research Database (Denmark)

    Federico, de Bosio; de Sousa Ribeiro, Luiz Antonio; Freijedo Fernandez, Francisco Daniel

    2016-01-01

    In stand-alone microgrids based on voltage source inverters state feedback coupling between the capacitor voltage and inductor current degrades significantly the dynamics performance of voltage and current regulators. The decoupling of the controlled states is proposed, considering the limitations...

  15. A SVPWM based on fluctuate capacitor voltage in 3L-NPC back-to-back converter applied to wind energy

    DEFF Research Database (Denmark)

    Chen, Quan; Wang, Qunjing; Chen, Zhe

    2014-01-01

    Three-level Neutral-point-clamped (3L-NPC) converters are becoming a realistic alternative to the conventional converters in high-power wind-energy applications. But the unbalance in the supported capacitors' voltage of back-to-back 3L-NPC converters, including the dynamics of the capacitors...... between the fluctuate voltage of upper and lower capacitors is extracted. Based on this error factor the duty-time of every active voltage vector is calculated. In order to validate the model and the control strategy proposed in this paper, a 2MW 3L-NPC converter used in wind energy has been simulated....

  16. Speed Control of Matrix Converter-Fed Five-Phase Permanent Magnet Synchronous Motors under Unbalanced Voltages

    Directory of Open Access Journals (Sweden)

    Borzou Yousefi

    2017-09-01

    Full Text Available Five-phase permanent magnet synchronous motors (PMSM have special applications in which highly accurate speed and torque control of the motor are a strong requirement. Direct Torque Control (DTC is a suitable method for the driver structure of these motors. If in this method, instead of using a common five-phase voltage source inverter, a three-phase to five-phase matrix converter is used, the low-frequency current harmonics and the high torque ripple are limited, and an improved input power factor is obtained. Because the input voltages of such converters are directly supplied by input three-phase supply voltages, an imbalance in the voltages will cause problems such as unbalanced stator currents and electromagnetic torque fluctuations. In this paper, a new method is introduced to remove speed and torque oscillator factors. For this purpose, motor torque equations were developed and the oscillation components created by the unbalanced source voltage, determined. Then, using the active and reactive power reference generator, the controller power reference was adjusted in such a way that the electromagnetic torque of the motor did not change. By this means, a number of features including speed, torque, and flux of the motor were improved in terms of the above-mentioned conditions. Simulations were analyzed using Matlab/Simulink software.

  17. Plug-and-Play Voltage/Current Stabilization DC Microgrid Clusters with Grid-Forming/Feeding Converters

    DEFF Research Database (Denmark)

    Han, Renke; Tucci, Michele; Martinelli, Andrea

    2018-01-01

    In this paper, we propose a new decentralized control scheme for Microgrid (MG) clusters, given by the interconnection of atomic dc MGs, each composed by grid-forming and grid-feeding converters. In particular, we develop a new Plug-and-Play (PnP) voltage/current controller for each MG in order...... to achieve simultaneous voltage support and current feeding function with local references. The coefficients of each stabilizing controller are characterized by explicit inequalities, which are related only to local electrical parameters of the MG. With the proposed controller, each MG can plug...

  18. Gabapentin Modulates HCN4 Channel Voltage-Dependence

    Directory of Open Access Journals (Sweden)

    Han-Shen Tae

    2017-08-01

    Full Text Available Gabapentin (GBP is widely used to treat epilepsy and neuropathic pain. There is evidence that GBP can act on hyperpolarization-activated cation (HCN channel-mediated Ih in brain slice experiments. However, evidence showing that GBP directly modulates HCN channels is lacking. The effect of GBP was tested using two-electrode voltage clamp recordings from human HCN1, HCN2, and HCN4 channels expressed in Xenopus oocytes. Whole-cell recordings were also made from mouse spinal cord slices targeting either parvalbumin positive (PV+ or calretinin positive (CR+ inhibitory neurons. The effect of GBP on Ih was measured in each inhibitory neuron population. HCN4 expression was assessed in the spinal cord using immunohistochemistry. When applied to HCN4 channels, GBP (100 μM caused a hyperpolarizing shift in the voltage of half activation (V1/2 thereby reducing the currents. Gabapentin had no impact on the V1/2 of HCN1 or HCN2 channels. There was a robust increase in the time to half activation for HCN4 channels with only a small increase noted for HCN1 channels. Gabapentin also caused a hyperpolarizing shift in the V1/2 of Ih measured from HCN4-expressing PV+ inhibitory neurons in the spinal dorsal horn. Gabapentin had minimal effect on Ih recorded from CR+ neurons. Consistent with this, immunohistochemical analysis revealed that the majority of CR+ inhibitory neurons do not express somatic HCN4 channels. In conclusion, GBP reduces HCN4 channel-mediated currents through a hyperpolarized shift in the V1/2. The HCN channel subtype selectivity of GBP provides a unique tool for investigating HCN4 channel function in the central nervous system. The HCN4 channel is a candidate molecular target for the acute analgesic and anticonvulsant actions of GBP.

  19. Biased low differential input impedance current receiver/converter device and method for low noise readout from voltage-controlled detectors

    Science.gov (United States)

    Degtiarenko, Pavel V [Williamsburg, VA; Popov, Vladimir E [Newport News, VA

    2011-03-22

    A first stage electronic system for receiving charge or current from voltage-controlled sensors or detectors that includes a low input impedance current receiver/converter device (for example, a transimpedance amplifier), which is directly coupled to the sensor output, a source of bias voltage, and the device's power supply (or supplies), which use the biased voltage point as a baseline.

  20. Pulse-Width-Modulation of Neutral-Point-Clamped Sparse Matrix Converter

    DEFF Research Database (Denmark)

    Loh, P.C.; Blaabjerg, Frede; Gao, F.

    2007-01-01

    input current and output voltage can be achieved with minimized rectification switching loss, rendering the sparse matrix converter as a competitive choice for interfacing the utility grid to (e.g.) defense facilities that require a different frequency supply. As an improvement, sparse matrix converter...... with improved waveform quality. Performances and practicalities of the designed schemes are verified in simulation and experimentally using an implemented laboratory prototype with some representative results captured and presented in the paper....

  1. Module Five: Relationships of Current, Voltage, and Resistance; Basic Electricity and Electronics Individualized Learning System.

    Science.gov (United States)

    Bureau of Naval Personnel, Washington, DC.

    This module covers the relationships between current and voltage; resistance in a series circuit; how to determine the values of current, voltage, resistance, and power in resistive series circuits; the effects of source internal resistance; and an introduction to the troubleshooting of series circuits. This module is divided into five lessons:…

  2. Hybrid Modulation of Bidirectional Three-Phase Dual-Active-Bridge DC Converters for Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Yen-Ching Wang

    2016-06-01

    Full Text Available Bidirectional power converters for electric vehicles (EVs have received much attention recently, due to either grid-supporting requirements or emergent power supplies. This paper proposes a hybrid modulation of the three-phase dual-active bridge (3ΦDAB converter for EV charging systems. The designed hybrid modulation allows the converter to switch its modulation between phase-shifted and trapezoidal modes to increase the conversion efficiency, even under light-load conditions. The mode transition is realized in a real-time manner according to the charging or discharging current. The operation principle of the converter is analyzed in different modes and thus design considerations of the modulation are derived. A lab-scaled prototype circuit with a 48V/20Ah LiFePO4 battery is established to validate the feasibility and effectiveness.

  3. Investigation on a Novel Discontinuous Pulse-Width Modulation Algorithm for Single-phase Voltage Source Rectifier

    DEFF Research Database (Denmark)

    Qu, Hao; Yang, Xijun; Guo, Yougui

    2014-01-01

    Single-phase voltage source converter (VSC) is an important power electronic converter (PEC), including single-phase voltage source inverter (VSI), single-phase voltage source rectifier (VSR), single-phase active power filter (APF) and single-phase grid-connection inverter (GCI). Single-phase VSC...

  4. A Comparative Study of Voltage, Peak Current and Dual Current Mode Control Methods for Noninverting Buck-Boost Converter

    Directory of Open Access Journals (Sweden)

    M. Č. Bošković

    2016-06-01

    Full Text Available This paper presents a comparison of voltage mode control (VMC and two current mode control (CMC methods of noninverting buck-boost converter. The converter control-to-output transfer function, line-to-output transfer function and the output impedance are obtained for all methods by averaging converter equations over one switching period and applying small-signal linearization. The obtained results are required for the design procedure of feedback compensator to keep a system stable and robust. A comparative study of VMC, peak current mode control (PCMC and dual-current mode control (DCMC is performed. Performance evaluation of the closed-loop system with obtained compensator between these methods is performed via numerical simulations.

  5. Empiric analysis of zero voltage switching in piezoelectric transformer based resonant converters

    DEFF Research Database (Denmark)

    Rødgaard, Martin Schøler; Andersen, Thomas; Andersen, Michael A. E.

    2012-01-01

    Research and development within piezoelectric transformer (PT) based converters are rapidly increasing, as the technology is maturing and starts to prove its capabilities. High power density and high efficiencies are reported and recently several inductor-less converters have emerged [1][2][7][10......Research and development within piezoelectric transformer (PT) based converters are rapidly increasing, as the technology is maturing and starts to prove its capabilities. High power density and high efficiencies are reported and recently several inductor-less converters have emerged [1...

  6. A flexible low-voltage ride-through operation for the distributed generation converters

    DEFF Research Database (Denmark)

    Chen, Hsin-Chih; Lee, Chia-Tse; Cheng, Po-Tai

    2013-01-01

    With more and more distributed energy resources (DERs) are installed in the utility grid, the utility requires the DER generation system to remain grid-connected and injects reactive and active power to support grid voltage during voltage sags. In this paper, a positive- and negative-sequence cur...

  7. A DC-DC Converter with Wide Input Voltage Range for Fuel Cell and Supercapacitor Application

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael Andreas E.

    2009-01-01

    This paper proposes a novel phase-shift plus duty cycle controlled hybrid bi-directional DC-DC converter based on fuel cells and supercapacitors. The described converter employs two high frequency transformers to couple the half-bridge and full-bridge circuits together in the primary side...

  8. Modular High Voltage Pulse Converter for Short Rise and Decay Times

    NARCIS (Netherlands)

    Mao, S.

    2018-01-01

    This thesis explores a modular HV pulse converter technology with short rise and decay times. A systematic methodology to derive and classify HV architectures based on a modularization level of power building blocks of the HV pulse converter is developed to summarize existing architectures and

  9. Optimization of Bi-Directional Flyback Converter for a High Voltage Capacitor Charging Application

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Schneider, Henrik; Zhang, Zhe

    2014-01-01

    This paper presents an optimization technique for a flyback converter with a bidirectional energy transfer. The main goal is to optimize the converter for driving an incremental dielectric electro active polymer actuator, which must be charged and discharged from 0 V to 2500 V DC, supplied from...

  10. Switched capacitor DC-DC converter with switch conductance modulation and Pesudo-fixed frequency control

    DEFF Research Database (Denmark)

    Larsen, Dennis Øland; Vinter, Martin; Jørgensen, Ivan Harald Holger

    A switched capacitor dc-dc converter with frequency-planned control is presented. By splitting the output stage switches in eight segments the output voltage can be regulated with a combination of switching frequency and switch conductance. This allows for switching at predetermined frequencies, 31...

  11. Experimental investigation of the cascadability of a cross-gain modulation wavelength converter

    DEFF Research Database (Denmark)

    Zheng, Xueyan; Liu, Fenghai; Kloch, Allan

    2000-01-01

    by adding a fiber grating-based optical add-drop multiplexer after the semiconductor optical amplifier (SOA) to enhance the high-frequency response of the wavelength converter. However, the low-frequency degradation of the signal together with amplified spontaneous emission (ASE) noise and jitter......The cascading characteristics of a wavelength converter based on cross-gain modulation (XGM) are studied experimentally using a recirculating loop at 10 Gb/s. The maximum cascaded number of the wavelength converter converting the signal to the same wavelength is improved from five to eight...

  12. Balanced Current Control Strategy for Current Source Rectifier Stage of Indirect Matrix Converter under Unbalanced Grid Voltage Conditions

    Directory of Open Access Journals (Sweden)

    Yeongsu Bak

    2016-12-01

    Full Text Available This paper proposes a balanced current control strategy for the current source rectifier (CSR stage of an indirect matrix converter (IMC under unbalanced grid voltage conditions. If the three-phase grid connected to the voltage source inverter (VSI of the IMC has unbalanced voltage conditions, it affects the currents of the CSR stage and VSI stage, and the currents are distorted. Above all, the distorted currents of the CSR stage cause instability in the overall system, which can affect the life span of the system. Therefore, in this paper, a control strategy for balanced currents in the CSR stage is proposed. To achieve balanced currents in the CSR stage, the VSI stage should receive DC power without ripple components from the CSR stage. This is implemented by controlling the currents in the VSI stage. Therefore, the proposed control strategy decouples the positive and negative phase-sequence components existing in the unbalanced voltages and currents of the VSI stage. Using the proposed control strategy under unbalanced grid voltage conditions, the stability and life span of the overall system can be improved. The effectiveness of the proposed control strategy is verified by simulation and experimental results.

  13. Digital Realization of Capacitor-Voltage Feedback Active Damping for LCL-Filtered Grid Converters

    DEFF Research Database (Denmark)

    Xin, Zhen; Wang, Xiongfei; Loh, Poh Chiang

    2015-01-01

    The capacitor voltage of an LCL-filter can also be used for active damping, if it is fed back for synchronization. By this way, an extra current sensor can be avoided. Compared with the existing active damping techniques designed with capacitor current feedback, the capacitor voltage feedback....... To overcome their drawbacks, a new derivative method is then proposed, based on the non-ideal generalized integrator. The performance of the proposed derivative has been found to match the ideal “s” function closely. Active damping based on capacitor voltage feedback can therefore be realized accurately...

  14. Highly Accurate Derivatives for LCL-Filtered Grid Converter with Capacitor Voltage Active Damping

    DEFF Research Database (Denmark)

    Xin, Zhen; Loh, Poh Chiang; Wang, Xiongfei

    2016-01-01

    The middle capacitor voltage of an LCL-filter, if fed back for synchronization, can be used for active damping. An extra sensor for measuring the capacitor current is then avoided. Relating the capacitor voltage to existing popular damping techniques designed with capacitor current feedback would...... are then proposed, based on either second-order or non-ideal generalized integrator. Performances of these derivatives have been found to match the ideal “s” function closely. Active damping based on capacitor voltage feedback can therefore be realized accurately. Experimental results presented have verified...

  15. An improved control method of power electronic converters in low voltage micro-grid

    DEFF Research Database (Denmark)

    Xiaofeng, Sun; Qingqiu, Lv; Yanjun, Tian

    2011-01-01

    control of the voltage and frequency deviation added to power references could achieve secondary regulation of the voltage and frequency. In this paper, the authors take the steady and transient transition of grid connecting and disconnecting of the micro-grid as an example, and demonstrate......With the increasing acceptance, micro-grid, combined with distributed generation (DG), may be operated in two modes: grid-connected mode and island mode. In grid connected mode, energy management is the control objective. While in island mode, the control of Voltage and frequency will take...... the place. The conventional droop control can perform the energy management in grid-connected mode, but may not so effective when micro-grid transferring between grid-connected mode and island mode. The paper analysis the micro-grid in different modes (Conventional droop control, Voltage reference...

  16. Carrier-based modulation schemes for various three-level matrix converters

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Loh, P.C.; Rong, R.C.

    2008-01-01

    different performance merits. To avoid confusion and hence fasten the converter applications in the industry, it would surely be better for modulation schemes to be developed from a common set of modulation principles that unfortunately has not yet been thoroughly defined. Contributing to that area...... a limited set of switching vectors because of its lower semiconductor count. Through simulation and experimental testing, all the evaluated matrix converters are shown to produce satisfactory sinusoidal input and output quantities using the same set of generic modulation principles, which can conveniently...

  17. Modification of Modulating Anode Voltage Supply of Klystron for PEFP 20 MeV Linac

    International Nuclear Information System (INIS)

    Kim, Dae Il; Kwon, Hyeok Jung; Kim, Han Sung; Cho, Yong Sub

    2011-01-01

    The klystron (TH2089F, THALES) for PEFP 20MeV proton linear accelerator has a triode type electron gun and the modulating anode voltage should be supplied. The klystron has gone through some modification in the modulating anode voltage supply circuit. Formerly, the mod-anode voltage was supplied by using the tetrode-controlled voltage divider. This system requires addition power supply for the tetrode and the grid control circuit. Recently we modified the mod-anode supply from the tetrode-controlled voltage divider to a resistive voltage divider. The resistors for the previous voltage divider were installed at a supporter with high voltage bushing structure next to the klystron. In the previous system, the resistors were exposed to the air and their size was very bulky, length of which was about 1m long. To reduce the space occupied by the voltage divider and to improve the electrical insulation performance, the voltage dividing resistors were moved into the oil tank of the klystron. During the operation of the 20 MeV linac, the klystron parameters were measured. In this paper, the modification of the voltage divider and the operational characteristics of the klystron with modified voltage divider circuit are presented

  18. Modeling and Simulation of Buck-Boost Converter with Voltage Feedback Control

    Directory of Open Access Journals (Sweden)

    Zhou Xuelian

    2015-01-01

    Full Text Available In order to design the control system, it is necessary to have an exact model of buck-boost converter. This paper put forward the transfer function model of buck-boost converter by the state-space average method. The open-loop transfer function model of uncompensated system is deduced according to the mathematic model of the buck-boost converter, the controller is designed according to frequency domain. The phase and magnitude margin of the open-loop system of the buck-boost converter with compensator have both been increased. After compensating, this control system has the advantages of small overshoot and short settling time. It can also improve control system’s real time property and anti-interference ability.

  19. Power Control of Grid-Connected Converters Under Unbalanced Voltage Conditions

    Czech Academy of Sciences Publication Activity Database

    Valouch, Viktor; Bejvl, Martin; Šimek, Petr; Škramlík, Jiří

    2015-01-01

    Roč. 62, č. 7 (2015), s. 4241-4248 ISSN 0278-0046 Institutional support: RVO:61388998 Keywords : converter * current control * current peaks Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 6.383, year: 2015

  20. Analog Amplitude Modulation of a High Voltage, Solid State Inductive Adder, Pulse Generator Using MOSFETS

    International Nuclear Information System (INIS)

    Gower, E J; Sullivan, J S

    2002-01-01

    High voltage, solid state, inductive adder, pulse generators have found increasing application as fast kicker pulse modulators for charged particle beams. The solid state, inductive adder, pulse generator is similar in operation to the linear induction accelerator. The main difference is that the solid state, adder couples energy by transformer action from multiple primaries to a voltage summing stalk, instead of an electron beam. Ideally, the inductive adder produces a rectangular voltage pulse at the load. In reality, there is usually some voltage variation at the load due to droop on primary circuit storage capacitors, or, temporal variations in the load impedance. Power MOSFET circuits have been developed to provide analog modulation of the output voltage amplitude of a solid state, inductive adder, pulse generator. The modulation is achieved by including MOSFET based, variable subtraction circuits in the multiple primary stack. The subtraction circuits can be used to compensate for voltage droop, or, to tailor the output pulse amplitude to provide a desired effect in the load. Power MOSFET subtraction circuits have been developed to modulate short, temporal (60-400 ns), voltage and current pulses. MOSFET devices have been tested up to 20 amps and 800 Volts with a band pass of 50 MHz. An analog modulation cell has been tested in a five cell high, voltage adder stack

  1. A High-Voltage Low-Power Switched-Capacitor DC-DC Converter Based on GaN and SiC Devices for LED Drivers

    DEFF Research Database (Denmark)

    Fan, Lin; Knott, Arnold; Jørgensen, Ivan Harald Holger

    2018-01-01

    Previous research on switched-capacitor DC-DC converters has focused on low-voltage and/or high-power ranges where the efficiencies are dominated by conduction loss. Switched-capacitor DC-DC converters at high-voltage (> 100 V) low-power (high efficiency and high power density...... are anticipated to emerge. This paper presents a switched-capacitor converter with an input voltage up to 380 V (compatible with rectified European mains) and a maximum output power of 10 W. GaN switches and SiC diodes are analytically compared and actively combined to properly address the challenges at high......-voltage low-current levels, where switching loss becomes significant. Further trade-off between conduction loss and switching loss is experimentally optimized with switching frequencies. Three variant designs of the proposed converter are implemented, and the trade-off between the efficiency and the power...

  2. Analysis of loss distribution of Conventional Boost, Z-source and Y-source Converters for wide power and voltage range

    DEFF Research Database (Denmark)

    Gadalla, Brwene Salah Abdelkarim; Schaltz, Erik; Siwakoti, Yam Prasad

    2017-01-01

    Boost converters are needed in many applications which require the output voltage to be higher than the input voltage. Recently, boost type converters have been applied for industrial applications, and hence it has become an interesting topic of research. Many researchers proposed different...... impedance source converters with their unique advantages as having a high voltage gain in a small range of duty cycle ratio. However, the thermal behaviour of the semiconductor devices and passive elements in the impedance source converter is an important issue from a reliability point of view and it has...... not been investigated yet. Therefore, this paper presents a comparison between the conventional boost, the Z-source, and the Y-source converters based on a thermal evaluation of the semiconductors. In addition, the three topologies are also compared with respect to their efficiency. In this study...

  3. Light weight, high power, high voltage dc/dc converter technologies

    Science.gov (United States)

    Kraus, Robert; Myers, Ira; Baumann, Eric

    1990-01-01

    Power-conditioning weight reductions by orders of magnitude will be required to enable the megawatt-power-level space systems envisioned by the Strategic Defense Initiative, the Air Force, and NASA. An interagency program has been initiated to develop an 0.1-kg/kW dc/dc converter technology base for these future space applications. Three contractors are in the first phase of a competitive program to develop a megawatt dc/dc converter. Researchers at NASA Lewis Research Center are investigating innovative converter topology control. Three different converter subsystems based on square wave, resonant, and super-resonant topologies are being designed. The components required for the converter designs cover a wide array of technologies. Two different switches, one semiconductor and the other gas, are under development. Issues related to thermal management and material reliability for inductors, transformers, and capacitors are being investigated in order to maximize power density. A brief description of each of the concepts proposed to meet the goals of this program is presented.

  4. Li-Po Battery Charger Based on the Constant Current/Voltage Parallel Resonant Converter Operating in ZVS

    Directory of Open Access Journals (Sweden)

    Alberto M. Pernía

    2018-04-01

    Full Text Available Battery requirements for electrical vehicles are continuously becoming more demanding in terms of energy density and reliability. Nowadays, batteries for drones must be able to supply 100 A for 15 min, not to mention the specifications required for batteries in electrical vehicles. These specifications result in more stringent specifications for battery chargers. They are required to be more efficient, flexible, and, as with any another power equipment, to have reduced size and weight. Since the parallel resonant converter can operate as a current source and as a voltage source, this paper presents a battery charger power stage for lithium ion polymer batteries, based on the above topology, operating in zero voltage switching mode, and implementing frequency and duty cycle control.

  5. Synchronous Control of Modular Multilevel Converters

    DEFF Research Database (Denmark)

    Oleschuk, Valentin; Blaabjerg, Frede; Bose, Bimal K.

    2002-01-01

    A novel method of direct synchronous pulsewidth modulation (PWM) is applied for control of modular multilevel converters consisting from three standard triphase inverter modules along with an 0.33 p.u. output transformer. The proposed method provides synchronisation of the voltage waveforms...... for each module and the composed voltage at the output of the converter. Multilevel output voltage of the converter has quarter-wave symmetry during the whole range including the zone of overmodulation. Both continuous and discontinuous versions of synchronous PWM, based on vector approach...

  6. Computer-aided analysis of power-electronic systems simulation of a high-voltage power converter

    International Nuclear Information System (INIS)

    Bordry, F.; Isch, H.W.; Proudlock, P.

    1987-01-01

    In the study of semiconductor devices, simulation methods play an important role in both the design of systems and the analysis of their operation. The authors describe a new and efficient computer-aided package program for general power-electronic systems. The main difficulty when taking into account non-linear elements, such as semiconductors, lies in determining the existence and the relations of the elementary sequences defined by the conduction or nonconduction of these components. The method does not require a priori knowledge of the state sequences of the semiconductor nor of the commutation instants, but only the circuit structure, its parameters and the commands to the controlled switches. The simulation program computes automatically both transient and steady-state waveforms for any circuit configuration. The simulation of a high-voltage power converter is presented, both for its steady-state and transient overload conditions. This 100 kV power converter (4 MW) will feed two klystrons in parallel

  7. Fault Ride-through Capability Enhancement of Voltage Source Converter-High Voltage Direct Current Systems with Bridge Type Fault Current Limiters

    Directory of Open Access Journals (Sweden)

    Md Shafiul Alam

    2017-11-01

    Full Text Available This paper proposes the use of bridge type fault current limiters (BFCLs as a potential solution to reduce the impact of fault disturbance on voltage source converter-based high voltage DC (VSC-HVDC systems. Since VSC-HVDC systems are vulnerable to faults, it is essential to enhance the fault ride-through (FRT capability with auxiliary control devices like BFCLs. BFCL controllers have been developed to limit the fault current during the inception of system disturbances. Real and reactive power controllers for the VSC-HVDC have been developed based on current control mode. DC link voltage control has been achieved by a feedback mechanism such that net power exchange with DC link capacitor is zero. A grid-connected VSC-HVDC system and a wind farm integrated VSC-HVDC system along with the proposed BFCL and associated controllers have been implemented in a real time digital simulator (RTDS. Symmetrical three phase as well as different types of unsymmetrical faults have been applied in the systems in order to show the effectiveness of the proposed BFCL solution. DC link voltage fluctuation, machine speed and active power oscillation have been greatly suppressed with the proposed BFCL. Another significant feature of this work is that the performance of the proposed BFCL in VSC-HVDC systems is compared to that of series dynamic braking resistor (SDBR. Comparative results show that the proposed BFCL is superior over SDBR in limiting fault current as well as improving system fault ride through (FRT capability.

  8. Analysis and design of grid-current-feedback active damping for LCL resonance in grid-connected voltage source converters

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Loh, Poh Chiang

    2014-01-01

    This paper investigates the active damping of LCL-filter resonance within single-loop grid current control of grid-connected voltage source converters. First, the basic analysis in the continuous s-domain reveals that the grid-current-feedback active damping forms a virtual impedance across...... in a digital control system. The instability induced by the negative virtual resistance, which is commonly experienced in the feedback-type active damping, can thus be avoided. A systematic design method of the highpass filter is also proposed by the help of root locus analysis in the discrete z-domain. Lastly...

  9. Grid-Current-Feedback Active Damping for LCL Resonance in Grid-Connected Voltage-Source Converters

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Loh, Poh Chiang

    2016-01-01

    This paper investigates active damping of LCL-filter resonance in a grid-connected voltage-source converter with only grid-current feedback control. Basic analysis in the s-domain shows that the proposed damping technique with a negative high-pass filter along its damping path is equivalent...... of phase-lag, in turn, helps to shrink the region of nonminimum-phase behavior caused by negative virtual resistance inserted unintentionally by most digitally implemented active damping techniques. The presented high-pass-filtered active damping technique with a single grid-current feedback loop is thus...

  10. Reactive Power Compensation of a 24 MW Wind Farm using a 12-Pulse Voltage Source Converter

    DEFF Research Database (Denmark)

    Pedersen, Knud Ole Helgesen; Pedersen, Jørgen Kaas

    1998-01-01

    Integration of large wind farms in distribution and transmission systems may have severe influence on the power quality at the connection point and may also influence the voltage controlling capability of the electrical system. The purpose of the described project has been to develop and investig......Integration of large wind farms in distribution and transmission systems may have severe influence on the power quality at the connection point and may also influence the voltage controlling capability of the electrical system. The purpose of the described project has been to develop...... and investigate the use of a STATCOM by modelling and field testing an 8 MVar unit in a 24 MW wind farm....

  11. A dual voltage control strategy for single-phase PWM converters with power decoupling function

    DEFF Research Database (Denmark)

    Tang, Yi; Qin, Zian; Blaabjerg, Frede

    2014-01-01

    on a symmetrical half bridge circuit is proposed to decouple the ripple power so that balanced instantaneous power flow is assured between source and load, and the required dc-link capacitance can be dramatically reduced. For proper closed-loop regulation, the small signal modeling of the proposed system...... of voltage control loop because the variation of dc-link voltage should be kept within an acceptable range during load transients. This is particularly important for systems with reduced dc-link capacitance because they are of lower energy capacity and very sensitive to step load changes. Simulation results...

  12. Loss of Synchronism of Wind Turbine Converters during Low Voltage Grid Faults

    DEFF Research Database (Denmark)

    Göksu, Ömer; Sørensen, Poul Ejnar; Iov, Florin

    2014-01-01

    In the recent grid codes, wind power plants are required to stay connected and inject reactive and active currents during grid short-circuit faults, even when the grid voltage drops down to zero. However, the physical fact, Loss of Synchronism (LOS) of wind turbines during these very low voltage ...... as whole. Additionally, existing methods to solve the LOS problem are briefly reviewed, and a closed loop frequency based solution is implemented within PowerFactory simulations of a detailed generic wind power plant model....

  13. Predictive Trailing-Edge Modulation Average Current Control in DC-DC Converters

    Directory of Open Access Journals (Sweden)

    LASCU, D.

    2013-11-01

    Full Text Available The paper investigates predictive digital average current control (PDACC in dc/dc converters using trailing-edge modulation (TEM. The study is focused on the recurrence duty cycle equation and then stability analysis is performed. It is demonstrated that average current control using trailing-edge modulation is stable on the whole range of the duty cycle and thus design problems are highly reduced. The analysis is carried out in a general manner, independent of converter topology and therefore the results can then be easily applied for a certain converter (buck, boost, buck-boost, etc.. The theoretical considerations are confirmed for a boost converter first using the MATLAB program based on state-space equations and finally with the CASPOC circuit simulation package.

  14. Resonance Damping Techniques for Grid-Connected Voltage Source Converters with LCL filters – A Review

    DEFF Research Database (Denmark)

    Zhang, Chi; Dragicevic, Tomislav; Vasquez, Juan Carlos

    2014-01-01

    LCL filters play an important role in grid-connected converters when trying to reduce switching-frequency ripple currents injected into the grid. Besides, their small size and low cost make them attractive for many practical applications. However, the LCL filter is a third-order system, which...... presents a resonance peak frequency. Oscillation will occur in the control loop in high frequency ranges, especially in current loop in double-loops controlled converters. In order to solve this, many strategies have been proposed to damp resonance, including passive and active methods. This paper makes...

  15. High power, medium voltage, series resonant converter for DC wind turbines

    DEFF Research Database (Denmark)

    Dincan, Catalin Gabriel; Kjær, Philip Carne; Chen, Yu-Hsing

    2018-01-01

    , and the resulting compact and efficient transformer, and soft-commutated inverter, present particular advantages in high-power, high-voltage applications, like DC offshore wind turbines. With transformer excitation frequency in hundreds of Hz range, line-frequency diodes can be employed in the high...

  16. Reactive Power Compensation of a 24 MW Wind Farm using a 12-Pulse Voltage Source Converter

    DEFF Research Database (Denmark)

    Søbrink, K.H.; Pedersen, Jørgen Kaas; Pedersen, Knud Ole Helgesen

    1998-01-01

    Integration of large wind farms in distribution and transmission systems may have severe influence on the power quality at the connection point and may also influence the voltage controlling capability of the electrical system. The purpose of the described project has been to develop and investig...

  17. A Survey on Voltage Boosting Techniques for Step-Up DC-DC Converters

    DEFF Research Database (Denmark)

    Forouzesh, Mojtaba; Siwakoti, Yam Prasad; Gorji, Saman Asghari

    2016-01-01

    boosting techniques and topologies are large, which at times may be confusing and difficult to follow/adapt for different applications. Considering these aspects and in order to make a clear sketch of the general law and framework of various voltage boosting techniques, this paper comprehensively reviews...

  18. Bidirectional Flyback Converter with Multiple Series Connected Outputs for High Voltage Capacitive Charge and Discharge Applications

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Schneider, Henrik; Zhang, Zhe

    2015-01-01

    is limited by the parasitics of the high voltage active components, which also prevent full utilization of valley switching during discharge process. A second implementation is therefore proposed, where the secondary of flyback transformer winding is split into multiple windings which are connected in series...

  19. High Order Voltage and Current Harmonic Mitigation Using the Modular Multilevel Converter STATCOM

    NARCIS (Netherlands)

    Kontos, E.; Tsolaridis, Georgios; Teodorescu, Remus; Bauer, P.

    2017-01-01

    Due to the increase of power electronic-based loads, the maintenance of high power quality poses a challenge in modern power systems. To limit the total harmonic distortion in the line voltage and currents at the point of the common coupling (PCC), active power filters are commonly employed. This

  20. Comparative Study of Modulation Techniques for Two-Level Voltage Source Inverters

    Directory of Open Access Journals (Sweden)

    Barry W. Williams

    2016-06-01

    Full Text Available A detailed comparative study of modulation techniques for single and three phase dc-ac inverters is presented.  Sinusoidal Pulse Width Modulation, Triplen Sinusoidal Pulse Width Modulation, Space Vector Modulation, Selective Harmonic Elimination and Wavelet Modulation are assessed and compared in terms of maximum fundamental output, harmonic performance, switching losses and operational mode.  The presented modulation techniques are applied to single and three phase voltage source inverters and are simulated using SIMULINK.  The simulation results clarify the inverter performance achieved using the different modulations techniques.

  1. Analysis on voltage stability of PFN in modulator using De-Qing network

    International Nuclear Information System (INIS)

    Wang Dong; Zhang Yongming; Zhu Fuquan

    1987-01-01

    Using the numerical simulation of PFN charging circuit and De-Qing network, a study of voltage stability of BEPC 80 MW klystron pulse modulator has been carried out. The results presented in the paper indicate the quantitative correlation between leakage inductance and voltage stability

  2. High Voltage Gain Dual Active Bridge Converter with an Extended Operation Range for Renewable Energy Systems

    DEFF Research Database (Denmark)

    Zhang, Zhe; Tomas Manez, Kevin; Yudi, Xiao

    2018-01-01

    Developing bidirectional dc-dc converters has become a critical research topic and gains more and more attention in recent years due to the extensive applications of smart grids with energy storages, hybrid and electrical vehicles and dc microgrids. In this paper, a Partial Parallel Dual Active...

  3. The Electrostatic Wind Energy Converter : Electrical performance of a high voltage prototype

    NARCIS (Netherlands)

    Djairam, D.

    2008-01-01

    Wind energy is converted to electrical energy by letting the wind move charged particles against the direction of an electric field. The advantage of this type of conversion is that no rotational movement, which occurs in conventional wind turbines, is required. An electrostatic wind energy

  4. A Voltage Feedback Based Harmonic Compensation Strategy for Current-Controlled Converters

    DEFF Research Database (Denmark)

    Zhao, Xin; Meng, Lexuan; Xie, Chuan

    2018-01-01

    Harmonics have been considered as one of the major issues in future power grids. With the increasing demand in advanced control functions, power electronic converter interfaced distributed generators (DGs) are expected to perform harmonic compensation when necessary. It has been demonstrated in a...

  5. Battery powered high output voltage bidirectional flyback converter for cylindrical DEAP actuator

    DEFF Research Database (Denmark)

    Huang, Lina; Thummala, Prasanth; Zhang, Zhe

    2012-01-01

    operating principle for both energy transfer process and energy recovery process is analyzed in detail. In order to verify the analysis, critical simulation results are provided. So far, a unidirectional flyback converter, which can realize the energy transfer process, has been implemented in the lab...

  6. An active trap filter for high-power voltage source converters

    DEFF Research Database (Denmark)

    Bai, Haofeng; Wang, Xiongfei; Loh, Poh Chiang

    2015-01-01

    This paper proposes a power electronic based device to actively trap the switching current ripples for highpower converters. Control principle and system design of the active trap filter are discussed first. Comparisons of the active trap filter with LCL and LLCL filters are then carried out...

  7. Design and development of high voltage MARX modulator technology for long pulse application

    International Nuclear Information System (INIS)

    Acharya, Mahesh; Shrivastava, Purushottam

    2013-01-01

    High power pulse modulators are used for powering the RF amplifier like klystrons. This paper describes the development of a 10 kV, 10 A, 1 ms Marx modulator for technology demonstration. The modulator is developed using four no. of main modules each of 2.5 kV. To reduce the over sizing factor of capacitors, the allowed drop of main Marx cell is 9%. A droop compensation circuit has been developed to reduce the output pulse voltage droop from 9% to within ±1%. Droop compensation consists of 10 numbers of corrector modules each of 200 V. A microcontroller based trigger circuit was used for simultaneous triggering of main modules and for staggered triggering of corrector modules. A 25 kV, 10 A, 1 ms Marx modulator is being developed. The advantages of this scheme are oil free design, low DC voltage, adjustable pulse width, adjustable rise time/fall time and modular design etc. (author)

  8. Voltage regulation of the Y-source boost DC-DC converter considering effects of leakage inductances based on cascaded sliding-mode control

    DEFF Research Database (Denmark)

    Ahmadzadeh, Soheil; Markadeh, Gholamreza Arab; Blaabjerg, Frede

    2017-01-01

    In this study, a sliding mode-based controller is designed for regulating the output voltage of a high step-up DC-DC converter with three coupled inductors called Y-source impedance network. As Y-source converter can provide a very high boost at a lower shoot-through duty cycle of the switch...

  9. Bi-Frequency Modulated Quasi-Resonant Converters: Theory and Applications

    Science.gov (United States)

    Zhang, Yuefeng

    1995-01-01

    To avoid the variable frequency operation of quasi -resonant converters, many soft-switching PWM converters have been proposed, all of them require an auxiliary switch, which will increase the cost and complexity of the power supply system. In this thesis, a new kind of technique for quasi -resonant converters has been proposed, which is called the bi-frequency modulation technique. By operating the quasi-resonant converters at two switching frequencies, this technique enables quasi-resonant converters to achieve the soft-switching, at fixed switching frequencies, without an auxiliary switch. The steady-state analysis of four commonly used quasi-resonant converters, namely, ZVS buck, ZCS buck, ZVS boost, and ZCS boost converter has been presented. Using the concepts of equivalent sources, equivalent sinks, and resonant tank, the large signal models of these four quasi -resonant converters were developed. Based on these models, the steady-state control characteristics of BFM ZVS buck, BFM ZCS buck, BFM ZVS boost, and BFM ZCS boost converter have been derived. The functional block and design consideration of the bi-frequency controller were presented, and one of the implementations of the bi-frequency controller was given. A complete design example has been presented. Both computer simulations and experimental results have verified that the bi-frequency modulated quasi-resonant converters can achieve soft-switching, at fixed switching frequencies, without an auxiliary switch. One of the application of bi-frequency modulation technique is for EMI reduction. The basic principle of using BFM technique for EMI reduction was introduced. Based on the spectral analysis, the EMI performances of the PWM, variable-frequency, and bi-frequency modulated control signals was evaluated, and the BFM control signals show the lowest EMI emission. The bi-frequency modulated technique has also been applied to the power factor correction. A BFM zero -current switching boost converter has

  10. Voltage-Sharing Converter to Supply Single-Phase Asymmetrical Four-Level Diode-Clamped Inverter With High Power Factor Loads

    DEFF Research Database (Denmark)

    Boora, Arash A.; Nami, Alireza; Zare, Firuz

    2010-01-01

    The output voltage quality of some of the single-phase multilevel inverters can be improved when their dc-link voltages are regulated asymmetrically. Symmetrical and asymmetrical multilevel diode-clamped inverters have the problem of dc-link capacitor voltage balancing, especially when power factor...... that the proposed combination of introduced multioutput dc–dc converter and single-phase ADCI is a good candidate for power conversion in residential photovoltaic (PV) utilization....

  11. State-plane trajectories used to observe and control the behavior of a voltage step-up dc-to-dc converter

    Science.gov (United States)

    Burns, W. W., III; Wilson, T. G.

    1976-01-01

    State-plane analysis techniques are employed to study the voltage step up energy storage dc-to-dc converter. Within this framework, an example converter operating under the influence of a constant on time and a constant frequency controller is examined. Qualitative insight gained through this approach is used to develop a conceptual free running control law for the voltage step up converter which can achieve steady state operation in one on/off cycle of control. Digital computer simulation data is presented to illustrate and verify the theoretical discussions presented.

  12. A dual voltage control strategy for single-phase PWM converters with power decoupling function

    DEFF Research Database (Denmark)

    Tang, Yi; Qin, Zian; Blaabjerg, Frede

    2015-01-01

    converter topology based on a symmetrical half bridge circuit is proposed to decouple the ripple power so that balanced instantaneous power flow is assured between source and load, and the required dc-link capacitance can be dramatically reduced. For proper closed-loop regulation, the small signal modeling...... is therefore very sensitive to step load changes. Comprehensive simulation results and experimental results are presented to show the effectiveness of the proposed circuit and control algorithm....

  13. Modulating the Voltage-sensitivity of a Genetically Encoded Voltage Indicator.

    Science.gov (United States)

    Jung, Arong; Rajakumar, Dhanarajan; Yoon, Bong-June; Baker, Bradley J

    2017-10-01

    Saturation mutagenesis was performed on a single position in the voltage-sensing domain (VSD) of a genetically encoded voltage indicator (GEVI). The VSD consists of four transmembrane helixes designated S1-S4. The V220 position located near the plasma membrane/extracellular interface had previously been shown to affect the voltage range of the optical signal. Introduction of polar amino acids at this position reduced the voltage-dependent optical signal of the GEVI. Negatively charged amino acids slightly reduced the optical signal by 33 percent while positively charge amino acids at this position reduced the optical signal by 80%. Surprisingly, the range of V220D was similar to that of V220K with shifted optical responses towards negative potentials. In contrast, the V220E mutant mirrored the responses of the V220R mutation suggesting that the length of the side chain plays in role in determining the voltage range of the GEVI. Charged mutations at the 219 position all behaved similarly slightly shifting the optical response to more negative potentials. Charged mutations to the 221 position behaved erratically suggesting interactions with the plasma membrane and/or other amino acids in the VSD. Introduction of bulky amino acids at the V220 position increased the range of the optical response to include hyperpolarizing signals. Combining The V220W mutant with the R217Q mutation resulted in a probe that reduced the depolarizing signal and enhanced the hyperpolarizing signal which may lead to GEVIs that only report neuronal inhibition.

  14. Full Space Vectors Modulation for Nine-Switch Converters Including CF & DF Modes

    DEFF Research Database (Denmark)

    Dehghan Dehnavi, Seyed Mohammad; Mohamadian, Mustafa; Andersen, Michael A. E.

    2010-01-01

    converter. As a space vector modulation for DF mode has already been proposed by authors. This paper proposes a full space vector modulation (SVM) for both CF and DF modes. Also practical methods are presented for SVM proposed. In addition a special SVM is proposed that offers minimum total harmonic...... distortion (THD) in DF mode. The performance of the proposed SVM is verified by simulation results....

  15. Voltage equalization of an ultracapacitor module by cell grouping using number partitioning algorithm

    Science.gov (United States)

    Oyarbide, E.; Bernal, C.; Molina, P.; Jiménez, L. A.; Gálvez, R.; Martínez, A.

    2016-01-01

    Ultracapacitors are low voltage devices and therefore, for practical applications, they need to be used in modules of series-connected cells. Because of the inherent manufacturing tolerance of the capacitance parameter of each cell, and as the maximum voltage value cannot be exceeded, the module requires inter-cell voltage equalization. If the intended application suffers repeated fast charging/discharging cycles, active equalization circuits must be rated to full power, and thus the module becomes expensive. Previous work shows that a series connection of several sets of paralleled ultracapacitors minimizes the dispersion of equivalent capacitance values, and also the voltage differences between capacitors. Thus the overall life expectancy is improved. This paper proposes a method to distribute ultracapacitors with a number partitioning-based strategy to reduce the dispersion between equivalent submodule capacitances. Thereafter, the total amount of stored energy and/or the life expectancy of the device can be considerably improved.

  16. Two-Stage Control Design of a Buck Converter/DC Motor System without Velocity Measurements via a Σ−Δ-Modulator

    Directory of Open Access Journals (Sweden)

    R. Silva-Ortigoza

    2013-01-01

    differential flatness property of the DC-motor model is exploited in order to propose a first-stage controller, which is designed to achieve the desired angular velocity trajectory. This controller provides the voltage profiles that must be tracked by the Buck converter. Then, a second-stage controller is meant to assure the aforementioned. This controller is based on flatness property of the Buck power converter model, which provides the input voltage to the DC motor. Due to the fact that the two-stage controller proposed uses the average model of the system, as a practical and effective implementation of this controller, a Σ − Δ-modulator is employed. Finally, in order to verify the control performance of this approach, numerical simulations are included.

  17. Modeling of parasitic elements in high voltage multiplier modules

    NARCIS (Netherlands)

    Wang, J.

    2014-01-01

    It is an inevitable trend that the power conversion module will have higher switching frequency and smaller volume in the future. Bandgap devices, such as SiC and GaN devices, accelerate the process. With this process, the parasitic elements in the module will probably have stronger influence on

  18. An Original Transformer and Switched-Capacitor (T & SC-Based Extension for DC-DC Boost Converter for High-Voltage/Low-Current Renewable Energy Applications: Hardware Implementation of a New T & SC Boost Converter

    Directory of Open Access Journals (Sweden)

    Sanjeevikumar Padmanaban

    2018-03-01

    Full Text Available In this article a new Transformer and Switched Capacitor-based Boost Converter (T & SC-BC is proposed for high-voltage/low-current renewable energy applications. The proposed T & SC-BC is an original extension for DC-DC boost converter which is designed by utilizing a transformer and switched capacitor (T & SC. Photovoltaic (PV energy is a fast emergent segment among the renewable energy systems. The proposed T & SC-BC combines the features of the conventional boost converter and T & SC to achieve a high voltage conversion ratio. A Maximum Power Point Tracking (MPPT controller is compulsory and necessary in a PV system to extract maximum power. Thus, a photovoltaic MPPT control mechanism also articulated for the proposed T & SC-BC. The voltage conversion ratio (Vo/Vin of proposed converter is (1 + k/(1 − D where, k is the turns ratio of the transformer and D is the duty cycle (thus, the converter provides 9.26, 13.88, 50/3 voltage conversion ratios at 78.4 duty cycle with k = 1, 2, 2.6, respectively. The conspicuous features of proposed T & SC-BC are: (i a high voltage conversion ratio (Vo/Vin; (ii continuous input current (Iin; (iii single switch topology; (iv single input source; (v low drain to source voltage (VDS rating of control switch; (vi a single inductor and a single untapped transformer are used. Moreover, the proposed T & SC-BC topology was compared with recently addressed DC-DC converters in terms of number of components, cost, voltage conversion ratio, ripples, efficiency and power range. Simulation and experimental results are provided which validate the functionality, design and concept of the proposed approach.

  19. Chapter 8: Design and Control of Voltage Source Converters With LCL-Filters

    DEFF Research Database (Denmark)

    Pena-Alzola, Rafael; Blaabjerg, Frede

    2018-01-01

    presents many options for the LCL-filter design, passive damping design, and active damping design, and this chapter will present well-known practical methods. In this chapter, the LCL-filter design uses a step-by-step procedure with simple formulas that avoid trial-and-error iterations. Different......-type procedures result in a robust design against line inductance variations. The capacitor-current feedback method requires an additional sensor and the lead-lag network avoid additional sensors by using the capacitor voltage also for synchronization. The filter-based procedure presented in the chapter uses...

  20. Internal balance during low-voltage-ride-through of the modular multilevel converter statcom

    DEFF Research Database (Denmark)

    Tsolaridis, Georgios; Kontos, Epameinondas; Chaudhary, Sanjay K.

    2017-01-01

    on the challenging internal control of the converter to allow the independent control of the energy levels of each arm, with the goal to maintain internal balancing of the MMC during contingencies. Extensive experimental results highlight the need for a sophisticated internal control. Moreover, the experimental...... analysis verifies that, by using the proposed control structure, the MMC can effectively ride through a fault on the AC side without tripping, while injecting the necessary positive and negative sequence reactive current levels according to the most recent grid codes....

  1. Modulation Technique for Four-Leg Voltage Source Inverter without a Look-Up Table

    DEFF Research Database (Denmark)

    Ebrahimzadeh, Esmaeil; Farhangi, Shahrokh; Iman-Eini, Hossein

    2016-01-01

    Three-dimensional space-vector modulation (3D SVM) has more popularity among the other modulation techniques of the four-leg inverter due to higher DC-link voltage utilisation. Sequencing schemes of the switching vectors in the 3D SVM are divided into Class I and II categories. Each of these clas...

  2. Intracellular calcium modulation of voltage-gated sodium channels in ventricular myocytes

    NARCIS (Netherlands)

    Casini, Simona; Verkerk, Arie O.; van Borren, Marcel M. G. J.; van Ginneken, Antoni C. G.; Veldkamp, Marieke W.; de Bakker, Jacques M. T.; Tan, Hanno L.

    2009-01-01

    AIMS: Cardiac voltage-gated sodium channels control action potential (AP) upstroke and cell excitability. Intracellular calcium (Ca(i)(2+)) regulates AP properties by modulating various ion channels. Whether Ca(i)(2+) modulates sodium channels in ventricular myocytes, is unresolved. We studied

  3. A Voltage Modulated DPC Approach for Three-Phase PWM Rectifier

    DEFF Research Database (Denmark)

    Gui, Yonghao; Li, Mingshen; Lu, Jinghang

    2018-01-01

    In this paper, a voltage modulated direct power control for three-phase pulse-width modulated rectifier is proposed. With the suggested method, the differential equations describing the rectifier dynamics are changing from a linear time-varying system into a linear time-invariant one. In this way...

  4. A driver IC for photovotaic module-integrated DC/Dc converters

    NARCIS (Netherlands)

    Doorn, T.S.; Bergveld, H.J.; Büthker, D.; Castello, C.; Jong, de A.; van Otten, R.; Waal, de K.; Ansem, van T.; Dijkstra, M.; Keekstra, I.; Sneep, J.

    2012-01-01

    Photovoltaic (PV) installations suffer from a disproportional decrease in output power in case irradiance differences are present in the system. The Delta converter improves the output power in such cases by routing current differences around the shaded substring or module. This paper presents a

  5. Impact of modulation strategies on power devices loading for 10 MW multilevel wind power converter

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Isidori, Andrea; Rossi, Fabio Mario

    2012-01-01

    This paper focuses on the control and modulation of a three-level Neutral Point Clamped (3L-NPC) back-to-back full scale converter for a 10 MW direct-drive wind turbine, equipped with a Permanent Magnet Synchronous Generator (PMSG). Emphasis is oriented towards the investigation of the power losses...

  6. Distributed control of PV strings with module integrated converters in presence of a central MPPT

    DEFF Research Database (Denmark)

    Sera, Dezso; Mathe, Laszlo; Blaabjerg, Frede

    2014-01-01

    In some cases it is unavoidable that part of the rooftop PV array is periodically shadowed by an adjacent object, greatly reducing yield. Usually, the time and amount of shadowing is known, and is considered as extra loss due to the location. Module Integrated Converter (MIC) systems are known...

  7. Comparison of three different Modulators for Power Converters with Respect to EMI Optimization

    DEFF Research Database (Denmark)

    Knott, Arnold; Pfaffinger, Gerhard; Andersen, Michael Andreas E.

    2008-01-01

    Switch-mode Power Converters are well known for emissions in the band of electromagnetic interference (EMI) interest. The spectrum shape depends on the type of modulator and its purpose. This paper gives design guidelines to choose the optimum topology depending on requirements of different appli...

  8. Very Thin Flexible Coupled Inductors for PV Module Integrated GaN Converter

    DEFF Research Database (Denmark)

    Acanski, Milos; Ouyang, Ziwei; Popovic-Gerber, Jelena

    2012-01-01

    converter integrated directly into a low cost flexible PV module. Additional problems arise in this case, specifically in magnetics design, due to the requirements for very low profile flexible construction and limited thermal headroom. Overcoming these limitations presents a challenge, but can lead...... to a cost effective, reliable solution for PV systems with improved integration level and power density....

  9. Voltage inverter with push-pull topology to inject energy into electrical systems with modulation SPWM

    Directory of Open Access Journals (Sweden)

    Emerson Charles M. Silva

    2013-09-01

    Full Text Available This paper presents a proposal for a voltage inverter topology based on push-pull converters, switched at high frequency to inject energy into the grid from a source of DC power. A system using two reverse voltage static converters provides the power grid; energy in the form of alternating current, that can work in conjunction with the provision of utility power. Aiming at the possible use of renewable energy sources, that can be stored in the form of voltage continuous, such as wind, solar, hydroelectric and others. The functioning of topology is presented, such as the power and control circuits, as well as sizing components, theoretical and practical results achieved with the assembly of a prototype 100W of power and switching in 40khz, which after filtering provides the frequency of 60Hz, which is compatible with the Brazilian electrical system.

  10. Application handbook for a Standardized Control Module (SCM) for DC-DC converters, volume 1

    Science.gov (United States)

    Lee, F. C.; Mahmoud, M. F.; Yu, Y.

    1980-01-01

    The standardized control module (SCM) was developed for application in the buck, boost and buck/boost DC-DC converters. The SCM used multiple feedback loops to provide improved input line and output load regulation, stable feedback control system, good dynamic transient response and adaptive compensation of the control loop for changes in open loop gain and output filter time constraints. The necessary modeling and analysis tools to aid the design engineer in the application of the SCM to DC-DC Converters were developed. The SCM functional block diagram and the different analysis techniques were examined. The average time domain analysis technique was chosen as the basic analytical tool. The power stage transfer functions were developed for the buck, boost and buck/boost converters. The analog signal and digital signal processor transfer functions were developed for the three DC-DC Converter types using the constant on time, constant off time and constant frequency control laws.

  11. Application handbook for a Standardized Control Module (SCM) for DC-DC converters, volume 1

    Science.gov (United States)

    Lee, F. C.; Mahmoud, M. F.; Yu, Y.

    1980-04-01

    The standardized control module (SCM) was developed for application in the buck, boost and buck/boost DC-DC converters. The SCM used multiple feedback loops to provide improved input line and output load regulation, stable feedback control system, good dynamic transient response and adaptive compensation of the control loop for changes in open loop gain and output filter time constraints. The necessary modeling and analysis tools to aid the design engineer in the application of the SCM to DC-DC Converters were developed. The SCM functional block diagram and the different analysis techniques were examined. The average time domain analysis technique was chosen as the basic analytical tool. The power stage transfer functions were developed for the buck, boost and buck/boost converters. The analog signal and digital signal processor transfer functions were developed for the three DC-DC Converter types using the constant on time, constant off time and constant frequency control laws.

  12. Design and simulation of maximum power point tracking (MPPT) system on solar module system using constant voltage (CV) method

    Science.gov (United States)

    Bhatara, Sevty Satria; Iskandar, Reza Fauzi; Kirom, M. Ramdlan

    2016-02-01

    Solar energy is one of renewable energy resource where needs a photovoltaic module to convert it into electrical energy. One of the problems on solar energy conversion is the process of battery charging. To improve efficiency of energy conversion, PV system needs another control method on battery charging called maximum power point tracking (MPPT). This paper report the study on charging optimation using constant voltage (CV) method. This method has a function of determining output voltage of the PV system on maximal condition, so PV system will always produce a maximal energy. A model represented a PV system with and without MPPT was developed using Simulink. PV system simulation showed a different outcome energy when different solar radiation and numbers of solar module were applied in the model. On the simulation of solar radiation 1000 W/m2, PV system with MPPT produces 252.66 Watt energy and PV system without MPPT produces 252.66 Watt energy. The larger the solar radiation, the greater the energy of PV modules was produced.

  13. Development of a Novel Bidirectional DC/DC Converter Topology with High Voltage Conversion Ratio for Electric Vehicles and DC-Microgrids

    Directory of Open Access Journals (Sweden)

    Ching-Ming Lai

    2016-05-01

    Full Text Available The main objective of this paper was to study a bidirectional direct current to direct current converter (BDC topology with a high voltage conversion ratio for electric vehicle (EV batteries connected to a dc-microgrid system. In this study, an unregulated level converter (ULC cascaded with a two-phase interleaved buck-boost charge-pump converter (IBCPC is introduced to achieve a high conversion ratio with a simpler control circuit. In discharge state, the topology acts as a two-stage voltage-doubler boost converter to achieve high step-up conversion ratio (48 V to 385 V. In charge state, the converter acts as two cascaded voltage-divider buck converters to achieve high voltage step-down conversion ratio (385 V to 48 V. The features, operation principles, steady-state analysis, simulation and experimental results are made to verify the performance of the studied novel BDC. Finally, a 500 W rating prototype system is constructed for verifying the validity of the operation principle. Experimental results show that highest efficiencies of 96% and 95% can be achieved, respectively, in charge and discharge states.

  14. Design of current controller of grid-connected voltage source converter based internal model control in wind power

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Xianping; Guo Jindong; Xu Honghua [Inst. of Electrical Engineering, Chinese Academy of Sciences, BJ (China)

    2008-07-01

    Grid-connected voltage source converter (VSC) is important for variable speed turbines with doubly fed induction generator (DFIG), and bad performance of current loop of VSC may cause VSC inject much low and high order harmonics into grid. Therefore, design of current controller of VSC is very important. PI regulator is often used to regulate current error in dq rotating coordinate to obtain zero steady error. However, it is complex to design PI parameters, and researchers need many trial-and-error steps. Therefore, a novel and simple design method of PI regulator for grid-connected VSC, which is based internal model control (IMC), has been presented in this paper. The parameters of PI regulator can be expressed directly with certain L-type line filter parameters and the desired closed-loop bandwidth. At last, The simulation has been done and result shows that the method in this paper is easy and useful to regulate PI parameters. (orig.)

  15. Effects of switching frequency and leakage inductance on slow-scale stability in a voltage controlled flyback converter

    International Nuclear Information System (INIS)

    Wang Fa-Qiang; Ma Xi-Kui

    2013-01-01

    The effects of both the switching frequency and the leakage inductance on the slow-scale stability in a voltage controlled flyback converter are investigated in this paper. Firstly, the system description and its mathematical model are presented. Then, the improved averaged model, which covers both the switching frequency and the leakage inductance, is established, and the effects of these two parameters on the slow-scale stability in the system are analyzed. It is found that the occurrence of Hopf bifurcation in the system is the main reason for losing its slow-scale stability and both the switching frequency and the leakage inductance have an important effect on this slow-scale stability. Finally, the effectiveness of the improved averaged model and that of the corresponding theoretical analysis are confirmed by the simulation results and the experimental results. (general)

  16. Process, Voltage and Temperature Compensation Technique for Cascode Modulated PAs

    DEFF Research Database (Denmark)

    Sira, Daniel; Larsen, Torben

    2013-01-01

    , that represents a transistor level model (empirical model) of the cascode modulated PA, is utilized in a PA analog predistorter. The analog predistorter linearizes and compensates for PVT variation of the cascode modulated PA. The empirical model is placed in the negative feedback of an operational...... transconductance amplifier. The predistorted varying envelope signal is applied to the cascode gate of the PA. It is shown that the proposed PVT compensation technique significantly reduces the PVT spread of the PA linearity indicators and improves the PA linearity. Simulations were performed in a 0.13 μm CMOS...

  17. Laboratory manual for pulse-width modulated DC-DC power converters

    CERN Document Server

    Kazimierczuk, Marian K

    2015-01-01

    Designed to complement a range of power electronics study resources, this unique lab manual helps students to gain a deep understanding of the operation, modeling, analysis, design, and performance of pulse-width modulated (PWM) DC-DC power converters.  Exercises focus on three essential areas of power electronics: open-loop power stages; small-signal modeling, design of feedback loops and PWM DC-DC converter control schemes; and semiconductor devices such as silicon, silicon carbide and gallium nitride. Meeting the standards required by industrial employers, the lab manual combines program

  18. FPGA Techniques Based New Hybrid Modulation Strategies for Voltage Source Inverters

    Science.gov (United States)

    Sudha, L. U.; Baskaran, J.; Elankurisil, S. A.

    2015-01-01

    This paper corroborates three different hybrid modulation strategies suitable for single-phase voltage source inverter. The proposed method is formulated using fundamental switching and carrier based pulse width modulation methods. The main tale of this proposed method is to optimize a specific performance criterion, such as minimization of the total harmonic distortion (THD), lower order harmonics, switching losses, and heat losses. The proposed method is articulated using fundamental switching and carrier based pulse width modulation methods. Thus, the harmonic pollution in the power system will be reduced and the power quality will be augmented with better harmonic profile for a target fundamental output voltage. The proposed modulation strategies are simulated in MATLAB r2010a and implemented in a Xilinx spartan 3E-500 FG 320 FPGA processor. The feasibility of these modulation strategies is authenticated through simulation and experimental results. PMID:25821852

  19. KCNE5 induces time- and voltage-dependent modulation of the KCNQ1 current

    DEFF Research Database (Denmark)

    Angelo, Kamilla; Jespersen, Thomas; Grunnet, Morten

    2002-01-01

    The function of the KCNE5 (KCNE1-like) protein has not previously been described. Here we show that KCNE5 induces both a time- and voltage-dependent modulation of the KCNQ1 current. Interaction of the KCNQ1 channel with KCNE5 shifted the voltage activation curve of KCNQ1 by more than 140 mV in th...... the I(Ks) current in certain parts of the mammalian heart....

  20. Overmodulation of n-level three-leg DC-AC diode-clamped converters with comprehensive capacitor voltage balance

    DEFF Research Database (Denmark)

    Busquets-Monge, S.; Maheshwari, Ram Krishan; Munk-Nielsen, Stig

    2013-01-01

    This paper presents a novel PWM strategy for nlevel three-leg semiconductor-clamped dc-ac converters in the overmodulation region, with dc-link capacitor voltage balance in every switching cycle. The strategy is based on the virtual-vector concept. Suitable reference vector trajectories are selec......This paper presents a novel PWM strategy for nlevel three-leg semiconductor-clamped dc-ac converters in the overmodulation region, with dc-link capacitor voltage balance in every switching cycle. The strategy is based on the virtual-vector concept. Suitable reference vector trajectories...

  1. Control of Grid Integrated Voltage Source Converters under Unbalanced Conditions: Development of an On-line Frequency-adaptive Virtual Flux-based Approach

    OpenAIRE

    Suul, Jon Are

    2012-01-01

    Three-Phase Voltage Source Converters (VSCs) are finding widespread applications in grid integrated power conversion systems. The control systems of such VSCs are in an increasing number of these applications required to operate during voltage disturbances and unbalanced conditions. Control systems designed for grid side voltagesensor- less operation are at the same time becoming attractive due to the continuous drive for cost reduction and increased reliability of VSCs, but are not commonly ...

  2. Three-phase Resonant DC-link Converter

    OpenAIRE

    Munk-Nielsen, Stig

    1997-01-01

    The purpose of the project is to develop a three-phase resonant converter suitable for standard speed drives. The motivation for working with resonant converters is found in the problem of the standard converter type used today. In standard converter type Pulse Width Modulated-Voltage Source Inverter, PWM-VSI, the switches are subject to high current and voltage stress during switching, which causes losses. The fast switching of modern switches reduces switching losses. Unfortunately this pro...

  3. Hybrid Design Optimization of High Voltage Pulse Transformers for Klystron Modulators

    CERN Document Server

    Sylvain, Candolfi; Davide, Aguglia; Jerome, Cros

    2015-01-01

    This paper presents a hybrid optimization methodology for the design of high voltage pulse transformers used in klystron modulators. The optimization process is using simplified 2D FEA design models of the 3D transformer structure. Each intermediate optimal solution is evaluated by 3D FEA and correction coefficients of the 2D FEA models are derived. A new optimization process using 2D FEA models is then performed. The convergence of this hybrid optimal design methodology is obtained with a limited number of time consuming 3D FEA simulations. The method is applied to the optimal design of a monolithic high voltage pulse transformer for the CLIC klystron modulator.

  4. Controlling DC-DC converters by chaos-based pulse width modulation to reduce EMI

    International Nuclear Information System (INIS)

    Li Hong; Zhang Bo; Li Zhong; Halang, Wolfgang A.; Chen Guanrong

    2009-01-01

    In this paper, periodic and chaotic behaviors of DC-DC converters under certain parametric conditions are simulated, experimentally verified, and analyzed. Motivated by the work of J.H.B. Deane and D.C. Hamill in 1996, where chaotic phenomena are useful in suppressing electromagnetic interference (EMI) by adjusting the parameters of the DC-DC converter and making it operate in chaos, a chaos-based pulse width modulation (CPWM) is proposed to distribute the harmonics of the DC-DC converters continuously and evenly over a wide frequency range, thereby reducing the EMI. The output waves and spectral properties of the EMI are simulated and analyzed as the carrier frequency or amplitude changes with regard to different chaotic maps. Simulation and experimental results are given to illustrate the effectiveness of the proposed CPWM, which provides a good example of applying chaos theory in engineering practice.

  5. Improvement of Shade Resilience in Photovoltaic Modules Using Buck Converters in a Smart Module Architecture

    NARCIS (Netherlands)

    Golroodbari, S. Mirbagheri; Waal, Arjen. de; Sark, Wilfried van

    2018-01-01

    Partial shading has a nonlinear effect on the performance of photovoltaic (PV) modules. Different methods of optimizing energy harvesting under partial shading conditions have been suggested to mitigate this issue. In this paper, a smart PV module architecture is proposed for improvement of shade

  6. Measuring modules for the research of compensators of reactive power with voltage stabilization in MATLAB

    Science.gov (United States)

    Vlasayevsky, Stanislav; Klimash, Stepan; Klimash, Vladimir

    2017-10-01

    A set of mathematical modules was developed for evaluation the energy performance in the research of electrical systems and complexes in the MatLab. In the electrotechnical library SimPowerSystems of the MatLab software, there are no measuring modules of energy coefficients characterizing the quality of electricity and the energy efficiency of electrical apparatus. Modules are designed to calculate energy coefficients characterizing the quality of electricity (current distortion and voltage distortion) and energy efficiency indicators (power factor and efficiency) are presented. There are described the methods and principles of building the modules. The detailed schemes of modules built on the elements of the Simulink Library are presented, in this connection, these modules are compatible with mathematical models of electrical systems and complexes in the MatLab. Also there are presented the results of the testing of the developed modules and the results of their verification on the schemes that have analytical expressions of energy indicators.

  7. GENETIC ALGORITHM BASED SOLUTION IN PWM CONVERTER SWITCHING FOR VOLTAGE SOURCE INVERTER FEEDING AN INDUCTION MOTOR DRIVE

    Directory of Open Access Journals (Sweden)

    V. Jegathesan

    2017-11-01

    Full Text Available This paper presents an efficient and reliable Genetic Algorithm based solution for Selective Harmonic Elimination (SHE switching pattern. This method eliminates considerable amount of lower order line voltage harmonics in Pulse Width Modulation (PWM inverter. Determination of pulse pattern for the elimination of some lower order harmonics of a PWM inverter necessitates solving a system of nonlinear transcendental equations. Genetic Algorithm is used to solve nonlinear transcendental equations for PWM-SHE. Many methods are available to eliminate the higher order harmonics and it can be easily removed. But the greatest challenge is to eliminate the lower order harmonics and this is successfully achieved using Genetic Algorithm without using Dual transformer. Simulations using MATLABTM and Powersim with experimental results are carried out to validate the solution. The experimental results show that the harmonics up to 13th were totally eliminated.

  8. High Voltage, Fast-Switching Module for Active Control of Magnetic Fields and Edge Plasma Currents

    Science.gov (United States)

    Ziemba, Timothy; Miller, Kenneth; Prager, James; Slobodov, Ilia

    2016-10-01

    Fast, reliable, real-time control of plasma is critical to the success of magnetic fusion science. High voltage and current supplies are needed to mitigate instabilities in all experiments as well as disruption events in large scale tokamaks for steady-state operation. Silicon carbide (SiC) MOSFETs offer many advantages over IGBTs including lower drive energy requirements, lower conduction and switching losses, and higher switching frequency capabilities; however, these devices are limited to 1.2-1.7 kV devices. As fusion enters the long-pulse and burning plasma eras, efficiency of power switching will be important. Eagle Harbor Technologies (EHT), Inc. developing a high voltage SiC MOSFET module that operates at 10 kV. This switch module utilizes EHT gate drive technology, which has demonstrated the ability to increase SiC MOSFET switching efficiency. The module will allow more rapid development of high voltage switching power supplies at lower cost necessary for the next generation of fast plasma feedback and control. EHT is partnering with the High Beta Tokamak group at Columbia to develop detailed high voltage module specifications, to ensure that the final product meets the needs of the fusion science community.

  9. The effect of Cr buffer layer thickness on voltage generation of thin-film thermoelectric modules

    International Nuclear Information System (INIS)

    Mizoshiri, Mizue; Mikami, Masashi; Ozaki, Kimihiro

    2013-01-01

    The effect of Cr buffer layer thickness on the open-circuit voltage generated by thin-film thermoelectric modules of Bi 0.5 Sb 1.5 Te 3 (p-type) and Bi 2 Te 2.7 Se 0.3 (n-type) materials was investigated. A Cr buffer layer, whose thickness generally needs to be optimized to improve adhesion depending on the substrate surface condition, such as roughness, was deposited between thermoelectric thin films and glass substrates. When the Cr buffer layer was 1 nm thick, the Seebeck coefficients and electrical conductivity of 1 µm thermoelectric thin films with the buffer layers were approximately equal to those of the thermoelectric films without the buffer layers. When the thickness of the Cr buffer layer was 1 µm, the same as the thermoelectric films, the Seebeck coefficients of the bilayer films were reduced by an electrical current flowing inside the Cr buffer layer and the generation of Cr 2 Te 3 . The open-circuit voltage of the thin-film thermoelectric modules decreased with an increase in the thickness of the Cr buffer layer, which was primarily induced by the electrical current flow. The reduction caused by the Cr 2 Te 3 generation was less than 10% of the total voltage generation of the modules without the Cr buffer layers. The voltage generation of thin-film thermoelectric modules could be controlled by the Cr buffer layer thickness. (paper)

  10. Comparison of three-phase three-level voltage source inverter with intermediate dc–dc boost converter and quasi-Z-source inverter

    DEFF Research Database (Denmark)

    Panfilov, Dmitry; Husev, Oleksandr; Blaabjerg, Frede

    2016-01-01

    This study compares a three-phase three-level voltage source inverter with an intermediate dc-dc boost converter and a quasi-Z-source inverter in terms of passive elements values and dimensions, semiconductor stresses, and overall efficiency. A comparative analysis was conducted with relative...

  11. 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...

  12. Elimination of bus voltage impact on temperature sensitive electrical parameter during turn-on transition for junction temperature estimation of high-power IGBT modules

    DEFF Research Database (Denmark)

    Luo, Haoze; Iannuzzo, Francesco; Blaabjerg, Frede

    2017-01-01

    Junction temperature is of great importance to safe operating area of IGBT modules. Various information of the IGBT operating state is reflected on electrical characteristics during turn-on transient. A unified extraction method for internal junction temperature via dynamic thermo......-sensitive electrical parameters (DTSEP) during turn-on transient is proposed. Two DTSEP, turn-on delay time (tdon) and the maximum increasing rate of collector current dic/dt(max), are combined to eliminate the bus voltage impact. Using the inherent emitter-auxiliary inductor LeE in high-power modules, the temperature......-dependent DTSEPs can be converted into a low-voltage and measurable signal. Finally, experiment results are exhibited to verify the effectiveness of proposed method....

  13. Inductor Design Comparison of Three-wire and Four-wire Three-phase Voltage Source Converters in Power Factor Correction Applications

    DEFF Research Database (Denmark)

    Kouchaki, Alireza; Nymand, Morten

    2015-01-01

    This paper studies the inductor design for three-wire and four-wire power factor correction converter (PFC). Designing the efficient inductor for this converter (regardless of connecting the midpoint to the ground) requires a comprehensive knowledge of the inductor current and voltage behavior....... This paper investigates how changing three-wire PFC to four-wire counterpart influences the inductor design in terms of size, losses, and overall efficiency of the converter. Therefore, the inductor current and voltage waveforms are analyzed and generalized in both cases for one switching cycle to build...... a foundation for comparison. Accordingly, the analyses are able to interpret the differences between both configurations and explain the core losses and the copper losses of inductors, especially those caused by the high frequency ac current ripple. Finally, two inductors are designed for a 5 kW PFC...

  14. Development of control system for multi-converter High voltage Power supply using programmable SoC

    Science.gov (United States)

    Dave, Rasesh; Dharangutti, Jagruti; Singh, N. P.; Thakar, Aruna; Dhola, Hitesh; Gajjar, Sandip; Parmar, Darshan; Zaveri, Tanish; Baruah, Ujjwal

    2017-04-01

    Multi-converter based High Voltage Power Supplies (HVPSs) find application in multi-megawatt accelerators, RF systems. Control system for HVPS must be a combination of superior parallel processing, real time performance, fast computation and versatile connectivity. The hardware platform is expected to be robust, easily scalable for future developments with minimal overheads. This paper describes development of control system on Zynq All Programmable SoC (System on Chip) for HVPS. Typical HVPS control mechanism involves communication, generation of precise control signals/pulses for few hundred numbers of chopper and closed loop control in microsecond range for regulated output. Such kind of requirements can be met with Zynq All Programmable SoC, which is a combination of Dual core ARM Cortex A-9 Processing System (PS) and Xilinx 7 series FPGA based Programmable Logic (PL). Deterministic functions of power supply control system such as generation of control signals with precise inter-channel delay of nanosecond range and communication with individual chopper at 100kbps can be implemented on PL. PS should implement corrective tasks based on field feedback received from individual chopper, user interface and OS management that allows to take full advantage of system capabilities. PS and PL are connected with on-chip AXI-4 interface with low latency and higher bandwidth through 9 AXI ports. Typically PS boots first, this ensures secure booting and prevents external environment from tampering PL.

  15. Development of control system for multi-converter high voltage power supply using programmable SoC

    International Nuclear Information System (INIS)

    Dave, Rasesh; Singh, N.P.; Thakar, Aruna; Dhola, Hitesh; Gajjar, Sandip; Parmar, Darshan Kumar; Baruah, Ujjwal Kumar; Dharangutti, Jagruti; Zaveri, Tanish

    2015-01-01

    Multi-converter based High Voltage Power Supplies (HVPSs) find application in multi-megawatt accelerators, RF systems. Control system for HVPS must be a combination of superior parallel processing, real time performance, fast computation and versatile connectivity. The hardware platform is expected to be robust, easily scalable for future developments without any cost overhead. Typical HVPS control mechanism involves communication, generation of precise control signals/pulses for few hundred Nos of chopper and closed loop control in microsecond range for regulated output. Such kind of requirements can be met with Zynq All Programmable SoC, which is a combination of Dual core ARM Cortex A-9 Processing System (PS) and Xilinx 7 series FPGA based Programmable Logic (PL). Deterministic functions of power supply control system such as generation of control signals with precise inter-channel delay of nanosecond range and communication with individual chopper at 100kbps can be implemented on PL. PS should implement corrective tasks based on field feedback received from individual chopper, user interface and OS management that allows to take full advantage of system capabilities. PS and PL are connected with on-chip AXI-4 interface with low latency and higher bandwidth through 9 AXI ports. Typically PS boots first, this ensures secure booting and prevents external environment from tampering PL. This paper describes development of control system on Zynq All Programmable SoC for HVPS. (author)

  16. Construction of an input sensitivity variable CAMAC module for measuring DC voltage

    International Nuclear Information System (INIS)

    Noda, Nobuaki.

    1979-03-01

    In on-line experimental data processing systems, the collection of DC voltage data is frequently required. In plasma confinement experiments, for example, the range of input voltage is very wide from over 1 kV applied to photomultiplier tubes to 10 mV full scale of the controller output for ionization vacuum gauges. A DC voltmeter CAMAC module with variable input range, convenient for plasma experiments and inexpensive, has been constructed for trial. The number of input channels is 16, and the input range is changeable in six steps from +-10 mV to +-200 V; these are all set by commands from a computer. The module is actually used for the on-line data processing system for JIPP T-2 experiment. The ideas behind its development, and the functions, features and usage of the module are described in this report. (J.P.N.)

  17. Linearity optimizations of analog ring resonator modulators through bias voltage adjustments

    Science.gov (United States)

    Hosseinzadeh, Arash; Middlebrook, Christopher T.

    2018-03-01

    The linearity of ring resonator modulator (RRM) in microwave photonic links is studied in terms of instantaneous bandwidth, fabrication tolerances, and operational bandwidth. A proposed bias voltage adjustment method is shown to maximize spur-free dynamic range (SFDR) at instantaneous bandwidths required by microwave photonic link (MPL) applications while also mitigating RRM fabrication tolerances effects. The proposed bias voltage adjustment method shows RRM SFDR improvement of ∼5.8 dB versus common Mach-Zehnder modulators at 500 MHz instantaneous bandwidth. Analyzing operational bandwidth effects on SFDR shows RRMs can be promising electro-optic modulators for MPL applications which require high operational frequencies while in a limited bandwidth such as radio-over-fiber 60 GHz wireless network access.

  18. A Cell-to-Cell Battery Equalizer With Zero-Current Switching and Zero-Voltage Gap Based on Quasi-Resonant LC Converter and Boost Converter

    DEFF Research Database (Denmark)

    Shang, Yunlong; Zhang, Chenghui; Cui, Naxin

    2015-01-01

    these difficulties, an innovative direct cell-to-cell battery equalizer based on quasi-resonant LC converter (QRLCC) and boost DC-DC converter (BDDC) is proposed. The QRLCC is employed to gain zero-current switching (ZCS), leading to a reduction of power losses. The BDDC is employed to enhance the equalization...

  19. Combined resonant tank capacitance and pulse frequency modulation control for ZCS-SR inverter-fed high voltage DC power supply

    International Nuclear Information System (INIS)

    Lee, S S; Iqbal, S; Kamarol, M

    2011-01-01

    Conventional pulse frequency modulated (PFM) zero current switching (ZCS) series resonant (SR) inverter fed high voltage dc power supplies have nearly zero switching loss. However, they have limitations of poor controllability at light loads and large output voltage ripple at low switching frequencies. To address these problems, this paper proposes a combined resonant tank capacitance and pulse frequency modulation based control approach. For the realization of the proposed control approach, the tank circuit of the resonant inverter is made up of several resonant capacitors that are switched into or out of the tank circuit by electromechanical switches. The output voltage of the converter is regulated by digitally modulating the resonant tank capacitance and narrowly varying the switching frequency. The proposed control scheme has several features, namely a wide range of controllability even at light loads, less output voltage ripple, and less current stress on the inverter's power switches at light loads. Therefore, the proposed control approach alleviates most of the problems associated with conventional PFM. Experimental results obtained from a scaled down laboratory prototype are presented to verify the effectiveness of the proposed system.

  20. Isolated DC-DC Converter for Bidirectional Power Flow Controlling with Soft-Switching Feature and High Step-Up/Down Voltage Conversion

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2017-03-01

    Full Text Available In this paper, a novel isolated bidirectional DC-DC converter is proposed, which is able to accomplish high step-up/down voltage conversion. Therefore, it is suitable for hybrid electric vehicle, fuel cell vehicle, energy backup system, and grid-system applications. The proposed converter incorporates a coupled inductor to behave forward-and-flyback energy conversion for high voltage ratio and provide galvanic isolation. The energy stored in the leakage inductor of the coupled inductor can be recycled without the use of additional snubber mechanism or clamped circuit. No matter in step-up or step-down mode, all power switches can operate with soft switching. Moreover, there is a inherit feature that metal–oxide–semiconductor field-effect transistors (MOSFETs with smaller on-state resistance can be adopted because of lower voltage endurance at primary side. Operation principle, voltage ratio derivation, and inductor design are thoroughly described in this paper. In addition, a 1-kW prototype is implemented to validate the feasibility and correctness of the converter. Experimental results indicate that the peak efficiencies in step-up and step-down modes can be up to 95.4% and 93.6%, respectively.

  1. Converter-Modulator Design and Operations for the ILC L-band Test Stand

    Energy Technology Data Exchange (ETDEWEB)

    Reass, William A.; /Los Alamos; Burkhart, C.; Adolphsen, Chris E.; Beukers, T.; Cassel, R.; de Lira, A.; Papas, C.; Nguyen, M.; Went, R.; /SLAC; Anderson, David E.; /Oak

    2007-09-10

    To facilitate a rapid response to the International Linear Collider (ILC) L-band development program at SLAC, a spare converter-modulator was shipped from LANL. This modulator was to be a spare for the spallation neutron source (SNS) accelerator at ORNL. The ILC application requires a 33% higher peak output power (15 MW) and output current (120 Amp). This presents significant design challenges to modify the existing hardware and yet maintain switching parameters and thermal cycling within the semiconductor component ratings. To minimize IGBT commutation and free-wheeling diode currents, a different set of optimizations, as compared to the SNS design, were used to tune the resonant switching networks. Additional complexities arose as nanocrystalline cores with different performance characteristics (as compared to SNS), were used to fabricate the resonant 'boost' transformers. This paper will describe the electrical design, modeling efforts, and resulting electrical performance as implemented for the ILC L-band test stand.

  2. Ciguatoxins: Cyclic Polyether Modulators of Voltage-gated Iion Channel Function

    Directory of Open Access Journals (Sweden)

    Richard J. Lewis

    2006-04-01

    Full Text Available Ciguatoxins are cyclic polyether toxins, derived from marine dinoflagellates, which are responsible for the symptoms of ciguatera poisoning. Ingestion of tropical and subtropical fin fish contaminated by ciguatoxins results in an illness characterised by neurological, cardiovascular and gastrointestinal disorders. The pharmacology of ciguatoxins is characterised by their ability to cause persistent activation of voltage-gated sodium channels, to increase neuronal excitability and neurotransmitter release, to impair synaptic vesicle recycling, and to cause cell swelling. It is these effects, in combination with an action to block voltage-gated potassium channels at high doses, which are believed to underlie the complex of symptoms associated with ciguatera. This review examines the sources, structures and pharmacology of ciguatoxins. In particular, attention is placed on their cellular modes of actions to modulate voltage-gated ion channels and other Na+-dependent mechanisms in numerous cell types and to current approaches for detection and treatment of ciguatera.

  3. Ciguatoxins: Cyclic Polyether Modulators of Voltage-gated Iion Channel Function

    Science.gov (United States)

    Nicholson, Graham M.; Lewis, Richard J.

    2006-01-01

    Ciguatoxins are cyclic polyether toxins, derived from marine dinoflagellates, which are responsible for the symptoms of ciguatera poisoning. Ingestion of tropical and subtropical fin fish contaminated by ciguatoxins results in an illness characterised by neurological, cardiovascular and gastrointestinal disorders. The pharmacology of ciguatoxins is characterised by their ability to cause persistent activation of voltage-gated sodium channels, to increase neuronal excitability and neurotransmitter release, to impair synaptic vesicle recycling, and to cause cell swelling. It is these effects, in combination with an action to block voltage-gated potassium channels at high doses, which are believed to underlie the complex of symptoms associated with ciguatera. This review examines the sources, structures and pharmacology of ciguatoxins. In particular, attention is placed on their cellular modes of actions to modulate voltage-gated ion channels and other Na+-dependent mechanisms in numerous cell types and to current approaches for detection and treatment of ciguatera.

  4. Voltage control on TEG-inverter system with pulse width modulation

    International Nuclear Information System (INIS)

    Kimura, N.; Kinoshita, H.; Matsuura, K.

    1984-01-01

    An ocean thermoelectric generating system can be expected to supply cheap electric power in future. And it can be used as base power supply or isolated power source in developing areas. The authors propose to apply forced-commutation inverter to thermoelectric energy conversion system and construct an electric power station which can be operated without any other synchronous generator (S-G) and can control ac system as stable as S-G. This paper shows that inverters can control voltage constant, though within a range of 10% load change, by using pulse width modulation (PWM). It also describes the design of the voltage control system covering from 50% to 100% load with combination of PWM and output voltage tap changing of TEG

  5. Three-Level Inverters with Common-Mode Voltage Cancellation Based on Synchronous Pulsewidth Modulation

    DEFF Research Database (Denmark)

    Oleschuk, Valentin; Blaabjerg, Frede

    2002-01-01

    A novel method of direct synchronous pulse-width modulation (PWM) is disseminated to three-level voltage source inverters with control algorithms with elimination of the common-mode voltages in three-phase drive systems with PWM. It provides smooth pulses-ratio changing and a quarter-wave symmetry...... of the voltage waveforms during the whole control range including overmodulation. Continuous, discontinuous and "direct-direct" schemes of synchronous PWM with both algebraic and trigonometric control functions have been analysed and compared. Simulations give the behaviour of the proposed methods and show some...... advantages of synchronous PWM in comparison with asynchronous at low ratios between the switching frequency and fundamental frequency....

  6. Non-linear Membrane Properties in Entorhinal Cortical Stellate Cells Reduce Modulation of Input-Output Responses by Voltage Fluctuations

    Science.gov (United States)

    Fernandez, Fernando R.; Malerba, Paola; White, John A.

    2015-01-01

    The presence of voltage fluctuations arising from synaptic activity is a critical component in models of gain control, neuronal output gating, and spike rate coding. The degree to which individual neuronal input-output functions are modulated by voltage fluctuations, however, is not well established across different cortical areas. Additionally, the extent and mechanisms of input-output modulation through fluctuations have been explored largely in simplified models of spike generation, and with limited consideration for the role of non-linear and voltage-dependent membrane properties. To address these issues, we studied fluctuation-based modulation of input-output responses in medial entorhinal cortical (MEC) stellate cells of rats, which express strong sub-threshold non-linear membrane properties. Using in vitro recordings, dynamic clamp and modeling, we show that the modulation of input-output responses by random voltage fluctuations in stellate cells is significantly limited. In stellate cells, a voltage-dependent increase in membrane resistance at sub-threshold voltages mediated by Na+ conductance activation limits the ability of fluctuations to elicit spikes. Similarly, in exponential leaky integrate-and-fire models using a shallow voltage-dependence for the exponential term that matches stellate cell membrane properties, a low degree of fluctuation-based modulation of input-output responses can be attained. These results demonstrate that fluctuation-based modulation of input-output responses is not a universal feature of neurons and can be significantly limited by subthreshold voltage-gated conductances. PMID:25909971

  7. SWITCH MODE PULSE WIDTH MODULATED DC-DC CONVERTER WITH MULTIPLE POWER TRANSFORMERS

    DEFF Research Database (Denmark)

    2009-01-01

    A switch mode pulse width modulated DC-DC power converter comprises at least one first electronic circuit on a input side (1) and a second electronic circuit on a output side (2). The input side (1) and the output side (2) are coupled via at least two power transformers (T1, T2). Each power...... transformer (T1, T2) comprises a first winding (T1a, T2a) arranged in a input side converter stage (3, 4) on the input side (1) and a second winding (T1 b, T2b) arranged in a output side converter stage (5) on the output side (2), and each of the windings (T1a, T1 b, T2a, T2b) has a first end and a second end....... The first electronic circuit comprises terminals (AO, A1) for connecting a source or a load, at least one energy storage inductor (L) coupled in series with at least one of the first windings (T1a, T2a) of the power transformers (T1, T2), and for each power transformer (T1, T2), an arrangement of switches...

  8. Notes on the voltage performance of accelerator tube sub-modules for the NSF tandem

    International Nuclear Information System (INIS)

    Eastham, D.A.; Groome, A.E.; Powell, P.

    1978-01-01

    Measurements are reported of the d.c. voltage performance of vacuum accelerator tube sub-modules for the Nuclear Structure Facility 30 MV Tandem at Daresbury. Using diagnostic techniques it has been possible to separate out the different processes in the tube which can lead to breakdown. As a result, improved sub-modules have been produced. Tests, have simulated the ion exchange processes which occur in longer tube lengths, and a better understanding has been obtained of the way in which these processes depend on the tube geometry and cleanliness. (U.K.)

  9. Characterization of a fully resonant, 1-MHz, 25-watt, DC/DC converter fabricated in a rad-hard BiCMOS/high-voltage process

    International Nuclear Information System (INIS)

    Titus, J.L.; Gehlhausen, M.A.; Desko, J.C. Jr.; Nguyen, T.T.; Roberts, D.J.; Shibib, M.A.; Hollenbach, K.E.

    1995-01-01

    This paper presents the characterization of a DC/DC converter prototype when its power integrated circuit (PIC) chip is exposed to total dose, dose rate, neutron, and heavy ion environments. This fully resonant, 1-MHZ, 25-Watt, DC/DC converter is composed of a brassboard, populated with input/output filters, isolation transformers, output rectifier, capacitors, resistors, and PIC chip, integrating the primary-side control circuitry, secondary-side control circuitry, power switch, gate-drive circuitry, and voltage references. The brassboard is built using commercial off-the-shelf components; and the PIC chip is fabricated using AT and T's rad-hard, bipolar complementary metal-oxide semiconductor (BiCMOS)/high-voltage process. The intent of this paper is to demonstrate that the PIC chip is fabricated with a radiation-hardened process and to demonstrate that various analog, digital, and power functions can be effectively integrated

  10. Optimizing design of converters using power cycling lifetime models

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Ørndrup; Munk-Nielsen, Stig

    2015-01-01

    Converter power cycling lifetime depends heavily on converter operation point. A lifetime model of a single power module switched mode power supply with wide input voltage range is shown. A lifetime model is created using a power loss model, a thermal model and a model for power cycling capability...... with a given mission profile. A method to improve the expected lifetime of the converter is presented, taking into account switching frequency, input voltage and transformer turns ratio....

  11. Molecular pathophysiology and pharmacology of the voltage-sensing module of neuronal ion channels.

    Science.gov (United States)

    Miceli, Francesco; Soldovieri, Maria Virginia; Ambrosino, Paolo; De Maria, Michela; Manocchio, Laura; Medoro, Alessandro; Taglialatela, Maurizio

    2015-01-01

    Voltage-gated ion channels (VGICs) are membrane proteins that switch from a closed to open state in response to changes in membrane potential, thus enabling ion fluxes across the cell membranes. The mechanism that regulate the structural rearrangements occurring in VGICs in response to changes in membrane potential still remains one of the most challenging topic of modern biophysics. Na(+), Ca(2+) and K(+) voltage-gated channels are structurally formed by the assembly of four similar domains, each comprising six transmembrane segments. Each domain can be divided into two main regions: the Pore Module (PM) and the Voltage-Sensing Module (VSM). The PM (helices S5 and S6 and intervening linker) is responsible for gate opening and ion selectivity; by contrast, the VSM, comprising the first four transmembrane helices (S1-S4), undergoes the first conformational changes in response to membrane voltage variations. In particular, the S4 segment of each domain, which contains several positively charged residues interspersed with hydrophobic amino acids, is located within the membrane electric field and plays an essential role in voltage sensing. In neurons, specific gating properties of each channel subtype underlie a variety of biological events, ranging from the generation and propagation of electrical impulses, to the secretion of neurotransmitters and to the regulation of gene expression. Given the important functional role played by the VSM in neuronal VGICs, it is not surprising that various VSM mutations affecting the gating process of these channels are responsible for human diseases, and that compounds acting on the VSM have emerged as important investigational tools with great therapeutic potential. In the present review we will briefly describe the most recent discoveries concerning how the VSM exerts its function, how genetically inherited diseases caused by mutations occurring in the VSM affects gating in VGICs, and how several classes of drugs and toxins

  12. 4Nx Non-Isolated and Non-Inverting Hybrid Interleaved Multilevel Boost Converter Based on VLCIm Cell and Cockroft Walton Voltage Multiplier for Renewable Energy Applications

    DEFF Research Database (Denmark)

    Bhaskar, Mahajan Sagar; Padmanaban, Sanjeevikumar; Blaabjerg, Frede

    2016-01-01

    In this treatise, 4Nx hybrid Non Inverting & Non Isolated (NI-NI) DC-DC interleaved multi-level boost converter (4Nx IMBC) for renewable energy applications is proposed. The proposed 4Nx IMBC is derived by coalescing the feature of 2Nx DC-DC Interleaved Multi-level Boost Converter (2Nx IMBC), vol...... or transformers. Simulations results of proposed circuitry are presented which verify the analysis, function, working modes & feasibility of proposed circuitry converter.......In this treatise, 4Nx hybrid Non Inverting & Non Isolated (NI-NI) DC-DC interleaved multi-level boost converter (4Nx IMBC) for renewable energy applications is proposed. The proposed 4Nx IMBC is derived by coalescing the feature of 2Nx DC-DC Interleaved Multi-level Boost Converter (2Nx IMBC...... applicable at user end its DC voltage magnitude needs to be incremented with high conversion. Existing and recently proposed DC-DC converter are not sufficiently expert to employ practically, because of stability issues, high duty cycle and high ripple in the output. To overcome the conversion ratio problem...

  13. DC-Link Voltage Coordinated-Proportional Control for Cascaded Converter With Zero Steady-State Error and Reduced System Type

    DEFF Research Database (Denmark)

    Tian, Yanjun; Loh, Poh Chiang; Deng, Fujin

    2016-01-01

    Cascaded converter is formed by connecting two subconverters together, sharing a common intermediate dc-link voltage. Regulation of this dc-link voltage is frequently realized with a proportional-integral (PI) controller, whose high gain at dc helps to force a zero steady-state tracking error....... The proposed scheme can be used with either unidirectional or bidirectional power flow, and has been verified by simulation and experimental results presented in this paper........ Such precise tracking is, however, at the expense of increasing the system type, caused by the extra pole at the origin introduced by the PI controller. The overall system may, hence, be tougher to control. To reduce the system type while preserving precise dc-link voltage tracking, this paper proposes...

  14. Soft-Switched Dual-Input DC-DC Converter Combining a Boost-Half-Bridge Cell and a Voltage-Fed Full-Bridge Cell

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2013-01-01

    This paper presents a new zero-voltage-switching (ZVS) isolated dc-dc converter which combines a boost halfbridge (BHB) cell and a full-bridge (FB) cell, so that two different type of power sources, i.e. both current-fed and voltage-fed, can be coupled effectively by the proposed converter...... for various applications, such as fuel cell and super-capacitor hybrid energy system. By fully using two high frequency transformers and a shared leg of switches, number of the power devices and associated gate driver circuits can be reduced. With phase-shift control, the converter can achieve ZVS turn......-on of active switches and zero-current switching (ZCS) turn-off of diodes. In this paper, derivation, analysis and design of the proposed converter are presented. Finally, a 25~50 V input, 300~400 V output prototype with a 600 W nominal power rating is built up and tested to demonstrate the effectiveness...

  15. Sample-Data Modeling of a Zero Voltage Transition DC-DC Converter for On-Board Battery Charger in EV

    Directory of Open Access Journals (Sweden)

    Teresa R. Granados-Luna

    2014-01-01

    Full Text Available Battery charger is a key device in electric and hybrid electric vehicles. On-board and off-board topologies are available in the market. Lightweight, small, high performance, and simple control are desired characteristics for on-board chargers. Moreover, isolated single-phase topologies are the most common system in Level 1 battery charger topologies. Following this trend, this paper proposes a sampled-data modelling strategy of a zero voltage transition (ZVT DC-DC converter for an on-board battery charger. A piece-wise linear analysis of the converter is the basis of the technique presented such that a large-signal model and, therefore, a small-signal model of the converter are derived. Numerical and simulation results of a 250 W test rig validate the model.

  16. Proportional-Resonant Controllers. A New Breed of Controllers Suitable for Grid-Connected Voltage-Source Converters

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Blaabjerg, Frede

    2004-01-01

    This paper is describing the recently introduced proportional-resonant (PR) controllers and their suitability for grid-connected converters current control. It is shown that the known shortcomings associated with PI controllers like steady - state error for single-phase converters and the need...... of decoupling for three-phase converters can be alleviated. Additionally, selective harmonic compensation is also possible with PR controllers. Suggested control-diagrams for three-phase grid converters and active filters are also presented. A practical application of PR current control for a photovoltaic (PV...

  17. Rad-Hard, Miniaturized, Scalable, High-Voltage Switching Module for Power Applications Rad-Hard, Miniaturized

    Science.gov (United States)

    Adell, Philippe C.; Mojarradi, Mohammad; DelCastillo, Linda Y.; Vo, Tuan A.

    2011-01-01

    A paper discusses the successful development of a miniaturized radiation hardened high-voltage switching module operating at 2.5 kV suitable for space application. The high-voltage architecture was designed, fabricated, and tested using a commercial process that uses a unique combination of 0.25 micrometer CMOS (complementary metal oxide semiconductor) transistors and high-voltage lateral DMOS (diffusion metal oxide semiconductor) device with high breakdown voltage (greater than 650 V). The high-voltage requirements are achieved by stacking a number of DMOS devices within one module, while two modules can be placed in series to achieve higher voltages. Besides the high-voltage requirements, a second generation prototype is currently being developed to provide improved switching capabilities (rise time and fall time for full range of target voltages and currents), the ability to scale the output voltage to a desired value with good accuracy (few percent) up to 10 kV, to cover a wide range of high-voltage applications. In addition, to ensure miniaturization, long life, and high reliability, the assemblies will require intensive high-voltage electrostatic modeling (optimized E-field distribution throughout the module) to complete the proposed packaging approach and test the applicability of using advanced materials in a space-like environment (temperature and pressure) to help prevent potential arcing and corona due to high field regions. Finally, a single-event effect evaluation would have to be performed and single-event mitigation methods implemented at the design and system level or developed to ensure complete radiation hardness of the module.

  18. A low-voltage high-speed terahertz spatial light modulator using active metamaterial

    Directory of Open Access Journals (Sweden)

    Saroj Rout

    2016-11-01

    Full Text Available An all solid-state metamaterial based terahertz (THz spatial light modulator (SLM is presented which uses high mobility 2DEG to manipulate the metamaterial resonant frequency (0.45 THz leading to terahertz wave modulation. The 2DEG is created by embedding pseudomorphic high-electron mobility transistors in the capacitive gap of each electrical-LC resonator, allowing the charge density to be controlled with very low voltage (1 V and modulating speeds up to 10 MHz while consuming sub-milliwatt power. We have demonstrated our SLM as a 2 × 2 pixel array operating around 0.45 THz by raster scanning a 6 × 6 image of an occluded metal object behind a thick polystyrene screen using a single-pixel THz imaging setup.

  19. A Low-Voltage Ride-Through Technique for Grid-Connected Converters with Reduced Power Transistors Stress

    DEFF Research Database (Denmark)

    Chen, Hsin-Chih; Lee, Chia-Tse; Cheng, Po-Tai

    2016-01-01

    With more and more distributed energy resources being installed in the utility grid, grid operators start imposing the low-voltage ride-through requirement on such systems to remain grid-connected and inject reactive and/or active current to support grid voltage during fault conditions. This pape...

  20. Elimination of DC-Link Current Ripple for Modular Multilevel Converters With Capacitor Voltage-Balancing Pulse-Shifted Carrier PWM

    DEFF Research Database (Denmark)

    Deng, Fujin; Chen, Zhe

    2015-01-01

    The modular multilevel converter (MMC) is attractive for medium- and high-power applications because of its high modularity, availability, and power quality. In this paper, the current ripple on the dc link of the three-phase MMC derived from the phase-shifted carrier-based pulse-width modulation...

  1. KCNQ1 channel modulation by KCNE proteins via the voltage-sensing domain.

    Science.gov (United States)

    Nakajo, Koichi; Kubo, Yoshihiro

    2015-06-15

    The gating of the KCNQ1 potassium channel is drastically regulated by auxiliary subunit KCNE proteins. KCNE1, for example, slows the activation kinetics of KCNQ1 by two orders of magnitude. Like other voltage-gated ion channels, the opening of KCNQ1 is regulated by the voltage-sensing domain (VSD; S1-S4 segments). Although it has been known that KCNE proteins interact with KCNQ1 via the pore domain, some recent reports suggest that the VSD movement may be altered by KCNE. The altered VSD movement of KCNQ1 by KCNE proteins has been examined by site-directed mutagenesis, the scanning cysteine accessibility method (SCAM), voltage clamp fluorometry (VCF) and gating charge measurements. These accumulated data support the idea that KCNE proteins interact with the VSDs of KCNQ1 and modulate the gating of the KCNQ1 channel. In this review, we will summarize recent findings and current views of the KCNQ1 modulation by KCNE via the VSD. In this context, we discuss our recent findings that KCNE1 may alter physical interactions between the S4 segment (VSD) and the S5 segment (pore domain) of KCNQ1. Based on these findings from ourselves and others, we propose a hypothetical mechanism for how KCNE1 binding alters the VSD movement and the gating of the channel. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

  2. Threshold-voltage modulated phase change heterojunction for application of high density memory

    International Nuclear Information System (INIS)

    Yan, Baihan; Tong, Hao; Qian, Hang; Miao, Xiangshui

    2015-01-01

    Phase change random access memory is one of the most important candidates for the next generation non-volatile memory technology. However, the ability to reduce its memory size is compromised by the fundamental limitations inherent in the CMOS technology. While 0T1R configuration without any additional access transistor shows great advantages in improving the storage density, the leakage current and small operation window limit its application in large-scale arrays. In this work, phase change heterojunction based on GeTe and n-Si is fabricated to address those problems. The relationship between threshold voltage and doping concentration is investigated, and energy band diagrams and X-ray photoelectron spectroscopy measurements are provided to explain the results. The threshold voltage is modulated to provide a large operational window based on this relationship. The switching performance of the heterojunction is also tested, showing a good reverse characteristic, which could effectively decrease the leakage current. Furthermore, a reliable read-write-erase function is achieved during the tests. Phase change heterojunction is proposed for high-density memory, showing some notable advantages, such as modulated threshold voltage, large operational window, and low leakage current

  3. Threshold-voltage modulated phase change heterojunction for application of high density memory

    Science.gov (United States)

    Yan, Baihan; Tong, Hao; Qian, Hang; Miao, Xiangshui

    2015-09-01

    Phase change random access memory is one of the most important candidates for the next generation non-volatile memory technology. However, the ability to reduce its memory size is compromised by the fundamental limitations inherent in the CMOS technology. While 0T1R configuration without any additional access transistor shows great advantages in improving the storage density, the leakage current and small operation window limit its application in large-scale arrays. In this work, phase change heterojunction based on GeTe and n-Si is fabricated to address those problems. The relationship between threshold voltage and doping concentration is investigated, and energy band diagrams and X-ray photoelectron spectroscopy measurements are provided to explain the results. The threshold voltage is modulated to provide a large operational window based on this relationship. The switching performance of the heterojunction is also tested, showing a good reverse characteristic, which could effectively decrease the leakage current. Furthermore, a reliable read-write-erase function is achieved during the tests. Phase change heterojunction is proposed for high-density memory, showing some notable advantages, such as modulated threshold voltage, large operational window, and low leakage current.

  4. Design of a High Voltage Bidirectional DC-DC Converter for Driving Capacitive Incremental Actuators usable in Electric Vehicles (EVs)

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Zhang, Zhe; Andersen, Michael A. E.

    2014-01-01

    the converter for efficiently charging and discharging the capacitive actuator from 0 V to 2.5 kV and vice versa, respectively. The converter is used to drive a dielectric electro active polymer (DEAP) based capacitive incremental actuator, which has the potential to be used in automotive (e.g., EVs), space...

  5. Comparative Study on  Paralleled vs. Scaled Dc-dc Converters  in High Voltage Gain Applications

    DEFF Research Database (Denmark)

    Klimczak, Pawel; Munk-Nielsen, Stig

    2008-01-01

    Today power converters are present in many commercial, medical and industrial applications. A lot of them are high power and high current applications. In order to increase power handling capability several transistors or diodes are paralleled often. However such paralleling may lead to converter...

  6. Resistive Switching and Voltage Induced Modulation of Tunneling Magnetoresistance in Nanosized Perpendicular Organic Spin Valves

    Science.gov (United States)

    Schmidt, Georg; Goeckeritz, Robert; Homonnay, Nico; Mueller, Alexander; Fuhrmann, Bodo

    Resistive switching has already been reported in organic spin valves (OSV), however, its origin is still unclear. We have fabricated nanosized OSV based on La0.7Sr0.3MnO3/Alq3/Co. These devices show fully reversible resistive switching of up to five orders of magnitude. The magnetoresistance (MR) is modulated during the switching process from negative (-70%) to positive values (+23%). The results are reminiscent of experiments claiming magnetoelectric coupling in LSMO based tunneling structures using ferroelectric barriers. By analyzing the I/V characteristics of the devices we can show that transport is dominated by tunneling through pinholes. The resistive switching is caused by voltage induced creation and motion of oxygen vacancies at the LSMO surface, however, the resulting tunnel barrier is complemented by a second adjacent barrier in the organic semiconductor. Our model shows that the barrier in the organic material is constant, causing the initial MR while the barrier in the LMSO can be modulated by the voltage resulting in the resistive switching and the modulation of the MR as the coupling to the states in the LSMO changes. A switching caused by LSMO only is also supported by the fact that replacing ALQ3 by H2PC yields almost identical results. Supported by the DFG in the SFB762.

  7. Iaverage current mode (ACM) control for switching power converters

    OpenAIRE

    2014-01-01

    Providing a fast current sensor direct feedback path to a modulator for controlling switching of a switched power converter in addition to an integrating feedback path which monitors average current for control of a modulator provides fast dynamic response consistent with system stability and average current mode control. Feedback of output voltage for voltage regulation can be combined with current information in the integrating feedback path to limit bandwidth of the voltage feedback signal.

  8. Modulation of voltage-gated channel currents by harmaline and harmane.

    Science.gov (United States)

    Splettstoesser, Frank; Bonnet, Udo; Wiemann, Martin; Bingmann, Dieter; Büsselberg, Dietrich

    2005-01-01

    Harmala alkaloids are endogenous substances, which are involved in neurodegenerative disorders such as M. Parkinson, but some of them also have neuroprotective effects in the nervous system. While several sites of action at the cellular level (e.g. benzodiazepine receptors, 5-HT and GABA(A) receptors) have been identified, there is no report on how harmala alkaloids interact with voltage-gated membrane channels. The aim of this study was to investigate the effects of harmaline and harmane on voltage-activated calcium- (I(Ca(V))), sodium- (I(Na(V))) and potassium (I(K(V)))-channel currents, using the whole-cell patch-clamp method with cultured dorsal root ganglion neurones of 3-week-old rats. Currents were elicited by voltage steps from the holding potential to different command potentials. Harmaline and harmane reduced I(Ca(V)), I(Na(V)) and I(K(V)) concentration-dependent (10-500 microM) over the voltage range tested. I(Ca(V)) was reduced with an IC(50) of 100.6 microM for harmaline and by a significantly lower concentration of 75.8 microM (P<0.001, t-test) for harmane. The Hill coefficient was close to 1. Threshold concentration was around 10 microM for both substances. The steady state of inhibition of I(Ca(V)) by harmaline or harmane was reached within several minutes. The action was not use-dependent and at least partly reversible. It was mainly due to a reduction in the sustained calcium channel current (I(Ca(L+N))), while the transient voltage-gated calcium channel current (I(Ca(T))) was only partially affected. We conclude that harmaline and harmane are modulators of I(Ca(V)) in vitro. This might be related to their neuroprotective effects.

  9. Conducted EMI Prediction and Mitigation Strategy Based on Transfer Function for a High-Low Voltage DC-DC Converter in Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Li Zhai

    2018-04-01

    Full Text Available The high dv/dt and di/dt outputs from power devices in a high-low voltage DC-DC converter on electric vehicles (EVs can always introduce the unwanted conducted electromagnetic interference (EMI emissions. A conducted EMI prediction and mitigation strategy that is based on transfer function for the high-low voltage DC-DC converter in EVs are proposed. A complete test for the DC-DC converter is conducted to obtain the conducted EMI from DC power cables in the frequency band of 150 kHz-108 MHz. The equivalent circuit with high-frequency parasitic parameters of the DC-DC converter is built`1 based on the measurement results to acquire the characteristics of the conducted EMI of the DC power cables. The common mode (CM and differential mode (DM propagation coupling paths are determined, and the corresponding transfer functions of the DM interference and CM interference are established. The simulation results of the conducted EMI can be obtained by software Matlab and Computer Simulation Technology (CST. By analyzing the transfer functions and the simulation results, the dominated interference is the CM interference, which is the main factor of the conducted EMI. A mitigation strategy for the design of the CM interference filter based on the dominated CM interference is proposed. Finally, the mitigation strategy of the conducted EMI is verified by performing the conducted voltage experiment. From the experiment results, the conducted voltage of the DC power cables is decreased, respectively, by 58 dBμV, 55 dBμV, 65 dBμV, 53 dBμV, and 54 dBμV at frequency 200 kHz, 400 kHz, 600 kHz, 1.4 MHz, and 50 MHz. The conduced voltage in the frequency band of 150 kHz–108 MHz can be mitigated by adding the CM interference filters, and the values are lower than the limit level-3 of CISPR25 standard (GB/T 18655-2010.

  10. New Modulation Strategy to Balance the Neutral-Point Voltage for Three-Level Neutral-Clamped Inverter Systems

    DEFF Research Database (Denmark)

    Choi, Uimin; Lee, June-Seok; Lee, Kyo-Beum

    2014-01-01

    This paper proposes a new modulation strategy that balances the neutral-point voltage for three-level neutral-clamped inverter systems. The proposed modulation replaces the P-type or N-type small switching states with other switching states that do not affect the neutral-point voltage. The zero...... and medium switching states are employed to help the neutral-point voltage balancing. This method little bit increases the switching events and output total harmonic distortion. However, this method has a strong balancing ability at all regions. Further, it is very simple to implement in both space vector...

  11. Control of grid integrated voltage source converters under unbalanced conditions: development of an on-line frequency-adaptive virtual flux-based approach

    Energy Technology Data Exchange (ETDEWEB)

    Suul, Jon Are

    2012-03-15

    Three-Phase Voltage Source Converters (VSCs) are finding widespread applications in grid integrated power conversion systems. The control systems of such VSCs are in an increasing number of these applications required to operate during voltage disturbances and unbalanced conditions. Control systems designed for grid side voltagesensor-less operation are at the same time becoming attractive due to the continuous drive for cost reduction and increased reliability of VSCs, but are not commonly applied for operation during unbalanced conditions. Methods for voltage-sensor-less grid synchronization and control of VSCs under unbalanced grid voltage conditions will therefore be the main focus of this Thesis. Estimation methods based on the concept of Virtual Flux, considering the integral of the converter voltage in analogy to the flux of an electric machine, are among the simplest and most well known techniques for achieving voltage-sensor-less grid synchronization. Most of the established techniques for Virtual Flux estimation are, however, either sensitive to grid frequency variations or they are not easily adaptable for operation under unbalanced grid voltage conditions. This Thesis addresses both these issues by proposing a simple approach for Virtual Flux estimation by utilizing a frequency-adaptive filter based on a Second Order Generalized Integrator (SOGI). The proposed approach can be used to achieve on-line frequency-adaptive varieties of conventional strategies for Virtual Flux estimation. The main advantage is, however, that the SOGI-based Virtual Flux estimation can be arranged in a structure that achieves inherent symmetrical component sequence separation under unbalanced conditions. The proposed method for Virtual Flux estimation can be used as a general basis for voltage-sensor-less grid synchronization and control during unbalanced conditions. In this Thesis, the estimated Virtual Flux signals are used to develop a flexible strategy for control of active

  12. Modular Multilevel Converters: Control and Applications

    Directory of Open Access Journals (Sweden)

    Fernando Martinez-Rodrigo

    2017-10-01

    Full Text Available This review article is mainly oriented to the control and applications of modular multilevel converters (MMC. The main topologies of the switching modules are presented, for normal operation and for the elimination of DC faults. Methods to keep the capacitor voltage balanced are included. The voltage and current modulators, that are the most internal loops of control, are detailed. Voltage control and current control schemes are included which regulate DC link voltage and reactive power. The cases of unbalanced and distorted networks are analyzed, and schemes are proposed so that MMC contribute to improve the quality of the grid in these situations. The main applications in high voltage direct current (HVDC transmission along with other medium voltage (MV and low voltage (LV applications are included. Finally, the application to offshore wind farms is specifically analyzed.

  13. Comparative Study of Modulation-Based Individual Inverter Techniques for Direct and Inverse by using Star-Connection Induction Motor in Extra Low Voltage Application

    Directory of Open Access Journals (Sweden)

    Ardhia Wishnuprakasa

    2016-12-01

    Full Text Available In this study, the IEEE 519 Standard as a basis benchmarking for voltage (THDV and current (THDI in draft performance. Comparative Study based onthree-techniques of 2-Level Converter (2LC by using a Star-Connection Induction Motor (Y-CIM in ExtraLow Voltage (ELV Configuration.For the detail explanation, a primary inverter as Direct-Inverterby PWMdirect (PWM degreesand asecondary inverter as Inverse-Inverterby PWMinverse(PWM + PI degrees. It tends a modified algorithm,for eachof SPWM in six rules, and FHIPWM in 5th harmonics Injectedin standard modulation as the purpose for the Open-Ends of Pre-Dual Inverter in Decoupled SPWM for twelve rules, and Decoupled FHIPWM in combination of 5th harmonics Injectedin combination of two-standard-modulation. Those techniques are the purpose of two-inverter combination, which namelythe Equal Direct-Inverse (EDI algorithmproduct of prototyping in similarities. The observation is restricted in voltage scope between Simulation by using Power Simulator (PSIMand Application by using Microcontroller ARM STM32F4 Discovery.

  14. Design of a Solid-State Fast Voltage Compensator for klystron modulators requiring constant AC power consumption

    CERN Document Server

    Aguglia, Davide; Viarouge, Philippe; Cros, Jerome

    2014-01-01

    This paper proposes a novel topological solution for klystron modulators integrating a Fast Voltage Compensator which allows an operation at constant power consumption from the utility grid. This kind of solution is mandatory for the CLIC project under study, which requires several hundreds of synchronously operated klystron modulators for a total pulsed power of 39 GW. The topology is optimized for the challenging CLIC specifications, which require a very precise output voltage flat-top as well as fast rise and fall times (3µs). The Fast Voltage Compensator is integrated in the modulator such that it only has to manage the capacitor charger current and a fraction of the charging voltage. Consequently, its dimensioning power and cost is minimized.

  15. A SQUID gradiometer module with wire-wound pickup antenna and integrated voltage feedback circuit

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Guofeng [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences (CAS), Shanghai 200050 (China); Peter Gruenberg Institute (PGI-8), Forschungszentrum Juelich (FZJ), D-52425 Juelich (Germany); Joint Research Laboratory on Superconductivity and Bioelectronics, Collaboration between CAS-Shanghai and FZJ, Shanghai 200050 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Yi, E-mail: y.zhang@fz-juelich.de [Peter Gruenberg Institute (PGI-8), Forschungszentrum Juelich (FZJ), D-52425 Juelich (Germany); Joint Research Laboratory on Superconductivity and Bioelectronics, Collaboration between CAS-Shanghai and FZJ, Shanghai 200050 (China); Zhang Shulin [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences (CAS), Shanghai 200050 (China); Joint Research Laboratory on Superconductivity and Bioelectronics, Collaboration between CAS-Shanghai and FZJ, Shanghai 200050 (China); Krause, Hans-Joachim [Peter Gruenberg Institute (PGI-8), Forschungszentrum Juelich (FZJ), D-52425 Juelich (Germany); Joint Research Laboratory on Superconductivity and Bioelectronics, Collaboration between CAS-Shanghai and FZJ, Shanghai 200050 (China); and others

    2012-10-15

    The performance of the direct readout schemes for dc SQUID, Additional Positive Feedback (APF), noise cancellation (NC) and SQUID bootstrap circuit (SBC), have been studied in conjunction with planar SQUID magnetometers. In this paper, we examine the NC technique applied to a niobium SQUID gradiometer module with an Nb wire-wound antenna connecting to a dual-loop SQUID chip with an integrated voltage feedback circuit for suppression of the preamplifier noise contribution. The sensitivity of the SQUID gradiometer module is measured to be about 1 fT/(cm {radical}Hz) in the white noise range in a magnetically shielded room. Using such gradiometer, both MCG and MEG signals are recorded.

  16. Fault identification in crystalline silicon PV modules by complementary analysis of the light and dark current-voltage characteristics

    DEFF Research Database (Denmark)

    Spataru, Sergiu; Sera, Dezso; Hacke, Peter

    2016-01-01

    This article proposes a fault identification method, based on the complementary analysis of the light and dark current-voltage (I-V) characteristics of the photovoltaic (PV) module, to distinguish between four important degradation modes that lead to power loss in PV modules: (a) degradation of t...

  17. Cable Insulation Breakdowns in the Modulator with a Switch Mode High Voltage Power Supply

    CERN Document Server

    Cours, A

    2004-01-01

    The Advanced Photon Source modulators are PFN-type pulsers with 40 kV switch mode charging power supplies (PSs). The PS and the PFN are connected to each other by 18 feet of high-voltage (HV) cable. Another HV cable connects two separate parts of the PFN. The cables are standard 75 kV x-ray cables. All four cable connectors were designed by the PS manufacturer. Both cables were operating at the same voltage level (about 35 kV). The PS’s output connector has never failed during five years of operation. One of the other three connectors failed approximately five times more often than the others. In order to resolve the failure problem, a transient analysis was performed for all connectors. It was found that transient voltage in the connector that failed most often was subjected to more high-frequency, high-amplitude AC components than the other three connectors. It was thought that these components caused partial discharge in the connector insulation and led to the insulation breakdown. Modification o...

  18. An air-breathing single cell small proton exchange membrane fuel cell system with AB5-type metal hydride and an ultra-low voltage input boost converter

    Energy Technology Data Exchange (ETDEWEB)

    Akiyama, Kazuya; Matsumoto, Satoshi; Miyasaka, Akihiro; Shodai, Takahisa [NTT Energy and Environment System Laboratories, 3-1 Morinosato-Wakamiya Atsugi-shi, Kanagawa (Japan)

    2009-01-01

    A new strategy for increasing the power density of an air-breathing small proton exchange membrane fuel cell (PEMFC) system for the main energy source of portable consumer electronics is presented. The small PEMFC system is composed of a single cell. Utilizing the output voltage of the single cell, we introduce a newly designed ultra-low voltage input boost converter. The boost converter can generate 4.1 V output from input sources with low voltage ranges, such as under 1.0 V. The cathode plate is made from a thin SUS 316L stainless steel plate and has ribs that prevent the cathode from bending. The hydrogen is supplied by a metal hydride (MH) tank cartridge. The MH tank contains highly packed AB5-type MH. The MH tank cartridge has a volume of 13.2 cm{sup 3} and can absorb 6.7 L of hydrogen. The maximum power of the small PEMFC is 4.42 W at room temperature. Using 6.7 L of hydrogen, the small PEMFC can generate 11 Wh of electricity. The power density of the small PEMFC reaches 0.51 Wh cm{sup -3}. And the power density of the whole small PEMFC system, which contains the boost converter, a small Li-ion battery for a load absorber, and a case for the system, reaches 0.14 Wh cm{sup -3}. This value matches that of external Li-ion battery chargers for cell phones. We installed the small PEMFC system in a cell phone and confirmed the operations of calling, receiving, videophone, connecting to the Internet, and watching digital TV. And also confirmed that the small PEMFC system provides approximately 8.25 h of talk time, which is about three times as long as that for the original Li-ion battery. (author)

  19. Conventional P-ω/Q-V Droop Control in Highly Resistive Line of Low-Voltage Converter-Based AC Microgrid

    DEFF Research Database (Denmark)

    Hou, Xiaochao; Sun, Yao; Yuan, Wenbin

    2016-01-01

    -ω/Q-V droop control is adopted in the low-voltage AC microgrid. As a result, the active power sharing among the distributed generators (DGs) is easily obtained without communication. More importantly, this study clears up the previous misunderstanding that conventional P-ω/Q-V droop control is only applicable...... to microgrids with highly inductive lines, and lays a foundation for the application of conventional droop control under different line impedances. Moreover, in order to guarantee the accurate reactive power sharing, a guide for designing Q-V droop gains is given, and virtual resistance is adopted to shape......In low-voltage converter-based alternating current (AC) microgrids with resistive distribution lines, the P-V droop with Q-f boost (VPD/FQB) is the most common method for load sharing. However, it cannot achieve the active power sharing proportionally. To overcome this drawback, the conventional P...

  20. High-performance control of a three-phase voltage-source converter including feedforward compensation of the estimated load current

    International Nuclear Information System (INIS)

    Leon, Andres E.; Solsona, Jorge A.; Busada, Claudio; Chiacchiarini, Hector; Valla, Maria Ines

    2009-01-01

    In this paper a new control strategy for voltage-source converters (VSC) is introduced. The proposed strategy consists of a nonlinear feedback controller based on feedback linearization plus a feedforward compensation of the estimated load current. In our proposal an energy function and the direct-axis current are considered as outputs, in order to avoid the internal dynamics. In this way, a full linearization is obtained via nonlinear transformation and feedback. An estimate of the load current is feedforwarded to improve the performance of the whole system and to diminish the capacitor size. This estimation allows to obtain a more rugged and cheaper implementation. The estimate is calculated by using a nonlinear reduced-order observer. The proposal is validated through different tests. These tests include performance in presence of switching frequency, measurement filters delays, parameters uncertainties and disturbances in the input voltage.

  1. Periodically Swapping Modulation (PSM) Strategy for Three-Level (TL) DC/DC Converter with Balanced Switch Currents

    DEFF Research Database (Denmark)

    Liu, Dong; Deng, Fujin; Zhang, Qi

    2018-01-01

    The asymmetrical modulation strategy is widely used in various types of three-level (TL) DC/DC converters, while the current imbalance among the power switches is one of the important issues. In this paper, a novel periodically swapping modulation (PSM) strategy is proposed for balancing the power...... switches’ currents in various types of TL DC/DC converters. In the proposed PSM strategy, the driving signals of the switch pairs are swapped periodically, which guarantees that the currents through the power switches are kept balanced in every two switching periods. Therefore, the proposed PSM...... strategy can effectively improve the reliability of the converter by balancing the power losses and thermal stresses among the power switches. The operation principle and performances of the proposed PSM strategy are analyzed in detail. Finally, the simulation and experimental results are presented...

  2. High-Efficiency Isolated Boost DCDC Converter for High-Power Low-Voltage Fuel-Cell Applications

    DEFF Research Database (Denmark)

    Nymand, Morten; Andersen, Michael A. E.

    2010-01-01

    high winding losses. The analysis of transformer leakage inductance reveals that extremely low leakage inductance can be achieved, allowing stored energy to be dissipated. Power MOSFETs fully rated for repetitive avalanches allow primary-side voltage clamp circuits to be eliminated. The oversizing...

  3. A New Tuning Method of Multi-Resonant Current Controllers for Grid-Connected Voltage Source Converters

    DEFF Research Database (Denmark)

    Xie, Chuan; Zhao, Xin; Li, Kai

    2018-01-01

    Resonant controllers (RSCs) are widely adopted for controlling power converters since they can track AC signals of both positive and negative sequences without steady-state error. However, the performance of RSCs has not been fully exploited due to the improper phase compensation angle and insuff...

  4. Thermal analysis of multilevel grid side converters for 10 MW wind turbines under Low Voltage Ride Through

    DEFF Research Database (Denmark)

    Ma, Ke; Blaabjerg, Frede; Liserre, Marco

    2011-01-01

    , and able to contribute to the grid recovery by injecting reactive current during grid faults. Consequently, the full-scale power converter solutions are becoming more and more popular to fulfill the growing challenges in the wind power application. Nevertheless, the loading of the power devices in full...

  5. Conventional P-ω/Q-V Droop Control in Highly Resistive Line of Low-Voltage Converter-Based AC Microgrid

    Directory of Open Access Journals (Sweden)

    Xiaochao Hou

    2016-11-01

    Full Text Available In low-voltage converter-based alternating current (AC microgrids with resistive distribution lines, the P-V droop with Q-f boost (VPD/FQB is the most common method for load sharing. However, it cannot achieve the active power sharing proportionally. To overcome this drawback, the conventional P-ω/Q-V droop control is adopted in the low-voltage AC microgrid. As a result, the active power sharing among the distributed generators (DGs is easily obtained without communication. More importantly, this study clears up the previous misunderstanding that conventional P-ω/Q-V droop control is only applicable to microgrids with highly inductive lines, and lays a foundation for the application of conventional droop control under different line impedances. Moreover, in order to guarantee the accurate reactive power sharing, a guide for designing Q-V droop gains is given, and virtual resistance is adopted to shape the desired output impedance. Finally, the effects of power sharing and transient response are verified through simulations and experiments in converter-based AC Microgrid.

  6. Operation of the matrix converter as energy sources link of variable voltage; Operacion del convertidor matricial como enlace de fuentes de energia de voltaje variable

    Energy Technology Data Exchange (ETDEWEB)

    Lozano-Garcia, J. M; Hernandez-Figueroa, M. A; Estrada Garcia, H. J; Martinez-Patino, J [Universidad de Guanajuato, Campus Irapuato-Salamanca, Salamanca, Guanajuato (Mexico)]. E-mails: jm.lozano@ugto.mx; mahf@ugto.mx; hestrada@ugto.mx; jesusmp23@ugto.mx

    2013-03-15

    Renewable energy technologies, as wind turbines, have had a remarkable penetration in power systems worldwide, causing that actual power grids became dependent and vulnerable to the variability of the energy generated by this type of resource. In that sense, power converters provide a crucial function in the performance of the overall electrical system when they are used as links between this type of generators and the power system. In this paper, a matrix converter is proposed as link device, to cope with distorted and variable voltages as the ones found in wind turbines operation where generated voltages are directly dependent on wind's speed. An analysis of its main functional characteristics when it operates subject to distorted input-voltage condition, in order to synthesize a set of output voltages with constant magnitude and frequency and without harmonic distortion, is presented. Numerical simulations and experimental results from a laboratory-scale prototype are presented to validate the converter performance. [Spanish] La gran penetracion que ha tenido la generacion de energia mediante recursos renovables, como los generadores eolicos, en el mercado energetico, han ocasionado que las redes electricas sean mas dependientes y vulnerables a la variabilidad de la energia que se genera con este tipo de recursos. En ese sentido, los convertidores de potencia utilizados como enlace entre este tipo de generadores y el sistema electrico son determinantes en el comportamiento final que se tendra en el sistema electrico. En el presente trabajo se propone la utilizacion del convertidor matricial como dispositivo de enlace y se analizan sus caracteristicas operativas en casos donde se requiere la generacion de senales de voltaje sinusoidales y con valores constantes tanto en magnitud como en frecuencia a partir de senales variables, situacion que se presenta comunmente en los aerogeneradores donde el voltaje generado depende directamente de la velocidad del

  7. Analysis of Input Currents in «Frequency Converter - Induction Motor» System under Asymmetry of Mains Voltage

    Directory of Open Access Journals (Sweden)

    B. I. Firago

    2006-01-01

    Full Text Available The influence of modem firequency converters with uncontrolled rectifiers on the supply network is investigated in this paper. The developed mathematical model permits us to analyze rectifier input currents with symmetrical and asymmetrical supply networks and in discontinuous operational mode. Results of modeling in case of asymmetrical supply network are shown in the form of mains current curves and current spectrum of one phase.

  8. Application of chaotic pulse width modulation control for suppressing electromagnetic interference in a half-bridge converter

    Directory of Open Access Journals (Sweden)

    Yuhong Song

    2014-08-01

    Full Text Available It was proposed in the former research that chaos control can be used to suppress electromagnetic interference (EMI in DC–DC converters. Analysis on a half-bridge converter is detailed in this study. Here, the practical example of the power supply of personal computers is given to show that, with an external chaotic signal to a pulse width modulation control circuit, the proposed approach can reduce EMI by reducing the amplitudes of power signals such as transformer current and output inductor currents at multiples of fundamental frequency.

  9. Novel screening techniques for wind turbine power converters

    DEFF Research Database (Denmark)

    Jørgensen, Asger Bjørn; Sønderskov, Simon Dyhr; Christensen, Nicklas

    2016-01-01

    Power converters represent one of the highest failure rates in the wind turbine. Therefore converter manufacturers perform burn-in tests to prevent shipping of faulty converters. Recent developments in junction temperature estimation, based on accurate online IGBT collector-emitter voltage...... measurements, allow for thermal stress estimation of the IGBT modules. This is utilized to detect infant mortalities in power converters, by comparing thermal responses of IGBTs for faulty and non-faulty converters. The method proves to be a time and cost efficient candidate to replace burn-in tests of power...... converters for wind turbines applications....

  10. The Application of Auto-Disturbance Rejection Control Optimized by Least Squares Support Vector Machines Method and Time-Frequency Representation in Voltage Source Converter-High Voltage Direct Current System.

    Science.gov (United States)

    Liu, Ying-Pei; Liang, Hai-Ping; Gao, Zhong-Ke

    2015-01-01

    In order to improve the performance of voltage source converter-high voltage direct current (VSC-HVDC) system, we propose an improved auto-disturbance rejection control (ADRC) method based on least squares support vector machines (LSSVM) in the rectifier side. Firstly, we deduce the high frequency transient mathematical model of VSC-HVDC system. Then we investigate the ADRC and LSSVM principles. We ignore the tracking differentiator in the ADRC controller aiming to improve the system dynamic response speed. On this basis, we derive the mathematical model of ADRC controller optimized by LSSVM for direct current voltage loop. Finally we carry out simulations to verify the feasibility and effectiveness of our proposed control method. In addition, we employ the time-frequency representation methods, i.e., Wigner-Ville distribution (WVD) and adaptive optimal kernel (AOK) time-frequency representation, to demonstrate our proposed method performs better than the traditional method from the perspective of energy distribution in time and frequency plane.

  11. The Application of Auto-Disturbance Rejection Control Optimized by Least Squares Support Vector Machines Method and Time-Frequency Representation in Voltage Source Converter-High Voltage Direct Current System.

    Directory of Open Access Journals (Sweden)

    Ying-Pei Liu

    Full Text Available In order to improve the performance of voltage source converter-high voltage direct current (VSC-HVDC system, we propose an improved auto-disturbance rejection control (ADRC method based on least squares support vector machines (LSSVM in the rectifier side. Firstly, we deduce the high frequency transient mathematical model of VSC-HVDC system. Then we investigate the ADRC and LSSVM principles. We ignore the tracking differentiator in the ADRC controller aiming to improve the system dynamic response speed. On this basis, we derive the mathematical model of ADRC controller optimized by LSSVM for direct current voltage loop. Finally we carry out simulations to verify the feasibility and effectiveness of our proposed control method. In addition, we employ the time-frequency representation methods, i.e., Wigner-Ville distribution (WVD and adaptive optimal kernel (AOK time-frequency representation, to demonstrate our proposed method performs better than the traditional method from the perspective of energy distribution in time and frequency plane.

  12. Optimization of Pockels electric field in transverse modulated optical voltage sensor

    Science.gov (United States)

    Huang, Yifan; Xu, Qifeng; Chen, Kun-Long; Zhou, Jie

    2018-05-01

    This paper investigates the possibilities of optimizing the Pockels electric field in a transverse modulated optical voltage sensor with a spherical electrode structure. The simulations show that due to the edge effect and the electric field concentrations and distortions, the electric field distributions in the crystal are non-uniform. In this case, a tiny variation in the light path leads to an integral error of more than 0.5%. Moreover, a 2D model cannot effectively represent the edge effect, so a 3D model is employed to optimize the electric field distributions. Furthermore, a new method to attach a quartz crystal to the electro-optic crystal along the electric field direction is proposed to improve the non-uniformity of the electric field. The integral error is reduced therefore from 0.5% to 0.015% and less. The proposed method is simple, practical and effective, and it has been validated by numerical simulations and experimental tests.

  13. Film size-dependent voltage-modulated magnetism in multiferroic heterostructures

    Science.gov (United States)

    Hu, J.-M.; Shu, L.; Li, Z.; Gao, Y.; Shen, Y.; Lin, Y. H.; Chen, L. Q.; Nan, C. W.

    2014-01-01

    The electric-voltage-modulated magnetism in multiferroic heterostructures, also known as the converse magnetoelectric (ME) coupling, has drawn increasing research interest recently owing to its great potential applications in future low-power, high-speed electronic and/or spintronic devices, such as magnetic memory and computer logic. In this article, based on combined theoretical analysis and experimental demonstration, we investigate the film size dependence of such converse ME coupling in multiferroic magnetic/ferroelectric heterostructures, as well as exploring the interaction between two relating coupling mechanisms that are the interfacial strain and possibly the charge effects. We also briefly discuss some issues for the next step and describe new device prototypes that can be enabled by this technology. PMID:24421375

  14. Maximum Power Point Tracking for Cascaded PV-Converter Modules Using Two-Stage Particle Swarm Optimization.

    Science.gov (United States)

    Mao, Mingxuan; Duan, Qichang; Zhang, Li; Chen, Hao; Hu, Bei; Duan, Pan

    2017-08-24

    The paper presents a novel two-stage particle swarm optimization (PSO) for the maximum power point tracking (MPPT) control of a PV system consisting of cascaded PV-converter modules, under partial shading conditions (PSCs). In this scheme, the grouping method of the shuffled frog leaping algorithm (SFLA) is incorporated with the basic PSO algorithm, ensuring fast and accurate searching of the global extremum. An adaptive speed factor is also introduced to improve its convergence speed. A PWM algorithm enabling permuted switching of the PV sources is applied. The method enables this PV system to achieve the maximum power generation for any number of PV and converter modules. Simulation studies of the proposed MPPT scheme are performed on a system having two chained PV buck-converter modules and a dc-ac H-bridge connected at its terminals for supplying an AC load. The results show that this type of PV system allows each module to achieve the maximum power generation according its illumination level without affecting the others, and the proposed new control method gives significantly higher power output compared with the conventional P&O and PSO methods.

  15. Power electronic converters PWM strategies and current control techniques

    CERN Document Server

    Monmasson, Eric

    2013-01-01

    A voltage converter changes the voltage of an electrical power source and is usually combined with other components to create a power supply. This title is devoted to the control of static converters, which deals with pulse-width modulation (PWM) techniques, and also discusses methods for current control. Various application cases are treated. The book is ideal for professionals in power engineering, power electronics, and electric drives industries, as well as practicing engineers, university professors, postdoctoral fellows, and graduate students.

  16. Three-phase Resonant DC-link Converter

    DEFF Research Database (Denmark)

    Munk-Nielsen, Stig

    The purpose of the project is to develop a three-phase resonant converter suitable for standard speed drives. The motivation for working with resonant converters is found in the problem of the standard converter type used today. In standard converter type Pulse Width Modulated-Voltage Source...... Inverter, PWM-VSI, the switches are subject to high current and voltage stress during switching, which causes losses. The fast switching of modern switches reduces switching losses. Unfortunately this procedure increased dv/dt and the size of the input/output filters of the PWM-SVI must be increased...

  17. Thermal Analysis of Multilevel Grid-side Converters for 10-MW Wind turbines under Low-Voltage Ride Through

    DEFF Research Database (Denmark)

    Ma, Ke; Blaabjerg, Frede; Liserre, Marco

    2013-01-01

    in the power network and able to contribute to the grid recovery by injecting reactive current during grid faults. Consequently, the full-scale power converter solutions are becoming more and more popular to fulfill the growing challenges in the wind power application. Nevertheless, the loading of the power...... devices (particularly the diodes) under LVRT operation. Moreover, the three-level and five-level H-bridge topologies show more potential to reduce the inequality and level of device stress than the well-known three-level neutral point clamped topology....

  18. New Technique for Voltage Tracking Control of a Boost Converter Based on the PSO Algorithm and LTspice

    DEFF Research Database (Denmark)

    Farhang, Peyman; Drimus, Alin; Mátéfi-Tempfli, Stefan

    2015-01-01

    In this paper, a new technique is proposed to design a Modified PID (MPID) controller for a Boost converter. An interface between LTspice and MATLAB is carried out to implement the Particle Swarm Optimization (PSO) algorithm. The PSO algorithm which has the appropriate capability to find out...... the optimal solutions is run in MATLAB while it is interfaced with LTspice for simulation of the circuit using actual component models obtained from manufacturers. The PSO is utilized to solve the optimization problem in order to find the optimal parameters of MPID and PID controllers. The performances...

  19. Control of improved full-bridge three-level DC/DC converter for wind turbines in a DC grid

    DEFF Research Database (Denmark)

    Deng, Fujin; Chen, Zhe

    2013-01-01

    transformer in the IFBTL dc/dc converter. A modulation strategy, including two operation modes, is proposed for the IFBTL dc/dc converter. Then, a voltage balancing control strategy is proposed for the IFBTL dc/dc converter. Furthermore, the control of the wind turbine based on the IFBTL dc/dc converter......This paper presents an improved full-bridge three-level (IFBTL) dc/dc converter for a wind turbine in a dc grid by inserting a passive filter into the dc/dc converter to improve the performance of the converter. The passive filter can effectively reduce the voltage stress of the medium frequency...

  20. Study and development of a multiphase voltage regulation module; Estudio y desarrollo de un modulo de regulacion de voltaje multifase

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Hernandez, Arturo

    2004-02-15

    Within the new generation of low voltage integrated circuits, the microprocessors constitute one of the applications that imposes the strictest regulation limits. Therefore, the requirements for the supplying sources oriented to feed these devices are more and more critical. The converters devoted to provide high currents at low output voltages with a fast dynamic response are known as Voltage Regulation Modules. The only way of maintaining the high efficiency of these feed sources is by means of the use of the Synchronous Rectifiers (SR), which implies the substitution of the conventional diodes by controlled devices of lesser tension drop, known as Synchronous Rectifiers (SR). The most convenient devices in applications of Synchronous Rectification are the MOSFET due to their low ignition resistance in addition of being able to operate at high commutation frequencies. Two forms exist by means of which we can operate the SR gate: by means of external excitation or by means of self-excitation. The conventional VRM has been based on the Buck topology with Synchronous Rectification. Nevertheless, due to the limitations that this topology presents as far as dynamic response and efficiency, it has been decided on the use of Multiphase VRM fed with an input bus on 48V. As a solution to these problems, in this research work a Multiphase VRM is proposed, based on the Half symmetrical Bridge converter with the primary windings connected in series and external Synchronous Rectification, with which it is possible to obtain a low output voltage with high current and a fast dynamic response. Next the contents of the chapters of this document of thesis are presented in a summarized way. In chapter 1 the background that gives rise to the necessity of designing power supplies with low output tension, is presented. The associated problems to this type of low tension DC/DC converters are mentioned, and the concept of Synchronous Rectification with external excitation is introduced

  1. A voltage control method for an active capacitive DC-link module with series-connected circuit

    DEFF Research Database (Denmark)

    Wang, Haoran; Wang, Huai; Blaabjerg, Frede

    2017-01-01

    Many efforts have been made to improve the performance of power electronic systems with active capacitive DC-link module in terms of power density as well as reliability. One of the attractive solution is an active capacitive DC-link with the series-connected circuit because of handling small......-rated power. However, in the existing control method of this circuit, the DC-link current of the backward-stage or forward-stage need to be sensed for extracting the ripple components, which limits the flexibility of the active DC-link module. Thus, in this paper, a voltage control method of an active...... capacitive DC-link module is proposed. Current sensor at the DC-link will be cancel from the circuit. The controller of the series-connected circuit requires internal voltage signals of the DC-link module only, making it possible to be fully independent without any additional connection to the main circuit...

  2. Development of a 33 kV, 20 A long pulse converter modulator for high average power klystron

    Energy Technology Data Exchange (ETDEWEB)

    Reghu, T.; Mandloi, V.; Shrivastava, Purushottam [Pulsed High Power Microwave Section, Raja Ramanna Centre for Advanced Technology, Indore 452013, M.P. (India)

    2014-05-15

    Research, design, and development of high average power, long pulse modulators for the proposed Indian Spallation Neutron Source are underway at Raja Ramanna Centre for Advanced Technology. With this objective, a prototype of long pulse modulator capable of delivering 33 kV, 20 A at 5 Hz repetition rate has been designed and developed. Three Insulated Gate Bipolar Transistors (IGBT) based switching modules driving high frequency, high voltage transformers have been used to generate high voltage output. The IGBT based switching modules are shifted in phase by 120° with respect to each other. The switching frequency is 25 kHz. Pulses of 1.6 ms pulse width, 80 μs rise time, and 70 μs fall time have been achieved at the modulator output. A droop of ±0.6% is achieved using a simple segmented digital droop correction technique. The total fault energy transferred to the load during fault has been measured by conducting wire burn tests and is found to be within 3.5 J.

  3. Development of a 33 kV, 20 A long pulse converter modulator for high average power klystron

    International Nuclear Information System (INIS)

    Reghu, T.; Mandloi, V.; Shrivastava, Purushottam

    2014-01-01

    Research, design, and development of high average power, long pulse modulators for the proposed Indian Spallation Neutron Source are underway at Raja Ramanna Centre for Advanced Technology. With this objective, a prototype of long pulse modulator capable of delivering 33 kV, 20 A at 5 Hz repetition rate has been designed and developed. Three Insulated Gate Bipolar Transistors (IGBT) based switching modules driving high frequency, high voltage transformers have been used to generate high voltage output. The IGBT based switching modules are shifted in phase by 120° with respect to each other. The switching frequency is 25 kHz. Pulses of 1.6 ms pulse width, 80 μs rise time, and 70 μs fall time have been achieved at the modulator output. A droop of ±0.6% is achieved using a simple segmented digital droop correction technique. The total fault energy transferred to the load during fault has been measured by conducting wire burn tests and is found to be within 3.5 J

  4. Development of a 33 kV, 20 A long pulse converter modulator for high average power klystron

    Science.gov (United States)

    Reghu, T.; Mandloi, V.; Shrivastava, Purushottam

    2014-05-01

    Research, design, and development of high average power, long pulse modulators for the proposed Indian Spallation Neutron Source are underway at Raja Ramanna Centre for Advanced Technology. With this objective, a prototype of long pulse modulator capable of delivering 33 kV, 20 A at 5 Hz repetition rate has been designed and developed. Three Insulated Gate Bipolar Transistors (IGBT) based switching modules driving high frequency, high voltage transformers have been used to generate high voltage output. The IGBT based switching modules are shifted in phase by 120° with respect to each other. The switching frequency is 25 kHz. Pulses of 1.6 ms pulse width, 80 μs rise time, and 70 μs fall time have been achieved at the modulator output. A droop of ±0.6% is achieved using a simple segmented digital droop correction technique. The total fault energy transferred to the load during fault has been measured by conducting wire burn tests and is found to be within 3.5 J.

  5. Adaptive Modulation for DFIG and STATCOM With High-Voltage Direct Current Transmission.

    Science.gov (United States)

    Tang, Yufei; He, Haibo; Ni, Zhen; Wen, Jinyu; Huang, Tingwen

    2016-08-01

    This paper develops an adaptive modulation approach for power system control based on the approximate/adaptive dynamic programming method, namely, the goal representation heuristic dynamic programming (GrHDP). In particular, we focus on the fault recovery problem of a doubly fed induction generator (DFIG)-based wind farm and a static synchronous compensator (STATCOM) with high-voltage direct current (HVDC) transmission. In this design, the online GrHDP-based controller provides three adaptive supplementary control signals to the DFIG controller, STATCOM controller, and HVDC rectifier controller, respectively. The mechanism is to observe the system states and their derivatives and then provides supplementary control to the plant according to the utility function. With the GrHDP design, the controller can adaptively develop an internal goal representation signal according to the observed power system states, therefore, to achieve more effective learning and modulating. Our control approach is validated on a wind power integrated benchmark system with two areas connected by HVDC transmission lines. Compared with the classical direct HDP and proportional integral control, our GrHDP approach demonstrates the improved transient stability under system faults. Moreover, experiments under different system operating conditions with signal transmission delays are also carried out to further verify the effectiveness and robustness of the proposed approach.

  6. 不同结构电压源换流器损耗对比分析%Comparative analysis of losses of voltage source converters with different structures

    Institute of Scientific and Technical Information of China (English)

    刘建涛; 王治华; 王珂

    2013-01-01

    Two-level voltage source converter (2Level-VSC) with IGBTs directly in series and modular multi-level converter (MMC) are two kinds of the most mainstream converters used in flexible HVDC. Their external features are similar; however, their characteristics of loss are different, which affects their economy and applicable workplace. Based on the device parameters provided by the manufacturer, a general loss calculation model is proposed which is applicable to calculating the losses of both the converters. Through analyzing the working status of devices of the two kinds of converters, loss calculation methods of the two are analyzed in detail. Finally, loss characteristics of 2Level-VSC and MMC are analyzed quantitatively through examples. The results show that loss characteristics of the two kinds of converters are different, and the efficiency of MMC is higher than that of the 2Level-VSC with IGBTs directly in series under different conditions.%  IGBT直接串联两电平电压源换流器(2Level-VSC)和模块化多电平换流器(MMC)是目前比较主流的两种柔性直流输电换流器结构,其外特性相似,但损耗特性不同,从而影响两种换流器的经济性和适用场合。基于器件厂商提供的器件特性参数,提出了适用于两种换流器的损耗计算模型。在分析典型调制方式下两种换流器中各器件的工作状态的基础上,详细分析了两者的损耗计算方法,最后通过算例对2Level-VSC和MMC的损耗特性进行了定量的对比分析,结果表明相同工况下两种换流器的损耗特性不同,且各工况下MMC的损耗率低于两电平换流器。

  7. Gyromagnetic nonlinear transmission line generator of high voltage pulses modulated at 4 GHz frequency with 1000 Hz pulse repetition rate

    International Nuclear Information System (INIS)

    Ulmasculov, M R; Sharypov, K A; Shunailov, S A; Shpak, V G; Yalandin, M I; Pedos, M S; Rukin, S N

    2017-01-01

    Results of testing of a generator based on a solid-state drive and the parallel gyromagnetic nonlinear transmission lines with external bias are presented. Stable rf-modulated high-voltage nanosecond pulses were shaped in each of the four channels in 1 s packets with 1000 Hz repetition frequencies. Pulse amplitude reaches -175 kV, at a modulation depth of rf-oscillations to 50 % and the effective frequency ∼4 GHz. (paper)

  8. A High Resolution Switched Capacitor 1bit Sigma-Delta Modulator for Low-Voltage/Low-Power Applications

    DEFF Research Database (Denmark)

    Furst, Claus Efdmann

    1996-01-01

    A high resolution 1bit Sigma-Delta modulator for low power/low voltage applications is presented. The modulator operates at a supply of 1-1.5V, the current drain is 0.1mA. The maximum resolution is 87dB equivalent to 14 bits of resolution. This is achieved with a signal-band of 5kHz, over-samplin...

  9. Voltage-dependent modulation of cardiac ryanodine receptors (RyR2 by protamine.

    Directory of Open Access Journals (Sweden)

    Paula L Diaz-Sylvester

    Full Text Available It has been reported that protamine (>10 microg/ml blocks single skeletal RyR1 channels and inhibits RyR1-mediated Ca2+ release from sarcoplasmic reticulum microsomes. We extended these studies to cardiac RyR2 reconstituted into planar lipid bilayers. We found that protamine (0.02-20 microg/ml added to the cytosolic surface of fully activated RyR2 affected channel activity in a voltage-dependent manner. At membrane voltage (V(m; SR lumen-cytosol = 0 mV, protamine induced conductance transitions to several intermediate states (substates as well as full block of RyR2. At V(m>10 mV, the substate with the highest level of conductance was predominant. Increasing V(m from 0 to +80 mV, decreased the number of transitions and residence of the channel in this substate. The drop in current amplitude (full opening to substate had the same magnitude at 0 and +80 mV despite the approximately 3-fold increase in amplitude of the full opening. This is more similar to rectification of channel conductance induced by other polycations than to the action of selective conductance modifiers (ryanoids, imperatoxin. A distinctive effect of protamine (which might be shared with polylysines and histones but not with non-peptidic polycations is the activation of RyR2 in the presence of nanomolar cytosolic Ca2+ and millimolar Mg2+ levels. Our results suggest that RyRs would be subject to dual modulation (activation and block by polycationic domains of neighboring proteins via electrostatic interactions. Understanding these interactions could be important as such anomalies may be associated with the increased RyR2-mediated Ca2+ leak observed in cardiac diseases.

  10. Non-isolated DC-AC converter with high voltage gain for autonomous systems of electric power; Conversor CC-CA nao isolado com alto ganho de tensao para aplicacao em sistemas autonomos de energia eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, George Cajazeiras [Centro Federal de Educacao Tecnologica do Ceara (CEFET/CE), Fortaleza, CE (Brazil); Torrico-Bascope, Rene P. [Universidade Federal do Ceara (PPGEE/UFC), Fortaleza, CE (Brazil). Programa de Pos Graduacao em Engenharia Eletrica; Borges Neto, Manuel Rangel [Centro Federal de Educacao Tecnologica de Petrolina (CEFET-PET), PE (Brazil)

    2008-07-01

    A non-isolated DC-AC converter with high voltage gain with two output sinusoidal voltage - 110 V and 220 V - and frequency 60 Hz for application in autonomous systems of electric power is proposed in this work. This topology consists of a boost converter with high voltage gain, based on three-state switching cell combined with a double half bridge inverter. This configuration type the size and the cost are reduced and the efficiency is gotten better, due to the reduced number of switches. The converters that compose this topology operate with high frequency, reducing the volume of the magnetic materials. can be mention as important characteristics: the voltage stress across the switches of the boost converter are low, due they be naturally clamped by one output filter capacitor, which allows the utilization of switches with lower conduction resistances, and the waveforms of the output voltage of the double half bridge inverter supplies for the load it is sinusoidal and it possesses low harmonic content. (author)

  11. Digital control of a high-voltage (2.5 kV) bidirectional DC-DC converter for driving a dielectric electro active polymer (DEAP) based capacitive actuator

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Zhang, Zhe; Andersen, Michael A. E.

    2014-01-01

    This paper presents a digital control technique toachieve valley switching in a bidirectional flyback converterused to drive a dielectric electro active polymer basedincremental actuator. The incremental actuator consists ofthree electrically isolated, mechanically connected capacitiveactuators...... switchingtechnique during both charge and discharge processes, withoutthe need to sense signals on the output high-voltage side.Experimental results verifying the bidirectional operation of asingle high voltage flyback converter are presented, using afilm capacitor as the load. Energy efficiency measurements...

  12. New methods for the voltage drop desensitization of frequency converters for asynchronous machines; De nouvelles methodes de desensibilisation aux creux de tension des convertisseurs de frequence pour machines asynchrones

    Energy Technology Data Exchange (ETDEWEB)

    David, A.

    1995-12-31

    In order to reduce the vulnerability of electronic speed variators to load transients and outages, and more especially to short ones (inferior to one second), which represent 95 pc of voltage drop and failures, Electricite de France (EDF) has developed (and patented) several insensitivity techniques: voltage drop compensation, free-wheel machine speed identification, automatic adjustment and synchronization of converter and machine during the drop. These techniques have been validated through experiments

  13. Digital control of grid connected converters for distributed power generation

    Energy Technology Data Exchange (ETDEWEB)

    Skjellnes, Tore

    2008-07-01

    Pulse width modulated converters are becoming increasingly popular as their cost decreases and power rating increases. The new trend of small scale power producers, often using renewable energy sources, has created new demands for delivery of energy to the grid. A major advantage of the pulse width modulated converter is the ability to control the output voltage at any point in the voltage period. This enables rapid response to load changes and non-linear loads. In addition it can shape the voltage in response to the output current to create an outward appearance of a source impedance. This is called a virtual impedance. This thesis presents a controller for a voltage controlled three phase pulse width modulated converter. This controller enables operation in standalone mode, in parallel with other converters in a micro grid, and in parallel with a strong main grid. A time varying virtual impedance is presented which mainly attenuates reactive currents. A method of investigating the overall impedance including the virtual impedance is presented. New net standards have been introduced, requiring the converter to operate even during severe dips in the grid voltage. Experiments are presented verifying the operation of the controller during voltage dips. (Author). 37 refs., 65 figs., 10 tabs

  14. Simplified Thermal Modeling for IGBT Modules with Periodic Power Loss Profiles in Modular Multilevel Converters

    DEFF Research Database (Denmark)

    Zhang, Yi; Wang, Huai; Wang, Zhongxu

    2018-01-01

    One of the future challenges in Modular Multilevel Converters (MMCs) is how to size key components with compromised costs and design margins while fulfilling specific reliability targets. It demands better thermal modeling compared to the state-of-the-art in terms of both accuracy and simplicity....... Different from two-level power converters, MMCs have inherent dc-bias in arm currents and the power device conduction time is affected by operational parameters. A time-wise thermal modeling for the power devices in MMCs is, therefore, an iteration process and time-consuming. This paper thus proposes...

  15. Bifurcation and Chaos in a Pulse Width modulation controlled Buck Converter

    DEFF Research Database (Denmark)

    Kocewiak, Lukasz; Bak, Claus Leth; Munk-Nielsen, Stig

    2007-01-01

    by a system of piecewise-smooth nonautonomous differential equations. The research are focused on chaotic oscillations analysis and analytical search for bifurcations dependent on parameter. The most frequent route to chaos by the period doubling is observed in the second order DC-DC buck converter. Other...... bifurcations as a complex behaviour in power electronic system evidence are also described. In order to verify theoretical study the experimental DC-DC buck converter was build. The results obtained from three sources were presented and compared. A very good agreement between theory and experiment was observed....

  16. E-beam high voltage switching power supply

    Science.gov (United States)

    Shimer, Daniel W.; Lange, Arnold C.

    1997-01-01

    A high power, solid state power supply is described for producing a controllable, constant high voltage output under varying and arcing loads suitable for powering an electron beam gun or other ion source. The present power supply is most useful for outputs in a range of about 100-400 kW or more. The power supply is comprised of a plurality of discrete switching type dc-dc converter modules, each comprising a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, and an output rectifier for producing a dc voltage at the output of each module. The inputs to the converter modules are fed from a common dc rectifier/filter and are linked together in parallel through decoupling networks to suppress high frequency input interactions. The outputs of the converter modules are linked together in series and connected to the input of the transmission line to the load through a decoupling and line matching network. The dc-dc converter modules are phase activated such that for n modules, each module is activated equally 360.degree./n out of phase with respect to a successive module. The phased activation of the converter modules, combined with the square current waveforms out of the step up transformers, allows the power supply to operate with greatly reduced output capacitance values which minimizes the stored energy available for discharge into an electron beam gun or the like during arcing. The present power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle using simulated voltage feedback signals and voltage feedback loops. Circuitry is also provided for sensing incipient arc currents reflected at the output of the power supply and for simultaneously decoupling the power supply circuitry from the arcing load.

  17. E-beam high voltage switching power supply

    International Nuclear Information System (INIS)

    Shimer, D.W.; Lange, A.C.

    1997-01-01

    A high power, solid state power supply is described for producing a controllable, constant high voltage output under varying and arcing loads suitable for powering an electron beam gun or other ion source. The present power supply is most useful for outputs in a range of about 100-400 kW or more. The power supply is comprised of a plurality of discrete switching type dc-dc converter modules, each comprising a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, and an output rectifier for producing a dc voltage at the output of each module. The inputs to the converter modules are fed from a common dc rectifier/filter and are linked together in parallel through decoupling networks to suppress high frequency input interactions. The outputs of the converter modules are linked together in series and connected to the input of the transmission line to the load through a decoupling and line matching network. The dc-dc converter modules are phase activated such that for n modules, each module is activated equally 360 degree/n out of phase with respect to a successive module. The phased activation of the converter modules, combined with the square current waveforms out of the step up transformers, allows the power supply to operate with greatly reduced output capacitance values which minimizes the stored energy available for discharge into an electron beam gun or the like during arcing. The present power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle using simulated voltage feedback signals and voltage feedback loops. Circuitry is also provided for sensing incipient arc currents reflected at the output of the power supply and for simultaneously decoupling the power supply circuitry from the arcing load. 7 figs

  18. The electrical, thermal and spatial integration of a converter in a power electronic module

    NARCIS (Netherlands)

    Gerber, M.B.

    2005-01-01

    This thesis is concerned with the design and implementation of a power electronic system (14/42V DC/DC converter) that is implemented in the automotive environment, specifically the engine compartment. The power electronic system must have a high power density while operating in a high temperature

  19. Impact of lifetime model selections on the reliability prediction of IGBT modules in modular multilevel converters

    DEFF Research Database (Denmark)

    Zhang, Yi; Wang, Huai; Wang, Zhongxu

    2017-01-01

    , this paper benchmarks the most commonly-employed lifetime models of power semiconductor devices for offshore Modular Multilevel Converters (MMC) based wind farms. The benchmarking reveals that the lifetime model selection has a significant impact on the lifetime estimation. The use of analytical lifetime...

  20. Control and modulation for loss minimization for dc/dc converters in wind farm

    DEFF Research Database (Denmark)

    Dincan, Catalin Gabriel; Kjær, Philip Carne

    2016-01-01

    For a DC wind turbine, a single phase series-resonant converter for unidirectional power is studied. This paper aims to identify and compare impact on electrical losses and component ratings from the choice of three candidate control strategies. The evaluation is purely based on circuit simulatio...

  1. A novel Modulation Topology for Power Converters utilizing Multiple Carrier Signals

    DEFF Research Database (Denmark)

    Knott, Arnold; Pfaffinger, Gerhard; Andersen, Michael Andreas E.

    2008-01-01

    Power converters are known to generate spectral components in the range of interest of electromagnetic compatibility measurements. Common approaches to manipulate some selected components in these frequency ranges are shown here. These approaches add components to the input signal of the modulato...

  2. Virtual-vector-based space vector pulse width modulation of the DC-AC multilevel-clamped multilevel converter (MLC2)

    DEFF Research Database (Denmark)

    Rodriguez, Pedro; Busquets-Monge, Sergio; Blaabjerg, Frede

    2011-01-01

    This work presents the development of the space vector pulse width modulation (SVPWM) of a new multi-level converter topology. First, the proposed converter and its natural space vector diagram are presented. Secondly, a modified space vector diagram based on the virtual-vectors technique is show...

  3. Performance of 22.4-kW nonlaminated-frame dc series motor with chopper controller. [a dc to dc voltage converter

    Science.gov (United States)

    Schwab, J. R.

    1979-01-01

    Performance data obtained through experimental testing of a 22.4 kW traction motor using two types of excitation are presented. Ripple free dc from a motor-generator set for baseline data and pulse width modulated dc as supplied by a battery pack and chopper controller were used for excitation. For the same average values of input voltage and current, the motor power output was independent of the type of excitation. However, at the same speeds, the motor efficiency at low power output (corresponding to low duty cycle of the controller) was 5 to 10 percentage points lower on chopped dc than on ripple free dc. The chopped dc locked-rotor torque was approximately 1 to 3 percent greater than the ripple free dc torque for the same average current.

  4. Converter Monitoring Unit for Retrofit of Wind Power Converters

    DEFF Research Database (Denmark)

    Rannestad, Bjorn; Maarbjerg, Anders Eggert; Frederiksen, Kristian

    2018-01-01

    A Converter Monitoring Unit (CMU), which will enable condition monitoring of wind turbine converters is presented in this paper. Reducing the cost of corrective maintenance by means of condition monitoring is a way of lowering Operation & Maintenance (O&M) costs for wind turbine systems....... The CMU must be able to detect a broad range of failure modes related to Insulated Gate Bipolar Transistor (IGBT) power modules and associated gate drives. IGBT collector-emitter on-state voltage (vceon) and current (ic) is sampled in the CMU and used for detection of emerging failures. A new method...... for compensation of unwanted inductive voltage drop in the vceon measurement path is presented, enabling retrofitting of CMUs in existing wind turbines. Finally, experimental results obtained on a prototype CMU are presented. Experimentally the vceon dependency to IGBT junction temperature and deterioration...

  5. Design and Analysis of Two-Phase Boost DC-DC Converter

    OpenAIRE

    Taufik Taufik; Tadeus Gunawan; Dale Dolan; Makbul Anwari

    2010-01-01

    Multiphasing of dc-dc converters has been known to give technical and economical benefits to low voltage high power buck regulator modules. A major advantage of multiphasing dc-dc converters is the improvement of input and output performances in the buck converter. From this aspect, a potential use would be in renewable energy where power quality plays an important factor. This paper presents the design of a 2-phase 200W boost converter for battery charging application. Analysis of results fr...

  6. The Impact of Mission Profile Models on the Predicted Lifetime of IGBT Modules in the Modular Multilevel Converter

    DEFF Research Database (Denmark)

    Zhang, Yi; Wang, Huai; Wang, Zhongxu

    2017-01-01

    and electrical power modeling methods on the estimated lifetime of IGBT modules in an MMC for offshore wind power application. In a 30 MW MMC case study, an annual wind speed profile with a resolution of 1 s/data, 10 minute/data, and 1 hour/data are considered, respectively. A method to re-generate higher......The reliability aspect study of Modular Multilevel Converter (MMC) is of great interest in industry applications, such as offshore wind. Lifetime prediction of key components is an important tool to design MMC with fulfilled reliability specifications. While many efforts have been made...... to the lifetime prediction of IGBT modules in renewable energy applications by considering long-term varying operation conditions (i.e., mission profile), the justifications of using the associated mission profiles are still missed. This paper investigates the impact of mission profile data resolutions...

  7. The theory and implementation of a high quality pulse width modulated waveform synthesiser applicable to voltage FED inverters

    Science.gov (United States)

    Lower, Kim Nigel

    1985-03-01

    Modulation processes associated with the digital implementation of pulse width modulation (PWM) switching strategies were examined. A software package based on a portable turnkey structure is presented. Waveform synthesizer implementation techniques are reviewed. A three phase PWM waveform synthesizer for voltage fed inverters was realized. It is based on a constant carrier frequency of 18 kHz and a regular sample, single edge, asynchronous PWM switching scheme. With high carrier frequencies, it is possible to utilize simple switching strategies and as a consequence, many advantages are highlighted, emphasizing the importance to industrial and office markets.

  8. Digitally Controlled Point of Load Converter with Very Fast Transient Response

    DEFF Research Database (Denmark)

    Jakobsen, Lars Tønnes; Andersen, Michael Andreas E.

    2007-01-01

    voltage mode control and very fast transient response. The DiSOM modulator is combined with a digital PID compensator algorithm is implemented in a hybrid CPLD/FPGA and is used to control a synchronous Buck converter, which is used in typical Point of Load applications. The computational time is only......This paper presents a new Digital Self-Oscillating Modulator (DiSOM) that allows the duty cycle to be changed instantly. The DiSOM modulator is shown to have variable switching that is a function of the duty cycle. Compared to a more traditional digital PWM modulator based on a counter...... and comparator the DiSOM modulator allows the sampling frequency of the output voltage control loop to be higher than the switching frequency of the power converter, typically a DC/DC converter. The features of the DiSOM modulator makes it possible to design a digitally controlled DC/DC converter with linear...

  9. Redundancy Determination of HVDC MMC Modules

    Directory of Open Access Journals (Sweden)

    Chanki Kim

    2015-08-01

    Full Text Available An availability and a reliability prediction has been made for a high-voltage direct-current (HVDC module of VSC (Voltage Source Converter containing DC/DC converter, gate driver, capacitor and insulated gate bipolar transistors (IGBT. This prediction was made using published failure rates for the electronic equipment. The purpose of this prediction is to determinate the additional module redundancy of VSC and the used method is “binomial failure method”.

  10. Cascaded resonant bridge converters

    Science.gov (United States)

    Stuart, Thomas A. (Inventor)

    1989-01-01

    A converter for converting a low voltage direct current power source to a higher voltage, high frequency alternating current output for use in an electrical system where it is desired to use low weight cables and other circuit elements. The converter has a first stage series resonant (Schwarz) converter which converts the direct current power source to an alternating current by means of switching elements that are operated by a variable frequency voltage regulator, a transformer to step up the voltage of the alternating current, and a rectifier bridge to convert the alternating current to a direct current first stage output. The converter further has a second stage series resonant (Schwarz) converter which is connected in series to the first stage converter to receive its direct current output and convert it to a second stage high frequency alternating current output by means of switching elements that are operated by a fixed frequency oscillator. The voltage of the second stage output is controlled at a relatively constant value by controlling the first stage output voltage, which is accomplished by controlling the frequency of the first stage variable frequency voltage controller in response to second stage voltage. Fault tolerance in the event of a load short circuit is provided by making the operation of the first stage variable frequency voltage controller responsive to first and second stage current limiting devices. The second stage output is connected to a rectifier bridge whose output is connected to the input of the second stage to provide good regulation of output voltage wave form at low system loads.

  11. Electromagnetic Compatibility of Matrix Converter System

    Directory of Open Access Journals (Sweden)

    S. Fligl

    2006-12-01

    Full Text Available The presented paper deals with matrix converters pulse width modulation strategies design with emphasis on the electromagnetic compatibility. Matrix converters provide an all-silicon solution to the problem of converting AC power from one frequency to another, offering almost all the features required of an ideal static frequency changer. They possess many advantages compared to the conventional voltage or current source inverters. A matrix converter does not require energy storage components as a bulky capacitor or an inductance in the DC-link, and enables the bi-directional power flow between the power supply and load. The most of the contemporary modulation strategies are able to provide practically sinusoidal waveforms of the input and output currents with negligible low order harmonics, and to control the input displacement factor. The perspective of matrix converters regarding EMC in comparison with other types of converters is brightly evident because it is no need to use any equipment for power factor correction and current and voltage harmonics reduction. Such converter with proper control is properly compatible both with the supply mains and with the supplied load. A special digital control system was developed for the realized experimental test bed which makes it possible to achieve greater throughput of the digital control system and its variability.

  12. Performance Analysis of a Four-Switch Three-Phase Grid-Side Converter with Modulation Simplification in a Doubly-Fed Induction Generator-Based Wind Turbine (DFIG-WT with Different External Disturbances

    Directory of Open Access Journals (Sweden)

    Kai Ni

    2017-05-01

    Full Text Available This paper investigates the performance of a fault-tolerant four-switch three-phase (FSTP grid-side converter (GSC in a doubly-fed induction generator-based wind turbine (DFIG-WT. The space vector pulse width modulation (SVPWM technique is simplified and unified duty ratios are used for controlling the FSTP GSC. Steady DC-bus voltage, sinusoidal three-phase grid currents and unity power factor are obtained. In addition, the balance of capacitor voltages is accomplished based on the analysis of current flows at the midpoint of DC bus in different operational modes. Besides, external disturbances such as fluctuating wind speed and grid voltage sag are considered to test its fault-tolerant ability. Furthermore, the effects of fluctuating wind speed on the performance of DFIG-WT system are explained according to an approximate expression of the turbine torque. The performance of the proposed FSTP GSC is simulated in Matlab/Simulink 2016a based on a detailed 1.5 MW DFIG-WT Simulink model. Experiments are carried out on a 2 kW platform by using a discrete signal processor (DSP TMS320F28335 controller to validate the reliability of DFIG-WT for the cases with step change of the stator active power and grid voltage sag, respectively.

  13. A New Modular Multilevel Converter with Integrated Energy Storage

    DEFF Research Database (Denmark)

    Trintis, Ionut; Munk-Nielsen, Stig; Teodorescu, Remus

    2011-01-01

    applications. Furthermore, this solution can interconnect a DC and AC grid with bidirectional power flow, where both of them can receive or generate excess power to the third source integrated in each converter sub-module. This particularity enables the converter usage as a high voltage UPS system......This paper introduces a new modular converter with integrated energy storage based on the cascaded half-bridge modular multilevel converter with common DC bus. It represents a complete modular solution with power electronics and energy storage building blocks, for medium and high voltage...... in the future HVDC meshed grids. Its functionality and flexibility makes the converter independent on the energy storage unit characteristic. The converter concept with its basic functions and control schemes are described and evaluated in this paper....

  14. Modular space-vector pulse-width modulation for nine-switch converters

    DEFF Research Database (Denmark)

    Dehghan, Seyed Mohammad; Amiri, Arash; Mohamadian, Mustafa

    2013-01-01

    Recently, nine-switch inverter (NSI) has been presented as a dual-output inverter with constant frequency (CF) or different frequency (DF) operation modes. However, the CF mode is more interesting because of its lower switching device rating. This study proposes a new space-vector modulation (SVM......) method for the NSI that supports both the CF and DF modes, whereas conventional SVM of NSI can be used only in the DF mode. The proposed SVM can be easily implemented based on the conventional six-switch inverter SVM modules. The performance of the proposed SVM is verified by the simulation...

  15. Radiation tolerant power converter controls

    CERN Document Server

    Todd, B; King, Q; Uznanski, S

    2012-01-01

    The Large Hadron Collider (LHC) at the European Organisation for Nuclear Research (CERN) is the world's most powerful particle collider. The LHC has several thousand magnets, both warm and super-conducting, which are supplied with current by power converters. Each converter is controlled by a purpose-built electronic module called a Function Generator Controller (FGC). The FGC allows remote control of the power converter and forms the central part of a closed-loop control system where the power converter voltage is set, based on the converter output current and magnet-circuit characteristics. Some power converters and FGCs are located in areas which are exposed to beam-induced radiation. There are numerous radiation induced effects, some of which lead to a loss of control of the power converter, having a direct impact upon the accelerator's availability. Following the first long shut down (LS1), the LHC will be able to run with higher intensity beams and higher beam energy. This is expected to lead to signifi...

  16. All-optical wavelength converter based on fiber cross-phase modulation and fiber Bragg grating

    Czech Academy of Sciences Publication Activity Database

    Honzátko, Pavel

    2010-01-01

    Roč. 283, č. 9 (2010), s. 1744-1749 ISSN 0030-4018 R&D Projects: GA AV ČR 1ET300670502 Institutional research plan: CEZ:AV0Z20670512 Keywords : Wavelength conversion * Fiber cross phase modulation * Fiber Bragg grating Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.517, year: 2010

  17. Pulse width modulated push-pull driven parallel resonant converter with active free-wheel

    Science.gov (United States)

    Reass, William A.; Schrank, Louis

    2004-06-22

    An apparatus and method for high frequency alternating power generation to control kilowatts of supplied power in microseconds. The present invention includes a means for energy storage, push-pull switching means, control electronics, transformer means, resonant circuitry and means for excess energy recovery, all in electrical communication. A push-pull circuit works synchronously with a force commutated free-wheel transistor to provide current pulses to a transformer. A change in the conduction angle of the push-pull circuit changes the amount of energy coupled into the transformer's secondary oscillating circuit, thereby altering the induced secondary resonating voltage. At the end of each pulse, the force commutated free-wheel transistor causes residual excess energy in the primary circuit to be transmitted back to the storage capacitor for later use.

  18. A behavioral simulator for switched-capacitor sigma-delta modulator analog-to-digital converter

    International Nuclear Information System (INIS)

    San, H. Y.; Rezaul Hasan, S. M.

    1998-01-01

    In this paper, a PC-based simulator for state of the art oversampled switched-capacitor sigma-delta analog-to-digital converters is presented. The proposed simulator employs behavioral model of switched-capacitor integrator and non-linear quantizer to stimulate the system. The behavioral simulation of the integrator is also verified with SPICE. The simulator is fully integrated and standalone. It integrates an input netlist file interpreter, a behavioral simulator, a generic part library and a powerful post-processor to evaluate the SNR, SDR And TSNR. Both passive and active sensitivities can be investigated by the proposed simulator. The simulator is coded in C++, and is very fast

  19. A two-level voltage source inverter with differentially sinusoidal pulse width modulation used in the interconnection system of a wind turbine generator

    Directory of Open Access Journals (Sweden)

    Alexandros C. Charalampidis

    2014-10-01

    Full Text Available This study analyses an interconnection system based on differentially sinusoidal pulse width modulation, used for the interconnection to the grid of a variable speed wind turbine. The modulation technique used provides specific advantages in comparison with the commonly used sinusoidal pulse width modulation (SPWM technique, such as lower DC bus voltage requirements, smaller switching losses for the same switching frequency as well as less higher harmonic content in the voltage waveforms produced. The respective control system is also described in detail. Thus this study provides a guide enabling the design of any interconnection system based on this modulation technique.

  20. Multilevel push pull power converter

    DEFF Research Database (Denmark)

    2007-01-01

    A power converter for converting an input voltage (Vin) into an output voltage (Vout), comprising a first supply potential and a second supply potential established by the input voltage, and at least one primary winding having two terminals, a center tap arranged between the two terminals and con...

  1. A Three-Level Quasi-Two-Stage Single-Phase PFC Converter with Flexible Output Voltage and Improved Conversion Efficiency

    DEFF Research Database (Denmark)

    Tang, Yi; Zhu, Dexuan; Jin, Chi

    2015-01-01

    voltages, and it will be very suitable for high-power applications where the output voltage can be either lower or higher than the peak ac input voltage, e.g., plug-in hybrid electric vehicle charging systems. Moreover, the involved dc/dc buck conversion stage may only need to process partial input power...

  2. Direct evidence that scorpion α-toxins (site-3 modulate sodium channel inactivation by hindrance of voltage-sensor movements.

    Directory of Open Access Journals (Sweden)

    Zhongming Ma

    Full Text Available The position of the voltage-sensing transmembrane segment, S4, in voltage-gated ion channels as a function of voltage remains incompletely elucidated. Site-3 toxins bind primarily to the extracellular loops connecting transmembrane helical segments S1-S2 and S3-S4 in Domain 4 (D4 and S5-S6 in Domain 1 (D1 and slow fast-inactivation of voltage-gated sodium channels. As S4 of the human skeletal muscle voltage-gated sodium channel, hNav1.4, moves in response to depolarization from the resting to the inactivated state, two D4S4 reporters (R2C and R3C, Arg1451Cys and Arg1454Cys, respectively move from internal to external positions as deduced by reactivity to internally or externally applied sulfhydryl group reagents, methane thiosulfonates (MTS. The changes in reporter reactivity, when cycling rapidly between hyperpolarized and depolarized voltages, enabled determination of the positions of the D4 voltage-sensor and of its rate of movement. Scorpion α-toxin binding impedes D4S4 segment movement during inactivation since the modification rates of R3C in hNav1.4 with methanethiosulfonate (CH3SO2SCH2CH2R, where R = -N(CH33 (+ trimethylammonium, MTSET and benzophenone-4-carboxamidocysteine methanethiosulfonate (BPMTS were slowed ~10-fold in toxin-modified channels. Based upon the different size, hydrophobicity and charge of the two reagents it is unlikely that the change in reactivity is due to direct or indirect blockage of access of this site to reagent in the presence of toxin (Tx, but rather is the result of inability of this segment to move outward to the normal extent and at the normal rate in the toxin-modified channel. Measurements of availability of R3C to internally applied reagent show decreased access (slower rates of thiol reaction providing further evidence for encumbered D4S4 movement in the presence of toxins consistent with the assignment of at least part of the toxin binding site to the region of D4S4 region of the voltage

  3. Progress in the structural understanding of voltage-gated calcium channel (CaV) function and modulation.

    Science.gov (United States)

    Minor, Daniel L; Findeisen, Felix

    2010-01-01

    Voltage-gated calcium channels (CaVs) are large, transmembrane multiprotein complexes that couple membrane depolarization to cellular calcium entry. These channels are central to cardiac action potential propagation, neurotransmitter and hormone release, muscle contraction, and calcium-dependent gene transcription. Over the past six years, the advent of high-resolution structural studies of CaV components from different isoforms and CaV modulators has begun to reveal the architecture that underlies the exceptionally rich feedback modulation that controls CaV action. These descriptions of CaV molecular anatomy have provided new, structure-based insights into the mechanisms by which particular channel elements affect voltage-dependent inactivation (VDI), calcium‑dependent inactivation (CDI), and calcium‑dependent facilitation (CDF). The initial successes have been achieved through structural studies of soluble channel domains and modulator proteins and have proven most powerful when paired with biochemical and functional studies that validate ideas inspired by the structures. Here, we review the progress in this growing area and highlight some key open challenges for future efforts.

  4. A PIPO Boost Converter with Low Ripple and Medium Current Application

    Science.gov (United States)

    Bandri, S.; Sofian, A.; Ismail, F.

    2018-04-01

    This paper presents a Parallel Input Parallel Output (PIPO) boost converter is proposed to gain power ability of converter, and reduce current inductors. The proposed technique will distribute current for n-parallel inductor and switching component. Four parallel boost converters implement on input voltage 20.5Vdc to generate output voltage 28.8Vdc. The PIPO boost converter applied phase shift pulse width modulation which will compare with conventional PIPO boost converters by using a similar pulse for every switching component. The current ripple reduction shows an advantage PIPO boost converter then conventional boost converter. Varies loads and duty cycle will be simulated and analyzed to verify the performance of PIPO boost converter. Finally, the unbalance of current inductor is able to be verified on four area of duty cycle in less than 0.6.

  5. Phase-Modulated Nonresonant Laser Pulses Can Selectively Convert Enantiomers in a Racemic Mixture

    DEFF Research Database (Denmark)

    Thomas, Esben Folger; Henriksen, Niels Engholm

    2017-01-01

    -modulated, nonresonant, linearly polarized Gaussian laser pulses that can selectively deracemize a racemic mixture of 3D-oriented, 3,5-difluoro-3',5'-dibromobiphenyl (F2H3C6-C6H3Br2) molecules, the laser-induced dynamics of which are well studied experimentally. These results strongly suggest that designing a closed......Deracemization occurs when a racemic molecular mixture is transformed into a mixture containing an excess of a single enantiomer. Recent advances in ultrafast laser technology hint at the possibility of using shaped pulses to generate deracemization via selective enantiomeric conversion; however......, experimental implementation remains a challenge and has not yet been achieved. Here we suggest a simple, yet novel approach to laser-induced enantiomeric conversion based on dynamic Stark control. We demonstrate theoretically that current laser and optical technology can be used to generate a pair of phase...

  6. Space Vector Modulation for DC-Link Current Ripple Reduction in Back-To-Back Current Source Converters for Microgrid Applications

    DEFF Research Database (Denmark)

    Guo, Xiaoqiang; Xu, David; Guerrero, Josep M.

    2015-01-01

    Back-to-back converters have been typically used to interconnect the microgrids. For a back-to-back current source converter, the dc-link current ripple is one of the important parameters. A large ripple will cause the electromagnetic interference, undesirable high-frequency losses, and system...... instability. Conventionally, with a given switching frequency and rated voltage, the current ripple can be reduced by increasing the dc-link inductor, but it leads to bulky size, high cost and slow dynamic response. In order to solve this problem, this paper reveals that the current ripple can...

  7. Dual-Input Soft-Switched DC-DC Converter with Isolated Current-Fed Half-Bridge and Voltage-Fed Full-Bridge for Fuel Cell or Photovoltaic Systems

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2013-01-01

    integrate a current-fed boost half-bridge (BHB) and a full-bridge (FB) into one equivalent circuit configuration which has dual-input ability and additionally it can reduce the number of the power devices. With the phase-shift control, it can achieve zero-voltage switching turn-on of active switches...... power rating are built up and tested to demonstrate the effectiveness of the proposed converter topology....

  8. Military Curricula for Vocational & Technical Education. Basic Electricity and Electronics Individualized Learning System. CANTRAC A-100-0010. Module Five: Relationships of Current, Voltage, and Resistance. Study Booklet.

    Science.gov (United States)

    Chief of Naval Education and Training Support, Pensacola, FL.

    This individualized learning module on the relationships of current, voltage, and resistance is one in a series of modules for a course in basic electricity and electronics. The course is one of a number of military-developed curriculum packages selected for adaptaticn to vocational instructional and curriculum development in a civilian setting.…

  9. Multirate Formulation for Mismatch Sensitivity Analysis of Analog-to-Digital Converters That Utilize Parallel ΣΔ-Modulators

    Directory of Open Access Journals (Sweden)

    Per Löwenborg

    2008-02-01

    Full Text Available A general formulation based on multirate filterbank theory for analog-to-digital converters using parallel sigmadelta modulators in conjunction with modulation sequences is presented. The time-interleaved modulators (TIMs, Hadamard modulators (HMs, and frequency-band decomposition modulators (FBDMs can be viewed as special cases of the proposed description. The usefulness of the formulation stems from its ability to analyze a system's sensitivity to aliasing due to channel mismatch and modulation sequence level errors. Both Nyquist-rate and oversampled systems are considered, and it is shown how the matching requirements between channels can be reduced for oversampled systems. The new formulation is useful also for the derivation of new modulation schemes, and an example is given of how it can be used in this context.

  10. Dc-To-Dc Converter Uses Reverse Conduction Of MOSFET's

    Science.gov (United States)

    Gruber, Robert P.; Gott, Robert W.

    1991-01-01

    In modified high-power, phase-controlled, full-bridge, pulse-width-modulated dc-to-dc converters, switching devices power metal oxide/semiconductor field-effect transistors (MOSFET's). Decreases dissipation of power during switching by eliminating approximately 0.7-V forward voltage drop in anti-parallel diodes. Energy-conversion efficiency increased.

  11. Ionization asymmetry effects on the properties modulation of atmospheric pressure dielectric barrier discharge sustained by tailored voltage waveforms

    Science.gov (United States)

    Zhang, Z. L.; Nie, Q. Y.; Zhang, X. N.; Wang, Z. B.; Kong, F. R.; Jiang, B. H.; Lim, J. W. M.

    2018-04-01

    The dielectric barrier discharge (DBD) is a promising technology to generate high density and uniform cold plasmas in atmospheric pressure gases. The effective independent tuning of key plasma parameters is quite important for both application-focused and fundamental studies. In this paper, based on a one-dimensional fluid model with semi-kinetics treatment, numerical studies of ionization asymmetry effects on the properties modulation of atmospheric DBD sustained by tailored voltage waveforms are reported. The driving voltage waveform is characterized by an asymmetric-slope fundamental sinusoidal radio frequency signal superimposing one or more harmonics, and the effects of the number of harmonics, phase shift, as well as the fluctuation of harmonics on the sheath dynamics, impact ionization of electrons and key plasma parameters are investigated. The results have shown that the electron density can exhibit a substantial increase due to the effective electron heating by a spatially asymmetric sheath structure. The strategic modulation of harmonics number and phase shift is capable of raising the electron density significantly (e.g., nearly three times in this case), but without a significant increase in the gas temperature. Moreover, by tailoring the fluctuation of harmonics with a steeper slope, a more profound efficiency in electron impact ionization can be achieved, and thus enhancing the electron density effectively. This method then enables a novel alternative approach to realize the independent control of the key plasma parameters under atmospheric pressure.

  12. Modulation of voltage-gated channel currents by harmaline and harmane

    OpenAIRE

    Splettstoesser, Frank; Bonnet, Udo; Wiemann, Martin; Bingmann, Dieter; Büsselberg, Dietrich

    2004-01-01

    Harmala alkaloids are endogenous substances, which are involved in neurodegenerative disorders such as M. Parkinson, but some of them also have neuroprotective effects in the nervous system.While several sites of action at the cellular level (e.g. benzodiazepine receptors, 5-HT and GABAA receptors) have been identified, there is no report on how harmala alkaloids interact with voltage-gated membrane channels.The aim of this study was to investigate the effects of harmaline and harmane on volt...

  13. High Voltage Smart Power Module For Fault-Tolerant Launcher Applications

    Directory of Open Access Journals (Sweden)

    Richard Debrouwere

    2017-01-01

    This paper presents the design of a low cost and highly integrated smart power module (SPM intended to be used into launchers applications, embedding technologies and components from automotive world and being mainly producible by large-scale industry.

  14. Ac-dc converter firing error detection

    International Nuclear Information System (INIS)

    Gould, O.L.

    1996-01-01

    Each of the twelve Booster Main Magnet Power Supply modules consist of two three-phase, full-wave rectifier bridges in series to provide a 560 VDC maximum output. The harmonic contents of the twelve-pulse ac-dc converter output are multiples of the 60 Hz ac power input, with a predominant 720 Hz signal greater than 14 dB in magnitude above the closest harmonic components at maximum output. The 720 Hz harmonic is typically greater than 20 dB below the 500 VDC output signal under normal operation. Extracting specific harmonics from the rectifier output signal of a 6, 12, or 24 pulse ac-dc converter allows the detection of SCR firing angle errors or complete misfires. A bandpass filter provides the input signal to a frequency-to-voltage converter. Comparing the output of the frequency-to-voltage converter to a reference voltage level provides an indication of the magnitude of the harmonics in the ac-dc converter output signal

  15. IGBT Based DC/DC Converter

    Directory of Open Access Journals (Sweden)

    M. Akherraz

    1997-12-01

    Full Text Available This paper presents an in-depth analytical and experimental investigation of an indirect DC-DC converter. The DC-AC conversion is a full bridge based on IGBT power modules, and the AC-DC conversion is done via a high  frequency AC link and a first diode bridge. The AC link, which consists of snubbing capacitors and a variable air-gap transformer, is analytically designed to fulfill Zero Voltage commutation requirement. The proposed converter is simulated using PSPICE and a prototype is designed built and tested in the laboratory. PSPICE simulation and experimental results are presented and compared.

  16. Low-Voltage Ride-Through Operation of Power Converters in Grid-Interactive Microgrids by Using Negative-Sequence Droop Control

    DEFF Research Database (Denmark)

    Zhao, Xin; Guerrero, Josep M.; Savaghebi, Mehdi

    2017-01-01

    of the utility grid during grid faults. In this paper, a LVRT control strategy based on positive/negative sequence droop control is proposed for grid-interactive MGs to ride-through voltage sags with not only inductive/resistive, but also complex line impedance. By using the proposed control strategy, MGs can......Due to the increasing penetration level of microgrids (MGs), it becomes a critical issue for MGs to help sustaining power system stability. Therefore, ancillary services, such as the low-voltage ride-through (LVRT) capability should be incorporated in MGs in order to guarantee stable operation...... support the grid voltage, make profits, and also ride-through the voltage dip during the whole fault period. A two layer hierarchical control strategy is proposed in this paper. The primary controller consists of voltage and current inner loops, a conventional droop control and a virtual impedance loop...

  17. Bidirectional dc-to-dc Power Converter

    Science.gov (United States)

    Griesbach, C. R.

    1986-01-01

    Solid-state, series-resonant converter uses high-voltage thyristors. Converter used either to convert high-voltage, low-current dc power to lowvoltage, high current power or reverse. Taking advantage of newly-available high-voltage thyristors to provide better reliability and efficiency than traditional converters that use vacuum tubes as power switches. New converter essentially maintenance free and provides greatly increased mean time between failures. Attractive in industrial applications whether or not bidirectional capability is required.

  18. A new method for compensation of the effect of charging transformer's leakage inductance on PFN voltage regulation in Klystron pulse modulators

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Akhil, E-mail: akhilpatel@rrcat.gov.in; Kale, Umesh; Shrivastava, Purushottam

    2017-04-21

    The Line type modulators have been widely used to generate high voltage rectangular pulses to power the klystron for high power RF generation. In Line type modulator, the Pulse Forming Network (PFN) which is a cascade combination of lumped capacitors and inductors is used to store the electrical energy. The charged PFN is then discharged into a klystron by firing a high voltage Thyratron switch. This discharge generates a high voltage rectangular pulse across the klystron electrodes. The amplitude and phase of Klystron's RF output is governed by the high voltage pulse amplitude. The undesired RF amplitude and phase stability issues arises at the klystron's output due to inter-pulse and during the pulse amplitude variations. To reduce inter-pulse voltage variations, the PFN is required to be charged at the same voltage after every discharge cycle. At present, the combination of widely used resonant charging and deQing method is used to regulate the pulse to pulse PFN voltage variations but the charging transformer's leakage inductance puts an upper bound on the regulation achievable by this method. Here we have developed few insights of the deQing process and devised a new compensation method to compensate this undesired effect of charging transformer's leakage inductance on the pulse to pulse PFN voltage stability. This compensation is accomplished by the controlled partial discharging of the split PFN capacitor using a low voltage MOSFET switch. Theoretically, very high values of pulse to pulse voltage stability may be achieved using this method. This method may be used in deQing based existing modulators or in new modulators, to increase the pulse to pulse voltage stability, without having a very tight bound on charging transformer's leakage inductance. Given a stable charging power supply, this method may be used to further enhance the inter-pulse voltage stability of modulators which employ the direct charging, after replacing the

  19. Lifetime Estimation of DC-link Capacitors in a Single-phase Converter with an Integrated Active Power Decoupling Module

    DEFF Research Database (Denmark)

    Ma, Siyuan; Wang, Haoran; Tang, Junchaojie

    2016-01-01

    In single-phase inverters, DC-link capacitors are installed at the DC-link to buffer the ripple power between the AC side and DC side. Active decoupling methods introduce additional circuits at the DC side or AC side to partially or fully supply the ripple power. So that the demanded DC-link capa......In single-phase inverters, DC-link capacitors are installed at the DC-link to buffer the ripple power between the AC side and DC side. Active decoupling methods introduce additional circuits at the DC side or AC side to partially or fully supply the ripple power. So that the demanded DC......-link capacitor capacitance can be decreased. However, few research is about the effect of DC side and AC side decoupling on the DC-link capacitor reliability considering its electro-thermal stresses. This paper presents a quantitative analysis on the lifetime of capacitors with power decoupling circuits...... at the DC side and AC side, respectively. The ripple current spectrum of the capacitors is obtained by double Fourier analysis of a H-bridge inverter with natural sampling PWM modulation. A study case is demonstrated by a 2,000 W H-bridge inverter with 400 V DC-link voltage....

  20. Characteristic Analysis and Fault-Tolerant Control of Circulating Current for Modular Multilevel Converters under Sub-Module Faults

    Directory of Open Access Journals (Sweden)

    Wen Wu

    2017-11-01

    Full Text Available A modular multilevel converter (MMC is considered to be a promising topology for medium- or high-power applications. However, a significantly increased amount of sub-modules (SMs in each arm also increase the risk of failures. Focusing on the fault-tolerant operation issue for the MMC under SM faults, the operation characteristics of MMC with different numbers of faulty SMs in the arms are analyzed and summarized in this paper. Based on the characteristics, a novel circulating current-suppressing (CCS fault-tolerant control strategy comprised of a basic control unit (BCU and virtual resistance compensation control unit (VRCCU in two parts is proposed, which has three main features: (i it can suppress the multi-different frequency components of the circulating current under different SM fault types simultaneously; (ii it can help fast limiting of the transient fault current caused at the faulty SM bypassed moment; and (iii it does not need extra communication systems to acquire the information of the number of faulty SMs. Moreover, by analyzing the stability performance of the proposed controller using the Root-Locus criterion, the election principle of the value of virtual resistance is revealed. Finally, the efficiency of the control strategy is confirmed with the simulation and experiment studies under different fault conditions.

  1. Precharge strategies for isolated modular DC-DC converters under two different start-up conditions

    DEFF Research Database (Denmark)

    Zhang, Yi; Wang, Huai; Li, Binbin

    2017-01-01

    The isolated modular DC-DC converter (IMDCC) is a new topology designed to connect high-voltage direct current (HVDC) lines with different voltage levels, which ties two DC grids by using two modular multilevel converters (MMCs) via a medium-frequency transformer. Due to the large value of capaci......The isolated modular DC-DC converter (IMDCC) is a new topology designed to connect high-voltage direct current (HVDC) lines with different voltage levels, which ties two DC grids by using two modular multilevel converters (MMCs) via a medium-frequency transformer. Due to the large value...... of capacitance in the IMDCC, proper precharge strategies before the start-up are significant for the safety and reliability of the whole system. This paper presents two closed-loop precharge control strategies to fully charge the sub-module (SM) capacitors of the IMDCC, considering two different start...

  2. A Hybrid Cascade Converter Topology With Series-Connected Symmetrical and Asymmetrical Diode-Clamped H-Bridge Cells

    DEFF Research Database (Denmark)

    Nami, Alireza; Zare, Firuz; Ghosh, Arindam

    2011-01-01

    to approach a very low total harmonic distortion of voltage and current, which leads to the possible elimination of the output filter. Regarding the proposed configuration, a new cascade inverter is verified by cascading an asymmetrical diode-clamped inverter, in which 19 levels can be synthesized in output......A novel H-bridge multilevel pulsewidth modulation converter topology based on a series connection of a high-voltage diode-clamped inverter and a low-voltage conventional inverter is proposed in this paper. A dc link voltage arrangement for the new hybrid and asymmetric solution is presented to have...... voltage with the same number of components. To balance the dc link capacitor voltages for the maximum output voltage resolution as well as synthesize asymmetrical dc link combination, a new multi-output boost converter is utilized at the dc link voltage of a seven-level H-bridge diode-clamped inverter...

  3. Assessment of an Average Controller for a DC/DC Converter via Either a PWM or a Sigma-Delta-Modulator

    Directory of Open Access Journals (Sweden)

    R. Silva-Ortigoza

    2014-01-01

    Full Text Available Sliding mode control is a discontinuous control technique that is, by its nature, appropriate for controlling variable structure systems, such as the switch regulated systems employed in power electronics. However, when designing control laws based on the average models of these systems a modulator is necessary for their experimental implementation. Among the most widely used modulators in power electronics are the pulse width modulation (PWM and, more recently, the sigma-delta-modulator (Σ-Δ-modulator. Based on the importance of achieving an appropriate implementation of average control laws and the relevance of the trajectory tracking task in DC/DC power converters, for the first time, this research presents the assessment of the experimental results obtained when one of these controllers is implemented through either a PWM or a Σ-Δ-modulator to perform such a task. A comparative assessment based on the integral square error (ISE index shows that, at frequencies with similar efficiency, the Σ-Δ-modulator provides a better tracking performance for the DC/DC Buck converter. In this paper, an average control based on differential flatness was used to perform the experiments. It is worth mentioning that a different trajectory tracking controller could have been selected for this research.

  4. Resistive switching and voltage induced modulation of tunneling magnetoresistance in nanosized perpendicular organic spin valves

    Directory of Open Access Journals (Sweden)

    Robert Göckeritz

    2016-04-01

    Full Text Available Nanoscale multifunctional perpendicular organic spin valves have been fabricated. The devices based on an La0.7Sr0.3MnO3/Alq3/Co trilayer show resistive switching of up to 4-5 orders of magnitude and magnetoresistance as high as -70% the latter even changing sign when voltage pulses are applied. This combination of phenomena is typically observed in multiferroic tunnel junctions where it is attributed to magnetoelectric coupling between a ferromagnet and a ferroelectric material. Modeling indicates that here the switching originates from a modification of the La0.7Sr0.3MnO3 surface. This modification influences the tunneling of charge carriers and thus both the electrical resistance and the tunneling magnetoresistance which occurs at pinholes in the organic layer.

  5. Simulated potential for enhanced performance of mechanically stacked hybrid III-V/Si tandem photovoltaic modules using DC-DC converters

    Science.gov (United States)

    MacAlpine, Sara; Bobela, David C.; Kurtz, Sarah; Lumb, Matthew P.; Schmieder, Kenneth J.; Moore, James E.; Walters, Robert J.; Alberi, Kirstin

    2017-10-01

    This work examines a tandem module design with GaInP2 mechanically stacked on top of crystalline Si, using a detailed photovoltaic (PV) system model to simulate four-terminal (4T) unconstrained and two-terminal voltage-matched (2T VM) parallel architectures. Module-level power electronics is proposed for the 2T VM module design to enhance its performance over the breadth of temperatures experienced by a typical PV installation. Annual, hourly simulations of various scenarios indicate that this design can reduce annual energy losses to ˜0.5% relative to the 4T module configuration. Consideration is given to both performance and practical design for building or ground mount installations, emphasizing compatibility with existing standard Si modules.

  6. Voltage balancing: Long-term experience with the 250 V supercapacitor module of the hybrid fuel cell vehicle HY-LIGHT

    Energy Technology Data Exchange (ETDEWEB)

    Koetz, R.; Sauter, J.-C.; Ruch, P.; Dietrich, P.; Buechi, F.N. [Paul Scherrer Institut, Electrochemistry Laboratory, CH-5232 Villigen PSI (Switzerland); Magne, P.A.; Varenne, P. [Conception et Developpement Michelin SA, CH-1762 Givisiez (Switzerland)

    2007-11-22

    On the occasion of the ''Challenge Bibendum'' 2004 in Shanghai, the hybrid fuel cell - supercapacitor vehicle HY-LIGHT, a joint project of Conception et Developpement Michelin and the Paul Scherrer Institut, was presented to the public. The drive train of this vehicle comprises a 30 kW polymer electrolyte fuel cell (PEFC) and a 250 V supercapacitor (SC) module for energy recuperation and boost power during short acceleration and start-up processes. The supercapacitor module was deliberately constructed without continuous voltage balancing units. The performance of the supercapacitor module was monitored over the 2 years of operation particularly with respect to voltage balancing of the large number of SC cells connected in series. During the investigated period of 19 months and about 7000 km driving, the voltage imbalance within the supercapacitor module proved negligible. The maximum deviation between best and worst SC was always below 120 mV and the capacitor with the highest voltage never exceeded the nominal voltage by more than 40 mV. (author)

  7. Stackable configurations of artificial muscle modules that is continuously-tunable by voltage

    Science.gov (United States)

    Khanh, Vo Tran Vy; Mathew, Anup Teejo; Koh, Soo Jin Adrian

    2017-04-01

    We present a stackable configuration of loudspeaker-type artificial muscle module. These modules are antagonisticallycoupled to enhance the delivery of blocking force and speed of deformation. We analyze a cycle of antagonisticallycouple configuration by theory, and maximize the cycle of the antagonistically-coupled loudspeaker configuration using a semi-empirical method. We realize an output force of about 4N for a single layer, and up to 15N for three stacked layers. The corresponding displacement at maximum actuation is about 10mm. We further introduce a control circuit to enhance output mechanical power of the cycle. This work serves to rationalize the analysis, design and construction of soft actuator systems capable of delivering high mechanical power output within a small space.

  8. DC-based smart PV-powered home energy management system based on voltage matching and RF module

    Science.gov (United States)

    Hasan, W. Z. W.

    2017-01-01

    The main tool for measuring system efficiency in homes and offices is the energy monitoring of the household appliances’ consumption. With the help of GUI through a PC or smart phone, there are various applications that can be developed for energy saving. This work describes the design and prototype implementation of a wireless PV-powered home energy management system under a DC-distribution environment, which allows remote monitoring of appliances’ energy consumptions and power rate quality. The system can be managed by a central computer, which obtains the energy data based on XBee RF modules that access the sensor measurements of system components. The proposed integrated prototype framework is characterized by low power consumption due to the lack of components and consists of three layers: XBee-based circuit for processing and communication architecture, solar charge controller, and solar-battery-load matching layers. Six precise analogue channels for data monitoring are considered to cover the energy measurements. Voltage, current and temperature analogue signals were accessed directly from the remote XBee node to be sent in real time with a sampling frequency of 11–123 Hz to capture the possible surge power. The performance shows that the developed prototype proves the DC voltage matching concept and is able to provide accurate and precise results. PMID:28934271

  9. DC-based smart PV-powered home energy management system based on voltage matching and RF module.

    Directory of Open Access Journals (Sweden)

    Ahmad H Sabry

    Full Text Available The main tool for measuring system efficiency in homes and offices is the energy monitoring of the household appliances' consumption. With the help of GUI through a PC or smart phone, there are various applications that can be developed for energy saving. This work describes the design and prototype implementation of a wireless PV-powered home energy management system under a DC-distribution environment, which allows remote monitoring of appliances' energy consumptions and power rate quality. The system can be managed by a central computer, which obtains the energy data based on XBee RF modules that access the sensor measurements of system components. The proposed integrated prototype framework is characterized by low power consumption due to the lack of components and consists of three layers: XBee-based circuit for processing and communication architecture, solar charge controller, and solar-battery-load matching layers. Six precise analogue channels for data monitoring are considered to cover the energy measurements. Voltage, current and temperature analogue signals were accessed directly from the remote XBee node to be sent in real time with a sampling frequency of 11-123 Hz to capture the possible surge power. The performance shows that the developed prototype proves the DC voltage matching concept and is able to provide accurate and precise results.

  10. DC-based smart PV-powered home energy management system based on voltage matching and RF module.

    Science.gov (United States)

    Sabry, Ahmad H; Hasan, W Z W; Ab Kadir, Mza; Radzi, M A M; Shafie, S

    2017-01-01

    The main tool for measuring system efficiency in homes and offices is the energy monitoring of the household appliances' consumption. With the help of GUI through a PC or smart phone, there are various applications that can be developed for energy saving. This work describes the design and prototype implementation of a wireless PV-powered home energy management system under a DC-distribution environment, which allows remote monitoring of appliances' energy consumptions and power rate quality. The system can be managed by a central computer, which obtains the energy data based on XBee RF modules that access the sensor measurements of system components. The proposed integrated prototype framework is characterized by low power consumption due to the lack of components and consists of three layers: XBee-based circuit for processing and communication architecture, solar charge controller, and solar-battery-load matching layers. Six precise analogue channels for data monitoring are considered to cover the energy measurements. Voltage, current and temperature analogue signals were accessed directly from the remote XBee node to be sent in real time with a sampling frequency of 11-123 Hz to capture the possible surge power. The performance shows that the developed prototype proves the DC voltage matching concept and is able to provide accurate and precise results.

  11. A single-phase PWM controlled AC to DC converter based on control of unity displacement power factor

    OpenAIRE

    Funabiki, Shigeyuki

    1990-01-01

    A modified pulse-width modulation (PWM) technique that improves the displacement power factor and the input power factor of a single-phase AC to DC converter is discussed. The modified converter is shown to have a high input power factor and allows the of DC voltage from zero to more than the maximum value of the source voltage. The displacement power factor is unity, and the input power factor is almost unity in the wide range of current command

  12. X-Y Converter Family

    DEFF Research Database (Denmark)

    Bhaskar, Mahajan Sagar; Sanjeevikumar, Padmanaban; Wheeler, Patrick

    2016-01-01

    A New breed of a buck boost converter, named as the XY converter family is proposed in this article. In the XY family, 16 topologies are presented which are highly suitable for renewable energy applications which require a high ratio of DC-DC converter; such as a photovoltaic multilevel inverter...... system, high voltage automotive applications and industrial drives. Compared to the traditional boost converter and existing recent converters, the proposed XY converter family has the ability to provide a higher output voltage by using less number of power devices and reactive components. Other distinct...... features of the XY converter family are i) Single control switch ii) Provide negative output voltage iii) Non-isolated topologies iv) High conversion ratio without making the use of high duty cycle and v) modular structure. XY family is compared with the recent high step-up converters and the detailed...

  13. Model and control of the isolated multi-modular converter

    DEFF Research Database (Denmark)

    Verdugo, Cristian; Candela, Jose Ignacio; Blaabjerg, Frede

    2017-01-01

    Multi-modular converters have proven to be one of the most suitable topology to be used in high and power applications. The modularity of these configurations offer several advantages, such as: high quality voltage, redundancy and high efficiency. In these converters, the series connection...... voltages. However, increasing the number of conversion stages, increase also the losses and the implementation costs. In order to overcome these drawbacks, a new configuration of multi-modular converter is proposed in this paper. The proposed converter provides isolation with one conversion stage by means...... of using low frequency transformers in each module. The main principle behind this concept, the control structure and simulation results are presented to validate the proposed configuration....

  14. Collector modulation in high-voltage bipolar transistor in the saturation mode: Analytical approach

    Science.gov (United States)

    Dmitriev, A. P.; Gert, A. V.; Levinshtein, M. E.; Yuferev, V. S.

    2018-04-01

    A simple analytical model is developed, capable of replacing the numerical solution of a system of nonlinear partial differential equations by solving a simple algebraic equation when analyzing the collector resistance modulation of a bipolar transistor in the saturation mode. In this approach, the leakage of the base current into the emitter and the recombination of non-equilibrium carriers in the base are taken into account. The data obtained are in good agreement with the results of numerical calculations and make it possible to describe both the motion of the front of the minority carriers and the steady state distribution of minority carriers across the collector in the saturation mode.

  15. Mutagenesis in mammalian cells can be modulated by radiation-induced voltage-dependent potassium channels

    International Nuclear Information System (INIS)

    Saad, A.H.; Zhou, L.Y.; Lambe, E.K.; Hahn, G.M.

    1994-01-01

    In mammalian cells, little is known about the initial events whose ultimate consequence is mutagenesis or DNA repair. The role the plasma membrane may play as an initiator of such a pathway is not understood. We show, for the first time, that membrane voltage-dependent potassium (K + ) currents, activated by ionizing radiation play a significant role in radiation mutagenesis. Specifically, we show that the frequency of mutation at the HGPRT locus is increased as expected to 37.6±4.0 mutations per 100,000 survivors by 800 cGy of ionizing radiation from a spontaneous frequency of 1.5±1.5. This increase, however, is abolished if either K + channel blocker, CsCl or BaCl 2 , is present for 2h following irradiation of the cells. RbCl, chemically similar to CsCl but known not to block K + channels, is ineffective in reducing the mutation frequency. Treatment of cells with CsCl or BaCl 2 had no effect on radiation-induced cell killing

  16. Simulation comparison of proportional integral derivative and fuzzy logic in controlling AC-DC buck boost converter

    Science.gov (United States)

    Faisal, A.; Hasan, S.; Suherman

    2018-03-01

    AC-DC converter is widely used in the commercial industry even for daily purposes. The AC-DC converter is used to convert AC voltage into DC. In order to obtain the desired output voltage, the converter usually has a controllable regulator. This paper discusses buck boost regulator with a power MOSFET as switching component which is adjusted based on the duty cycle of pulse width modulation (PWM). The main problems of the buck boost converter at start up are the high overshoot, the long peak time and rise time. This paper compares the effectiveness of two control techniques: proportional integral derivative (PID) and fuzzy logic control in controlling the buck boost converter through simulations. The results show that the PID is more sensitive to voltage change than fuzzy logic. However, PID generates higher overshoot, long peak time and rise time. On the other hand, fuzzy logic generates no overshoot and shorter rise time.

  17. The Sensorless Pore Module of Voltage-gated K+ Channel Family 7 Embodies the Target Site for the Anticonvulsant Retigabine.

    Science.gov (United States)

    Syeda, Ruhma; Santos, Jose S; Montal, Mauricio

    2016-02-05

    KCNQ (voltage-gated K(+) channel family 7 (Kv7)) channels control cellular excitability and underlie the K(+) current sensitive to muscarinic receptor signaling (the M current) in sympathetic neurons. Here we show that the novel anti-epileptic drug retigabine (RTG) modulates channel function of pore-only modules (PMs) of the human Kv7.2 and Kv7.3 homomeric channels and of Kv7.2/3 heteromeric channels by prolonging the residence time in the open state. In addition, the Kv7 channel PMs are shown to recapitulate the single-channel permeation and pharmacological specificity characteristics of the corresponding full-length proteins in their native cellular context. A mutation (W265L) in the reconstituted Kv7.3 PM renders the channel insensitive to RTG and favors the conductive conformation of the PM, in agreement to what is observed when the Kv7.3 mutant is heterologously expressed. On the basis of the new findings and homology models of the closed and open conformations of the Kv7.3 PM, we propose a structural mechanism for the gating of the Kv7.3 PM and for the site of action of RTG as a Kv7.2/Kv7.3 K(+) current activator. The results validate the modular design of human Kv channels and highlight the PM as a high-fidelity target for drug screening of Kv channels. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Effects of synchronous irradiance monitoring and correction of current-voltage curves on the outdoor performance measurements of photovoltaic modules

    Science.gov (United States)

    Hishikawa, Yoshihiro; Doi, Takuya; Higa, Michiya; Ohshima, Hironori; Takenouchi, Takakazu; Yamagoe, Kengo

    2017-08-01

    Precise outdoor measurement of the current-voltage (I-V) curves of photovoltaic (PV) modules is desired for many applications such as low-cost onsite performance measurement, monitoring, and diagnosis. Conventional outdoor measurement technologies have a problem in that their precision is low when the solar irradiance is unstable, hence, limiting the opportunity of precise measurement only on clear sunny days. The purpose of this study is to investigate an outdoor measurement procedure, that can improve both the measurement opportunity and precision. Fast I-V curve measurements within 0.2 s and synchronous measurement of irradiance using a PV module irradiance sensor very effectively improved the precision. A small standard deviation (σ) of the module’s maximum output power (P max) in the range of 0.7-0.9% is demonstrated, based on the basis of a 6 month experiment, that mainly includes partly sunny days and cloudy days, during which the solar irradiance is unstable. The σ was further improved to 0.3-0.5% by correcting the curves for the small variation of irradiance. This indicates that the procedure of this study enables much more reproducible I-V curve measurements than a conventional usual procedure under various climatic conditions. Factors that affect measurement results are discussed, to further improve the precision.

  19. High voltage photo-switch package module having encapsulation with profiled metallized concavities

    Science.gov (United States)

    Sullivan, James S; Sanders, David M; Hawkins, Steven A; Sampayan, Stephen A

    2015-05-05

    A photo-conductive switch package module having a photo-conductive substrate or wafer with opposing electrode-interface surfaces metalized with first metallic layers formed thereon, and encapsulated with a dielectric encapsulation material such as for example epoxy. The first metallic layers are exposed through the encapsulation via encapsulation concavities which have a known contour profile, such as a Rogowski edge profile. Second metallic layers are then formed to line the concavities and come in contact with the first metal layer, to form profiled and metalized encapsulation concavities which mitigate enhancement points at the edges of electrodes matingly seated in the concavities. One or more optical waveguides may also be bonded to the substrate for coupling light into the photo-conductive wafer, with the encapsulation also encapsulating the waveguides.

  20. Multi-functional Converter with Integrated Motor Control, Battery Charging and Active Module Balancing for Electric Vehicular Application

    DEFF Research Database (Denmark)

    Mathe, Laszlo; Schaltz, Erik; Teodorescu, Remus

    2014-01-01

    , weight and volume in comparison with other Li-Ion based chemistries. The control of the energy flow has been done through a Modular Multilevel Converter (MMC), which has demonstrated advantages over 2 level converters in terms of efficiency, fault tolerant operation, flexible operation modes. It has been...