DEFF Research Database (Denmark)
Blaabjerg, Frede; Aquila, A. Dell; Liserre, Marco;
2004-01-01
A systematic approach to study dc/ac and ac/dc converters without the use of synchronous transformation is proposed. The use of a frequency-shift technique allows a straightforward analysis of single-phase and three-phase systems. The study of dc/ac and of ac/dc converters is reported to the study...... of dc/dc converters via a 50 Hz frequency-shift. The input admittance is calculated and measured for two study examples (a three-phase active rectifier and a single-phase photovoltaic inverter). These examples show that the purpose of a well designed controller for grid-connected converters...
Phase controlled dc-ac converter with high frequency switching
Harada, Koosuke; Sakamoto, Hiroshi; Shoyama, Masahito
A sinusoidal dc-ac converter is presented in which a pair of switches is placed on each side of the primary and secondary of the isolation transformer. This converter is controlled by the phase difference between the two pairs of switches. The transformer is miniaturized by making the switching frequency high. This converter is especially suitable for small uninterruptible power supply systems.
Isolated PDM and PWM DC-AC SICAMs[Pulse Density Modulated; Pulse Width Modulated
Energy Technology Data Exchange (ETDEWEB)
Ljusev, P.
2004-03-15
In this report a class of isolated PDM and PWM DC-AC SICAMs is described, which introduce the audio reference only in the output stage. AC-DC power supply is implemented in its simplest form: diode rectifier followed by a medium-size charge-storage capacitor. Isolation from the AC mains is achieved using a high frequency (HF) transformer, receiving the HF voltage pulses from the input 'inverter' stage and transferring them to the output 'rectifier+inverter' stage, which can use either PDM or PWM. The latter stage is then interfaced to the load using an output low-pass filter. Each of the dedicated stages is discussed in detail. Measurements on the master/slave PWM DC-AC SICAM prototype are presented to help benchmarking the performance of this class of SICAMs and identify the advantages and drawbacks. (au)
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...
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)
DOUBLE-BOOST DC-AC CONVERTER WITH SLIDING-MODE CONTROL FOR PORTABLE AUDIO
DEFF Research Database (Denmark)
Bolten Maizonave, Gert; Andersen, Michael Andreas E.; Kjærgaard, Claus
2009-01-01
The double-boost topology is studied for operation as a dc-ac converter and single stage audio amplifier. A sliding-mode controller is designed in order to achieve fast enough response for the whole audio frequency range. Symmetric, asymmetric and interleaved operation modes are analyzed....
"Assessment of Potentially-Efficient DC-AC Converter Architectures"
Energy Technology Data Exchange (ETDEWEB)
Chapman, Jamie
2004-04-29
Two alternate and potentially-efficient power electronic architectures are assessed and compared with a conventional, three-phase, voltage-source converter. The comparisons are in terms of a 750 kVA converter as might be used with a variable-speed wind turbine or a photovoltaic array, The two architectures are projected to cost 1.15 and 1.39 times the comparable (factory) cost of the conventional system. However the present value of the recovered energy stream may justify the added cost.
"Assessment of Potentially-Efficient DC-AC Converter Architectures"
Energy Technology Data Exchange (ETDEWEB)
Chapman, Jamie
2004-04-29
Two alternate and potentially-efficient power electronic architectures are assessed and compared with a conventional, three-phase, voltage-source converter. The comparisons are in terms of a 750 kVA converter as might be used with a variable-speed wind turbine or a photovoltaic array, The two architectures are projected to cost 1.15 and 1.39 times the comparable (factory) cost of the conventional system. However the present value of the recovered energy stream may justify the added cost.
Optimization Control of Bidirectional Cascaded DC-AC Converter Systems
DEFF Research Database (Denmark)
Tian, Yanjun
in different power flow directions, a bidirectional impedance control method is also proposed to unify and improve the system stability. Control system type number is also analyzed in this thesis, then a symmetric proportional control method for the two stage cascaded converter is proposed to reduce the dc...
Implementation and Control of an AC/DC/AC Converter for Double Wound Flywheel Application
Directory of Open Access Journals (Sweden)
J. G. Oliveira
2012-01-01
Full Text Available An all-electric driveline based on a double wound flywheel, connected in series between main energy storage and a wheel motor, is presented. The flywheel works as a power buffer, allowing the battery to deliver optimized power. It also separates electrically the system in two sides, with the battery connected to the low voltage side and the wheel motor connected to the high voltage side. This paper presents the implementation and control of the AC/DC/AC converter, used to connect the flywheel high voltage windings to the wheel motor. The converter general operation and the adopted control strategy are discussed. The implementation of the AC/DC/AC converter has been described from a practical perspective. Results from experimental tests performed in the full-system prototype are presented. The prototype system is running with satisfactory stability during acceleration mode. Good efficiency and unity power factor could be achieved, based on vector control and space vector modulation.
A new DC/AC boost transformerless converter in application of photovoltaic power generation
DEFF Research Database (Denmark)
Wei, Mo; Loh, Poh Chiang; Blaabjerg, Frede
2011-01-01
This paper presents a new DC/AC boost transformerless converter in the applications of photovoltaic (PV) power generation. A new circuit topology of single phase full bridge power inverter with additional DC/DC boost stage is proposed. The proposed topology overcomes two commonly existing...... shortcomings of transformerless PV system: namely one, the voltage generated sometimes low and insufficient to fulfill the load requirement; and two, there always leakage current flowing through parasitic capacitance between PV panel and ground. This configuration helps to boost the voltage at the PV side...
Converter DC/AC Multilevel of Three Cells: Modeling and Simulation
Directory of Open Access Journals (Sweden)
Julián Peláez-Restrepo
2013-11-01
Full Text Available This paper presents a three-cell converter DC / AC. Multilevel topologies are attracting attention in the industry, obtained as a ripple on the state variables much smaller, and reduces stress on the switching devices. The topology used in this work is known in the technical literature as floating capacitor multilevel inverter, which imposes the challenge of balancing the voltage across each cell switching using floating capacitors, besides obtaining a sinusoidal signal regulated. The paper presents the averaged model of the inverter, and results obtained through simulation.
Three-Level AC-DC-AC Z-Source Converter Using Reduced Passive Component Count
DEFF Research Database (Denmark)
Loh, Poh Chiang; Gao, Feng; Tan, Pee-Chin;
2007-01-01
This paper presents a three-level ac-dc-ac Z-source converter with output voltage buck-boost capability. The converter is implemented by connecting a low cost front-end diode rectifier to a neutral-point-clamped inverter through a single X-shaped LC impedance network. The inverter is controlled...... to switch with a three-level output voltage, where the middle neutral potential is uniquely tapped from the star-point of a wye-connected capacitive filter placed before the front-end diode rectifier for input current filtering. Through careful control, the resulting converter can accurately produce...... the correct volt-sec average at its output, while simultaneously achieving inductive voltage boosting. More interestingly, these performance features are achieved with no increase in the number of semiconductor commutations, and hence no increase in switching losses. The proposed converter therefore offers...
Chen, Juan
2008-01-01
This report is the result of a Master Thesis work done at Seaward Electronics Inc. in Beijing, China from June to December in 2007. The main goal for this thesis is to verify and improve the performance of Honey-PWM DC-DC converter, which has been fabricated by a standard 0.6um CMOS processes. The project was started with studying of Buck converter structure. After the understanding of the converter structure, the project goes in to the analyses phase for each sub-cells, including the theory,...
DEFF Research Database (Denmark)
Poulsen, Søren; Andersen, Michael Andreas E.
2004-01-01
This paper proposes a novel control topology for a mains isolated single conversion audio amplifier and DC-AC converters. The topology is made for use in audio applications, and differs from prior art in terms of significantly reduced distortion as well as lower system complexity. The topology can...
PWM Converter Power Density Barriers
Kolar, Johann W.; Drofenik, Uwe; Biela, Juergen; Heldwein, Marcelo; Ertl, Hans; Friedli, Thomas; Round, Simon
Power density of power electronic converters has roughly doubled every 10 years since 1970. Behind this trajectory is the continuous advancement of power semiconductor devices, which has increased the converter switching frequencies by a factor of 10 every decade. However, today's cooling concepts and passive components are major barriers for a continuation of this trend. To identify such technological barriers, this paper investigates the volume of the cooling system and passive components as a function of the switching frequency for power electronic converters and determines the switching frequency that minimizes the total volume. A power density limit of 28kW/dm3 at 300kHz is calculated for an isolated DC-DC converter, 44kW/dm3 at 820kHz for a three-phase unity power factor PWM rectifier, and 26kW/dm3 at 21kHz for a sparse matrix converter. For single-phase AC-DC conversion a general limit of 35kW/dm3 results from the DC link capacitor. These power density limits highlight the need to broaden the scope of power electronics research to include cooling systems, high frequency electromagnetics, interconnection and packaging technology, and multi-domain modelling and simulation to ensure further advancement along the power density trajectory.
DEFF Research Database (Denmark)
Qin, Zian; Loh, Poh Chiang; Blaabjerg, Frede
2015-01-01
ulation schemes can significantly change the performance of a power converter in steady state, and they have been extensively studied, but mostly directed to three-phase topologies, where triplen offsets are added. Single-phase systems, including ac-dc-ac systems, are less widely pursued, even...... among their switches, while keeping their dc-link voltages low. Single points of failure are thus minimized, allowing the converters to have longer lifetimes. Simulation and experimental results have demonstrated the intended performances and hence verifying the idea....
Integrated PWM converter/inverter system feeding three-phase induction motor
Energy Technology Data Exchange (ETDEWEB)
Bayoumi, E.
2001-07-01
The integrated PWM converter/inverter system has the capability of unity power factor, sinusoidal supply current, bi-directional power capabilities and constant dc link voltage. Also, it has the ability to minimize the dc link capacitance. The integrated PWM converter/inverter fed three-phase induction motor consists of two identical PWM converters. One is used to serve as power regulator with unity power factor and constant dc voltage bus, while the other serve as inverter for the induction motor drive. By using the synchronous rotating-frame the current controllers in both the input and the output of the integrated system are characterized by fast current response and low harmonic distortion. The dc link is the intermediate stage between the PWM converter and the PWM inverter. It mainly consists of aluminium electrolytic capacitors, which are normally installed in the system as the energy storage element, but in some applications, such as high power voltage motor drives, the electrolytic capacitor has several drawbacks from the viewpoints of size, weight, cost and reliability. Due to continuous outgassing, the properties of the electrolytic capacitor deteriorate gradually (as time goes by). Hence, the capacitor is the major factor limiting the lifetime of the inverter systems. The aim of this work is to reduce the dc link capacitor size, as it means reduction of the cost and the volume of the converter/inverter systems. The work consists of 8 chapters: Chapter one illustrate the historical overview for the ac/dc/ac fed induction motor drive systems. It describes the benefits of the integrated PWM converter/inverter fed induction motor drive. It classified the integrated PWM converter/inverter systems into two types independent and dependent systems. It demonstrates some ideas for the control algorithms of these types of integrated systems. Chapter two introduces the mathematical model for the PWM converter. It explains the space vector PWM (SVPWM) method for
Wind-powered asynchronous AC/DC/AC converter system. [for electric power supply regulation
Reitan, D. K.
1973-01-01
Two asynchronous ac/dc/ac systems are modelled that utilize wind power to drive a variable or constant hertz alternator. The first system employs a high power 60-hertz inverter tie to the large backup supply of the power company to either supplement them from wind energy, storage, or from a combination of both at a preset desired current; rectifier and inverter are identical and operate in either mode depending on the silicon control rectifier firing angle. The second system employs the same rectification but from a 60-hertz alternator arrangement; it provides mainly dc output, some sinusoidal 60-hertz from the wind bus and some high harmonic content 60-hertz from an 800-watt inverter.
DEFF Research Database (Denmark)
Tian, Yanjun; Chen, Zhe; Deng, Fujin;
2015-01-01
Two stage cascaded converters are widely used in DC/AC hybrid systems to achieve the bidirectional power transmission. The topology of dual active bridge cascaded with inverter (DABCI) is commonly used in this application. This paper proposes a coordinative control method for DABCI and it’s able...... to reduce the DC-link voltage fluctuation between the DAB and inverter, then reduce the stress on the switching devices, as well as improve the system dynamic performance. In the proposed control method, the DAB and inverter are coordinated to control the DC-link voltage and the power......, and this responsibility sharing control can effectively suppress the impact of the power variation on the DC-link voltage, without sacrificing stability. The proposed control method is also effective for DABCI in unidirectional power transmission. The effectiveness of the propose control has been validated by both...
Large-signal stability analysis of PWM converters
Energy Technology Data Exchange (ETDEWEB)
Huynh, P.T. [Philips Labs., Briarcliff Manor, NY (United States); Cho, B.H. [Seoul National Univ. (Korea, Republic of). Dept. of Electrical Engineering
1995-12-31
Investigation of the effects of existing nonlinearities on the stability of PWM converters is performed. The bilinear structure, the duty cycle saturation, and the opamp saturation are the principal nonlinearities in PWM converters. These nonlinearities are incorporated in the large-signal analytical models of PWM converters, and the basic input-output stability theory is applied to analyze their stability. Design and optimization of the small-signal loop gains to counteract the undesirable nonlinear effects are also discussed.
Improved Design Methods for Robust Single- and Three-Phase ac-dc-ac Power Converters
DEFF Research Database (Denmark)
Qin, Zian
becomes a emerging challenge. Accordingly, installation of sustainable power generators like wind turbines and solar panels has experienced a large increase during the last decades. Meanwhile, power electronics converters, as interfaces in electrical system, are delivering approximately 80 % electricity...
Mohammed, K. G.; Ramli, A. Q.; Amirulddin, U. A. U.
2013-06-01
This paper proposes the design of a new bi-directional DC-AC rotary converter machine to convert a d.c. voltage to three-phase voltage and vice-versa using a two-stage energy conversion machine. The rotary converter consists of two main stages which are combined into single frame. These two stages are constructed from three main electromagnetic components. The first inner electromagnetic component represents the input stage that enables the DC power generated by solar energy from photo-voltaic cells to be transformed by the second and third components electro-magnetically to produce multi-phase voltages at the output stage. At the same time, extra kinetic energy from wind, which is sufficiently available, can be added to existing torque on the second electromagnetic component. Both of these input energies will add up to the final energy generated at the output terminals. Therefore, the machine will be able to convert solar and wind energies to the output terminals simultaneously. If the solar energy is low, the available wind energy will be able to provide energy to the output terminals and at the same time charges the batteries which are connected as backup system. At this moment, the machine behaves as wind turbine. The energy output from the machine benefits from two energy sources which are solar and wind. At night when the solar energy is not available and also the load is low, the wind energy is able to charge the batteries and at the same time provides output electrical power to the remaining the load. Therefore, the proposed system will have high usage of available renewable energy as compared to separated wind or solar systems. MATLAB codes are used to calculate the required dimensions, the magnetic and electrical circuits parameters to design of the new bi-directional rotary converter machine.
DEFF Research Database (Denmark)
Qin, Zian; Loh, Poh Chiang; Blaabjerg, Frede
2015-01-01
. With the SVPWM or DPWM proposed in literatures, the generation of the references is phase voltage based. But the phase voltages actually cannot be controlled directly by the PWM converter, since they can be influenced by both of terminal voltages and the load network while the PWM converter can only control...
Three-Level AC-DC-AC Z-Source Converter Using Reduced Passive Component Count
DEFF Research Database (Denmark)
Loh, Poh Chiang; Gao, Feng; Tan, Pee-Chin;
2009-01-01
to switch with a three-level output voltage, where the middle neutral potential is uniquely tapped from the star-point of a wye-connected capacitive filter placed before the front-end diode rectifier for input current filtering. Through careful control, the resulting converter can produce the correct volt......-second average at its output, while simultaneously achieving inductive voltage boosting by shooting through either an appropriately selected inverter phase-leg or two phase-legs being commanded simultaneously. More interestingly, these performance features are achieved with no increase in the number...
DEFF Research Database (Denmark)
Liu, Xiong; Wang, Peng; Loh, Poh Chiang
2011-01-01
This paper proposes an approach for DC-link second-order harmonic power cancellation in single-phase AC/DC/AC converter with reduced number of switches. The proposed six-switch converter has two bridges with three switches in each of them, where the middle switch in each bridge is shared by the AC...... on their modulation indices of the six-switch converter, and high modulation indices are proved to be feasible for second-order power cancellation in the DC-link based on the phase difference analysis. Both reduced switch numbers and DC electrolytic capacitor size can be achieved using the proposed converter...
DEFF Research Database (Denmark)
Liu, Xiong; Wang, Peng; Loh, Poh Chiang
2011-01-01
/DC rectifier and DC/AC inverter. A small size DC-link capacitor can be achieved through coordination control of rectifier and inverter to cancel the second-order oscillation power. Maximum available phase difference between rectifier’s and inverter’s modulation references is investigated to be dependent...... on their modulation indices of the six-switch converter, and high modulation indices are proved to be feasible for second-order power cancellation in the DC-link based on the phase difference analysis. Both reduced switch numbers and DC electrolytic capacitor size can be achieved using the proposed converter...
Directory of Open Access Journals (Sweden)
Janaína G. Oliveira
2011-01-01
Full Text Available The integration of a flywheel as a power handling can increase the energy storage capacity and reduce the number of battery charge/discharge cycles. Furthermore, the ability of recovering energy of the vehicle during breaking can increase the system efficiency. The flywheel-based all-electric driveline investigated here has its novelty in the use of a double-wound flywheel motor/generator, which divides the system in two different voltage levels, enhancing the efficiency of the electric driveline. The connection of two AC electrical machines (i.e., the flywheel and the wheel motor with different and variable operation frequency is challenging. A power matching control applied to an AC/DC/AC converter has been implemented. The AC/DC/AC converter regenerates the electric power converted during braking to the flywheel machine, used here as power handling device. By controlling the power balance, the same hardware can be used for acceleration and braking, providing the reduction of harmonics and robust response. A simulation of the complete system during braking mode has been performed both in Matlab and Simulink, and their results have been compared. The functionality of the proposed control has been shown and discussed, with full regeneration achieved. A round-trip efficiency (wheel to wheel higher than 80% has been obtained.
Directory of Open Access Journals (Sweden)
Padmanaban Sanjeevikumar
2008-01-01
Full Text Available This paper presents an artificial neural network (ANN based approach to tune the parameters of the cascaded d-q axis controller for an AC-DC-AC converter without dc link capacitor. The proposed converter uses the cascaded d-q axis controller on the rectifier side and space vector pulse width modulation on the inverter side. The feed-forward ANN with the error back-propagation training is employed to tune the parameters of the cascaded d-q axis controller. The converter topology provides simple commutation procedure with reduced number of switches and has additional advantages such as good voltage transfer ratio, four quadrant operation, unity power factor, no DC link capacitor and less THD in both the line and load sides. Simulation results closely match with theoretical analysis.
Simulation and performance enhancement of the air cooling system in a DC/AC power converter station
Energy Technology Data Exchange (ETDEWEB)
Lozowy, R.; El-Shaboury, A.; Soliman, H.; Ormiston, S. [Manitoba Univ., Winnipeg, MB (Canada). Dept. of Mechanical and Manufacturing Engineering
2010-07-01
This study analyzed the flow structure and heat transfer in a large 3-dimensional domain with turbulence, mixed convection, an impinging jet, and flow over heated blocks. The objective was to better understand turbulent mixed-convection cooling of heat-generating bodies in 3-dimensional enclosures, which is important to industry. The cooling of 2 thyristor valve halls was simulated. Each valve hall housed 3 towers that contained electronics used in DC/AC power conversion. The simulation results included the magnitudes of the net air flows for all the inter-block gaps and the maximum temperature in each gap. A parametric study was also performed to investigate the effects of the air inlet location, size and aspect ratio. The effects of the air injection angle on cooling effectiveness was also examined. The study showed that for fixed inlet mass flow rate, significant improvement in the cooling effectiveness can be obtained by changing the injection angle of the inlet air jet, the location of the inlet grill, or the size of the inlet grill. It was concluded that these study results may be relevant to other applications, such as the design of power transformers, the design of cooling systems for spent nuclear fuel and computer server cooling racks. 13 refs., 12 figs.
Power electronic converters PWM strategies and current control techniques
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.
New PWM switched-mode converter topologies
Hua, Gui-Chao; Huang, Shi-Peng
Two augmented switching cells are proposed from which four novel topologies can be derived: an augmented buck converter, an augmented boost converter, a novel switching power amplifier, and a novel switching controlled rectifier. The augmented buck and the augmented boost converters realize higher step-down and step-up ratios, respectively, under a given switch duty ratio by proper design of the turn ratios of the transformer and coupled inductor. The switching power amplifier achieves four-quadrant output by the use of two bidirectional current switches and a single power supply, while the inverse converter can be used as a switching controlled rectifier. The experimental verification of the power amplifier is presented.
Dynamics of IGBT based PWM Converter A Case Study
Directory of Open Access Journals (Sweden)
Vijay Shukla
2012-04-01
Full Text Available Optimizing the efficiency and dynamics of power converters is a critical tradeoff in power electronics. The increase of switching frequency can improve the dynamics of power converters, but theefficiency may be degraded as well as the switching losses. As power semiconductor devices like diodes, MOSFETS, IGBTs, Thyristors, BJTs have their own characterstics and dynamic responses. It is desired toanalyze and observe the dynamics of different semiconductor devices before they actually employed in the model. Inclusion of different PWM techniques help in the removal of power line interferences like harmonic losses, unwanted ripples, chopped frequencies, spikes. In this paper, we have studied and analyzed the dynamics of IGBT based PWM converter with subjected to different conditions like transient state, steady state feeding the RLC load. Snubber circuits are used to reduce the switching losses. The IGBT based PWM converter reflects the better dynamics with improved efficiency and reduced harmonics as compared to some other power semiconductor devices when FFT is performed and subjected to standard parameterized RLC load understeady state and transient analysis.
Parametric algorithms for frequency estimation in PWM converter systems
Energy Technology Data Exchange (ETDEWEB)
Lobos, T.; Hejke, I.; Rezmer, J.; Sikorski, T.; Kostyla, P. [Dept. of Electrical Engineering, Wroclaw University of Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw (Poland)
2009-11-15
Proper estimation of voltage parameters has a significant meaning for power converters control systems. One of the measured parameter, directly associated with control process, is frequency of the basic voltage component at the converter output. Unfortunately, power converters generate a wide spectrum of harmonics as well as interharmonics, that makes difficulties in estimation this frequency. Measurement carried out in industrial applications exhibits complex nature of investigated signals often corrupted by resonances or overvoltages phenomena. It entails searching a new digital algorithms for frequency measurement. This work presents algorithm using modification of high-resolution Prony method connected with digital filtering. The investigations was based on simulations and real measured signals recorded in two different commercial PWM converters. Obtained results indicate accuracy of the method as well as its fast response. (author)
Single Phase Bidirectional PWM Converter for Microgrid System
Directory of Open Access Journals (Sweden)
C.Kalavalli
2013-06-01
Full Text Available Smart grid is a newly flourishing research area because of its viable applications and expected to address the drawback of existing grid. Microgrids are the part of the Smart grid and they are designed to supply electricity for a small community such as residential areas, universities or industrial sites. Power electronics plays a vital role for connecting the renewable energy sources to Microgrid system. This paper deals the Microgrid connected single phase Bidirectional PWM converter which operates in Rectification and Inverting mode. This converter helps to connect renewable energy sources to loads as well as excess power are given to power grid. Double Loop PID control technique is used for controlling the converter for both modes. The designed Converter is simulated in MATLAB/Simulink software and results are verified using the Hardware.
Advanced power electronics converters PWM converters processing AC voltages
dos Santos, Euzeli
2014-01-01
This book covers power electronics, in depth, by presenting the basic principles and application details, which can be used both as a textbook and reference book. Introduces a new method to present power electronics converters called Power Blocks Geometry. Applicable for courses focusing on power electronics, power electronics converters, and advanced power converters. Offers a comprehensive set of simulation results to help understand the circuits presented throughout the book
Electrical Discharge Machining Flyback Converter using UC3842 Current Mode PWM Controller
Directory of Open Access Journals (Sweden)
Nazriah Mahmud
2014-10-01
Full Text Available This paper presents a current mode Pulse Width Modulation (PWM controlled Flyback converter using UC3842 for Electrical Discharge Machining current generator control circuit. Circuit simplicity and high efficiency can be achieved by a Flyback converter with current mode PWM controller. The behaviors of the system's operation is analyzed and discussed by varying the load resistance. Matlab sofware is used to simulate the Flyback converter where a prototype has been built and tested to verify it's performance.
Soft-switching PWM full-bridge converters topologies, control, and design
Ruan, Xinbo
2014-01-01
Soft-switching PWM full-bridge converters have been widely used in medium-to-high power dc-dc conversions for topological simplicity, easy control and high efficiency. Early works on soft-switching PWM full-bridge converter by many researchers included various topologies and modulation strategies. However, these works were scattered, and the relationship among these topologies and modulation strategies had not been revealed. This book intends to describe systematically the soft-switching techniques for pulse-width modulation (PWM) full-bridge converters, including the topologies, control and
High Frequency Soft Switching Of PWM Boost Converter Using Auxiliary Resonant Circuit
Directory of Open Access Journals (Sweden)
C. P. Sai Kiran
2014-10-01
Full Text Available This thesis presents High frequency Soft Switching DC-DC boost Converter. The circuit consists of a general Boost Converter with an additional resonant circuit which has a switch, inductor, capacitor and a diode.In general Boost Converter circuits have snubber circuits where switching losses are dissipated in external passive resistors; which is known as hard switching. As the switching frequency of PWM converters is increased its switching losses and conduction losses also increases. This restricts the use of PWM technique. New Zero Voltage Transition-Zero Current Transition (ZVT-ZCT PWM converter equipped with the snubber provides the most desirable features of both ZVT and ZCT converters presented previously. Moreover all semiconductors devices operate with soft switching and hence losses are reduced.
Synchronization of the distributed PWM carrier waves for modular multilevel converters
DEFF Research Database (Denmark)
Burlacu, Paul Dan; Mathe, Laszlo; Teodorescu, Remus
2014-01-01
The half-bridge modular multilevel converter has proven itself to be a suitable solution for HVDC application. In order to achieve high modularity and fault tolerance, distributed control strategy is one possible solution and is discussed in this paper. When distributed control strategy is used, ...... the PWM outputs of each sub-module increasing the total harmonic distortion of the output voltage. This paper presents a solution to synchronize the PWM outputs of the MMC submodules using EtherCAT communication protocol focusing on phase shifted PWM modulation technique....
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.
The efficiency of three-level Active NPC converter for different PWM strategies
DEFF Research Database (Denmark)
Floricau, D.; Gateau, G.; Leredde, A.;
2009-01-01
The efficiency of power conversion is an important factor to design static converters. The paper is focused on the calculus of total losses of 3L-NPC and 3L-Active-NPC converters for different PWM strategies. The calculus was made in the most critical operating points when certain switches have...
New PWM method and commutation strategy for HF-link converters for fuel cells and photovoltaics
DEFF Research Database (Denmark)
Ljusev, Petar; Andersen, Michael Andreas E.
2005-01-01
This paper presents a new PWM method and commutation strategy for HF-link converters, which leads to safe commutation of the load current in the output bidirectional bridge. The proposed implementation is independent of the particular HF-link converter topology and bidirectional switch selection...
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)
Comparison of soft and hard-switching effiency in a three-level single phase 60kW dc-ac converter
DEFF Research Database (Denmark)
Munk-Nielsen, Stig; Teodorescu, Remus; Bech, Michael Møller;
2003-01-01
Efficiency measurements on a three-level single-phase soft-switched converter are presented and show a slightly improved efficiency compared with the hard-switched converter for output powers higher than 25 % of rated power. The resonant converter switches are Zero Voltage Switched (ZVS) and a si......Efficiency measurements on a three-level single-phase soft-switched converter are presented and show a slightly improved efficiency compared with the hard-switched converter for output powers higher than 25 % of rated power. The resonant converter switches are Zero Voltage Switched (ZVS...
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...
Soft Switching Full-Bridge PWM DC/DC Converter Using Secondary Snubber
Directory of Open Access Journals (Sweden)
Jaroslav Dudrik
2009-05-01
Full Text Available A novel full-bridge PWM DC/DCconverter with controlled secondary side rectifier usingsecondary snubber is presented in this paper.Limitation of the circulating current as well as softswitching for all power switches of the inverter isachieved for full load range from no-load to shortcircuit by using controlled rectifier and snubber on thesecondary side. Phase shift PWM control strategy isused for the converter. The principle of operation isexplained and analyzed and the experimental resultson a 1kW, 50 kHz laboratory model of the converterare presented.
Performance Comparison of Phase Shifted PWM and Sorting Method for Modular Multilevel Converters
DEFF Research Database (Denmark)
Haddioui, Marcos Rejas; Máthé, Lászlo; Burlacu, Paul Dan;
2015-01-01
Modular Multilevel Converters (MMC) are the solution of preference in HVDC applications due to modularity, scalability, low losses and low filtering requirement. Carrier-based (PWM) and carrier-less (nearest level control) modulation can be applied. By using advanced sorting methods focusing...... on keeping the capacitor voltage ripple under some limit, unnecessary switching events are eliminated leading to reduced switching losses. This paper presents a comparison between the steady-state performances in terms of output voltage THD and equivalent switching frequency of the Phase Shifted Carrier PWM...
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 shown....... Simulation results by using a space vector approach are presented. Special emphasis is given on the total harmonic distortion (THD) by making a comparison with those of the classical NPC topologies....
DEFF Research Database (Denmark)
Gohil, Ghanshyamsinh Vijaysinh; Maheshwari, Ram Krishan; Bede, Lorand;
2015-01-01
for the maximum value of the flux linkage are derived for each of these PWM schemes. In addition, the effect of the proposed PWM scheme on the line current ripple and the switching losses is also analyzed and compared. To verify the analysis, experimental results are presented, which prove the effectiveness......Parallel voltage-source converters (VSCs) require an inductive filter to suppress the circulating current. The size of this filter can be minimized by reducing either the maximum value of the flux linkage or the core losses. This paper presents a modified discontinuous pulsewidth modulation (DPWM......) scheme to reduce the maximum value of the flux linkage and the core losses in the circulating current filter. In the proposed PWM scheme, the dwell time of an active vector is divided within a half-carrier cycle to ensure simultaneous occurrence of the same zero vectors in both VSCs. A function to decide...
Institute of Scientific and Technical Information of China (English)
易映萍; 郭利辉; 刘普; 邓祥纯
2009-01-01
介绍了一种新型的单相有源逆变蓄电池回馈放电装置中DC/AC变换保护电路的设计方法,电路具有IGBT过流、过热、直流过压、输出交流过压、输出交流欠压、输出交流过流等多种保护类型,对从事电力电子技术特别是蓄电池放电技术研究的工程技术人员具有较高的参考价值.%This paper brings forward a new style of discharging device--single-phase active inverter battery feedback discharging device, the design method of DC/AC convert protection circuit is obtained. The circuit has multifold protection functions such as IGBT over-current and over thermal protection, DC over-voltage, AC over-voltage or low-voltage, output over-current, etc. This method will have high value for the engineers.
PWM Technique for Non-Isolated Three-Phase Buck-Boost PFC Converter
Morizane, Toshimitsu; Shimomori, Wataru; Taniguchi, Katsunori; Kimura, Noriyuki; Ogawa, Masanori
The buck-boost power factor corrected (PFC) converter has the wide range of the dc output voltage. A new non-isolated three-phase hard-switching and a soft-switching buck-boost PFC converter are proposed. Removing the three-phase transformer from the converters makes their size more compact and their costs lower. In addition, the new control method based on the PWM technique is proposed in this paper to achieve the high power factor. Complete soft-switching is also achieved under the discontinuous current mode (DCM) operation.
A digitally controlled PWM/PSM dual-mode DC/DC converter
Institute of Scientific and Technical Information of China (English)
Zhen Shaowei; Zhang Bo; Luo Ping; Hou Sijian; Ye Jingxin; Ma Xiao
2011-01-01
A digitally controlled pulse width modulation/pulse skip modulation (PWM/PSM) dual-mode buck DC/DC converter is proposed.Its operation mode can be automatically chosen as continuous conduction mode (CCM) or discontinuous conduction mode (DCM).The converter works in PSM at DCM and in 2 MHz PWM at CCM.Switching loss is reduced at a light load by skipping cycles.Thus high conversion efficiency is realized in a wide load current.The implementations of PWM control blocks,such as the ADC,the digital pulse width modulator (DPWM) and the loop compensator,and PSM control blocks are described in detail.The parameters of the loop compensator can be programmed for different external component values and switching frequencies,which is much more flexible than its analog rivals.The chip is manufactured in 0.13 μm CMOS technology and the chip area is 1.21 mm2.Experimental results show that the conversion efficiency is high,being 90% at 200 mA and 67% at 20 mA.Meanwhile,the measured load step response shows that the proposed dual-mode converter has good stability.
Calderone, Luigi; Pinola, Licia; Varoli, Vincenzo
1992-04-01
The paper describes an analytical procedure to optimize the feed-forward compensation for any PWM dc/dc converters. The aims of achieving zero dc audiosusceptibility was found to be possible for the buck, buck-boost, Cuk, and SEPIC cells; for the boost converter, however, only nonoptimal compensation is feasible. Rules for the design of PWM controllers and procedures for the evaluation of the hardware-introduced errors are discussed. A PWM controller implementing the optimal feed-forward compensation for buck-boost, Cuk, and SEPIC cells is described and fully experimentally characterized.
Closed loop control of ZVS half bridge DC-DC converter with DCS PWM Control
Directory of Open Access Journals (Sweden)
JANAPATI SIVAVARA PRASAD
2012-10-01
Full Text Available
The main drawback of the conventional symmetric control is that both primary switches in the converter operate at hard switching condition. Moreover, during the off-time period of two switches, the oscillation between the transformer leakage inductance and junction capacitance of the switches results in energy dissipation and electromagnetic interference (EMI emissions due to reverse recovery of MOSFETs body diodes. The asymmetric (complementary control was proposed to achieve ZVS operation for HB switches. However, asymmetric stresses distribution on the corresponding components may occur due to the asymmetric duty cycle distribution for the two primary switches. A new control scheme, to be known as duty-cycle shifted PWM (DCS PWM control, is proposed and applied to the conventional HB dc–dc converters to achieve ZVS for both the switches without adding extra components and without adding asymmetric penalties of the complementary control. The concept of this new control scheme is shifting one of the two symmetric PWM driving signals close to the other, such that ZVS may be achieved for the lagging switch due to the shortened resonant interval. Moreover, based on the DCS PWM control, a new half-bridge topology is proposed to achieve ZVS for both the main switches and auxiliary switch by adding an auxiliary switch and diode in the proposed half bridge. ZVS for the switch is achieved by utilizing the energy trapped in the leakage inductance. There are two control schemes. One is open loop and the other is closed loop. In open loop scheme, the given dc-dc converter is operating under disturbance. This disturbance effect is eliminated in closed loop scheme.
Simulation on Soft-Switching PWM Converter with High Power Factor
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
A new PWM converter based on soft-switching is introduced. The converter uses a minimum number of devices, and requires less switching operations than conventional techniques. Switching is realized solely in a ZVS (zero voltage switching) mode,therefore the loss is reduced and EMI (electromagnetic interference) is suppressed. The paper analyzes the operation of ZVS, and discusses the methods for maintaining a unit power factor and constant DC voltage. Changing the modulation index M and the phase angle θ keeps the input current in phase with the voltage. It also keeps the current sinusoidal, and ensures a constant output voltage.
A single leg switched PWM method for three-phase H-Bridge Voltage Source Converters
DEFF Research Database (Denmark)
Senturk, Osman Selcuk; Helle, Lars; Munk-Nielsen, Stig;
2009-01-01
This paper proposes a single leg switched or a hybrid PWM (HPWM) method for three-phase three-level H-Bridge Voltage Source Converters (3L-HB-VSCs). By means of the proposed modulation, a 3L-HB-VSC can generate the same output as a three-level neutral point clamped (3L-NPC) VSC with phase...... disposition (PD) PWM provided that the outputs of 3L-HBVSC are isolated by transformers or connected to open winding machines. Thus, the proposed method is called PD-HPWM. Moreover, it is emphasized that 3L-HB-VSC with HPWM utilizes its switches similar to 3L-NPC-VSC. Compared to 3L-NPC-VSCs, 3L......-HB-VSCs (without neutral point clamping diodes) have simpler, more modular, and more reliable 2L circuit structure. Therefore, this method encourages the use of 3L-HB-VSCs in the applications utilizing transformers such as grid-side converters of multi-MW wind turbines. The proposed PWM method's performance...
DEFF Research Database (Denmark)
Zhang, Gang; Yang, Yongheng; Iannuzzo, Francesco
2016-01-01
of the 3L-ANPC topology. This paper presents a novel loss balancing modulation strategy - Splitting Switching Loss Distribution PWM (SSLD-PWM) strategy to achieve more even loss distribution in the 3L-ANPC converter. Basically, in the proposed PWM strategy, the switching-on losses and switching-off losses...
Advanced Control Strategy of Back-to-Back PWM Converters in PMSG Wind Power System
Directory of Open Access Journals (Sweden)
Tan Luong Van
2015-01-01
Full Text Available This paper proposes a control scheme of back-to-back PWM converters for the permanent magnet synchronous generator (PMSG wind turbine system. The DC-link voltage can be controlled at the machine-side converter (MSC, while the grid-side converter (GSC controls the grid active power for a maximum power point tracking (MPPT. At the grid fault condition, the DC-link voltage controller is designed using a feedback linearization (FL theory. For the MPPT, a proportional control loop is added to the torque control to reduce the influence of the inertia moment in the wind turbines, which can improve its dynamic performance. The validity of this control algorithm has been verified by the simulation of the 2-MW PMSG wind turbine system.
矩阵变换器的谐波注入PWM控制策略%Harmonic injected PWM control strategy for matrix converter
Institute of Scientific and Technical Information of China (English)
王汝田; 王秀云; 崔永恒
2013-01-01
The non-controlled rectification and HIPWM(Harmonic Injected PWM) are respectively applied to the virtual rectifier and virtual inverter of equivalent AC/DC/AC model for matrix converter.The virtual rectifier generates fluctuant DC voltage when symmetric or asymmetric three-phase voltages are supplied.The compensation function is deduced based on the concept of switching function for compensating the modulation wave to eliminate the effect of fluctuant DC voltage on the HIPWM output voltage of virtual inverter.Its hardware implementation is very simple.Results of simulation with MATLAB/Simulink show that,the voltage gain of matrix converter can reach to 0.866,the theoretical maximum,and there is no loworder harmonics in its output voltage,verifying the correctness and effectiveness of the proposed control strategy.%在矩阵变换器间接变换法等效的交直和直交2个虚拟的环节上,分别采用不控整流和谐波注入PWM(HIPWM)2种简单易实现的调制方式.在三相输入电压是对称或非对称的情况下,虚拟整流环节输出的是直流波动电压,为消除此直流波动电压对虚拟逆变环节HIPWM输出的电压波形的影响,利用开关函数概念推导了对HIPWM的调制波进行补偿的补偿函数,此控制策略的硬件实现电路非常简单.应用MATLAB/Simulink进行了仿真,仿真结果表明:应用HIPWM控制策略,矩阵变换器的电压增益能够达到理论最大值0.866,输出电压中不含低次谐波,验证了所提控制算法的正确性和有效性.
A Study of Novel ZVZCT SoftSwitching PWM Boost Converters%新型ZVZCT软开关PWM Boost 变换器的研究
Institute of Scientific and Technical Information of China (English)
林国庆; 张冠生; 陈为; 黄是鹏
2000-01-01
The paper presents a novel ZVZCT softswitching PWM converter:the voltage and current waveforms of the transistor are laddershaped and stagger each other,and auxiliary switches are turned on and off under zero current.It is very attractive for high power application where IGBT is predomi nantly used as the power switches.Theoretical analysis,parameters selection,comp uter simulation,and experiment results are presented to explain the proposed sch eme.
Yamada, Hiroaki; Tanaka, Toshihiko; Funabiki, Shigeyuki
This paper proposes a novel method of suppressing the inrush current of transformers. A small-rated voltage-source PWM converter is connected in series to the transformers through a matching transformer. As the connected PWM converter performs a resistor for the source current, no inrush phenomena occurs. The required-ratings of the PWM converter, which performs the damping resistor for the inrush phenomena, is one-four-hundredth as compared to that of the main transformers in single-phase circuits. In three-phase circuits, it is one-nine-hundredth. The basic principle of the proposed method is discussed. Digital computer simulation is implemented to confirm the validity and excellent practicability of the proposed method using the PSCAD/EMTDC. A prototype experimental-model is constructed and tested. The experimental results demonstrate that the proposed method can perfectly suppress the inrush phenomena.
Institute of Scientific and Technical Information of China (English)
陈强; 郝思鹏; 章心因; 吕干云
2016-01-01
以三相DC/AC变流器为研究对象，给出了一种无锁相环直接功率预测控制方法，能实现对并网功率的无差拍控制，并且为降低锁相环对控制性能的影响，实现无锁相环控制。根据采样控制导致的两拍延时，采样控制频率为载波频率两倍，精确计算得到下一拍的变流器状态量，然后针对给定功率参考值根据公式直接计算得到三相变流电路的输出。推导得到控制系统设定的频率与电网频率的偏差对所提出控制方法的性能没有影响，论证了无锁相环的可行性。最后构建了三相并网变流器Simulink仿真模型和实验样机，利用Simulink中的Embedded Coder模块实现控制系统仿真模型到DSP硬件控制系统C语言程序的转换，通过仿真和实验验证了控制方法的有效性。%A predictive direct power control method without the phase locked loop (PLL) is presented,the research obj ect of which is the three-phase DC/AC converter.This method can achieve the deadbeat control of grid-connected power.In order to reduce the influence on the control performance by PLL,the method without PLL is realized.According to the two-beat delay resulting from the sampling control,the sampling frequency which is twice the carrier frequency is adopted to calculate the grid voltage,the grid-connected power and current after one cycle accurately.The output of the converter is calculated by the formula given in the paper.The deviation between the frequency set by the control system and the grid frequency has no influence on the performance of the control method proposed in this paper.The feasibility of the absence of phase locked loop (PLL) is demonstrated.The three-phase grid-connected converter simulation model and experimental prototype are built.The conversion from a control system simulation model into the C language program of DSP is realized by the Embedded Coder block of Simulink.The control method is validated and
A PAC Based Current Feedforward Control for Three-Phase PWM Voltage-Type Converter
Institute of Scientific and Technical Information of China (English)
屈克庆; 陈国呈; 孙承波
2004-01-01
This paper presents a novel current feedforward control strategy for a three-phase pulse-width modulation (PWM) DC voltage-type converter based on phase and amplitude control (PAC). With right-angle triangle relation of phasors and principle of conservation of energy, a phasor adjustment method and the relevant low-frequency mathematical model of the system are analyzed in detail, both in rectification and regeneration modes for the converter, are discussed. For improving the traditional PAC dynamic performance, variable load current is detected indirectly by the change of the DC voltage, which is fed to the control system as an additional control variable to generate modulation index and phase angle. Also, the algorithm is derived and the system principle is introduced. Experimental results from a 3 kw laboratory device are included to demonstrate the effectiveness of the proposed control strategy.
Directory of Open Access Journals (Sweden)
Taizhou Bei
2014-01-01
Full Text Available Considering the disadvantages of the traditional high-gain DC-DC converter such as big size, high voltage stress of switches, and large input current ripple, a novel high-gain interleaved boost converter with coupled-inductor and switched-capacitor was proposed correspondingly and the operation principle together with the steady-state analysis of this converter was also described. Besides, a new control approach-dynamic sliding mode evolution PWM controller (DSME PWM for the novel topological converter based on both dynamic evolution and sliding mode control was also presented. From the simulation results and experimental validation the proposed converter can fulfill high-gain boost, low ripple of both the input current and the output voltage. Furthermore, MPPT technique can be also achieved in a short time by simulation. The efficiency and stability of the converter proposed in this paper can be improved.
Bifurcation boundary conditions for current programmed PWM DC-DC converters at light loading
Fang, Chung-Chieh
2012-10-01
Three types of bifurcations (instabilities) in the PWM DC-DC converter at light loading under current mode control in continuous-conduction mode (CCM) or discontinuous-conduction mode (DCM) are analysed: saddle-node bifurcation (SNB) in CCM or DCM, border-collision bifurcation during the CCM-DCM transition, and period-doubling bifurcation in CCM. Different bifurcations occur in some particular loading ranges. Bifurcation boundary conditions separating stable regions from unstable regions in the parametric space are derived. A new methodology to analyse the SNB in the buck converter based on the peak inductor current is proposed. The same methodology is applied to analyse the other types of bifurcations and converters. In the buck converter, multiple stable/unstable CCM/DCM steady-state solutions may coexist. Possibility of multiple solutions deserves careful study, because an ignored solution may merge with a desired stable solution and make both disappear. Understanding of SNB can explain some sudden disappearances or jumps of steady-state solutions observed in switching converters.
Yamada, Hiroaki; Tanaka, Toshihiko; Funabiki, Shigeyuki
This paper proposes a new inrush current suppressor using a series-connected small-rated PWM converter for a transformer. The PWM converter is directly connected in series between the source and transformer without a matching transformer. The inrush phenomena of the matching transformer, thus, can be avoided. The control gain and required-ratings of the series-connected small-rated PWM converter is discussed in detail. The capacity of the dc capacitor of the PWM converter is also discussed considering the active power flows into the PWM converter. The PSCAD/EMTDC is used to verify the validity of the proposed inrush current suppressor. A prototype experimental model is constructed and tested. The experimental results demonstrate that the proposed suppressor can perfectly overcome the inrush phenomena of transformers.
Directory of Open Access Journals (Sweden)
Yüksel Oğuz
2013-01-01
Full Text Available The control strategy and design of an AC/DC/AC IGBT-PMW power converter for PMSG-based variable-speed wind energy conversion systems (VSWECS operation in grid/load-connected mode are presented. VSWECS consists of a PMSG connected to a AC-DC IGBT-based PWM rectifier and a DC/AC IGBT-based PWM inverter with LCL filter. In VSWECS, AC/DC/AC power converter is employed to convert the variable frequency variable speed generator output to the fixed frequency fixed voltage grid. The DC/AC power conversion has been managed out using adaptive neurofuzzy controlled inverter located at the output of controlled AC/DC IGBT-based PWM rectifier. In this study, the dynamic performance and power quality of the proposed power converter connected to the grid/load by output LCL filter is focused on. Dynamic modeling and control of the VSWECS with the proposed power converter is performed by using MATLAB/Simulink. Simulation results show that the output voltage, power, and frequency of VSWECS reach to desirable operation values in a very short time. In addition, when PMSG based VSWECS works continuously with the 4.5 kHz switching frequency, the THD rate of voltage in the load terminal is 0.00672%.
Oğuz, Yüksel; Güney, İrfan; Çalık, Hüseyin
2013-01-01
The control strategy and design of an AC/DC/AC IGBT-PMW power converter for PMSG-based variable-speed wind energy conversion systems (VSWECS) operation in grid/load-connected mode are presented. VSWECS consists of a PMSG connected to a AC-DC IGBT-based PWM rectifier and a DC/AC IGBT-based PWM inverter with LCL filter. In VSWECS, AC/DC/AC power converter is employed to convert the variable frequency variable speed generator output to the fixed frequency fixed voltage grid. The DC/AC power conversion has been managed out using adaptive neurofuzzy controlled inverter located at the output of controlled AC/DC IGBT-based PWM rectifier. In this study, the dynamic performance and power quality of the proposed power converter connected to the grid/load by output LCL filter is focused on. Dynamic modeling and control of the VSWECS with the proposed power converter is performed by using MATLAB/Simulink. Simulation results show that the output voltage, power, and frequency of VSWECS reach to desirable operation values in a very short time. In addition, when PMSG based VSWECS works continuously with the 4.5 kHz switching frequency, the THD rate of voltage in the load terminal is 0.00672%.
Oğuz, Yüksel; Güney, İrfan; Çalık, Hüseyin
2013-01-01
The control strategy and design of an AC/DC/AC IGBT-PMW power converter for PMSG-based variable-speed wind energy conversion systems (VSWECS) operation in grid/load-connected mode are presented. VSWECS consists of a PMSG connected to a AC-DC IGBT-based PWM rectifier and a DC/AC IGBT-based PWM inverter with LCL filter. In VSWECS, AC/DC/AC power converter is employed to convert the variable frequency variable speed generator output to the fixed frequency fixed voltage grid. The DC/AC power conversion has been managed out using adaptive neurofuzzy controlled inverter located at the output of controlled AC/DC IGBT-based PWM rectifier. In this study, the dynamic performance and power quality of the proposed power converter connected to the grid/load by output LCL filter is focused on. Dynamic modeling and control of the VSWECS with the proposed power converter is performed by using MATLAB/Simulink. Simulation results show that the output voltage, power, and frequency of VSWECS reach to desirable operation values in a very short time. In addition, when PMSG based VSWECS works continuously with the 4.5 kHz switching frequency, the THD rate of voltage in the load terminal is 0.00672%. PMID:24453905
DEFF Research Database (Denmark)
Song, Kejian; Konstantinou, Georgios; Mingli, Wu
2017-01-01
AC electric locomotives that use a number of interleaved four-quadrant converters generate high-frequency switching harmonics which may stimulate certain resonances in traction power supply systems (TPSSs). A windowed selective harmonic elimination pulse-width modulation (SHE-PWM) method...
DEFF Research Database (Denmark)
Liu, Dong; Deng, Fujin; Chen, Zhe
2017-01-01
The capacitor current would be imbalanced under the conventional control strategy in the half-bridge three-level (HBTL) DC/DC converter due to the effect of the output inductance of the power supply and the input line inductance, which would affect the converter's reliability. This paper proposes...... a pulse-wide modulation (PWM) strategy composed of two operation modes for the HBTL DC/DC converter, which can realize the zero-voltage switching (ZVS) for the efficiency improvement. In addition, a capacitor current balancing control is proposed by alternating the two operation modes of the proposed ZVS...... PWM strategy, which can eliminate the current imbalance among the two input capacitors. Therefore, the proposed control strategy can improve the converter's performance and reliability in: 1) reducing the switching losses and noises of the power switches; 2) balancing the thermal stresses...
DEFF Research Database (Denmark)
Zhang, Zhe; Andersen, Michael A. E.
2013-01-01
This paper presents an isolated dual-input DC-DC converter with a PWM plus phase-shift control for fuel cell hybrid energy systems. The power switches are controlled by phase shifted PWM signals with a variable duty cycle, and thus the two input voltages as well as the output voltage can...
DEFF Research Database (Denmark)
Forouzesh, Mojtaba; Siwakoti, Yam Prasad; Blaabjerg, Frede
2016-01-01
Magnetically coupled Y-source impedance network is a newly proposed structure with versatile features intended for various power converter applications e.g. in the renewable energy technologies. The voltage gain of the Y-source impedance network rises exponentially as a function of turns ratio......, which is inherited from a special coupled inductor with three windings. Due to the importance of modeling in the converter design procedure, this paper is dedicated to dc and ac small signal modeling of the PWM Y-source converter. The derived transfer functions are presented in detail and have been...
Apparatus and method for heat-run test on high-power PWM converters with low energy expenditure
Indian Academy of Sciences (India)
J S Siva Prasad; G Narayanan
2013-06-01
Before installation, a voltage source converter is usually subjected to heat-run test to verify its thermal design and performance under load. For heat-run test, the converter needs to be operated at rated voltage and rated current for a substantial length of time. Hence, such tests consume huge amount of energy in case of high-power converters. Also, the capacities of the source and loads available in the research and development (R & D) centre or the production facility could be inadequate to conduct such tests. This paper proposes a method to conduct heat-run tests on highpower, pulse width modulated (PWM) converters with low energy consumption. The experimental set-up consists of the converter under test and another converter (of similar or higher rating), both connected in parallel on the ac side and open on the dc side. Vector-control or synchronous reference frame control is employed to control the converters such that one draws certain amount of reactive power and the other supplies the same; only the system losses are drawn from the mains. The performance of the controller is validated through simulation and experiments. Experimental results, pertaining to heat-run tests on a high-power PWM converter, are presented at power levels of 25 kVA to 150 kVA.
Simple digital PWM and PSM controlled DC-DC boost converter for luminance-regulated WLED driver
Institute of Scientific and Technical Information of China (English)
LIU Xin; GUO Shu-xu; CHANG Yu-chun; ZHU Shun-dong; WANG Shuai
2009-01-01
This article presents a control strategy based on simple digital pulse-width modulation (DPWM) and pulse-skip modulation (PSM) for a DC-DC boost converter, to drive a luminance-regulated white light emitting diodes (WLEDs). The presented control strategy not only retains most of the advantages and flexibilities of traditional digital PWM, but also reduces complexity and cost. Based on analyzing the principle of the presented control strategy, the white light emitting diode (WLED) driver is designed and simulated using the 0.6 (m CMOS process. Simulation results of the boost converter show that the power efficiency is above 76% for a full load, with a peak efficiency of 88% when supply voltage varies from 2.7 V to 5.5 V. The control strategy overcomes low efficiency for PWM mode with light load.
Institute of Scientific and Technical Information of China (English)
YanfengCHEN; ShuishengQIU; 等
1999-01-01
An extension of characteristic equation analysis method to the stability analysis of equilibrium points for closed-loop PWM power switching converters is introduced based on equivalent small parameter method.The basic principle of the method is described in detail.The provided example shows that the method,incorporating with the system's state-plane trajectories,offers the advantages of both simplicity and practicality.
Sugimura, Hisayuki; Muraoka, Hidekazu; Hiraki, Eiji; Hirota, Izuo; Yasui, Kenji; Omori, Hideki; Lee, Hyun-Woo; Nakaoka, Mutsuo
In this paper, high frequency power converter without DC smoothing electrolytic capacitor filter link which convert the 100V/200Vrms and 60Hz single phase utility frequency AC power into a high frequency AC. This proposed high frequency AC power converter without electrolytic capacitor filter can operate under a principle of soft switching PWM based on a lossless capacitor snubber is proposed and demonstrated for consumer high frequency induction heating (IH). In particular, this high frequency power converter capable of producing a high frequency AC more than 20kHz is developed for consumer IH applications as hot water producer and steamer based on the specially designed spiral type IH-Dual Packs Heater (DPH), which includes the dual mode pulse modulation control scheme based on soft switching PWM for high output power setting and commercial frequency AC zero voltage soft switching pulse density modulation (PDM) for low output power settings. This developed high frequency power frequency converter using trench gate IGBTs is clarified on the basis of experimental and simulation results for its circuit operation of the utility frequency AC to high frequency AC frequency PWM power converter without the electrolytic capacitor bank DC filter link for the IH hot water and IH steamer. These IH appliances are based upon an innovative electromagnetic IH-DPH for fluid heating as heat exchanger in consumer pipeline. Finally, its power regulation characteristics, power conversion efficiency and harmonic current components characteristics including power factor in utility AC grid side are evaluated and discussed from an experimental point of view. The practical effectiveness of this utility frequency AC to high frequency AC soft switching high power frequency converter defined conveniently as high frequency soft switching cyclo-inverter is proved as one of the important products effective for next generation IH application all electricity power utilizations.
随机PWM CCM Boost变换器非脆弱H∞控制%Non-fragile H∞ control for random PWM CCM Boost converter
Institute of Scientific and Technical Information of China (English)
冉华军; 张涛
2013-01-01
With two - state - Markov - chain random PWM scheme introduced into CCM Boost converter , the random discrete - time jumping model is established first. Then, non - fragile H∞ controller is derived on the basis of non - fragile H∞ control theory of stochastic jumping system. Finally, the simulation circuit is designed to check the validity of non - fragile H∞ controller on the Simulink platform. The results show that the controller designed in this paper has improved the EMI level of Boost converter with non - fragility to its parameters uncertainty, and the whole converter system is robust.%对CCM Boost变换器引入两模态马尔科夫链稳态期望平均脉宽固定的随机PWM策略,首先推导建立变换器的离散随机跳变模型,然后基于随机跳变系统非脆弱H∞控制理论为Boost变换器设计了非脆弱H∞控制器,最后在Simulink仿真平台上设计仿真电路进行验证.仿真结果表明,设计的控制器改善了Boost变换器的EMI品质,对控制器参数摄动表现出非脆弱性,整个变换器系统具有较好的鲁棒性.
Chen, Lei; Tang, Yuejin; Shi, Jing; Li, Zhi; Ren, Li; Cheng, Shijie
2010-02-01
The integrated voltage compensation type active superconducting fault current limiter (SFCL) is composed of three air-core superconducting transformers and a three-phase four-wire PWM converter. In order to realize the current-limiting characteristics of the integrated active SFCL, it is needed to control the three-phase four-wire PWM converter flexibly and reasonably. Thereby, the control strategy for the converter is analyzed in this paper. In dq0 reference frame, the mathematical model of the converter is founded. The double-loop control strategy, consisting of voltage outer loop and current inner loop, is presented. Moreover, the voltage balance control for the split DC link capacitors is also considered. Using MATLAB, the simulation model of the integrated active SFCL is built. According to the simulation results, it is known that, the presented control strategy is feasible and valid, and the converter can work well under unsymmetrical and symmetrical fault conditions, and then the fault current can be limited quickly and effectively.
Lorentz, V. R. H.; Schwarzmann, H.; März, M.; Bauer, A. J.; Ryssel, H.; Frey, L.; Poure, P.; Braun, F.
2011-08-01
A novel CMOS integrated pulse-width modulation (PWM) control circuit allowing smooth transitions between conversion modes in full-bridge based bi-directional DC-DC converters operating at high switching frequencies is presented. The novel PWM control circuit is able to drive full-bridge based DC-DC converters performing step-down (i.e. buck) and step-up (i.e. boost) voltage conversion in both directions, thus allowing charging and discharging of the batteries in mobile systems. It provides smooth transitions between buck, buck-boost and boost modes. Additionally, the novel PWM control loop circuit uses a symmetrical triangular carrier, which overcomes the necessity of using an output phasing circuit previously required in PWM controllers based on sawtooth oscillators. The novel PWM control also enables to build bi-directional DC-DC converters operating at high switching frequencies (i.e. up to 10 MHz and above). Finally, the proposed PWM control circuit also allows the use of an average lossless inductor-current sensor for sensing the average load current even at very high switching frequencies. In this article, the proposed PWM control circuit is modelled and the integrated CMOS schematic is given. The corresponding theory is analysed and presented in detail. The circuit simulations realised in the Cadence Spectre software with a commercially available 0.18 µm mixed-signal CMOS technology from UMC are shown. The PWM control circuit was implemented in a monolithic integrated bi-directional CMOS DC-DC converter ASIC prototype. The fabricated prototype was tested experimentally and has shown performances in accordance with the theory.
A Dual-Bridge LLC Resonant Converter with Fixed-Frequency PWM Control for Wide Input Applications
DEFF Research Database (Denmark)
Xiaofeng, Sun; Li, Xiaohua; Shen, Yanfeng;
2017-01-01
. Compared with the traditional pulse frequency modulation (PFM) controlled HB/FB LLC resonant converter, the voltage gain range is independent of the quality factor and the magnetizing inductor has little influence on the voltage gain, which can simplify the parameter selection process and benefit...... the design of magnetic components as well. Over the full load range, zero voltage switching (ZVS) and zero current switching (ZCS) can be achieved for primary switches and secondary rectifier diodes, respectively. Detailed analysis on the modulation schedule and operating principle of the proposed converter......This paper proposes a dual-bridge (DB) LLC resonant converter for wide input applications. The topology is an integration of a half-bridge (HB) LLC circuit and a full-bridge (FB) LLC circuit. The fixed-frequency PWM control is employed and a range of twice the minimum input voltage can be covered...
DEFF Research Database (Denmark)
Liu, Dong; Deng, Fujin; Zhang, Qi
2017-01-01
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...... modes is proposed. Based on the proposed ZVS PWM strategy, a capacitor current-balancing control is proposed for the HBTL DC/DC converter, where the currents on the two input capacitors can be kept balanced by alternating the two operation modes of the proposed ZVS PWM strategy. Therefore, the proposed...... control strategy can improve the performance and reliability of the converter in the aspect of balancing the thermal stresses and lifetimes among the two input capacitors. Finally, simulation and experimental studies are conducted and results verify the proposed control strategy....
Energy Technology Data Exchange (ETDEWEB)
Onar, Omer C [ORNL
2011-01-01
This study presents a bi-directional multi-level power electronic interface for the grid interactions of plug-in hybrid electric vehicles (PHEVs) as well as a novel bi-directional power electronic converter for the combined operation of battery/ultracapacitor hybrid energy storage systems (ESS). The grid interface converter enables beneficial vehicle-to-grid (V2G) interactions in a high power quality and grid friendly manner; i.e, the grid interface converter ensures that all power delivered to/from grid has unity power factor and almost zero current harmonics. The power electronic converter that provides the combined operation of battery/ultra-capacitor system reduces the size and cost of the conventional ESS hybridization topologies while reducing the stress on the battery, prolonging the battery lifetime, and increasing the overall vehicle performance and efficiency. The combination of hybrid ESS is provided through an integrated magnetic structure that reduces the size and cost of the inductors of the ESS converters. Simulation and experimental results are included as prove of the concept presenting the different operation modes of the proposed converters.
Advanced DC/AC inverters applications in renewable energy
Luo, Fang Lin
2013-01-01
DC/AC inversion technology is of vital importance for industrial applications, including electrical vehicles and renewable energy systems, which require a large number of inverters. In recent years, inversion technology has developed rapidly, with new topologies improving the power factor and increasing power efficiency. Proposing many novel approaches, Advanced DC/AC Inverters: Applications in Renewable Energy describes advanced DC/AC inverters that can be used for renewable energy systems. The book introduces more than 100 topologies of advanced inverters originally developed by the authors,
Integrated modeling and control of a PEM fuel cell power system with a PWM DC/DC converter
Energy Technology Data Exchange (ETDEWEB)
Choe, Song-Yul; Ahn, Jong-Woo [Mechanical Engineering Department, Auburn University, Auburn, AL 36848 (United States); Lee, Jung-Gi [Electrical Engineering Department, Pohang University of Science and Technology, Pohang (Korea); Baek, Soo-Hyun [Electrical Engineering Department, Dong-guk University, Seoul (Korea)
2007-02-10
A fuel cell powered system is regarded as a high current and low voltage source. To boost the output voltage of a fuel cell, a DC/DC converter is employed. Since these two systems show different dynamics, they need to be coordinated to meet the demand of a load. This paper proposes models for the two systems with associated controls, which take into account a PEM fuel cell stack with air supply and thermal systems, and a PWM DC/DC converter. The integrated simulation facilitates optimization of the power control strategy, and analyses of interrelated effects between the electric load and the temperature of cell components. In addition, the results show that the proposed power control can coordinate the two sources with improved dynamics and efficiency at a given dynamic load. (author)
Directory of Open Access Journals (Sweden)
Imen Ouerdani
2017-03-01
Full Text Available This paper focuses on the carrier disposition Pulse Width Modulation (PWM strategies for Modular Multilevel Converters (MMC. The authors propose a new Phase Opposition Disposition PWM (PODPWM scheme applicable regardless of the converter’s sub-modules number. Moreover, a capacitor voltage sorting algorithm is synthesized aiming to ensure the converter’s balanced operation. Simulation results of a 3.6 MVA, 3-SM-MMC are presented and discussed. In addition, a Hardware In the Loop (HIL validation of the proposed PODPWM has been made using Field Programmable Gate Array (FPGA target. The actual power system (the 3-SM-MMC and the 3-phase RL load is then replaced by its real-time emulator. The latter is interfaced to the PODPWM control under test and both are implemented and run altogether in the same Xilinx XC7Z020 Zynq FPGA device. The obtained real-time HIL emulation results are presented and compared to the offline simulation results.
双PWM变换器一体化控制策略%Integrated control strategy for dual-PWM converter
Institute of Scientific and Technical Information of China (English)
李昆鹏; 万健如; 宫成; 李世群
2013-01-01
针对双PWM变换器依赖附加协调控制策略解决一体化的问题,研究PWM整流器及逆变器独立控制策略对协调性能的影响,借助瞬时功率中间变量,提出一种不外加其他协调方法的双PWM变换器一体化控制策略.整流器侧建立在离散化数学模型基础上,在固定时间周期内,以满足指标函数最小为原则预测下一时刻电网电流,借助空间矢量调制技术获得整流器期望开关状态.逆变器侧采用基于空间矢量调制技术的直接转矩控制.理论分析表明,由负载参数变化直接引起的直流母线电压波动通过电压环调节以瞬时功率形式作用于整流器电网电流预测环节.仿真和实验结果表明,双PWM变换器能快速响应负载变化情况并恢复稳态,对负载及系统参数扰动具有鲁棒性,验证了所提策略的有效性.%Aiming at the problem that dual pulse width modulation (PWM) converter relys on additional coordination control strategy to realize integrative control, the influences of PWM rectifier and inverter to coordination are studied. An integrated control strategy for dual PWM converter that not depends on the other harmonious methods is presented by use of the middle variable of instantaneous power. The control strategy for rectifier was built on the discrete mathematical model, and a cost function was chosen for pre dicting ac input current through minimizing itself in fixed cyclical time. Meanwhile, the state of switches for rectifier was determined with the help of space vector pulse width modulation technology. The control strategy for inverter adopted direct torque control method based on the space vector pulse width modula tion technique. A theoretical analysis shows that load parameter variation causes fluctuation of DC-bus voltage, and the fluctuation in instantaneous power shape acts on the predictive current for rectifier by voltage loop. The experiment and simulation results show quick response to the
A single-phase embedded Z-source DC-AC inverter.
Kim, Se-Jin; Lim, Young-Cheol
2014-01-01
In the conventional DC-AC inverter consisting of two DC-DC converters with unipolar output capacitors, the output capacitor voltages of the DC-DC converters must be higher than the DC input voltage. To overcome this weakness, this paper proposes a single-phase DC-AC inverter consisting of two embedded Z-source converters with bipolar output capacitors. The proposed inverter is composed of two embedded Z-source converters with a common DC source and output AC load. Though the output capacitor voltages of the converters are relatively low compared to those of a conventional inverter, an equivalent level of AC output voltages can be obtained. Moreover, by controlling the output capacitor voltages asymmetrically, the AC output voltage of the proposed inverter can be higher than the DC input voltage. To verify the validity of the proposed inverter, experiments were performed with a DC source voltage of 38 V. By controlling the output capacitor voltages of the converters symmetrically or asymmetrically, the proposed inverter can produce sinusoidal AC output voltages. The experiments show that efficiencies of up to 95% and 97% can be achieved with the proposed inverter using symmetric and asymmetric control, respectively.
Simple PWM modulator topology with excellent dynamic behavior
DEFF Research Database (Denmark)
Poulsen, Søren; Andersen, Michael Andreas E.
2004-01-01
This paper proposes a new PWM modulator topology. The modulator is used in switch mode audio power amplifiers, but the topology can be used in a wide range of applications. Due to excellent transient behavior, the modulator is very suited for VRMs or other types of DC-DC or DC-AC applications....
Grid-connected Photovoltaic Micro-inverter with New Hybrid Control LLC Resonant Converter
DEFF Research Database (Denmark)
Xingkui, Mao; Qisheng, Huang; Qingbo, Ke;
2016-01-01
A high-efficiency photovoltaic (PV) micro-inverter consisting of two power stages i.e. a LLC resonant converter with a new hybrid control scheme and a dc-ac inverter is proposed, studied and designed in this paper. In the first power stage, the new hybrid control combining pulse-frequency modulat......A high-efficiency photovoltaic (PV) micro-inverter consisting of two power stages i.e. a LLC resonant converter with a new hybrid control scheme and a dc-ac inverter is proposed, studied and designed in this paper. In the first power stage, the new hybrid control combining pulse......-frequency modulation (PFM) and phase-shift pulse-width modulation (PS-PWM) is employed on a full-bridge LLC dc-dc converter, in order to achieve high efficiency when PV output voltage varies in a wide range. Moreover, a maximum power point tracking (MPPT) method based on power perturbation is implemented in the dc......-ac inverter. Therefore, the complexity of regulating LLC converter can be reduced effectively, and efficiency optimal design can be carried out through the proposed designing procedure for the resonant tank of LLC converter. Finally, a prototype of the proposed PV micro-inverter (PVMI) is developed with rated...
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
The inherent double line ripple power in singlephase systems is adverse to the converter performance, e.g. limited lifetime due to the requirement of large electrolytic capacitors and low voltage control bandwidth due to harmonic disturbance. In this paper, an active 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 of the proposed system...... is presented, and a dual voltage control strategy is then proposed, which comprises one voltage loop implemented in the synchronous reference frame for active power balancing, and another one implemented in the harmonic reference frame for ripple power compensation. Special attention is given to the bandwidth...
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......The inherent double line ripple power in single-phase systems is adverse to the performance of power electronics converters, e.g. limited lifetime due to the requirement of large electrolytic capacitors and low voltage control bandwidth due to harmonic disturbance. In this paper, an active...... of the proposed system is presented, and a dual voltage control strategy is then proposed, which comprises one voltage loop implemented in the synchronous reference frame for active power balancing, and another one implemented in the stationary reference frame for ripple power compensation. Special attention...
Smooth-Transition Simple Digital PWM Modulator for Four-Switch Buck-Boost Converters
Rodriguez, Alberto; Rodriguez, Miguel; Vazquez, Aitor; Maija, Pablo F.; Sebastian, Javier
2014-08-01
Four Switch non-inverting Buck-Boost (4SBB) converters are extensively used in non-isolated applications where voltage step-up and step-down are required. In order to achieve high efficiency operation it is preferred to control the 4SBB as a Buck or Boost converter, depending on the input/output voltage ratio. However, when input and output voltages are close this approach requires near- unity conversion ratios, which are difficult to achieve in practice. Several alternative operating modes have been proposed in the literature to overcome this issue. In particular, operating the 4SBB as a Buck and Boost at the same time (Buck+Boost mode) has proven to be adequate to achieve near-unity conversion ratios.This paper proposes a simple, hardware-efficient digital pulse width modulator for a 4SBB that enables operation in Buck, Boost and Buck+Boost modes, thus allowing near-unity conversion ratios, while achieving smooth transitions between the different modes. The proposed modulator is simulated with Simulink and experimentally demonstrated using a 500W 4SBB converter with 24V input voltage and 12V-36V output voltage range.
DEFF Research Database (Denmark)
Huang, Shaojun; Mathe, Laszlo; Teodorescu, Remus
2013-01-01
of inaccuracy in terms of switching instant, while the latter is inflexible with higher cost. In order to overcome these drawbacks, this paper proposes an alternative solution, which uses high frequency saw-tooth carrier and two independent comparators, usually available in microcontrollers, to create......Two existing methods to implement resampling modulation technique for modular multilevel converter (MMC) (the sampling frequency is a multiple of the carrier frequency) are: the software solution (using a microcontroller) and the hardware solution (using FPGA). The former has a certain level...
EFFICIENT STEADY-STATE ANALYSIS METHOD FOR CLOSED-LOOP PWM SWITCHING CONVERTERS
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
Since the early70s,many s mall-signal fre-quency-domain modeling technique have been de-veloped to study the dynamic perfor mances and sta-bilities ofPWMs witching converters around thestatic operating point.However,the accuracy of thederived models relies on accurate deter mination ofthe steady state operating point,and usually manyperfor mances of circuits are given based on steady-state,so it is very essential to analyze the steadystate of circuits.Analysis methods for steadystate ofnonlinear circuits ca...
A PWM Buck Converter with High-efficiency under Light-load%一种具有高轻载效率的PWM Buck变换器
Institute of Scientific and Technical Information of China (English)
刘南; 梁亮
2013-01-01
本文提出了一种在轻载工作环境下依然高效的PWM DC/DC buck变换器.该变换器由TSMC 1.8/3.3 V 0.18 μmCMOS技术设计而成.通过DCM操作,不仅能在满载时达到高效率,而且在不利用任何PFM技术的情况下大大提升轻载下的效率.这种变换器轻载时的输出精确性和输出纹波都优于PFM变换器,而在满载时与普通的PWM变换器同样稳定、高效,通过Saber仿真与电路实验验证了变换器的可行性.
桥式直流PWM变换器的建模与仿真研究%Research on Modeling and Simulation of bridge DC PWM converter
Institute of Scientific and Technical Information of China (English)
朱莉波; 荣军; 王峰; 刘正; 钟颖
2015-01-01
首先介绍了PWM控制技术的基本原理，然后结合无源逆变器，详细地阐述了桥式直流PWM变换器的工作原理。最后在MATLAB/Simulink建立了桥式直流PWM变换器的仿真模型，然后对仿真结果进行了分析，仿真结果表明通过调节占空比，可以改变电压和电流的大小和方向，与理论分析完全一致。%The paper firstly introduces the basic principle of PWM control technology, and then combines with passive inverter, and also expounds in detail the working principle of PWM bridge DC converter. Finally, the simulation model is built in the MATLAB/Simulink of bridge DC PWM converter, and then the simulation results have been carried on the analysis. The simulation results show that the size and the direction of the voltage and current can be changed by adjusting the duty ratio, and it is fully consistent with the theoretical analysis.
Research on Double PWM Converter Based on the Soft-Switch Technology%零压变换软开关的双PWM变换器的研究
Institute of Scientific and Technical Information of China (English)
胡正轩; 冷光夺; 袁冬柏; 王建任
2013-01-01
Double Pulse Width Modulation (PWM) converter in wind power system is used widely, the power switch device Insulated Gate Bipolar Transistor (IGBT) has the good switching characteristics. However,the circuit which is opened or turn off will produce switch loss and noise pollution. These interference in small power circuits can be ignored, but it should be avoid in the larger wind power system. In order to reduce or even avoid these disadvantages influence to the running of system smoothly, this paper design a Double PWM converter which is based on the soft-switching technology, and it combines with Space Vector Pulse Width Modulation (SVPWM) technique and PR control method. The simulation test and analysis results proved that optimal converter can be a good improvement in input and output performance of traditional converter.%对于双脉宽调制(PWM)变换器,当电路开通或关断的时候都会产生开关损耗和噪声污染.这些干扰在小功率电路中可以被忽略,但在较大型的风力发电系统中是应该极力避免的.为了减小甚至避免这些不利因素影响系统的平稳运行,设计了一种基于零电压变换软开关技术的双PWM变换器,并且结合了空间矢量脉宽调制技术和PR控制方法.通过仿真试验和结果分析,验证了优化的变换器能够很好地改善传统变换器的输入和输出性能.
Institute of Scientific and Technical Information of China (English)
冯阳; 王奔; 王亚芳; 马明智
2014-01-01
Using the current mode PWM rectifier technology in the cascade speed regulation system for motor can e-liminate the need for the dc Boost chopper of the voltage - type converter cascade speed regulation system,thus,sim-plify the topology of the system,and improve the power factor of the regulation system and reduce the content of the transformer network side harmonic. But thecurrent mode PWM inverter under the dq coordinate system is a nonlinear coupling system,which is not conducive to the controller design,so This paper proposed precise linearization to line-arize and decouple the original system,constructed its pseudo linear system model,and designed a closed loop con-troller of the pseudo linear system by usingthe sliding mode variable structure control theory. At the same time,in the Matlab / Simulink software,a simulation model was established based on this control strategy. The simulation results showed that the control strategy could achieve rapidand effective regulation of the motor speed,and meanwhile could improve th epower factor of the system and reduce the harmonic content.%采用电流型 PWM 整流技术的串级调速系统，省去了电压型斩波串级调速系统中的直流 Boost 斩波环节，简化了系统的拓扑结构，同时也能够实现系统功率因数的提高和变压器网侧谐波含量的减少。考虑到电流型PWM 逆变器在 dq 坐标系下是一个非线性耦合系统，不利于控制器的设计，采用精确线性化方法对原系统进行线性化并解耦，构造其伪线性系统模型，运用滑模变结构控制理论设计该伪线性系统的闭环控制器。同时，在Matlab/ Simulink 软件下，建立了基于此控制策略的模型并进行仿真。结果表明，该控制策略可实现电动机转速的快速、有效调节，同时可提高系统的功率因数，减少谐波含量。
Electrical machine PWM loss evaluation basics
Energy Technology Data Exchange (ETDEWEB)
Ruderman, A. [The School of Engineering, Bar-Ilan Univ., Ramat-Gan (Israel); Welch, R. Jr. [IEEE, Welch Enterprise, Oakdale (United States)
2005-07-01
Modern power converters utilize pulse-width modulation (PWM) voltage control. Output voltage high frequency harmonics induce additional electrical machine loss. As there is no accepted PWM loss theory, PWM loss is usually accounted for by machine power de-rating. In-depth understanding of PWM loss mechanisms is important for predicting losses and improving energy efficiency of electrical machines. In this paper we suggest a new time domain PWM loss approach. It assumes that PWM eddy current iron loss dominates over PWM copper and hysteresis iron losses and comprises theoretical normalized PWM loss evaluation and experimental characterization. Once maximal PWM loss is measured, it can be scaled for an arbitrary operating point using simple formula. Theoretical results are shown to be in a good agreement with a published experimental data. (orig.)
AC Motor Drive Fed by Renewable Energy Sources with PWM
Directory of Open Access Journals (Sweden)
J. Pavalam
2014-01-01
Full Text Available In this fast aproaching nature of technology the ned of Electricity becomes a mandatory in developing technology. The ned of Electricity increases the power demand where the power demand met by the conventional sources of energy has some disadvantage of polution, this disadvantage can be decreased by the use of the Renewable energy sources like Fuel Cel and available solar energy. When a FUEL cel produces AC power, basicaly two stages are required for conversion first a bosting stage and second is inversion stage. In this paper the Bost inverter topology is achieved where in the conventional methods the normal DC - AC power conversion method is used where as in this paper the PWM based DC - AC inverter has ben used which is useful in reducing the harmonics in the output of the Inverter. The voltage controled output is produced in the bost inverter the curent controled output is taken from dc-dc bidirectional converter. The Fuel cel canot be relied as a whole so a Solar PV module is conected acros the Load so while the Sunlight days the PV arays generate power and in the night time the Fuel cel is used to generate power for the load. Since, the Fuel cel and PV arays can generate power in Partial load they are prefered than any other sources. When the output from the Solar PV aray is low or when the sunlight available is not eficient in generating the power a automatic switch over is provided in the junction betwen the Solar PV aray and Fuel cel so that whenever it hapens the switch automaticaly switch over to another source. The simulation results are presented to confirm the operational feature of the proposed system.
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.
Kondo, Yosuke; Natchpong, Hatti; Akagi, Hirofumi
This paper discusses a 6.6-kV transformerless motor drive system based on the back-to-back connection of two five-level diode-clamped PWM converters. In addition, this paper designs, constructs and experimentally tests a down-scaled model rated at 200V and 5.5kW. This system consist of the two five-level converters, a common dc-link, and voltage-balancing circuits using two bi-directional buck-boost choppers. Experimental results obtained from the down-scaled model verify the validity of the system design, giving promise of the viability of the 6.6-kV transformerless motor drive system.
Directory of Open Access Journals (Sweden)
Rasoul Shalchi Alishah
2015-06-01
Full Text Available In recent, several numbers of multilevel inverter structures have been introduced that the numbers of circuit devices have been reduced. This paper introduces a new structure for multilevel inverter which can be used in high-power applications. The proposed topology is based on cascaded connection of basic units. This topology consists of minimum number of circuit components such as IGBT, gate driver circuit and antiparallel diode. For proposed topology, two methods are presented for determination of dc voltage sources values. Multi-carrier PWM method for 25-level proposed topology is used. Verification of the analytical results is done using MATLAB simulation.
Morimoto, Keiki; Doi, Toshimitsu; Manabe, Haruhiko; Ahmed, Tarek; Hiraki, Eiji; Lee, Hyun-Woo; Nakaoka, Mutsuo
This paper presents a new circuit topology of full-bridge soft-switching PWM inverter linked DC-DC power converter composed of conventional full-bridge high frequency PWM inverter with high frequency transformer and an active quasi-resonant snubber consisting of an additional power switching device in series with DC busline and a lossless capacitor in parallel with DC busline. Under this proposed high frequency soft-switching PWM inverter linked DC-DC converter, four power switches in the full-bridge arms and DC busline series switch can achieve ZVS at turn-off commutation. By developing the advanced soft-switching PWM high frequency inverter type DC-DC converter, although the conduction power loss of DC busline series power switch increases a little, the total turn-off switching loss of full-bridge high frequency inverter power modules can be sufficiently lowered more and more in the higher frequency range of 60kHz. As a result, when the switching frequency of high frequency inverter power stage using IGBT power modules is designed so as to be more than about 10kHz, the more the switching frequency of inverter increases, the more this high frequency soft-switching DC-DC converter has remarkable advantage as for the power conversion efficiency as compared with the conventional hard-switching PWM inverter DC-DC converter. Its practical effectiveness of high power density and high performance is actually proved for TIG arc welding equipment in industry.
Design of a New AC–DC Single-Stage Full-Bridge PWM Converter with Two Controllers
Directory of Open Access Journals (Sweden)
R. Ramesh,
2014-03-01
Full Text Available Single phase power factor correction ac-dc converters are widely used in industry for ac-dc power conversion from single phase ac mains to an required output dc voltage. In case of high power application these types of converter use an ac-dc boost converter followed by dc-dc converter. These converters has the features of excellent input power factor, continuous input and output currents, and intermediate dc bus voltage and reduce the number of semiconductor devices for such cost-effective applications.
A novel three-phase-bridge cascaded PWM converter%一种新型的三相桥级联型PWM变换器
Institute of Scientific and Technical Information of China (English)
陆治国; 赵丽丽; 吴春军; 祝万平
2012-01-01
The traditional single-phase cascaded H-bridge converter (CHBC) can not be used for three-phase high-voltage applications directly, thus a novel topology of three-phase-bridge (3P-Bridge) cascaded PWM converter is proposed and its basic cell is a 3P-Bridge. Its construction idea is analyzed and the currents and power expressions are derived. The proposed topology in this paper can not only be operated as a rectifier but also an inverter. One-cycle control (OCC) and CPS-PWM are employed for their simulation research separately. Simulation results verify the feasibility of the proposed 3P-Bridge cascaded converter and show that the proposed topology can improve the voltage level, and comparing with the traditional single-phase CHBC, it can reduce the number of switches and DC capacitors (or separated DC sources), and the voltage ripple at DC side is smaller. So the proposed 3P-Bridge cascaded converter has better prospect in three-phase high-voltage applications.%传统的单相级联H桥变换器不易直接应用于三相高压场合,为此提出了三相桥级联型PWM变换器的拓扑结构,其子模块为电压源型三相桥式变换器.分析了该新型拓扑的构成思想,推导了二级和三级级联拓扑的电流和功率表达式,其可做整流器也可做逆变器,分别采用单周控制和载波相移控制对其进行仿真研究.仿真结果验证了该新型拓扑的可行性,表明其能够提升电压等级,与传统的单相级联H桥变换器构成的三相变换器相比,能够节省开关管和直流侧电容(独立电源)个数,且直流侧电压纹波较小,在三相高压场合具有较好的应用前景.
Park, Sung-Yun; Cho, Jihyun; Lee, Kyuseok; Yoon, Euisik
2015-12-01
We report a pulse width modulation (PWM) buck converter that is able to achieve a power conversion efficiency (PCE) of > 80% in light loads 100 μA) for implantable biomedical systems. In order to achieve a high PCE for the given light loads, the buck converter adaptively reconfigures the size of power PMOS and NMOS transistors and their gate drivers in accordance with load currents, while operating at a fixed frequency of 1 MHz. The buck converter employs the analog-digital hybrid control scheme for coarse/fine adjustment of power transistors. The coarse digital control generates an approximate duty cycle necessary for driving a given load and selects an appropriate width of power transistors to minimize redundant power dissipation. The fine analog control provides the final tuning of the duty cycle to compensate for the error from the coarse digital control. The mode switching between the analog and digital controls is accomplished by a mode arbiter which estimates the average of duty cycles for the given load condition from limit cycle oscillations (LCO) induced by coarse adjustment. The fabricated buck converter achieved a peak efficiency of 86.3% at 1.4 mA and > 80% efficiency for a wide range of load conditions from 45 μA to 4.1 mA, while generating 1 V output from 2.5-3.3 V supply. The converter occupies 0.375 mm(2) in 0.18 μm CMOS processes and requires two external components: 1.2 μF capacitor and 6.8 μH inductor.
零电压转换PWMDC/DC变换器的研究%Research on Zero-voltage-transition PWM DC/DC Converters
Institute of Scientific and Technical Information of China (English)
高原; 邱新芸
2005-01-01
介绍了PWM DC/DC变换器的软开关控制.阐述了零电压转换PWM DC/DC变换器的缺点.研究了带吸收电容的零电压转换PWM DC/DC变换器电路.给出了仿真电路和仿真结果.
DEFF Research Database (Denmark)
Beltran, H.; Perez, E.; Chen, Zhe
2009-01-01
This paper describes a Fixed Maximum Power Point analog control used in a step-down Pulse Width Modulated power converter. The DC/DC converter drives a DC motor used in small water pumping installations, without any electric storage device. The power supply is provided by PV panels working around...
Passivity-Based Control by Series/Parallel Damping of Single-Phase PWM Voltage Source Converter
del Puerto Flores, Dunstano; Scherpen, Jacqueline; Liserre, Marco; de Vries, Martijn M. J.; Kransse, Marco J.; Monopoli, Vito Giuseppe
2014-01-01
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 preferr
One-cycle-controlled Single-phase Half-bridge PWM Converter%单相半桥PWM变换器单周期控制研究
Institute of Scientific and Technical Information of China (English)
黄刚; 王友阳; 徐镭; 夏泽中
2015-01-01
在基本单周期控制基础上，提出一种单相半桥脉冲宽度调制变换器改进单周期控制算法，引进桥臂电容电压差值变量，构建桥臂电容电压闭环控制，明显改善了基本单周期控制算法应用在单相半桥脉冲宽度调制变换器中桥臂电容电压严重不平衡的问题，限制了桥臂电容中心点电压波动范围，使变换器系统稳定性增强，增强了带载能力，同时实现交流侧高功率。在理论分析的基础上，对控制算法进行了系统的建模仿真，仿真结果表明单相半桥变换器能改进单周期控制算法的有效性。%An improved one -cycle control algorithm was applied in single -phase half -bridge PWM converter .It was based on the basic one -cycle-controlled algorithm .The difference between the variable capacitor voltage arms was introduced to build the bridge arm capacitor voltage closed -loop control .This algorithm can improve the imbalance of the arm capacitor voltage in single-phase half-bridge PWM converter , and limit the fluctuation range of the center of the bridge capacitor volt-age.So the stability and the load capacity of the system could be enhanced .The high power factor in the AC side was achieved . Based on the theoretical analysis of this algorithm , system simulation was realized to demonstrate the effectiveness of this algo-rithm.
single-phase dc phase dc-ac boost converter ac boost converter ...
African Journals Online (AJOL)
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Change of load current flow is achieved with achieved ... increased efficiency and simpler controllers. 814698 .... Figure 2. Power circuit and controllers for the proposed boost inverter. ..... [13] R.D.Middlebrook and S. Cuk, ''A general unified.
DEFF Research Database (Denmark)
Fatu, Marius; Tutelea, Lucian; Teodorescu, Remus;
2007-01-01
This paper presents concepts and tests results on a flexible sensorless control strategy for a PMSG driven by a small wind turbine with back-to-back power converters capable to function in both stand alone and grid connection mode. A new automatic seamless transfer method, based on phase...
DEFF Research Database (Denmark)
Lin, Ma; Kerekes, Tamas; Rodriguez, Pedro
2015-01-01
Photovoltaic systems technological development is driven by the request for higher efficiency and safety. These concerns influence also the choice of the power converter stage. Several topologies have been proposed and many of them are available commercially. Among them, the neutral point clamped...
Directory of Open Access Journals (Sweden)
P. Gopal,
2015-11-01
Full Text Available The main objective of this concept is to examine the operation of fundamental buck-based three-phase singlestage ac–dc full-bridge converters. In this concept, the operation of this fundamental converter is explained and analyzed, and a procedure for the design of its key components is derived and demonstrated with an example and general concluding remarks comparing Buck-Based and Boost Based three Phase single-stage AC to DC full Bridge converters are made.
DEFF Research Database (Denmark)
Fatu, Marius; Tutelea, Lucian; Teodorescu, Remus
2007-01-01
This paper presents concepts and tests results on a flexible sensorless control strategy for a PMSG driven by a small wind turbine with back-to-back power converters capable to function in both stand alone and grid connection mode. A new automatic seamless transfer method, based on phase-locked-l......This paper presents concepts and tests results on a flexible sensorless control strategy for a PMSG driven by a small wind turbine with back-to-back power converters capable to function in both stand alone and grid connection mode. A new automatic seamless transfer method, based on phase......-locked-loop technique, from grid connected to stand alone and vice versa in the event of a fault on grid is proposed. Tests results show the proposed method works properly...
Full Bridge ZVT—PWM DC—DC Converter①
Institute of Scientific and Technical Information of China (English)
WEIYanjun; QIHanhong; 等
1997-01-01
A new FB-ZVT-PWM converter is proposed.The new converter operates at a fixed frequency and implements ZVS for power devices without increasing voltage in both turn-on and turn-off transient.A 80kHz/50 W FB-ZVT-PWM boost converter using MOSFETs is analysed theoretically.
Dynamic Localization Condition of Two Electrons in a Strong dc-ac Biased Quantum Dot Molecule
Institute of Scientific and Technical Information of China (English)
WANG Li-Min; DUAN Su-Qing; ZHAO Xian-Geng; LIU Cheng-Shi
2004-01-01
@@ We present a perturbation investigation of dynamic localization condition of two electrons in a strong dc-ac biased quantum dot molecule. By reducing the system to an Hubbard-type effective two-site model and by applying Floquet theory, we find that the dynamical localization phenomenon occurs under certain values of the large strength of the dc and ac field. This demonstrates the possibility of using appropriate dc-ac fields to manipulate dynamical localized states in mesoscopic devices, which is an essential component of practical schemes for quantum information processing. Our conclusion is instructive to the field of quantum function devices.
Influence of Load Modes on Voltage Stability of Receiving Network at DC/AC System
Directory of Open Access Journals (Sweden)
Mao Chizu
2016-01-01
Full Text Available This paper analyses influence of load modes on DC/AC system. Because of widespread use of HVDC, DC/AC system become more complex than before and the present modes used in dispatch and planning departments are not fit in simulation anymore. So it is necessary to find load modes accurately reflecting characteristics of the system. For the sake of the voltage stability, commutation failure, etc. the practical example of the receiving network in a large DC/AC system in China is simulated with BPA, and the influence of Classical Load Mode (CLM and Synthesis load model (SLM on simulation results is studies. Furthermore, some important parameters of SLM are varied respectively among an interval to analyse how they affect the system. According to this practical examples, the result is closely related to load modes and their parameters, and SLM is more conservative but more reasonable than the present modes. The consequences indicate that at critical states, micro variation in parameters may give rise to change in simulation results radically. Thus, correct mode and parameters are important to enhance simulation accuracy of DC/AC system and researches on how they affect the system make senses.
Institute of Scientific and Technical Information of China (English)
屈克庆; 陈国呈; 孙承波
2005-01-01
A novel software implementation for current polarity detection and current compensation is presented. For a three-phase zero-voltage soft-switching (ZVS) PWM converter based on phase and amplitude control (PAC), when saw-tooth carriers with alternate positive and negative slopes are adopted, the positive or negative slopes are chosen according to the phase current polarity. Since polarity reversal causes current distortion, current at the instant of reversal should be compensated for. Based on the characteristic of unity power factor converter in rectification and regeneration modes, a software implementation for current polarity detection is proposed.Distortion of current zero-crossing caused by using saw-tooth carriers with alternate positive and negative slopes is analyzed, and the relevant compensation method is proposed. Experimental study with a 1.5 kW device shows that phase current has a small harmonic content and power factor is high both in rectification and regeneration modes.
PV Power-Generation System with a Phase-Shift PWM Technique for High Step-Up Voltage Applications
Directory of Open Access Journals (Sweden)
Cheng-Tao Tsai
2012-01-01
Full Text Available A PV power-generation system with a phase-shift pulse-width modulation (PWM technique for high step-up voltage applications is proposed. The proposed power-generation system consists of two stages. In the input stage, all power switches of the full-bridge converter with phase-shift technique can be operated with zero-current switching (ZCS at turn-on or turn-off transition. Hence, the switching losses of the power switches can be reduced. Then, in the DC output stage, a voltage-doubler circuit is used to boost a high dc-link bus voltage. To supply a utility power, a dc/ac inverter is connected to induce a sinusoidal source. In order to draw a maximum power from PV arrays source, a microcontroller is incorporated with the perturbation and observation method to implement maximum power point tracking (MPPT algorithm and power regulating scheme. In this study, a full load power of 300 W prototype has been built. Experimental results are presented to verify the performance and feasibility of the proposed PV power-generation system.
Single stage buck-boost DC-AC neutral point clamped inverter
DEFF Research Database (Denmark)
Mo, Wei; Loh, Poh Chiang; Andrew, A.;
2012-01-01
This paper proposes a new single stage buck-boost DC-AC neutral point clamped inverter topology which integrates the cascaded configurations of recently introduced inductor-capacitor-capacitor-transformer impedance source network (by Adamowicz) and classic NPC configuration. As a consequence...... windings thus preventing the core from saturation; lowers the voltage stresses and power losses of inverter switches and reduces the sizes of filtering devices and as well as obtains better output performance compared to the original two-level Z-source inverters. A phase disposition pulse width modulation...
CONVERSION EFFICIENCY IMPROVEMENT FOR ENERGY CONSERVATION USING MATRIX CONVERTER
Directory of Open Access Journals (Sweden)
G.N. SURYA
2012-04-01
Full Text Available Efficient conversion of electrical energy from one form to another has always been a fascinating domain for researchers. Right from the era of mercury arc rectifiers to present AC-DC-AC two stage converters and cycloconverters, efforts are consistently being laid to minimize the losses involved in conversion process. In the present study the AC-AC conversion topology known as Matrix Converter (MC, is modeled using MATLAB. Venturini’s simplified algorithm is used to determine the switch modulation duty cycle. The model is designedfor conversion of 50 Hz input frequency to 100 Hz and 25 Hz, using a simplified switch modulation strategy. The waveforms generated by MATLAB/simulink confirm the reduction of conversion losses by 12% to 15% with use of proposed model as compared to conventional (PWM converters. It is not intended in this study just to list out various works done so for but to establish the brevity of fundamental concept representing the simplified design along with its application areas mainly the VFDs and Wind Energy Conversion Systems (WECS. The model has also been tested for control of induction motor with 100 HZ and 25 Hz output frequencies. The waveforms of changed frequencies and reduced losses confirm the results anticipated at design stage.
Directory of Open Access Journals (Sweden)
Mechouma Rabiaa
2014-01-01
Full Text Available In recent years, power demand of industrial applications has increased significantly reaching some megawatts. The use of multilevel converters for applications of medium and high powers is proposed as a solution to drawback semiconductor technology. A multilevel converter not only achieves high power ratings, but also enables the use of renewable energy sources. Renewable energy sources such as photovoltaic can be easily interfaced to a multilevel converter system for a high power application. This paper presents the simulation study in Matlab/Simulink of a grid connected photovoltaic three phase Neutral Point Clamped (NPC inverter with DC/DC boost converter for constant and variable solar radiation.
Institute of Scientific and Technical Information of China (English)
刘波; 金昊
2014-01-01
由于双 P WM变换器的永磁直驱风电系统在常规控制策略下，当风速变化时，存在直流侧电容电压波动较大、控制系统的响应速度较慢的现象，提出有功功率前馈补偿协调控制策略。将发电机侧瞬时有功功率作为前馈信号送到网侧变换器功率控制内环，对有功功率变化扰动直接调节，协调控制双P WM变换器两侧有功功率，实现瞬时有功功率平衡，有效抑制直流侧电压的波动，同时加快控制系统的响应速度。在此基础上，在前馈控制通道中加入补偿环节，进一步提高前馈控制效果。并通过对比仿真，验证了控制策略的正确性和有效性。%Considering the fact that in conventional control strategy,the DC side capacitor voltage of dual PWM converter-based direct-drive permanent-magnet wind power system has lager fluctuation and slower con-trol system response,a coordinated control strategy of active power feed-forward compensation was proposed, in which,having motor-side instantaneous active power sent to the grid-side converter power control loop as a feed-forward signal to regulate active power change disturbance directly and to control active power of dual PWM converter on both sides coordinately so that the instantaneous active power can be balanced and the DC bus voltage fluctuation can be inhibited effectively,as well as the control system response can be accelerated. On this basis,a compensation step added in the feed-forward control channel can further improve feed-forward control.Simulation and comparison results verify both correctness and effectiveness of this control strategy.
Institute of Scientific and Technical Information of China (English)
李宁; 王跃; 王兆安
2014-01-01
In modulation strategies for three-level neutral point clamped (NPC) converters the double modulation wave carrier-based PWM (DMWPWM) strategy is such a modulation strategy, by which the neutral point voltage control under the entire modulation index and full power factor can be achieved. Firstly, the basic principle of existing DMWPWM strategies are analyzed and the relation between modulation wave in DMWPWM and that in traditional sinusoidal pulse width modulation (SPWM) is analyzed, and on this basis a DMWPWM strategy for three-level NPC converter is proposed;secondly, in the aspects of total harmonic distortion (THD) characteristic of output phase voltage, DC voltage utilization and switching loss of the device the proposed DMWPWM strategy is compared with traditional SPWM strategy to further expound the features of the proposed method. The correctness of theoretical analysis is validated by results from simulation and experiments.%三电平NPC变流器的调制策略中，双调制波载波调制策略(double modulation wave carrier-based PWM ， DMWPWM)是一种可以实现全调制度和全功率因数中点电压无波动的调制策略。首先分析了已有DMWPWM策略的基本原理，推导了DMWPWM策略调制波与传统SPWM策略调制波的关系，在此基础上提出了应用于三电平NPC变流器的DMWPWM策略。然后，从输出相电压总谐波畸变率(total harmonic distortion，THD)特性、直流电压利用率以及器件开关损耗三方面对新型DMWPWM策略与传统正弦脉冲宽度调制(sinusoidal pulse width modulation，SPWM)策略进行对比，进一步阐明了所提方法特点。仿真和实验结果验证了理论分析的正确性。
Institute of Scientific and Technical Information of China (English)
刘勇; 黎建勋
2015-01-01
Electric propulsion system has been used widely in fishing vessels the technology improving. Electric propulsion system with three-phase PWM rectifier, has already been mature in the technology. But for part of fishing vessel with single-phase AC power supply system, the research and application for electric propulsion system is less. This paper introduces the basic principlesof single-phase voltage source PWM rectifier, analyze the predictive current control methods. The dynamic response and the static precision of four-quadrant converter with predictive current control methodsare much better. In this paper, through computer simulations to verify the feasibility of predictive current control methods and validity of the main circuit parameter selection. Then, through experimental platform debugging which withTMS320LF2407 DSP chip as the core, the result is very well coincident with the simulated result. It shows that this method has good dynamic and static performance, can meet the need of four-quadrant converter design requirementscompletely. It is an ideal control method.%随着电力推进系统在我国渔业船舶上的不断推广应用，在系统中采用三相交流PWM整流器在技术上已经比较成熟。本文从单相电压型PWM整流器的基本原理出发，对预测电流控制方法进行了分析，认为该方法进一步改善了四象限变流器的动态响应特征，提高了稳态控制精度。通过计算机仿真试验，验证了预测电流算法的可行性以及主电路参数选择的正确性，并在仿真的基础上，以TMS320LF2407 DSP控制芯片为核心，实现了预测电流控制算法在三相PWM整流器小功率实验平台上的软件调试。试验结果与仿真有很好的一致性，表明该方法具有较好的动态、静态性能，完全能够达到四象限变流器的设计要求，是一种比较理想的控制方法。
Research on the Core Loss Model Under PWM Wave and DC Bias Excitations%PWM波及直流偏磁励磁下磁芯损耗模型研究
Institute of Scientific and Technical Information of China (English)
叶建盈; 陈为; 汪晶慧
2015-01-01
In order to evaluate and predict the core losses of magnetics in power converters, by equivalently replacing the dynamic B-H loop which surrounding area reflects the core losses in a magnetizing cycle period with an elliptical loop, the model of magnetics core losses under the PWM excitation without DC bias was derived. The core losses of magnetics under both DC bias and PWM excitations using a DC/AC inverter as the test circuit were measured by differential loss test idea. By the analysis of the core loss test results and their characteristics, a new core loss model considering the effects of both DC bias and PWM excitations was conceived based on the basic B-H curve. Finally, the test results were compared with the proposed model and the model accuracy was verified.%为了有效地评估和预测功率变换器中磁元件的磁芯损耗，将反映磁芯一个励磁周期内损耗的动态磁滞回线以椭圆回线等效，推导出了无直流偏磁工况下脉宽调制(pulse width modulation，PWM)波形励磁的磁芯损耗模型。采用差值损耗测量思想，以DC/AC逆变电路作为测试电路，测量了直流偏磁及PWM波励磁下的磁芯损耗。进一步根据直流偏磁下磁芯损耗的测量结果及其特征的分析，构思了以磁芯基本磁化曲线模型为基础的直流偏磁和 PWM 波励磁下的磁芯损耗模型。最后，对比了测试数据和所提出的模型的计算结果，验证了模型的正确性。
Round, Simon; Schafmeister, Frank; Heldwein, Marcelo; Pereira, Eduardo; Serpa, Leonardo; Kolar, Johann
This paper undertakes a comparison of the very sparse matrix converter (VSMC) and the back-to-back voltage DC-link converter (BBC) for a permanent magnetic synchronous motor drive application. The VSMC has the same functionality as the conventional matrix converter but a reduced number of switches and lower control complexity. The two converters are designed, using the same IGBT power modules, with a switching frequency of 40kHz and a thermal rating of 6.8kW at an ambient temperature of 45°C. From the design, the volume of the VSMC is 2.3 liters and is half that of the BBC. The efficiency for the VSMC at full load is 94.5% compared to 92% for the BBC. At very low output frequencies the output current of the VSMC can be increased by 25% above nominal compared to a 54% decrease for the BBC. Overall the VSMC offers advantages in volume and efficiency for motor drive applications requiring switching frequencies above 10kHz.
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...
Application of film capacitor in DC-link of wind power PWM converter%薄膜电容器在风电PWM变流器直流环节的应用
Institute of Scientific and Technical Information of China (English)
辛倩; 林资旭; 赵斌; 许洪华
2011-01-01
An appropriate film capacitor was selected to take the place of aluminum electrolytic capacitor apply in DC-link of the PWM converter system through the calculation of capacitance and ripple current. The feasibility of the principle of selecting the minimum capacitance is proven by using improved control strategy in Matlab simulation. The film capacitor, which was selected based on the selection principle performed well in DC-link of 2MW DFIG system.%通过计算变流器直流环节的电容量和纹波电流,选取合适的薄膜电容器应用于风电变流器直流环节,取代铝电解电容器.利用Matlab仿真软件,使用改进的控制策略,验证了最小电容量选取原则的可行性.将此原则应用于2 MW风电用双馈变流器直流环节薄膜电容器的选型,取得了较为理想的效果.
Institute of Scientific and Technical Information of China (English)
杨博; 杜海江; 吕剑刚; 孙航
2014-01-01
基于功率变换器脉宽调制(pulse width modulation PWM)技术实现通信功能，就是在保证对功率变换器输出功率进行控制的同时，实现设备间的有效通信。文章以光伏阵列发电系统为应用对象，设计了相应的通信方法实现系统中设备之间的通信：改变载波频率对信源信号进行调制，生成PWM开关驱动信号作为信源信号的调制信号，同时驱动开关管控制功率传输；解调时，提出以电流信号作为检测对象，设计了幅值阈值判定法和能量值阈值判定法确定信源信号的起始码元及后续码元，最终实现同一光伏组串内的不同光伏组件之间、以及组件与阵列通信终端之间的有效通信。仿真设计相应的系统参数和工况来模拟光伏阵列系统的通信过程，并在通信的同时改变占空比实现功率调节，结果表明了所提方法的有效性。%The essence of communication function based on pulse width modulation (PWM) technology of power converter is to implement effective communication among devices while the output power control of power inverter is ensured. Taking the generation system composed of photovoltaic cell arrays as the object to apply the proposed communication method, a corresponding method for the communication among devices in PV array generation system is designed, that is, the source signal is modulated by changing carrier frequency to generate the driving signal of PWM switch, which is taken as the modulation signal of source signal;for the demodulation, it is proposed to take the current signal as the detected object, and the amplitude threshold based judgment method and the energy threshold based judgment method are designed to determine the initial code element and subsequent code elements, eventually the effective communication among different PV modules in the same PV module string and that among modules and array communication terminals are realized. Corresponding
Self oscillating PWM modulators, a topological comparison
DEFF Research Database (Denmark)
Poulsen, Søren; Andersen, Michael Andreas E.
2004-01-01
or fs/ð range respectively, where fs is the switching frequency of the converter. For some applications this will require unacceptable high switching frequency to achieve enough control loop bandwidth for the desired dynamic performance. With self oscillating modulators, the open loop bandwidth is equal...... to fs which makes this type of modulators an excellent choice for a wide range of applications. Self oscillating PWM modulators can be made in a number of ways, either as voltage or current mode modulators, and the self oscillating behavior can be achieved either by using hysteresis control......High precision control of the output voltage or current of a switch mode converter with fast response is required for a number of applications. Dependent on the type of application, the desired precision and transient response can be difficult, if not impossible, to achieve with standard PWM...
Perra, Andre
1992-04-01
The use of pulse-width-modulated (PWM) inverter technology by on-line uninterruptible power supplies (UPSs) of 250 VA-750 kVA rating improves transient performance, lowers harmonic distortion, and enhances nonlinear load performance. An account is presently given of the means employed for optimization of a PWM inverter used in a multi-kHz UPS. By using computer modeling to optimize the feedback control loop, the best level of response was furnished, while minimizing switching losses and achieving the highest level of efficiency.
DEFF Research Database (Denmark)
Wang, Songcen; Teodorescu, Remus; Máthé, Lászlo
2015-01-01
This paper focuses on modeling and SOC (State of Charge) balancing control of lithium-ion battery energy storage system based on cascaded multilevel converter for both grid integration and electric vehicle propulsion applications. The equivalent electrical circuit model of lithium-ion battery...... is adopted to control active power and reactive power independently, and the zero-sequence voltage injection and a sorting and select algorithm are employed for SOC balancing control. The simulation results have been carried out with PLECS Simulation Software and are presented to validate the SOC control...
Analysis and Simulation of a High Performance Quasi Resonant PWM Inverter for Solar Power Generation
Institute of Scientific and Technical Information of China (English)
Yun-Parn Lee; Yu-Huang Lin; Yu-Lun Lin
2016-01-01
A quasi resonant pulse width modulation (PWM) inverter is used in a solar power system to convert the solar panel and battery charger’s direct current (DC) output to alternating current (AC). Although much has been published about DC to AC PWM inverters, none of the previous work has shown modeling and simulation results for DC to AC inverters. In this study, we suggest a new topology for a quasi resonant PWM inverter. Experimental results are also presented.
Simulation of the Relaxation Potential Profile of an ac-dc-ac Test
Directory of Open Access Journals (Sweden)
Kerry N. Allahar
2014-01-01
Full Text Available The relaxation period of the accelerated ac-dc-ac test for coatings is associated with the transient electrochemistry that occurs when the immersed coated system is allowed to return to a stable open-circuit condition after being subjected to a cathodic potential. A mathematical model of the transient electrochemistry that occurs during this relaxation period is presented for coated aluminum. Expressions for the corrosion potential and corrosion current as functions of the local pH at the metal-coating interface were developed using reported experimental results. These expressions enabled the simulation of the transient electrochemistry under the constraint of balanced anodic and cathodic current densities. Regression of the transient relaxation potential profiles to exponential decay functions provided time-constant characterization of the profiles. Simulated results are presented that demonstrate the influences of the coating's porosity and thickness, the applied dc potential and the metal-coating interface condition on the time-constants associated with the relaxation profile. Interpretation of experimentally reported relaxation potential profiles supported the analysis of the simulated results.
Wind Energy Conversion System with Boost Converter and CHB MLI with single DC input
Directory of Open Access Journals (Sweden)
Porselvi T
2014-03-01
Full Text Available The developments in power electronics technology have led to the developments in the wind energy conversion system (WECS. The output voltage of the WECS depends on the speed of the wind, which is not constant. Hence, a power conversion unit is required to maintain the output voltage of the WECS constant. This paper presents the design of a boost converter and a voltage controller for maintaining the DC-link voltage of the system constant. A new topology of the cascaded H-bridge multilevel inverter (CHB MLI is proposed for the DC/ AC conversion. The proposed topology eliminates the requirement of separate DC sources. The multilevel inverter is controlled by the selective harmonic elimination pulse width modulation (SHE-PWM technique. The system is simulated in MATLAB/ Simulink for varying wind speeds. The simulated waveforms of the PMSG rotor speed, the PMSG voltage, the boost converter voltage and the CHBMLI voltages are shown and the results obtained are found to be satisfactory.
EMC Increasing of PWM Rectifier in Comparison with Classical Rectifier
Directory of Open Access Journals (Sweden)
R. Dolecek
2008-12-01
Full Text Available Pulse width modulated rectifier is a very popular topic nowadays. The modern industrial production demands continuous and lossless conversion of electrical energy parameters. This need leads to wide spread of power semiconductor converters. The rapid development in power electronics and microprocessor technology enables to apply sophisticated control methods that eliminate negative side effects of the power converters on the supply network. The phase controlled thyristor rectifiers overload the supply network with higher harmonics and reactive power consumption. That is why the PWM rectifier is being examined. In comparison with the phase controlled rectifier it can be controlled to consume nearly sinusoidal current with power factor equal to unity. Another advantage is its capability of energy recuperation. The PWM rectifier can assert itself for its good behavior in many applications, for example as an input rectifier in indirect frequency converter, or in traction. Traction vehicles equipped with PWM rectifier do not consume reactive power, do not load the supply network with higher harmonics, and the recuperation is possible. The paper deals with the PWM rectifier functional model realization and examination. Electromagnetic compatibility of PWM rectifier and classical phase controlled rectifier is compared on the basis of the input current harmonic analysis.
Inga Llanez, Eddison de Jesús; Juela Juela, John José
2013-01-01
Diseño y construcción de cuatro módulos para convertidores DC-AC, módulo de sensores de corriente con una máxima a medir de 25A, módulo de sensores de tensión a 500V, módulo de transistores IGBTs de 100A cada uno y módulo generador de modulaciones vectoriales, al trabajar en conjunto permiten monitorear y convertir de corriente continua a alterna sin sobrepasar los niveles máximos de operación. Design and construction of four modules for DC-AC converters, sensor module with a maximum curre...
Harada, Taro; Murakoshi, Yuino; Torii, Yuka; Tanase, Koji; Onozaki, Takashi; Morita, Shigeto; Masumura, Takehiro; Satoh, Shigeru
2011-04-01
Carnation (Dianthus caryophyllus) flowers exhibit climacteric ethylene production followed by petal wilting, a senescence symptom. DcACS1, which encodes 1-aminocyclopropane-1-carboxylate synthase (ACS), is a gene involved in this phenomenon. We determined the genomic DNA structure of DcACS1 by genomic PCR. In the genome of 'Light Pink Barbara', we found two distinct nucleotide sequences: one corresponding to the gene previously shown as DcACS1, designated here as DcACS1a, and the other novel one designated as DcACS1b. It was revealed that both DcACS1a and DcACS1b have five exons and four introns. These two genes had almost identical nucleotide sequences in exons, but not in some introns and 3'-UTR. Analysis of transcript accumulation revealed that DcACS1b is expressed in senescing petals as well as DcACS1a. Genomic PCR analysis of 32 carnation cultivars showed that most cultivars have only DcACS1a and some have both DcACS1a and DcACS1b. Moreover, we found two DcACS1 orthologous genes with different nucleotide sequences from D. superbus var. longicalycinus, and designated them as DsuACS1a and DsuACS1b. Petals of D. superbus var. longicalycinus produced ethylene in response to exogenous ethylene, accompanying accumulation of DsuACS1 transcripts. These data suggest that climacteric ethylene production in flowers was genetically established before the cultivation of carnation.
Institute of Scientific and Technical Information of China (English)
王建华; 张方华; 龚春英
2014-01-01
提出了双向功率流动场合的PWM Switch模型,同时选取典型的Buck/Boost双向变换器作为评估平台.小信号分析结果表明,Buck/Boost双向直直变换器通过仅控制Buck模式主控管可以对电池充放电模式进行切换.其提供了对变换器稳态及动态性能研究的一种快速仿真方法.基于改进PWM Switch模型及器件级电路的详尽仿真对比验证了模型的精确性.
DEFF Research Database (Denmark)
Mathe, Laszlo; Lungeanu, Florin; Rasmussen, Peter Omand;
2010-01-01
This paper presents a new fixed carrier frequency random PWM method, where a new type of carrier wave is proposed for modulation. Based on the measurements, it is shown that the spread effect of the discrete components from the motor current spectra is very effective independent of the modulation...... index. The flat motor current spectrum generates an acoustical noise close to the white noise, which may improve the acoustical performance of the drive. The new carrier wave is easy to implement digitally, without employing any external circuits. The modulation method can be used in open, as well...
Institute of Scientific and Technical Information of China (English)
屈克庆; 陈国呈; 孙承波
2004-01-01
This paper presents a novel current feedforward control strategy for a three-phase pulse-width modulation (PWM) DC voltage-type converter based on phase and amplitude control (PAC).With right-angle triangle relation of phasors and principle of conservation of energy, a phasor adjustment method and the relevant low-frequency mathematical model of the system are analyzed in detail, both in rectification and regeneration modes for the converter, are discussed.For improving the traditional PAC dynamic performance, variable load current is detected indirectly by the change of the DC voltage, which is fed to the control system as an additional control variable to generate modulation index and phase angle.Also, the algorithm is derived and the system principle is introduced.Experimental results from a 3 kw laboratory device are included to demonstrate the effectiveness of the proposed control strategy.
Neural network based PWM AC chopper fed induction motor drive
Directory of Open Access Journals (Sweden)
Venkatesan Jamuna
2009-01-01
Full Text Available In this paper, a new Simulink model for a neural network controlled PWM AC chopper fed single phase induction motor is proposed. Closed loop speed control is achieved using a neural network controller. To maintain a constant fluid flow with a variation in pressure head, drives like fan and pump are operated with closed loop speed control. The need to improve the quality and reliability of the drive circuit has increased because of the growing demand for improving the performance of motor drives. With the increased availability of MOSFET's and IGBT's, PWM converters can be used efficiently in low and medium power applications. From the simulation studies, it is seen that the PWM AC chopper has a better harmonic spectrum and lesser copper loss than the Phase controlled AC chopper. It is observed that the drive system with the proposed model produces better dynamic performance, reduced overshoot and fast transient response. .
Large-Signal Lyapunov-Based Stability Analysis of DC/AC Inverters and Inverter-Based Microgrids
Kabalan, Mahmoud
Microgrid stability studies have been largely based on small-signal linearization techniques. However, the validity and magnitude of the linearization domain is limited to small perturbations. Thus, there is a need to examine microgrids with large-signal nonlinear techniques to fully understand and examine their stability. Large-signal stability analysis can be accomplished by Lyapunov-based mathematical methods. These Lyapunov methods estimate the domain of asymptotic stability of the studied system. A survey of Lyapunov-based large-signal stability studies showed that few large-signal studies have been completed on either individual systems (dc/ac inverters, dc/dc rectifiers, etc.) or microgrids. The research presented in this thesis addresses the large-signal stability of droop-controlled dc/ac inverters and inverter-based microgrids. Dc/ac power electronic inverters allow microgrids to be technically feasible. Thus, as a prelude to examining the stability of microgrids, the research presented in Chapter 3 analyzes the stability of inverters. First, the 13 th order large-signal nonlinear model of a droop-controlled dc/ac inverter connected to an infinite bus is presented. The singular perturbation method is used to decompose the nonlinear model into 11th, 9th, 7th, 5th, 3rd and 1st order models. Each model ignores certain control or structural components of the full order model. The aim of the study is to understand the accuracy and validity of the reduced order models in replicating the performance of the full order nonlinear model. The performance of each model is studied in three different areas: time domain simulations, Lyapunov's indirect method and domain of attraction estimation. The work aims to present the best model to use in each of the three domains of study. Results show that certain reduced order models are capable of accurately reproducing the performance of the full order model while others can be used to gain insights into those three areas of
DEFF Research Database (Denmark)
Abdelhakim, Ahmed; Mattavelli, Paolo; Davari, Pooya
2017-01-01
This paper investigates and evaluates the performance of a single-phase split-source inverter (SSI), where an alternative unidirectional dc-ac configuration is used. Such configuration is utilized in order to use two common-cathode diodes in a single-device instead of using two separate diodes......, resulting in minimum parasitic inductance in the commutation paths. In this paper, the analysis and modulation of the single-phase SSI using this alternative configuration is discussed, and the analysis of the low frequency component in the dc side is introduced. Moreover, the features behind employing...... the triangular, the trailing-edge sawtooth, and the leading-edge sawtooth carriers with the single-phase SSI are discussed, and the differences among these carriers are highlighted. In order to highlight the performance of the proposed SSI, a comparative study is conducted with the two-stage architecture...
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
This letter presents a multi-frequency proportional-resonant (MFPR) current controller developed for PWM voltage source converter (VSC) under the unbalanced supply voltage conditions. The delta operator is used in place of the shift operator for the implementation of MFPR by using a low-cost fixed-point DSP. The experimental results with an alternative control strategy validated the feasibility of the proposed MFPR current controller for the PWM VSC during voltage unbalance.
Institute of Scientific and Technical Information of China (English)
巫付专; 侯婷婷; 韩梁; 冯占伟
2015-01-01
针对输入侧采用不可控整流AC／DC／AC结构的单相动态电压恢复器（ DVR ）输入侧功率因数低，谐波含量高等问题，提出了一种基于PWM斩波变换器的动态电压恢复器来补偿负载两端电压的跌落。该新型拓扑结构采用PWM斩波控制节省了直流侧电容，简化了滤波器设计，使输入侧线路中谐波含量降低，同时达到单位功率因数；电压检测采用单相信号构造成两相信号，利用瞬时无功理论对信号进行检测与处理，实时性高；搭建MATLAB／Simulink仿真和系统实验平台，验证其合理性和可行性。%In view of such problems as the low input side power factor of the single-phase dynamic voltage restorer ( DVR) with the structure of uncontrolled rectifier AC/DC/AC and high harmonic content , this paper proposed a DVR based on the PWM chopper to compensate for the voltage drop at the two load ends .The new topology , which a-dopted the PWM chopper control , saved the DC capacitor and simplified the filter design so that the harmonic content in the input-side circuit was reduced and the input side achieved the unit power factor .Single-phase signals were con-structed into two-phase signals to detect voltage and the instantaneous reactive power theory was used to detect and process the signals , which attained high real time .Finally, a MATLAB/Simulink simulation and experimental plat-form was constructed to verify the rationality and feasibility of the new structure .
On the Well-posedness of the PWM Control System
Institute of Scientific and Technical Information of China (English)
FAN Qi-fu; SHI Song-jiao
2006-01-01
One of the basic issues in the study of hybrid systems is the well-posedness (existence and uniqueness of solutions) problem of discontinuous dynamical systems.This paper addresses this problem for a class of piecewise affine discontinuous systems with affine inequalities such as systems with pulse-width modulator under the definition lexicographic inequalities and the smooth continuation property of solutions.Furthermore,it is clear that when carrier signal h(t)=0,closed-loop pulse-width modulation (PWM) DC-DC converters are not well posed,and when some condition is satisfied,the closed-loop PWM DC-DC converters with a P controller are well posed.
Digital model for harmonic interactions in AC/DC/AC systems
Energy Technology Data Exchange (ETDEWEB)
Guarini, A.P.; Rangel, R.D.; Pilotto, L.A.S.; Pinto, R.J.; Passos Junior, R. [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)
1994-12-31
The main purpose of this paper is to present a model for calculation of HVdc converter harmonics taking into account the influence of the harmonic interactions between the ac systems in dc link transmissions. The ideas and methodologies used in the model development take into account the dc current ripple and ac voltage distortion in the ac systems. The theory of switching functions is applied to contemplate for the frequency conversions between the ac and dc sides, in an iterative process. It is possible then to obtain, even in balanced situations, non-characteristic harmonics that are produced by frequencies originated in the other terminal, which can be significant in a strongly coupled system, such as back-to-back configuration. (author) 9 refs., 3 figs.
Bidirectional converter interface for a battery energy storage test bench
DEFF Research Database (Denmark)
Trintis, Ionut; Thomas, Stephan; Blank, Tobias;
2011-01-01
This paper presents the bidirectional converter interface for a 6 kV battery energy storage test bench. The power electronic interface consists a two stage converter topology having a low voltage dc-ac grid connected converter and a new dual active bridge dc-dc converter with high transformation...... ratio. The dc-dc converter controls the battery charge/discharge current while the grid converter controls the common dc-link voltage and the grid current. The applied control structures and the hardware implementation of both converters are presented, together with their interaction. Experimental...
Bidirectional converter interface for a battery energy storage test bench
DEFF Research Database (Denmark)
Trintis, Ionut; Thomas, Stephan; Blank, Tobias
2011-01-01
This paper presents the bidirectional converter interface for a 6 kV battery energy storage test bench. The power electronic interface consists a two stage converter topology having a low voltage dc-ac grid connected converter and a new dual active bridge dc-dc converter with high transformation...... ratio. The dc-dc converter controls the battery charge/discharge current while the grid converter controls the common dc-link voltage and the grid current. The applied control structures and the hardware implementation of both converters are presented, together with their interaction. Experimental...
DC to DC converters: operation; Hacheurs: fonctionnement
Energy Technology Data Exchange (ETDEWEB)
Bernot, F. [Ecole d' Ingenieurs de Tours, 37 (France)
2002-05-01
This article deals with pulse width modulation (PWM) and pulse position modulation (PPM) DC to DC converters. A tri-phase PWM converter is made of 6 simple DC/DC converters grouped together into 3 reversible converters of the same type: 1 - single-quadrant voltage lowering converters (hydraulic analogy, study with ideal elements, full scheme with input and output filters); 2 - single-quadrant voltage raising converters (hydraulic analogy, operation); 3 - two quadrants reversible converters (structure construction, quadrants of operation, reversible converter connected to a DC motor); 4 - four-quadrants reversible converters; 5 - other converters structure (current converters and converters with intermediate storage, asymmetrical converters, converters with capacitive storage, insulated converters, resonating converters, status); 6 - conclusion. (J.S.)
Three-Phase PWM Power Conversion--The Route to Ultra High Power Density and Efficiency
Institute of Scientific and Technical Information of China (English)
J W Kolar; J Minib(o)ck; T Nussbaumer
2005-01-01
A review of three-phase PWM converter topologies which do show a low complexity/high reliability and high efficiency and power density and are therefore of main interest for a future industrial application is presented.A three-switch/level Boost-type PWM rectifier (VIENNA Rectifier),a Buck+Boost-type PWM rectifier with wide output voltage range and the AC/AC Sparse Matrix Converter concept are discussed in detail and topics to be treated in the course of further research are identified. Finally,it is shown how the aspects being relevant for the realization of highly compact converter systems could be integrated into education in the field.
DEFF Research Database (Denmark)
Nguyen-Duy, Khiem; Liu, Tian-Hua; Chen, Der-Fa
2011-01-01
The matrix converter system is becoming a very promising candidate to replace the conventional two-stage ac/dc/ac converter, but system reliability remains an open issue. The most common reliability problem is that a bidirectional switch has an open-switch fault during operation. In this paper, a...
OFDM-PWM scheme for visible light communications
Zhang, Tian; Ghassemlooy, Zabih; Rajbhandari, Sujan; Popoola, Wasiu O.; Guo, Shuxu
2017-02-01
In this paper, we propose an improved hybrid optical orthogonal frequency division multiplexing (O-OFDM) and pulse-width modulation (PWM) scheme for visible light communications. In this scheme, a bipolar O-OFDM signal is converted into a PWM format where the leading and trailing edges convey the frame synchronization and modulated information, respectively. The proposed scheme is insensitive to the non-linearity of the light emitting diode (LED) as LEDs are switched 'on' and 'off' between two points. Therefore, the tight requirement on the high peak-to-average-power-ratio (PAPR) in O-OFDM is no longer a major issue. The simulation and experimental results demonstrate that the proposed scheme offers an improved bit error rate performance compared to the traditional asymmetrically clipped O-OFDM (ACO-OFDM).
Energy Technology Data Exchange (ETDEWEB)
Cocquerelle, J.L.
1996-07-01
This book deals with the analysis of power electronic converters and of their conducted disturbances, in particular the emission of harmonic currents. The basic electrical and electrotechnical knowledge is recalled first (power distribution systems, transformers..) and then the different types of converters are presented in a first chapter and illustrated with a description and a numerical analysis of each of them: DC-DC, AC-AC, AC-DC and DC-AC converters. A second chapter is devoted to low voltage single-phase and tri-phase distribution systems and transformers. (J.S.)
Institute of Scientific and Technical Information of China (English)
郑玮仪; 曾志勇; 赵荣祥
2016-01-01
对故障后并网型三相脉宽调制(pulse width modulation, PWM)变换器系统建模、矢量调制技术和系统控制策略3个方面进行详细的研究.分析容错后变换器工作原理,建立容错后电力变换器三相静止模型.该模型揭示了故障后电容中性点电压波动的固有原因.利用伏秒平衡原理,推导基于三相静止系下矢量调制方法,该方法无需复杂的三角函数运算,且具有统一的表达公式.利用电流纹波有效值对容错后矢量调制算法进行评估,以便选择电流性能良好的调制算法.为防止中性点电压偏移对系统造成的影响,提出一种基于修正故障相调制波的中性点电压偏移控制方法,保证故障后并网变换器稳定安全运行.实验结果证明,所提方法提高电流品质,实现了故障后并网变换器稳定安全运行.
Institute of Scientific and Technical Information of China (English)
池伟; 石庆均; 陈宏伟; 马智泉
2012-01-01
Aiming at the control of direct-driven wind-power system with permanent magnet synchronous generators(PMSG) based on back-to-back PWM converter, the control strategies of generator-side converter and grid-side converter were analyzed in detail, and a control strategy of pitch angle was presented. A simulation for direct-driven wind-power system with PMSG using Matlab/Simulink was implemented. The simulation results show that direct-driven wind-power system with PMSG can operate stably under different wind speed, while it can achieve maximum power point tracking for wind energy under rated wind speed and. Limit the output power of wind-power system to rating power by pitch angle control. The results prove that the proposed control strategy of pitch angle is correct and viable.%针对基于双PWM变换器的永磁直驱风电系统的控制问题,对该风电系统电机侧变换器、电网侧变换器的控制策略进行了详细的分析,提出了一种桨距角控制策略,并基于Matlab/Simulink对永磁直驱风电系统进行了仿真.仿真结果表明,永磁直驱风电系统能够在不同风速下稳定运行,在额定风速以下可实现风能的最大功率跟踪,在额定风速以上通过桨距角控制能将风机系统的功率输出限制在额定值附近.研究结果验证了所提出的桨距控制策略的可行性.
Analysis of DC/DC Converter Efficiency for Energy Storage System Based on Bidirectional Fuel Cells
DEFF Research Database (Denmark)
Pittini, Riccardo; Zhang, Zhe; Andersen, Michael A. E.
2013-01-01
Renewable energy sources are fluctuating depending on the availability of the energy source. For this reason, energy storage is becoming more important and bidirectional fuel cells represent an attractive technology. Fuel cells require highcurrent low-voltage dc-dc or dc-ac converters as power...
Energy Technology Data Exchange (ETDEWEB)
Barbosa, Peter Mantovanelli
1993-10-01
This work introduces a new power supply by PWM, operating at constant frequency, with soft communication. The new topology uses only two active switches and absorbs the transformer leakage inductance. Besides, the soft communication takes place with no conduction loss penalty, in comparison with conventional hard switch PWM converters. Principle of operation, analysis, design and experimentation results taken from laboratory prototype rated at 400 W/48 v, 40 Khz, using IGBT are presented. (author) 10 refs., 71 figs.
Novel Topology for (plus minus 600 A,plus minus 12 V) four-Quadrant Converter
Bordry, Frederick; Coulibaly, P; Meynard, T
1998-01-01
The LHC machine makes extensive use of true bipolar power converters. All these converters will be installed underground; this installation leads to the necessity for reduced volume and high efficiency for the power converters.This paper presents a novel four-quadrant topology. This DC-AC-DC topology is fully reversible and the soft-commutation is achieved in all the switches over the full range of operation. Thorough analysis, simulation and experimental results are presented.
Selection of Carrier Waveforms for PWM Inverter
Institute of Scientific and Technical Information of China (English)
陈国呈; 屈克庆; 许春雨; 孙承波
2003-01-01
In this paper the influence of different carrier waveforms upon the output characteristics of PWM inverter is described in detail. When a triangular carrier waveform is used in hard-switching PWM inverters, harmonics exist in the neighborhood of the output frequency of the inverter output voltage and current due to the dead time. The triangular carrier waveform used in soft-switching PWM inverter will cause difficulties in controlling resonance-trigger time, higher loss in the resonant circuit, and less utilization of the DC bus voltage. If a sawtooth carrier is used in hard-switching PWM inverter, there will be severe distortion in the current waveform. When sawtooth carriers with alternate positive and negative slopes are used in soft-switching PWM inverters, the resonancetrigger time is easy to control, and distortion in the output voltage and current caused by the dead time will not appear.
Power Electronic Transformer based Three-Phase PWM AC Drives
Basu, Kaushik
A Transformer is used to provide galvanic isolation and to connect systems at different voltage levels. It is one of the largest and most expensive component in most of the high voltage and high power systems. Its size is inversely proportional to the operating frequency. The central idea behind a power electronic transformer (PET) also known as solid state transformer is to reduce the size of the transformer by increasing the frequency. Power electronic converters are used to change the frequency of operation. Steady reduction in the cost of the semiconductor switches and the advent of advanced magnetic materials with very low loss density and high saturation flux density implies economic viability and feasibility of a design with high power density. Application of PET is in generation of power from renewable energy sources, especially wind and solar. Other important application include grid tied inverters, UPS e.t.c. In this thesis non-resonant, single stage, bi-directional PET is considered. The main objective of this converter is to generate adjustable speed and magnitude pulse width modulated (PWM) ac waveforms from an ac or dc grid with a high frequency ac link. The windings of a high frequency transformer contains leakage inductance. Any switching transition of the power electronic converter connecting the inductive load and the transformer requires commutation of leakage energy. Commutation by passive means results in power loss, decrease in the frequency of operation, distortion in the output voltage waveform, reduction in reliability and power density. In this work a source based partially loss-less commutation of leakage energy has been proposed. This technique also results in partial soft-switching. A series of converters with novel PWM strategies have been proposed to minimize the frequency of leakage inductance commutation. These PETs achieve most of the important features of modern PWM ac drives including 1) Input power factor correction, 2) Common
Simulation research of matrix converter and asynchronous motor control system%矩阵变换器-异步电机矢量控制系统仿真研究
Institute of Scientific and Technical Information of China (English)
姜香菊; 刘二林
2012-01-01
Space vector pulse width modulation of matrix converter and rotor field oriented vector control of asynchronous motor are combined, and the paper researchs combination strategy for vector control of the matrix converter and rotor field oriented vector control of asynchronous motor. Input voltage and current of matrix converter are simulated by MATLAB, at the same time, no-load starting torque and speed waveform and the electrical load torque waveform of motor are simulated. The simulation results show that the combined control strategy for matrix converter-asynchronous vector control system has good speed performance, and has the advantage of a AC-DC-AC voltage type PWM variable frequency speed regulation system.%研究了将矩阵变换器的空间矢量脉宽调制与异步电机转子磁场定向矢量控制相结合的组合控制策略,并采用MATLAB对矩阵变换器的输入电压波形、输入电流波形、电机空载启动转矩波形、电机空载启动转速波形以及在电机突加负载时的转矩波形等进行仿真.仿真结果表明了采用组合控制策略的矩阵变换器-异步电机矢量控制系统具备良好的调速性能,并且较交-直-交电压型PWM变频调速系统而言具有更多的优势.
Led spectral and power characteristics under hybrid PWM/AM dimming strategy
DEFF Research Database (Denmark)
Beczkowski, Szymon; Munk-Nielsen, Stig
2010-01-01
In order to dim LEDs the pulse width modulation (PWM) or amplitude modulation (AM) dimming scheme is typically used. Previous studies show that these dimming schemes can have opposite effects on diodes peak wavelength shift. An experimental study was conducted to test the behavior of InGaN diodes...... and phosphor-converted white diodes under hybrid PWM/AM modulation. Feed forward control schemes that provide stable peak wavelength position during dimming and the ability to compensate the thermally induced color shifts and the decrease of the luminous flux are investigated....
Pulse-width modulated DC-DC power converters
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,
Institute of Scientific and Technical Information of China (English)
邱长青; 黄声华; 林珍君; 王正昊
2015-01-01
Based on the mathematical model of power cells in four-quadrant cascade converters, a current control strategy for PWM rectifier was proposed with the control target being the balance of the input and output instantaneous power. The complex vector PI (CVPI) regulators were introduced to track various frequency currents and decoupled control completely. CVPI regulators were proved to have better robustness than traditional regulators with the resonant frequency change. Moreover, the DC bus output current model based on Kalman filter was established to identify the current magnitude and frequency in real time. The proposed control strategy was validated by the experimental results based on the platform of power cells.%在分析四象限级联型变频器功率单元数学模型的基础上,以输入和输出瞬时有功功率平衡为控制目标,给出了PWM整流电流指令.为保证各频率电流的准确跟踪,提出了复矢量PI(complex vector PI,CVPI)调节器,实现了各频率电流的完全解耦控制,论证了CVPI调节器相比传统调节器,对谐振频率变化具有更好的鲁棒性.同时,建立了基于卡尔曼(Kalman)滤波的直流母线输出电流辨识模型,实时地辨识电流大小及其频率.构建了功率单元实验平台,对所提控制策略的正确性与可行性进行了实验验证.
适用于纹波控制型DC-DC变换器的比较器设计%Design of PWM Comparator for DC-DC Converter Based on Ripple Control
Institute of Scientific and Technical Information of China (English)
杨靖; 冯全源
2014-01-01
设计一种适用于纹波控制( Output-Ripple-Based Control)的Buck型DC-DC变换器的比较器,根据PSIM搭建的仿真模型,分析主环比较器性能对系统的影响,设计具有三级预放大的高增益,低延时,低失调电压的比较器电路,采用两种温度系数的电流补偿比较器增益,稳定增益,采用0.5μm BiCOMS工艺进行仿真验证,下降沿延时27 ns,增益123 dB,随温度最大增益变化3.2%,失调电压90μV,达到系统要求。%A kind of comparator applicable to Output-Ripple-Based Control DC-DC Converter was put forward. By using PSIM to build simulation model,and analysing the main loop comparator's performance,the influence of the system,a comparator circuit with preamplifier of high gain,low delay,low disorder voltage were designed. The two kinds of temperature coefficient of bias current are using to compensate the comparator's gain,By using 0. 5 μm BiCOMS process to simulation verification,the falling edge delay is 27 ns,gain is 123 dB,the biggest gain 3. 2%with temperature changes,offset voltage 90 μV and they all reach the system requirements.
DSP controlled power converter
Chan, CH; Pong, MH
1995-01-01
A digital controller is designed and implemented by a Digital Signal Processor (DSP) to replace the Pulse Width Modulator (PWM) and error amplifier compensation network in a two wheeler forward converter. The DSP controller is designed in three approaches: a) Discretization of analog controller - the design is based on the transfer function of the error amplifier compensation network. b) Digital PID controller design - the design is based on the general form of the pulse transfer function of ...
SINGLE PHASE HIGH FREQUENCY AC CONVERTER FOR INDUCTION HEATING APPLICATION
Directory of Open Access Journals (Sweden)
M.A INAYATHULLAAH,
2010-12-01
Full Text Available The proposed topology reduces the total harmonic distortion (THD of a high frequency AC/AC Converter well below the acceptable limit. This paper deals with a novel single phase AC/DC/AC soft switching utility frequency AC to high frequency AC converter. In this paper a single phase full bridge inverter with Vienna rectifier as front end is used instead of conventional diode bridge rectifier to provide continuous sinusoidal input current with nearly unity power factor at the source side with extremely low distortion.. This power converter is more suitable and acceptable for cost effective high frequency (HF consumer induction heating applications.
Institute of Scientific and Technical Information of China (English)
林珍君; 黄声华; 万山明
2016-01-01
In order to decrease the carbon emissions and reduce the fuel cost of large-scale marine, the ideal way is to minimize the operational time of diesel generation system, and ship shaft synchronous generator converter is the best solution. The traditional ship shaft synchronous generator converter can''t make the full use of generator capacity, and has some deficiency of lower power factor, poor current THD, large fluctuations of DC link voltage, which leads to instability of invertor output voltage. This paper proposed a novel model combining the broad-frequency brushless excite synchronous generator (BFBESG) with the four-quadrant converter (FQC). On the generator side, a variable frequency PWM rectifier scheme had been proposed, including an inner current loop based on complex vector PI controller and an outer voltage loop based on balance of the instantaneous power.The resonant phase locked loop was adopted to lock the phase of generator terminal voltage. The 100kW experimental prototype of shaft synchronous generator converter had been developed. Through the prototype load experiment, the feasibility and superiority of the proposed control scheme are verified.%为了降低大型船舶航行时的碳排量和燃油成本,缩短柴油发电系统的运行时间成为一种理想的解决方案,而采用轴带发电系统则能较好地实现这一目标.传统轴带同步发电机变流器系统无法充分利用发电机容量,发电机侧功率因数较低且电流谐波含量高,直流母线电压波动较大,导致逆变侧输出的交流电压幅值不稳定.该文采用一种新型的宽频无刷励磁同步发电机(broad-frequency brushless excite synchronous generator,BFBESG)与四象限变流器(four- quadrant converter,FQC)相结合的方式.在轴带发电机侧,提出基于复矢量PI控制器电流内环和基于瞬时功率平衡的电压平方外环的双闭环变频PWM整流控制策略.采用变频谐振锁相环对发电机
Institute of Scientific and Technical Information of China (English)
吕永灿; 林桦; 杨化承; 罗咏
2013-01-01
To track the given sinusoidal current under stationary frame and suppress the effect of the low harmonics in the grid, a multi-resonant proportional resonant (PR) controller was adopted for pulse width modulation (PWM) converter with LCL filter based on capacitor current feedback active damping. Because the system is of high order, many parameters and complicated, the effects of the control parameters on the current-loop performance were investigated with frequency theory, i.e. the stability, steady-state error and phase margin. Based on this, a decoupling-simplified analytic design method was proposed. According to the requests of the stability, steady-state error and phase margin, the capacitor-current-feedback coefficient, the relative resonant gain factor and the proportional factor could be designed separately. The proposed method uses the analytic method and simplifies the couple of the parameters without trial-and-error procedure. Finally, a battery storage power conversion system (PCS) was built. Experiment results verify the effectiveness of the proposed design method.%基于电容电流反馈有源阻尼的LCL型脉宽调制(pulse width modulation，PWM)变换器并网电流控制中，通常采用多谐振比例谐振(proportional resonant，PR)控制器来实现静止αβ坐标系下正弦电流给定的无静差跟踪和抑制电网电压特定次谐波影响。针对电流环控制器复杂、参数多、设计难的问题，采用频率域理论分析电容电流反馈系数和准PR控制器各参数对电流环性能的影响。在此基础上，提出一种电流环控制器参数解耦简化解析设计方法，根据稳定性、稳态误差和相位裕度要求，分别设计电容电流反馈系数及PR控制器相对谐振增益系数和比例系数。该设计方法简化了控制器参数之间的耦合关系，且多采用解析计算，不需要反复试凑。实验结果验证了所提出的参数解耦解析设计方法是可行和有效的。
A new high performance DC/AC converter inverse%一种新型高性能DC/AC逆换器
Institute of Scientific and Technical Information of China (English)
李峰; 任继锋; 朱音璇
2014-01-01
在比较不同DC/AC逆变器的基础上,以单相全桥逆变电路为主拓扑结构,设计了一款高性能逆变器.该逆变器采用推挽升压和全桥逆变两级变换,主控回路采用STC89C52单片机,前级推挽升压电路采用SG3525芯片控制,闭环反馈,逆变部分采用IR2110芯片进行全桥逆变,运用U3990F6芯片完成对SPWM波的调制,功率驱动元件使用IRF540,数模转换采用ADC0832芯片,后级输出采用电流互感器进行采样反馈,形成双重反馈环节,增加了逆变器的稳定性.最后输出的交流电压通过AD637有效值转换后,再由STC89C52单片机的控制进行模数转换,最终将电压值显示到液晶12864上,形成了良好的人机界面.
Llopis, Francisco
2013-01-01
The circuit presented in this paper aims at providing three 40 Vpp 50Hz AC voltages sources with 120-degree phase separation between them. This is a fully analogue circuit that uses standard, low-cost electronic components without resorting to a microcontroller as previously proposed by Shirvasar et al [1]. This circuit may serve as a basis for a low-voltage 3P-AC power supply that students may safely use to realize experiments, i.e. about the principles and applications of three-phase AC power lines, without the risk of electric shocks.
改进型DC-AC电路分析与实现%Analysis and implementation of improved DC-AC circuits
Institute of Scientific and Technical Information of China (English)
蒋大玉; 张一斌; 李森涛
2014-01-01
For improving the defects of the traditional DC-AC system with low power,low efficiency and high loss,a scheme of the improved DC-AC system is presented. The symmetric voltage controlled MOS switch tube push-pull work mode and the scheme that MOS is driven by soft switch tube were adopted instead of mechanical switch(such as relay),triode(BJT) and silicon controlled rectifier(SCR)in the traditional design scheme. The improved circuit system has high stability,high effi-ciency and low loss. The working principle of the circuit is analyzed. The PSpice-simulation software was used to evaluate the fea-sibility of the control circuit. The reliability of the circuit was verified by experiment.%为改善传统DC-AC系统功率小、效率低、系统自身损耗大等缺陷，提出了一种改进型的DC-AC系统实现方案，引入对称式电压控制型MOS型开关管推挽工作、软开关驱动MOS管方案替代机械开关（如继电器）、三极管（BJT）、可控硅（SCR）等传统设计方案，改进的电路系统稳定性强、效率高、系统自身损耗极小。对电路进行工作原理分析，通过PSpice仿真软件评估控制电路可行性并通过实验验证电路的实际使用及可靠性。
Scalar Controlled Boost PWM Rectifier for Micro Wind Energy Systems
Directory of Open Access Journals (Sweden)
J. Chelladurai
2015-05-01
Full Text Available Uses of Permanent Magnet Synchronous Generators (PMSG are increasing in variable speed micro-Wind Energy Conversion Systems (WECS. In stand-alone or grid-connected Micro-WECS, extraction of maximum power is vital. To extract maximum power output and to obtain a constant DC bus voltage from variable magnitude and variable frequency voltage output of PMSG and generally a two stage scheme namely i conventional diode bridge rectifier and ii DC-DC Boost/Buck/Buck-Boost converters are used. In this study, a single stage Scalar Controlled PWM (SCPWM Boost Rectifier is proposed in order to minimize the current harmonics and to improve the power factor on source side. The modeling and simulation of PMSG based wind generator and SCPWM Boost rectifier was developed in MATLAB. The harmonic content in the input current waveform of the proposed SCPWM rectifier is compared with the conventional three-phase bridge rectifier. The Simulation results show the effectiveness of the PWM Boost rectifier in terms of effective utilization of source, improved efficiency and harmonic mitigation for PMSG based Wind Generator. Simulation results demonstrate the effectiveness of the proposed system in reducing the current and voltage THD on source side.
Power converter simulation and analysis
Energy Technology Data Exchange (ETDEWEB)
Ghazy, M.A.
1989-01-01
There has been a great deal of progress made in computer aided design and analysis in the power electronic field. Many of the simulation packages are inefficient and time consuming in simulating switching converters. This thesis proposes an efficient, simple, general simulation approach to simulate any power converter with less computation time and space requirements on computer. In this approach the equations of power converters are formulated using network topology. In this thesis several procedures have been explained for the steady-state computation of power electronic circuits. Also, the steady-state analyses have been accomplished by a new technique called Fourier series method. For a complete system consisting of converters, filters, and electric machines, the simulation is complicated if a frequency domain technique is used. This thesis introduces a better technique which decouples the system into subsystems and simulates it in the time domain. The design of power converters using optimization techniques is presented in this thesis. Finally, the theory of Variable Structured Systems has been applied to power converters. Sliding mode control for DC-DC and DC-AC power converters is introduced as a tool to accomplish desired characteristics.
A novel five-level optimized carrier multilevel PWM quad-inverter six-phase AC drive
DEFF Research Database (Denmark)
Sanjeevikumar, P.; Blaabjerg, F.; Wheeler, Pat
2016-01-01
A novel single carrier pulse-width modulation (PWM) for a new quad-inverter configuration for multilevel six-phase asymmetrical open-winding ac converter is proposed in this article. Modularity of the circuit consist of four standard two-level voltage source inverters (VSIs) with slight modificat...
Highly-Efficient and Modular Medium-Voltage Converters
2015-09-28
4. TITLE AND SUBTITLE Highly-Efficient and Modula Medium -Voltage Converters 6. AUTHOR(S) Maryam Saeedifard 7. PERFORMING ORGANIZATIC i NAME(S...realization of highly efficient, modular medium - voltage dc-ac and dc-dc energy conversion systems by development of new control strategies that improve the...Z39.18 a 01^ 100(0^5 Final Report for Grant N00014-14-1-0615 Highly-Efficient and Modular Medium -Voltage Converters Lead Organization: Georgia Tech
Two phase interleaved buck converter for driving high power LEDs
DEFF Research Database (Denmark)
Beczkowski, Szymon; Munk-Nielsen, Stig
2011-01-01
increases luminous efficacy of LED compared to PWM dimmed system. Because of the low dynamic resistance of LEDs the duty cycle of the converter does not change greatly with controlled current. By setting the input voltage of the buck converter to around twice the voltage of diode strings, converter can...
Institute of Scientific and Technical Information of China (English)
Jie ZHANG; Ryuichi YOKOYAMA; Jinhua SHE; Win WU
2013-01-01
One problem with a single source three-level inverter is the drafting of its neutral-point voltage. This may occur during transition or when unbalanced loads are connected to the inverter system. Variation of neutral-point voltage may greatly deteriorate the power quality. In this paper, we employ an equivalent-input-disturbance approach to deal with this problem. By adding an extra neutral leg, the control problem of neutral-point voltage is converted to a disturbance rejection problem. This method suppresses the variation of the neutral-point voltage to a low level and reduces the capacity of DC-link capacitors. Simulation results show the effectiveness of the method.
PWM Switching Strategy for Torque Ripple Minimization in BLDC Motor
Salah, Wael A.; Ishak, Dahaman; Hammadi, Khaleel J.
2011-05-01
This paper describes a new PWM switching strategy to minimize the torque ripples in BLDC motor which is based on sensored rotor position control. The scheme has been implemented using a PIC microcontroller to generate a modified Pulse Width Modulation (PWM) signals for driving power inverter bridge. The modified PWM signals are successfully applied to the next up-coming phase current such that its current rise is slightly delayed during the commutation instant. Experimental results show that the current waveforms of the modified PWM are smoother than that in conventional PWM technique. Hence, the output torque exhibits lower ripple contents.
Directory of Open Access Journals (Sweden)
Amin Shabanpour
2012-01-01
Full Text Available A dynamic voltage restorer (DVR with no energy storage is studied. By using a matrix converter instead of the conventional AC/DC/AC converters, elimination of the DC-link capacitor is possible. The switching algorithm of matrix converter is the space vector modulation. There are different compensation algorithms to control the conventional DVR. These methods have been analyzed in this paper for the proposed matrix-converter-based DVR. A deep analysis through different diagrams would show the advantages or disadvantages of each compensation method. Equations for all methods are derived, and the characteristics of algorithms are compared with each other.
High Efficiency Reversible Fuel Cell Power Converter
DEFF Research Database (Denmark)
Pittini, Riccardo
The large scale integration of renewable energy sources requires suitable energy storage systems to balance energy production and demand in the electrical grid. Bidirectional fuel cells are an attractive technology for energy storage systems due to the high energy density of fuel. Compared...... entitled "High Efficiency Reversible Fuel Cell Power Converter" and it presents the design of a high efficiency dc-dc converter developed and optimized for bidirectional fuel cell applications. First, a brief overview of fuel cell and energy storage technologies is presented. Different system topologies...... to traditional unidirectional fuel cell, bidirectional fuel cells have increased operating voltage and current ranges. These characteristics increase the stresses on dc-dc and dc-ac converters in the electrical system, which require proper design and advanced optimization. This work is part of the PhD project...
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 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...
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 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...
Discrete/PWM Ballast-Resistor Controller
King, Roger J.
1994-01-01
Circuit offers low switching loss and automatic compensation for failure of ballast resistor. Discrete/PWM ballast-resistor controller improved shunt voltage-regulator circuit designed to supply power from high-resistance source to low-impedance bus. Provides both coarse discrete voltage levels (by switching of ballast resistors) and continuous fine control of voltage via pulse-width modulation.
Regeneration of ZVS converter with Resonant inductor
Directory of Open Access Journals (Sweden)
J.Sivavara Prasad
2011-09-01
Full Text Available This paper presents an analysis of the regeneration of zero-voltage-switching converter with resonant inductor, quasi-resonant converters, and full-bridge zero-voltage-switched PWM Converter. The design of a clamping circuit considering a saturable resonant inductor is presented and compared with the design of a clamping circuit with a linear resonant inductor. A diode model with reverse recovery is employed to simulate the effects.
Fundamental Approach in Digital Circuit Design for 1-MHz Frequency PWM Gate Drive Application
Directory of Open Access Journals (Sweden)
Nor Zaihar Yahaya
2011-01-01
Full Text Available This paper discusses the design of a digital programmable logic circuit to produce a 5 V - output square wave pulses for four high power MOSFET switches using a fixed PWM circuit. It will be applied to drive the synchronous rectifier buck converter(SRBC circuit. The PWM signals with multiple fixed time delay of 15 ns, 232 ns, 284 ns and 955 ns are generated. The steps taken to analyze each propagation time delay of each logic gate used and its combination are carefully studied. A multiplexer is added at the output of the logic circuit to select and produce the desired output pulses of 20% duty ratio. The logic outputs are compared with the analog pulses and results match each other within 1% in difference.
Institute of Scientific and Technical Information of China (English)
邓翔; 韦徵; 龚春英; 王建华; 张方华
2011-01-01
两级式直交单相逆变器输入电流中含有两倍于逆变器输出频率的低频分量,这些低频分量幅值相对其平均值的比例很高,可达到30%以上,严重时将会影响直流电源系统的稳定性,也会大大影响输入电压源的蓄电池、燃料电池的使用寿命。通过研究该电流低频分量产生的原因,对前级直直变换器提出一种新的控制策略,即在传统的控制策略中引入谐振控制器,可以有效的抑制直直变换器输出滤波电感电流的低频脉动,进而可以有效抑制变换器低压侧输入电源电流低频脉动分量。给出谐振控制器的设计方法,以及引入谐振控制器之后系统各环路的传递函数,分析满足系统稳定性要求的设计准则。最后通过仿真和实验验证该控制策略对于抑制两级式直交逆变器输入电流低频脉动的有效性。%The input current of the two-stage DC-AC inverter contains low frequency ripple which is twice the inverter＇s output frequency.The proportion of the low frequency current ripple＇s amplitude to the average current is very high and it could be achieved more than 30%.The stability of DC power system and the longevity of the input voltage source such as battery or fuel cell could be influenced seriously.The new control strategy for the previous stage DC/DC converter was proposed by analyzing the reason of the low frequency current ripple production in this paper.The resonant controller is introduced in the traditional control strategy.The proposed new control strategy will be very useful to reduce the current ripple of output filter inductor in the DC/DC converter,and the input current ripple of the two-stage DC-AC inverter will also be lower.The design of the resonant controller and the transfer function of the system were given in the paper,and the design principles of system stability were also analyzed.At last,the effectiveness of proposed new control strategy to reduce the input
Directory of Open Access Journals (Sweden)
Rathnakannan Kailasam
2008-01-01
Full Text Available This paper describes the modelling and the analysis of control logic for a Nano-Device- based PWM controller. A comprehensive simple SPICE schematic model for Single Electron transistor has been proposed. The operation of basic Single Electron Transistor logic gates and SET flip flops were successfully designed and their performances analyzed. The proposed design for realizing the logic gates and flip-flops is used in constructing the PWM controller utilized for switching the buck converter circuit. The output of the converter circuit is compared with reference voltage, and when the error voltage and the reference are matched the latch is reset so as to generate the PWM signal. Due to the simplicity and accuracy of the compact model, the simulation time and speed are much faster, which makes it potentially applicable in large-scale circuit simulation. This study confirms that the SET-based PWM controller is small in size, consumes ultra low power and operates at high speeds without compromising any performance. In addition these devices are capable of measuring charges of extremely high sensitivity.
Switching power converters medium and high power
Neacsu, Dorin O
2013-01-01
An examination of all of the multidisciplinary aspects of medium- and high-power converter systems, including basic power electronics, digital control and hardware, sensors, analog preprocessing of signals, protection devices and fault management, and pulse-width-modulation (PWM) algorithms, Switching Power Converters: Medium and High Power, Second Edition discusses the actual use of industrial technology and its related subassemblies and components, covering facets of implementation otherwise overlooked by theoretical textbooks. The updated Second Edition contains many new figures, as well as
PWM模拟DAC的关键参数分析%Key parameters analysis of DAC using PWM
Institute of Scientific and Technical Information of China (English)
赵月丽
2014-01-01
PWM 模拟 DAC 技术由于其价格便宜、技术简单在低成本嵌入式系统中应用广泛，然而其性能指标却无法与集成的 DAC 相比。建模讨论了影响 PWM 模拟实现 DAC 系统的性能的主要因素。仿真发现，滤波器环节对于 PWM 模拟 DAC 的性能参数是至关重要的，在不考虑 PWM 的位数限制时，滤波级数越高 DAC 精度越高，然而 DAC 的建立时间也会显著增加。分析发现，这两个主要参数分别取决于滤波系统对于高频成分的频率响应和对于直流分量的阶跃响应。具体应用中应该权衡DAC 精度和转换速度，以确保应用 PWM 模拟 DAC 可以满足具体应用需求。%DAC (Digital-to-Analog Converter) using PWM (Pulse Width Modulation) technology is widely used in low cost embedded systems due to cheap price and simple to use, however its performance index cannot match the real DAC. In this paper, models are built to discuss the main factors which affect the performance of PWM imitated DAC system. Through simulation it finds that the filter plays a key role in the DAC, without considering the digits limit of PWM, the higher the filter series the more accurate the DAC is, however, the establishment time of the DAC will increase significantly. Through analysis it finds that the two main parameters depend on the high frequency response and DC step response of the filtering system respectively. In specific applications, the precision and transformation speed of the DAC should be carefully weighed to meet specific requirements.
Institute of Scientific and Technical Information of China (English)
杨堤; 程浩忠; 姚良忠; 曾平良
2016-01-01
The voltage source converter based high voltage direct current (VSC-HVDC) transmission technology has good application prospects owing to its excellent controllability,voltage stability and good adaptability to power supply for load center,wind power accommodation,and power transmission among islands.The present research on power flow of VSC-HVDC system is mostly based on constant power control mode without considering the practical converter voltage control characteristics.In order to more accurately reflect the voltage control characteristics of VSC in the actual power grid,a voltage control model based on VSC is developed.As well,converter loss,AC filter,and converter capacity limit are considered in the power flow model.And a general power flow algorithm is proposed for power flow of the VSC based multi-terminal DC/AC system.Some cases with changed DC grid power injection,N -1 contingency and multi-terminal DC/AC system,are built and analyzed.The case analysis indicates that the power flow algorithm is able to reflect the voltage control ability of DC converters,while verifying the effectiveness,rationality and algorithm rapidity based on voltage control characteristics.%由于基于电压源型换流器的高压直流(VSC-HVDC)输电技术具有良好的可控性，对负荷中心供电、风电消纳、孤岛电力传输等适应能力强，电压稳定性好，因此具有良好的应用前景。当前对VSC-HVDC 系统主要基于定功率控制模式进行潮流计算，而很少考虑到实际的换流器电压控制能力。为了更加精确地反映实际电网中 VSC 的电压控制特性，文中建立了基于 VSC 的电压控制模型，考虑了换流器损耗、交流滤波器、换流器容量限制等的影响，并基于电压控制特性提出了 VSC多端直流/交流系统的通用潮流求解方法。对直流电网功率分布变化和 N -1故障以及多端直流/交流系统的潮流算例分析表明，所提的潮流算法能够反
DEFF Research Database (Denmark)
Behrouzian, Ehsan; Bongiorno, Massimo; Teodorescu, Remus
2014-01-01
The purpose of this paper is to investigate the impact of switching harmonics on the instantaneous power that flows in the cells of a chain-link based STATCOM when using Phase-Shifted PWM. Two different cases are investigated for the converter cells: low, and high switching frequency. It is shown...... distribution among cells of the same phase leg, thus contributing to the capacitors balancing. Theoretical conclusions are validated through PSCAD simulation results....
Comparison of Performance of VSI and Z-Source Inverter for Space Vector PWM
Directory of Open Access Journals (Sweden)
E. Sai Prateek
2014-05-01
Full Text Available Z-Source Inverters have the ability to boost the dc link voltage, thus increasing the output ac voltage beyond the values reached by conventional inverters. The enhanced ratio from ac output voltage to dc link voltage is possible due to an impedance network connected between the dc power supply and the main converter. The space vector pulse width modulation techniques gives more dc bus utilisation and low harmonics than other pulse width modulation techniques. In this paper space vector pwm is implemented for conventional VSI and Zsource inverter. The results are supported by SIMULINK simulation
A New Hard Switching Bidirectional Converter With High Power Density
Directory of Open Access Journals (Sweden)
Bahador Fani
2010-01-01
Full Text Available In this paper, a new isolated dc-dc bidirectional converter is proposed. This converter consists of two transformers (flyback and forward and only one switch in primary side and one switch in secondary side of transformers. In this converter energy transfers to the output in both on and off switch states so power density of this converter is high This converter controlled by PWM signal. Also this converter operates over a wide input voltage range. Theoretical analysis is presented and computer simulation and experimental results verify the converter analysis.
Research on a Three-Phase DC/AC Inverter Based on Buck-Boost Circuit%基于升降压斩波电路的三相DC/AC逆变器研究
Institute of Scientific and Technical Information of China (English)
陈荣
2013-01-01
In order to solve the problems brought about by the common inverter,we propose a novel three-phase DC/AC inverter topology based on buck-boost circuit,and describes how it works.The implementation method applied for three-phase DC/AC inverter using single phase inverter is given.The single-phase inverter and threephase inverter are studied using PSIM software.The parameters adopted in the realistic simulation,waveforms such as load current,voltage of modulation reference and load were given.The simulation results proved that adopting the three-phase DC/AC inverter could achieve a good performance with wide input voltage range and the output voltage of it can gain a line frequency as 50 Hz and the correctness of theoretical analysis.%为了解决常用的逆变器所带来的问题,我们提出一种新型的带升降压功能的三相DC/AC变换器拓扑,并介绍了其工作原理.借助于PSIM仿真软件,对单相和三相电路进行了仿真研究,提出了由单相组成三相电压输出的构成方法.在列出仿真参数的前提下,给出了负载电压,负载电流以及调制给定电压和逆变器输出电压的仿真结果.仿真结果表明三相DC/AC逆变器可以实现50 kHz高频功率变换下宽输入电压范围工频逆变输出,证明了理论分析的正确性.
Grid-connected Photovoltaic Micro-inverter with New Hybrid Control LLC Resonant Converter
DEFF Research Database (Denmark)
Xingkui, Mao; Qisheng, Huang; Qingbo, Ke;
2016-01-01
A high-efficiency photovoltaic (PV) micro-inverter consisting of two power stages i.e. a LLC resonant converter with a new hybrid control scheme and a dc-ac inverter is proposed, studied and designed in this paper. In the first power stage, the new hybrid control combining pulse...... power of 250W and output voltage of 220VAC/50Hz. The experiment shows that the peak efficiency of the PVMI is 95.5%, where efficiency of LLC converter is up to 97.7%, and the MPPT accuracy is more than 99%. Thus the validity of the proposed system structure, design and control method is verified....
DEFF Research Database (Denmark)
Qin, Zian; Loh, Poh Chiang; Blaabjerg, Frede
2016-01-01
various topologies have since been proposed. The intention of this paper is, thus, to study two promising single-phase ac-dc-ac converters using reduced number of switches, and subsequently proposes modulation schemes for them. The proposed schemes help the converters to achieve better thermal spread...... among their switches, while keeping their dc-link voltages low. Single points of failure are thus minimized, allowing the converters to have longer lifetimes. Simulation and experimental results have demonstrated the intended performances, hence verifying the analyses presented in this paper....
Analysis of Input and Output Ripples of PWM AC Choppers
Directory of Open Access Journals (Sweden)
Pekik Argo Dahono
2008-11-01
Full Text Available This paper presents an analysis of input and output ripples of PWM AC choppers. Expressions of input and output current and voltage ripples of single-phase PWM AC choppers are first derived. The derived expressions are then extended to three-phase PWM AC choppers. As input current and output voltage ripples specification alone cannot be used to determine the unique values of inductance and capacitance of the LC filters, an additional criterion based on the minimum reactive power is proposed. Experimental results are included in this paper to show the validity of the proposed analysis method.
Three-Phase Back PWM-PFC Rectifier
Institute of Scientific and Technical Information of China (English)
Yasuyuki Nishida
2005-01-01
A new 3-phase back (or current-source-type) PWM-PFC rectifier is proposed in this paper. The necessity,the advantages and disadvantages of this type PWM rectifier are discussed first.Then,the new power circuit topology and the modulation scheme to eliminate or mitigate the disadvantages and obtain further new advantages of the buck PWM rectifier are introduced.The features of the new rectifier, i.e., high efficiency, simple modulation process, robustness of the line-current modulation for distortion of the utility voltages and DC current ripples have been confirmed through experimental results obtained from a 12kW prototype.
Institute of Scientific and Technical Information of China (English)
何伊妮; 杭乃善; 方柳; 曾智翔
2012-01-01
从电磁感应原理出发,仿照同步机电磁耦合机理,提出一种静止的电磁型DC/AC电能传输方式.同时给出该原理的数学推导和新型逆变电路的工作原理.通过对电路模型进行仿真分析,验证了理论的正确性和可行性.最后总结预测了该原理作为一种新型逆变技术的应用前景.对换流输电领域开展研究具有一定的参考价值.%Starting from the principle of electromagnetic inductive and by use of the synchronous generator electromagnetic coupling mechanism, this paper proposes the way of static electromagnetic DC/AC power transmission, presenting the mathematic derivation of the principle and the working principle of the new inverter circuit. Through the simulation analysis of the electric circuit model,the theory is proved accurate and feasible. Finally, the application prospect of the new DC/AC electromagnetic equipment is discussed. The discussion in the paper has a certain reference value in the conversion technology research.
Design of a PWM Speed - governing System for DC Motor Based on PLC%基于PLC的直流电机PWM调速系统设计
Institute of Scientific and Technical Information of China (English)
何新霞; 邢瑞军
2011-01-01
设计了基于SIMATIC S7-200 PLC直流电机PWM调速系统.主电路采用双极式可逆PWM变换器,选用集成驱动器M57962L,通过设计其驱动外围电路,实现了对IGBT的导通和关断控制.采用硬件延时电路,防止上、下桥臂直通事故的发生.利用PLC的高速计数功能实现了对电机转速的测量,设计开发了基于PLC的PI控制程序及PWM信号产生程序.从而实现了直流电机的PWM调速,并实现了转速的无静差调节.%The paper presents the design of PWM speed - governing system for DC motor based on S7 - 200 - PLC. The double - polar reversible PWM converter is used and integrated drive electronics M57962 is selected in main circuit. The conduction and switch control of IGBT is realized by designing the peripheral driving circuitry. The delayed circuit is adopted to prevent the shoot -through phenomenon between upper and lower bridge arm in a PWM. Programs for PLC PI control and for PWM signal generation are developed to implement PWM speed- governing for DC motor and floating control on speed.
基于PSIM的PWM逆变器通用仿真模型%The General Simulation Model of PWM Inverter on PSIM
Institute of Scientific and Technical Information of China (English)
赵春柳
2013-01-01
PWM（Pusle Width Modulation，PWM）逆变器的应用越来越广泛，而PWM逆变器的控制模式又多种多样，因此对于系统仿真而言，建立PWM逆变器的通用仿真模型就尤为重要。该文建立三相全桥PWM逆变器的仿真模型，通过仿真表明该模型具有结构简单、通用性好和仿真效率高的特点。%Application of PWM(Pusle Width Modulation,PWM)inverter is more and more extensive, and there are all kinds of control method of PWM inverter, so the establishment of general simulation model of PWM inverter is very important when sys?tem simulation is needed. A simualtion model of three-phase full bridge PWM converter is established in this paper, it is proved that the configuration of simulation model is simple, the generality of this model is good and the simulation efficiency is high.
Design of a Single-three Phase Power Converter Based on SPMC75F2413A%基于SPMC75F2413A的一种单三相功率变换器的设计
Institute of Scientific and Technical Information of China (English)
杨超; 崔昊辰; 郑建兰; 沙成
2013-01-01
The main circuit structure using two levels of AC-DC-AC (AC/DC/AC1 - AC2/DC/AC) transform as the main body, the core of control part is SPMC75F2413A, according to the principle of SPWM formation,the direct digital synthesis (DDS) technology in the application of driving parts of forward stage and backforward stage. Finally, the experiment results show that the output voltage ,frequency of the power converter can be adjusted continuously and the output waveform is good quality, high stability.,drive three-phase asynchronous motor shows good electrical properties.%主电路主要结构采用两级交-直-交（AC/DC/AC1-AC2/DC/AC）变换为主体，控制部分以 SPMC75F2413A为核心，根据 SPWM生成的原理，将直接频率数字合成（DDS）技术应用在前后级的驱动部分。最后试验结果表明功率变换器输出的电压，频率连续可调而且输出波形质量好，稳定性高，驱动三相异步电机显示了很好的电气特性。
Directory of Open Access Journals (Sweden)
Ibekwe B.E
2014-10-01
Full Text Available The ac to dc converters’ power factors correction in ac transmission system were investigated. The studies include: phase-controlled converter; pulse width modulated (PWM converter and ac input current shaped converter. Using Fourier series, power factors of these converters were calculated and simulated using MATLAB. The resulting curves are displayed in the hard copies for practical guides in the choice of converters; and comparatively, current shaped type is the best.
Soft switching bidirectional DC-DC converter for ultracapacitor-batteries interface
Energy Technology Data Exchange (ETDEWEB)
Adib, Ehsan; Farzanehfard, Hosein [Dept. of Electrical and Computer Engineering, Isfahan Univ. of Technology (Iran)
2009-12-15
In this paper a new soft switching bidirectional DC-DC converter is introduced which can be applied as the interface circuit between ultracapacitors and batteries or fuel cells. All semiconductor devices in the proposed converter are soft switched while the control circuit remains PWM. Due to achieved soft switching condition, the energy conversion through the proposed converter is highly efficient. The proposed converter is analyzed and a prototype converter is implemented. The presented experimental results confirm the theoretical analysis. (author)
Selective harmonic control for power converters
DEFF Research Database (Denmark)
Zhou, Keliang; Yang, Yongheng; Blaabjerg, Frede;
2014-01-01
This paper proposes an Internal Model Principle (IMP) based Selective Harmonic Controller (SHC) for power converters. The proposed SHC offers an optimal control solution for power converters to mitigate power harmonics. It makes a good trade-off among cost, complexity and performance. It has high...... accuracy and fast transient response, and it is cost-effective, easy for real-time implementation, and compatible for design rules-of-thumb. An application on a three-phase PWM converter has confirmed the effectiveness of the proposed control scheme in terms of harmonic mitigation....
Analysis of a novel phase-shifted soft switch converter
Institute of Scientific and Technical Information of China (English)
蒋志宏; 黄立培; 张义
2002-01-01
In this paper, on the basis of the phase-shifted controlled zero-voltage-switch (ZVS) full-bridge converter with pulse width modulation (PWM), a novel zero-voltage and zero-current switch (ZVZCS) PWM converter using a simple auxiliary circuit was designed. The ZVZCS soft switch is achieved by the resonance among the resisting electromagnetic deflection capacitor, the capacitor of the simple auxiliary network and the leakage inductor of transformer. There are no dissipation devices of the saturation inductor and the auxiliary switch in the converter, meantime the capacitor of the auxiliary circuit is also used to clamp the voltage of the rectifier, and there is no additional clamped circuit. There is no big circulating current in the converter, all the active and passive devices work on the condition of the low current and voltage stress, and the proposed converter has wide load range and small duty loss.
A Fuzzy-Logic-Based Controller for Three-Phase PWM Rectifier With Unity Power Factor Operation
Directory of Open Access Journals (Sweden)
A. Bouafia
2008-03-01
Full Text Available In this paper, direct power control (DPC of three-phase PWM rectifiers based on fuzzy logic controller is presented, without line voltage sensors. The control technique is built upon the ideas of the well known direct torque control (DTC for induction motors. The instantaneous active and reactive powers, directly controlled by selecting the optimum state of the converter, are used as the PWM control variables instead of the phase line currents being used. The proposed fuzzy logic controller presents the advantage to be based on linguistic description and does not require a mathematical model of the system. The controller ensures a good regulation of the output voltage, and guarantees the power factor close to one. The simulation results show that the designed fuzzy controller has a good dynamic behavior, a good rejection of impact load disturbance, and is very robust.
Hysteretic Current Controlled Zvs Dc/Dc Converter For Automobile
DEFF Research Database (Denmark)
Cernat, M.; Scortarul, P.; Tanase, A.
2007-01-01
A novel bi-directional dc-dc converter with ZVS and interleaving for dual voltage systems in automobiles is presented. A variable frequency extended band hysteretic current control method is proposed. In comparison with classical fixed frequency current control PWM, the reverse polarity peak curr...
A Three-level 4 x 3 Conventinal Matrix Converter
DEFF Research Database (Denmark)
Rong, Runjie; Loh, Poh Chiang; Wang, Peter;
2007-01-01
This paper proposes a topology of a three-level 4 × 3 conventional matrix converter with 12 bi-directional switches. PWM control and modulation index compensation have been investigated. Operation theory has been verified by the simulation results using Matlab. The simulation results show that th...
A Non-linear Controller for Single-Phase AC-AC Power Converter to meet UPS Performance Index
Directory of Open Access Journals (Sweden)
Abdelhafid Ait Elmahjoub
2012-07-01
Full Text Available This article focuses on AC-AC power converter that can be used for uninterruptible power supply (UPS. The converter is built on two stages: a AC-DC input stage and a DC-AC output stage. The two blocks are connected by an intermediate DC bus. The aim of control is threefold: i power factor correction ii regulation of DC bus iii generating a sinusoidal voltage at the output. The synthesis of controllers has been achieved through the technique of nonlinear backstepping control. A detailed analysis of the stability control system is presented. The performances of regulators have been validated by numerical simulation in MATLAB / SIMULINK.
Directory of Open Access Journals (Sweden)
Kawa Adam
2014-09-01
Full Text Available The paper treats about main problems of one phase DC-AC microinverters that allow single solar cell to be joined with the grid. One of the issues is to achieve high voltage gain with high efficiency in DC circuit, which is necessary for proper operation of inverter. The operating principles, results of practical implementation and investigations on boost-flyback converter, which meets mentioned demands, are presented. (high step-up DC-DC boost-flyback converter for single phase grid microinverter
DEFF Research Database (Denmark)
Gohil, Ghanshyamsinh Vijaysinh; Wang, Huai; Liserre, Marco
2014-01-01
A method to selectively control the amount of dc link voltage ripple by processing desired reactive power by a DC/DC converter in isolated AC/DC or AC/DC/AC system is proposed. The concept can reduce the dc link capacitors used for balancing the input and output power and thereby limiting...... the voltage ripple. It allows the use of smaller dc link capacitor and hence a longer lifetime and at the same time high power density and low cost can be achieved. The isolated DC/DC converter is controlled to process the desired reactive power in addition to the active power. The control system to achieve...
imulation Results of Single Stage AC- AC Converter for Induction Heating
Directory of Open Access Journals (Sweden)
S. ARUMUGAM
2010-12-01
Full Text Available This paper presents simulation of single stage Induction heating system with series Load Resonance. Low frequency AC is converted in to High Frequency Ac using newly developed ZVS-PWM high frequency inverter. This High Frequency is used for Induction Heating .Single stage AC-AC converter system is modeled and simulated using Matlab Simulink. The simulation results of ZVS-PWM high frequency system are presented. The effectiveness of this UFAC-to-HFAC direct power frequency converter using IGBTs for consumer high-frequency IH appliances is evaluated and proved on the basis of simulation results.
Energy Technology Data Exchange (ETDEWEB)
Rodrigues, Kleiber David; Oliveira, Jose Carlos de; Penna, Cristiane [Universidade Federal de Uberlandia (UFU), MG (Brazil)
2001-10-15
This article aims at presenting the results of investigations made in laboratory involving frequency converters performance fed by voltage, PWM sinusoidal type, in relation to the electric energy quality. For that, it was used a commercial converter of the type VSI-PWM fed by a programmable source capable to reproduce disturbances related to the several variable items of energy quality for measurements of spectra of harmonics.
Simple Digital Control of a Two-Stage PFC Converter Using DSPIC30F Microprocessor
DEFF Research Database (Denmark)
Török, Lajos; Munk-Nielsen, Stig
2010-01-01
and built for 70W rated output power. Average current mode control for boost converter and current programmed control for forward converter are implemented on a dsPIC30F1010. Pulse Width Modulation (PWM) technique is used to drive the switching MOSFETs. Results show that digital solutions with ds...
Two-Phase Interleaved Buck Converter with a new Digital Self-Oscillating Modulkator
DEFF Research Database (Denmark)
Jakobsen, Lars Tønnes; Andersen, Michael Andreas E.
2007-01-01
for traditional digital PWM modulators given a certain switching frequency. A synchronised version of the DiSOM modulator is derived for interleaved converters. A prototype interleaved Buck converter for Point of Load applications has been designed and built to test the performance of DiSOM modulator. The Di...
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
in the semiconductor devices of three-level converter adopting continuous and discontinuous PWM modulation strategies. This aspect strongly influences the operation of the converter and directly affects its efficiency. Therefore, a simulation platform is developed in Matlab/Simulink and PLECS environment to analyse...
Pulse-Width-Modulation of Neutral-Point-Clamped Sparse Matrix Converter
DEFF Research Database (Denmark)
Loh, P.C.; Blaabjerg, Frede; Gao, F.
2007-01-01
literature. Addressing the afore-described issues, this paper focuses on the operational mode analysis of a three-level sparse matrix converter implemented using a neutral-point-clamped inversion stage, and the design of a number of PWM and modulation ratio compensation schemes for controlling the converter...
Noise Shaping Filter Compensating PWM Distortion for Fully Digital Amplifier
Yoneya, Akihiko
The full-digital audio amplifiers have several merits such as a high power enabling a small size of the amplifier and digital implementation of the signal processing which allows desired precision of the processing except for the final stage switching amplifiers. Unfortunately, the pulse width modulation (PWM) causes signal distortions because of the non-linearity of the modulation from the viewpoint of the transient response. This paper proposes a compensation method of the PWM distortion with feedback approach. In the noise-shaping filter of the delta-sigma modulator to calculate the pulse codes for the PWM, the distortion caused by the PWM is evaluated and fed it back to compensate the distortion. Eventually the filter is implemented as a state-variable filter with non-linear feedback from the quantizer. The calculation of the filter elements is also described. By using proposed filters, PWM signals with small distortions and small floor noise can be obtained to realize high-fidelity audio amplifiers.
A High-Precision Control for a ZVT PWM Soft-Switching Inverter to Eliminate the Dead-Time Effect
Directory of Open Access Journals (Sweden)
Baoquan Kou
2016-07-01
Full Text Available Attributing to the advantages of high efficiency, low electromagnetic interference (EMI noise and closest to the pulse-width-modulation (PWM converter counterpart, zero-voltage-transition (ZVT PWM soft-switching inverters are very suitable for high-performance applications. However, the conventional control algorithms intended for high efficiency generally results in voltage distortion. Thus, this paper, for the first time, proposes a high-precision control method to eliminate the dead-time effect through controlling the auxiliary current in the auxiliary resonant snubber inverter (ARSI, which is a typical ZVT PWM inverter. The dead-time effect of ARSI is analyzed, which is distinguished from hard-switching inverters. The proposed high-precision control is introduced based on the investigation of dead-time effect. A prototype was developed to verify the effectiveness of the proposed control. The experimental results shows that the total harmonic distortion (THD of the output current of the ARSI can be reduced compared with that of the hard-switching inverter, because the blanking delay error is eliminated. The quality of the output current and voltage can be further improved by utilizing the proposed control method.
Institute of Scientific and Technical Information of China (English)
吴桂清; 李泓霖; 戴瑜兴; 郑宗伟
2012-01-01
本文针对嵌入式应用中PWM (Pulse-Width Modulation)方式DAC(Digital-to-Analog Converter)和独立DAC芯片选择问题,提出了通过插值方式和多PWM组合方式提高PWM方式DAC分辨率的方法；分析了PWM信号频谱,提出了模拟滤波器设计原则与方法.以MCU(Micro Control Unit)的PWM通道方式实现DAC,经过数据分析证明此方法稳定可靠.%A method that improving the resolution of PWM(Pulse-Width Modulation) mode DAC(Digital-To-Analog Converter) by interpolator was proposed for the problem that PWM mode DAC in embedded applications and how to choose DAC chip. The PWM signal spectrum was analyzed. The design principle and method of analog filter was proposed. The design of High-Resolution DAC using MCU' s(Micro Control Unit) PWM proved that this method is stable and reliable by analysis of experiments.
Synchronised PWM Schemes for Three-level Inverters with Zero Common-mode Voltage
DEFF Research Database (Denmark)
Oleschuk, Valentin; Blaabjerg, Frede
2002-01-01
PWM with synchronous smooth pulses-ratio changing and a quarter-wave symmetry of the voltage waveforms. Three basic versions of both algebraic and trigonometric synchronised PWM have been analysed. Simulations give the behaviour of the proposed methods and show some advantage of synchronised PWM...
Synchronised PWM Schemes for Three-level Inverters with Zero Common-mode Voltage
DEFF Research Database (Denmark)
Oleschuk, Valentin; Blaabjerg, Frede
2002-01-01
PWM with synchronous smooth pulses-ratio changing and a quarter-wave symmetry of the voltage waveforms. Three basic versions of both algebraic and trigonometric synchronised PWM have been analysed. Simulations give the behaviour of the proposed methods and show some advantage of synchronised PWM...
SYNTHESIS OF VOLTAGES OF UNIFORM PWM IN TIME REGULATION
Directory of Open Access Journals (Sweden)
A. G. Stryzhniou
2014-01-01
Full Text Available The article describes a process of synthesis and qualitative assessment of the harmonic composition of voltages of multiple and single PWM pulses in time regulation, being, along with amplitude, frequency and phase method, one of control methods of an asynchronous motor. The main point of time regulation is that a pause after any two single PWM pulses with different polarity or after any two groups of multiple PWM pulses with different polarity changes during a process of regulation. Feature of time regulation is that a motor has fast response in the range of small-signal of control and good linearity of speed-torque characteristics in the whole control range. Analytical expressions of parameters of PWM pulses ai and ti are obtained which allow to simplify considerably a process of formation and implementation of time regulation using tabular or indexed-tabular methods. These expressions allow not only to define voltage amplitude of harmonic but also to perform qualitative assessment of harmonic composition of output voltages at time regulation. It is specified that harmonic frequencies wi = w0/q change in inverse proportion to magnitude of parameter q during a process of regulation and there is a replacement of a fundamental frequency by frequencies of higher harmonics.The offered approach allows to synthesize voltage of uniform single and multiple PWM pulses and to perform their comparative and qualitative analysis and the obtained expressions can be used at modeling of AC motor work. Voltage of multiple PWM pulses which is formed using stepped reference voltage with even quantity of steps in a half period and a pause on a zero level has the best parameters by criterion of a minimum of harmonic components and a maximum of a factor of anharmonicity Kнс at time regulation.
Analysis of Capacitive Parasitism in PWM Inverter-Fed Motor
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
The effects of parasitic capacitance in induction motor system are unnoticed when it is fed from the AC line. but they are obvious when supplied directly from a PWM inverter. Consequently. many parasitic problems occur, such as motor-to-earth leakage current, bearing current, incoming line current distortion and uneven distribution of electrical stresses along the winding. On the ba sis of the uniform transmission line principle, a complete equivalent circuit of the PWM inverter-fed motor system is presented, based on which all the capacitive parasitic problems mentioned above are analyzed and simulated by means of PSPICE. All the results are consistent with the existing ones.
Small-signal, continuous, exact model of PWM voltage regulators
Burkhardt, W.; Maranesi, P.; Varoli, V.
1985-02-01
The small-signal time-continuous open-loop response of buck, boost, and buck-boost pulse-width-modulation (PWM) voltage regulators using MOSFET switches in their power stages is modeled, applying a time-domain sampling theorem (Woodward, 1953) to obtain the Fourier open-loop transfer function corresponding to the comb function describing the response at the chopping instants only. The results are presented graphically along with simplified circuit diagrams of the PWM devices, and the accuracy and computational efficiency of the analytical approach are indicated.
A Novel Soft-Switching Synchronous Buck Converter for Portable Applications
Directory of Open Access Journals (Sweden)
Anup Kumar Panda
2008-01-01
Full Text Available This paper proposes a zero-voltage-transition (ZVT pulse-width-modulated (PWM synchronous buck converter, which is designed to operate at low voltage and high efficiency typically required for portable systems. A new passive auxiliary circuit that allows the main switch to operate with zero-voltage switching has been incorporated in the conventional PWM synchronous buck converter. The operation principles and a detailed steady-state analysis of the ZVT-PWM synchronous converter implemented with the auxiliary circuit are presented. Besides, the main switch and all of the semiconductor devices operate under soft-switching conditions. Thus, the auxiliary circuit provides a larger overall efficiency. The feasibility of the auxiliary circuit is confirmed by simulation and experimental results.
Directory of Open Access Journals (Sweden)
Boumediène Allaoua
2013-01-01
Full Text Available The development of electric vehicles power electronics system control comprising of DC-AC inverters and DC-DC converters takes a great interest of researchers in the modern industry. A DC-AC inverter supplies the high power electric vehicle motors torques of the propulsion system and utility loads, whereas a DC-DC converter supplies conventional low-power, low-voltage loads. However, the need for high power bidirectional DC-DC converters in future electric vehicles has led to the development of many new topologies of DC-DC converters. Nonlinear control of power converters is an active area of research in the fields of power electronics. This paper focuses on a fuzzy sliding mode strategy (FSMS as a control strategy for boost DC-DC converter power supply for electric vehicle. The proposed fuzzy controller specifies changes in the control signal based on the surface and the surface change knowledge to satisfy the sliding mode stability and attraction conditions. The performances of the proposed fuzzy sliding controller are compared to those obtained by a classical sliding mode controller. The satisfactory simulation results show the efficiency of the proposed control law which reduces the chattering phenomenon. Moreover, the obtained results prove the robustness of the proposed control law against variation of the load resistance and the input voltage of the studied converter.
Directory of Open Access Journals (Sweden)
Ramakrishna Manohar Anaparthi
2014-12-01
Full Text Available This paper explains that how to develop and design, control of single phase to three phase drive system. The proposed topology of drive system consisting of two parallel connected rectifiers, inverter and induction motor, connected through inductor and capacitor, where used to produce balanced output to the motor drive. The main objective of this proposed method is to reduce the circulating currents and harmonic distortions at the converter input side, here the control strategy of drive system is PWM (pulse width modulations techniques control strategy, the proposed topology also provides fault compensation in the case of short circuit faults and failure of switches for uninterrupted Power supplies. We also develop and simulate the MATLAB models for proposed drive system, by using MATLAB/ Simulink the output results simulate and observed.
Design of a High Efficiency Boost DC-DC Converter
Institute of Scientific and Technical Information of China (English)
GAO Jing; YAO Suying; XU Jiangtao; SHI Zaifeng
2009-01-01
An accurate circuit of PWM/PFM mode converting and a circuit of auto-adaptively adjusting dimension of power transistor are described. The duty cycle of the signal when the control mode converts can be gained accu-rately by using ratios of currents and capacitances, and an optimal dimension of power transistor is derived with different loads. The converter is designed by 0.35 μm standard CMOS technology. Simulation results indicate that the converter starts work at 0.8 V input voltage. Combined with synchronized rectification, the transfer efficiency is higher than 90% with full load range, and achieves 97.5% at rating output.
LARGE SIGNAL DISCRETE-TIME MODEL FOR PARALLELED BUCK CONVERTERS
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
As a number of switch-combinations are involved in operation of multi-converter-system, conventional methods for obtaining discrete-time large signal model of these converter systems result in a very complex solution. A simple sampled-data technique for modeling distributed dc-dc PWM converters system (DCS) was proposed. The resulting model is nonlinear and can be linearized for analysis and design of DCS. These models are also suitable for fast simulation of these networks. As the input and output of dc-dc converters are slow varying, suitable model for DCS was obtained in terms of the finite order input/output approximation.
Directory of Open Access Journals (Sweden)
Mohammad Sadegh Orfi Yegane
2017-02-01
Full Text Available This paper investigates multi-carrier PWM methods in multi-level inverters. Two new MCPWM methods are introduced. This study proposes a new optimized MCPWM method to improve the output voltage characteristics like THD and LOH. The proposed method is based on variable frequency with a specific range. It means each carrier wave has a determined frequency. It is calling Variable Frequency Triangular Carrier-PWM. MOPSO algorithm is used to optimize the answers. This work considers some different levels of inverters like five, seven and nine levels. The results are compared with SPWM method.
Simulation and Implementation of Quasi Resonant DC-DC Converter
Directory of Open Access Journals (Sweden)
N. Devarajan
2012-01-01
Full Text Available Problem statement: A half-bridge LLC resonant converter with a voltage doubler rectifier has a simple structure and its Zero-Voltage-Switching (ZVS capability is excellent from zero to full load condition. But conduction loss is more due to high circulating energy thus reducing the system efficiency. Moreover a variable frequency control method makes the control circuits more complicated than those using the Pulse Width Modulation (PWM control method. Thus, DC drive has lower efficiency when it operates on light loads. Approach: To improve the efficiency of the DC drive under light loads, a PWM-controlled quasi-resonant converter is proposed .It has simple control circuits and less conduction loss compared to a half-bridge LLC resonant converter under light load conditions. The proposed converter has a half-bridge LLC resonant converter along with an auxiliary circuit. The load regulation of the proposed converter can be achieved by an auxiliary circuit. Thus the proposed converter is expected to be suitable sustaining power module for the efficiency enhancement of DC drives. As the magnetizing inductance of the proposed converter is larger the circulating energy is considerably reduced under light load conditions. In this study the operational principle, design and modeling of QRC DC-DC converters for DC drives are presented. The PWM controlled quasi resonant converter is implemented using PIC microcontroller 16F184A. Results: The capacitor filter in the output is replaced by pi filter to produce DC with minimum ripple. The experimental results and simulation results are compared. This converter has the advantages like reduced number of switches, reduced transformer and filter size, reduced ripple, reduced switching losses, reduced switching stresses and increased power density. Conclusion: The experimental results closely agree with the simulation results.
Decentralized Interleaving of Paralleled Dc-Dc Buck Converters: Preprint
Energy Technology Data Exchange (ETDEWEB)
Johnson, Brian B [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rodriguez, Miguel [National Renewable Energy Laboratory (NREL), Golden, CO (United States)
2017-09-01
We present a decentralized control strategy that yields switch interleaving among parallel connected dc-dc buck converters without communication. The proposed method is based on the digital implementation of the dynamics of a nonlinear oscillator circuit as the controller. Each controller is fully decentralized, i.e., it only requires the locally measured output current to synthesize the pulse width modulation (PWM) carrier waveform. By virtue of the intrinsic electrical coupling between converters, the nonlinear oscillator-based controllers converge to an interleaved state with uniform phase-spacing across PWM carriers. To the knowledge of the authors, this work represents the first fully decentralized strategy for switch interleaving of paralleled dc-dc buck converters.
A new Zero-Current-Transition PWM switching cell
Energy Technology Data Exchange (ETDEWEB)
Grigore, V. [Electronics and Telecommunications Faculty, `Politechnica` University Bucharest (Romania); Kyyrae, J. [Helsinki University of Technology, Otaniemi (Finland): Institute of Intelligent Power Electronics
1997-12-31
In this paper a new Zero-Current-Transition (ZCT) PWM switching cell is presented. The proposed switching cell is composed of the normal hard-switched PWM cell (consisting of one active switch and one passive switch), plus as auxiliary circuit. The auxiliary circuit is inactive during the ON ad OFF intervals of the switches in the normal PWM switch. The transitions between the two states are controlled by the auxiliary circuit. Prior to turn-off, the current through the active switch in the PWM cell is forced to zero, thus the turn-off losses of the active switch are practically eliminated. At turn-on the auxiliary circuit slows down the growing rate of the current through the main switch. Thus, turn-on losses are also very much reduced. The active switch operates under ZCT conditions, the passive switch (diode) has a controlled reverse recovery, while the switch in the auxiliary circuit operates under Zero-Current-Switching (ZCS) conditions. (orig.) 3 refs.
A new Zero-Voltage-Transition PWM switching cell
Energy Technology Data Exchange (ETDEWEB)
Grigore, V. [Electronics and Telecommunications Faculty `Politebuica` University Bucharest (Romania); Kyyrae, J. [Helsinki University of Technology, Otaniemi (Finland): Institute of Intelligent Power Electronics
1997-12-31
In this paper a new Zero-Voltage-Transition (ZVT) PWM switching cell is presented. The proposed switching cell is composed of the normal hard-switched PWM cell (consisting of one active switch and one passive switch), plus an auxiliary circuit (consisting of one active switch and some reactive components). The auxiliary circuit is inactive during the ON and OFF intervals of the switches in the normal PWM switch. However, the transitions between the two states are controlled by the auxiliary circuit. Prior to turn-on, the voltage across the active switch in the PWM cell is forced to zero, thus the turn-on losses of the active switch are practically eliminated. At turn-off the auxiliary circuit behaves like a non-dissipative passive snubber reducing the turn-off losses to a great extent. Zero-Voltage-Transition switching technique almost eliminates switching losses. The active switch operates under ZVT conditions, the passive switch (diode) has a controlled reverse recovery, and the switch in the auxiliary circuit operates under Zero-Current-Switching (ZCS) conditions. (orig.) 6 refs.
Spread Spectrum Modulation by Using Asymmetric-Carrier Random PWM
DEFF Research Database (Denmark)
Mathe, Laszlo; Lungeanu, Florin; Sera, Dezso;
2012-01-01
This paper presents a new fixed carrier frequency random PWM method, where a new type of carrier wave is proposed for modulation. Based on simulations and experimental measurements, it is shown that the spread effect of the discrete components from the motor current spectra and acoustic spectra i...
Laboratory manual for pulse-width modulated DC-DC power converters
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
National Research Council Canada - National Science Library
Jaime Ayala Taco; Roberto Gutiérrez; Susset Guerra Jiménez; Alexander Fernandez Correa
2015-01-01
..., con el objetivo de lograr a voluntad un nivel de CD introducido en la señal de alterna. Se ingresan perturbaciones de tensión en la entrada del convertidor y se producen variaciones en la carga con el objetivo de probar la robustez del sistema de control propuesto. El control se implementa en un microcontrolador AVR Atmega164PA y se prueba de manera práctica. Finalmente, se expone una comparación de los resultados obtenidos de manera experimental con las simulaciones realizadas en SCILAB5. Palabras clave: C...
Wind Energy Conversion Based on Matrix Converter
Directory of Open Access Journals (Sweden)
Mutharasan Anburaj
2014-07-01
Full Text Available In recent years renewable sources such as solar, wave and wind are used for the generation of electricity. Wind is one of the major renewable sources. The amount of energy from a Wind Energy Conversion System (WECS depends not only on the wind at the site, but also on the control strategy used for the WECS. In assistance to get the appropriate wind energy from the conversion system, wind turbine generator will be run in variable speed mode. The variable speed capability is achieved through the use of an advanced power electronic converter. Fixed speed wind turbines and induction generators are often used in wind farms. But the limitations of such generators are low efficiency and poor power quality which necessitates the variable speed wind turbine generators such as Doubly Fed Induction Generator (DFIG and Permanent Magnet Synchronous Generator (PMSG. A high-performance configuration can be obtained by using Scherbius drive composed of a DFIG and a converter in combination AC-DC-AC connect between stator & rotor points for providing the required variable speed operation
Institute of Scientific and Technical Information of China (English)
刘胜文; 包广清; 范少伟; 刘峻; 李正元
2011-01-01
The low-voltage ride-through (LVRT) capability of a MW-Level variable speed wind turbine with a direct-driven permanent magnet synchronous generator (PMSG) is investigated. In this paper a novel DC link voltage control scheme was proposed to prevent DC link dynamic voltage from too high value. Comparison of the traditional control method, the machine-side converter uses a double control with the current inner loop and the DC link voltage outer loop; and network-side converter has dual-loop control with grid current inner loop and generator speed outer ring, to output the best energy. The simulation results show that the new control method can effectively improve the low voltage ride through capability of variable speed wind turbines with PMSG.%通过对兆瓦级双PMW直驱式永磁同步风力发电机(PMSG)系统低电压穿越能力的研究,本文提出了一种改进的功率变换控制方法来抑制过高的直流母线动态电压.与传统控制方法相比,该方法中机侧整流器采用电流内环、直流母线电压外环的双闭环控制结构,同时网侧逆变器采用电网电流为内环、发电机转速为外环的双闭环控制结构,保证系统输出最佳能量.仿真结果表明本文提出的控制方法有效提高了PMSG系统的低电压穿越能力.
Nakamura, Mantaro; Yamazaki, Takayuki; Fujii, Yuma; Ahmed, Tarek; Nakaoka, Mutsuo
This paper proposes a new circuit topology of the three-phase soft switching PWM inverter and PFC converter using IGBT power modules, which has the improved active auxiliary switch and edge resonant bridge leg-commutation-link soft-switching snubber circuit with pulse current regenerative feedback loop as compared with the typical auxiliary resonant pole snubber discussed previously. This three-phase soft switching PWM double converter is more suitable and acceptable for a large capacity uninterruptible power supply, PFC converter, utility-interactive bi-directional converter and so forth. In this paper, the soft switching operation and optimum circuit design of the novel type active auxiliary edge resonant bridge leg commutation link snubber treated here are described for high power applications. Both the main active power switches and the auxiliary active power switches achieve soft switching under the principles of ZVS or ZCS in this three-phase inverter switching. This three-phase soft switching commutation scheme can effectively minimize the switching surge related electromagnetic noise and the switching power losses of the power semiconductor devices; IGBTs and modules used here. This three-phase inverter and rectifier coupled double converter system does not need any sensing circuit and its peripheral logic control circuits to detect the voltage or the current and does not require any unwanted chemical electrolytic capacitor to make the neutral point of the DC power supply voltage source. The performances of this power conditioner are proved on the basis of the experimental and simulation results. Because the power semiconductor switches (IGBT module packages) have the relation of the trade-off in the switching fall time and tail current interval characteristics as well as the conductive saturation voltage characteristics, this three-phase soft-switching PWM double converter can perform to improve actual efficiency in the output power ranges with a trench
2010-01-01
The technique to derive a dc-ac full bridge switching converter for a PV grid-connected system are proposed in this paper. An analysis of islanding phenomena due to load variations of R and RLC connections can be easily derived by using the state-space averaging technique and the piecewise technique with feedback current control by setting up the duty cycle with sinusoidal terms around constant value of 0.5. The solution of the two proposed models can be handled via MATLAB/SIMULINK in fast sp...
Diode-clamped multilevel converters with integrable gate-driver power-supply circuits
Busquets Monge, Sergio; Rocabert Delgado, Joan; Crébier, Jean-Christophe; Peracaula Roura, Joan
2009-01-01
International audience; Recent contributions in pulse width modulations (PWM) for multilevel diode-clamped converters enable the use of these converters with passive front-ends, any number of levels, and small dc-link capacitors. Highly compact converters designs based on these topologies can be envisioned. However, the design of the gate-driver power-supply for the multiple controlled semiconductor devices remains an important issue to be addressed. This paper focuses on the design of such c...
Analysis of Dither in PWM Control on Electro-hydraulic Proportional Valve
Directory of Open Access Journals (Sweden)
Guoping LIU
2013-11-01
Full Text Available Plus with modulation (PWM is widely used in proporational control systems for it is efficient, flexible and anti-interference. Due to the friction and hysteresis of electromagnet, hysteresis exists when hydraulic valve in steady-state, and hysteresis influences the dynamic characteristics of the valve seriously,the hysteresis can be improved by superimposing dithers with certain frequency and amplitude to the valve coil. Aiming at the character of anti-unloading power driver circuit ,this paper analyzed the parasitic dither which exists in ±24V PWM control，besides，the experiment shows that in a high frequency PWM, dither with independent frequency and amplitude can be generated by changing the frequency of the PWM, in this way, the dithers and average current of coil can be adjusted separately by changing PWM frequency and PWM duty cycle.
A Study on Power Quality Improvement in PWM Controlled AC Voltage Controller
Directory of Open Access Journals (Sweden)
Ahmet ALTINTAŞ
2009-04-01
Full Text Available A lot of topologies of pulse-width modulated (PWM-AC controllers for single-phase and three-phase systems are proposed up to date. PWM-AC controllers have important advantages compared with the phase-controlled AC controllers using thyristors and triacs. The PWM-AC controller has sinusoidal current waveforms, smaller THD values, better power factor, faster dynamics, and smaller input/output filter. This article presents a novel control technique for application to PWM-AC controllers with ability of generating fewer harmonics. In the proposed control method, both the traditional AC voltage controllers and the PWM-AC controllers are combined; and smaller THD values are obtained. Thus, the harmonic pollution in the power system will be reduced; and consequently, the power quality will be increased. For this purpose, computer simulations are performed in order to investigate the proposed controller performance. The obtained results are compared with the conventional PWM-AC controller.
Synthesis of Voltages of Multiple Uniform PWM, Generated by Trapezoidal and Sinusoidal Functions
Directory of Open Access Journals (Sweden)
A. Ctryzhniou
2013-01-01
Full Text Available The problem of synthesis and qualitative estimation of the harmonic composition of voltages of multiple uniform PWM pulses generated by trapezoidal and sinusoidal functions is considered. Analytical expressions for PWM pulses parameters ai and ti have been received and they can be used for program-based generation of multiple uniform PWM, determination of n-harmonic magnitude in pulse-width regulation and AC motor operation simulation.
Controlling DC Motor using Microcontroller (PIC16F72) with PWM
Shruti Shrivastava, Jageshwar Rawat, Amit Agrawal
2012-01-01
Motion control plays a vital role in industrial atomization. Different types of motors AC, DC, SERVO or stepper are used depending upon the application; of these DC motors are widely used because of easier controlling. Among the different control methods for DC motor armature voltage control method using pulse width modulation (PWM) is best one. We can realize the PWM using H-bridge built with IGBT switches or transistors. To generate PWM signals we use PIC16F7...
High-Frequency Link Inverter for Fuel Cells Based on Multiple-Carrier PWM （to continue）
Institute of Scientific and Technical Information of China (English)
无
2004-01-01
C. Operation of a PWM Cycloconverter The concepts in Section Ⅱ-B, present a progression of solutions to known design difficulties. To incorporate these benefits and eliminate the redundant conversion step shown in Fig. 6, we propose the PWM cycloconverter shown in Fig. 7. It will be shown in Section Ⅲ. that the conventional PWM inverter can be unified through a multiple-carrier PWM framework. The control concept introduced is extended to demonstrate that multiple-carrier PWM methods lead to HF link inverters that are nearly as simple to control as conventional PWM inverters.
Performance optimization of a photovoltaic chain conversion by the PWM control
Rezoug, M. R.; Chenni, R.
2017-02-01
The interest of the research technique of maximum power point tracking, exposed by this article, lays in the fact of work instantly on the real characteristic of the photovoltaic module. This work is based on instantaneous measurements of its terminals' current & voltage as well as the exploitation of the characteristic "Power - Duty Cycle" to define rapidly the Duty cycle in which power reaches its maximum value. To ensure instantaneous tracking of the point of maximum power, we use "DC/DC Converter" based on "Pulse Wave Modulation's (PWM) Command" controlled by an algorithm implanted in a microcontroller's memory. This algorithm responds to the quick changes in climate (sunlight and temperature). To identify the control parameters "VPV & IPV" at any change in operating conditions, sensors are projected. this algorithm applied to the Duty cycle of the static converter enables the control of power supplied by the photovoltaic generator thanks to oscillatory movement around the MPP. Our article highlights the importance of this technique which lays in its simplicity and performance in changing climatic conditions. This efficiency is confirmed by experimental tests and this technique will improve its predecessors.
ABNORMAL AND TRANSIENT MODES OF THE CONVERTER BOOSTER TYPE FOR DC TRACTION SUBSTATIONS
Directory of Open Access Journals (Sweden)
Yu. P. Goncharov
2008-12-01
Full Text Available The results of analytical research and computer design of the anomalous, steady-state and transitional modes related to the resonance in the input filter of voltage added converter based on IGBT with the PWM are presented. The ways of resonance removal by both the control means and the power blocks, combined with the overvoltage protection, are offered.
Power Controllability of Three-phase Converter with Unbalanced AC Source
DEFF Research Database (Denmark)
Ma, Ke; Chen, Wenjie; Liserre, Marco
2015-01-01
Three-phase DC-AC power converters suffer from power oscillation and overcurrent problems in case of unbalanced AC source voltage that can be caused by grid/generator faults. Existing solutions to handle these problems are properly selecting and controlling the positive and negative sequence...... currents. In this work a new series of control strategies which utilize the zerosequence components are proposed to enhance the power control ability under this adverse condition. It is concluded that by introducing proper zero sequence current controls and corresponding circuit configurations, the power...... converter can enable more flexible control targets, achieving better performances in the delivered power and load current when suffering from unbalanced AC voltage....
Power Controllability of Three-phase Converter with Unbalanced AC Source
DEFF Research Database (Denmark)
Ma, Ke; Liserre, Marco; Blaabjerg, Frede
2013-01-01
Three-phase DC-AC power converters suffer from power oscillation and overcurrentt problems in case of unbalanced AC source voltage that can be caused by grid/generator faults. Existing solutions to handle these problems are properly selecting and controlling the positive and negative sequence...... converter can enable more flexible control targets, achieving better performances in the delivered power and load current when suffering from unbalanced AC sources....... currents. In this work a new series of control strategies which utilize the zero-sequence components are proposed to enhance the power control ability under this adverse conditions. It is concluded that by introducing proper zero sequence current controls and corresponding circuit configurations, the power...
Closed Loop Control of Soft Switched Interleaved Buck Converter
Directory of Open Access Journals (Sweden)
R. Shenbagalakshmi
2012-06-01
Full Text Available Design, Modeling and Simulation of a closed loop control is presented for Interleaved Buck Converter with Soft Switching. The features of the closed loop system are to reduce the switching losses and load current sharing among the parallel connected converters. The control system of the converter is designed using PWM technique. In order to improve the transient response and dynamic stability of the converters, the controller parameters are designed based on current mode control. Resonant components thus designed enable the application of zero current switching for both the converters connected in parallel thereby maintaining greater efficiency and minimizing voltage and current oscillations. The system analysis, design and performance are verified through simulation using MATLAB/Simulink environment. The simulation approach reveals the high speed dynamic performance of the closed loop system designed using robust PID controller. The laboratory prototype of the Buck converter is developed to verify the controller platform using PIC16F877A microcontroller.
A Dual-Mode Step-up DC/DC Converter IC with Current-Limiting and EMI Reduction Techniques
Institute of Scientific and Technical Information of China (English)
Wan-Rone Liou; Chun-Ting Kuo; Mei-Ling Yeh; Ping-Hsing Chen; Marynelle L. Z. Rosales
2008-01-01
This paper presents a novel dual-mode step-up (boost) DC/DC converter. Pulse-frequency modulation (PFM) is used to improve the efficiency at light load. This converter can operate between pulse-width modulation (PWM) and pulse-frequency modulation. The converter will operate in PFM mode at light load and in PWM mode at heavy load. The maximum conversion efficiency of this converter is 96%. The conversion efficiency is greatly improved when load current is below 100 mA. Additionally, a soft-start circuit and a variable-sawtooth frequency circuit are proposed in this paper. The former is used to avoid the large switching current at the start up of the converter and the latter is utilized to reduce the EMI of the converter.
Triner, J. E.
1979-01-01
The basic magnetic properties under various operating conditions encountered in the state-of-the-art DC-AC/DC converters are examined. Using a novel core excitation circuit, the basic B-H and loss characteristics of various core materials may be observed as a function of circuit configuration, frequency of operation, input voltage, and pulse-width modulation conditions. From this empirical data, a mathematical loss characteristics equation is developed to analytically predict the specific core loss of several magnetic materials under various waveform excitation conditions.
A low noise high efficiency buck DC-DC converter with sigma-delta modulation
Energy Technology Data Exchange (ETDEWEB)
Cai Shujiang; Pi Changming; Yan Wei; Li Wenhong, E-mail: wenhongli@fudan.edu.cn [State Key Laboratory of ASIC and Systems, Fudan University, Shanghai 201203 (China)
2011-07-15
Some research efforts to improve the efficiency and noise performance of buck DC-DC converters are explored. A carefully designed power MOSFET driver, including a dead time controller, discontinuous current mode (DCM) controller and gate width controller, is proposed to improve efficiency. Instead of PWM modulation, sigma-delta modulation is introduced into the feedback loop of the converter to move out the clock-referred harmonic spike. The proposed converter has been designed and fabricated by a 0.35 {mu}m CMOS process. Measured results show that the peak efficiency of the converter can reach 93% and sigma-delta modulation suppresses the harmonic spike by 30 dB over PWM modulation. (semiconductor integrated circuits)
Hwu, K. I.; Tu, W. C.; Wang, C.R.
2013-01-01
A photovoltaic energy conversion system, constructed by high step-up converter with hybrid maximum power point tracking (HMPPT), is presented. A voltage converter with a high voltage conversion ratio is proposed, which is simple in circuit and easy in control. After this, such a converter operating with a suitable initial duty cycle of the pulsewidth-modulated (PWM) control signal, together with the proposed HMPPT algorithm combining the fractional open-circuit voltage method and the incremen...
Development of a PWM precision spraying controller for unmanned aerial vehicles
This paper presents a new pulse width modulation (PWM) controller for unmanned aerial vehicle (UAV) precision sprayer for agriculture using a TL494 fix-frequency pulse width modulator together with a data acquisition board and developed software. The PWM controller was implemented through the guidan...
CONTROL TECHNIQUES FOR VARIOUS BIPOLAR PWM STRATEGIES OF THREE PHASE FIVE LEVEL CASCADED INVERTER
Directory of Open Access Journals (Sweden)
C. R. BALAMURUGAN
2015-07-01
Full Text Available This paper presents different types of bipolar Pulse Width Modulation (PWM strategies for the chosen Cascaded MultiLevel Inverter (CMLI. The main purpose of MLI is to use power semiconductor devices of lower voltage ratings to realize high voltage levels at inverter output. Due to their ability to obtain refined output voltage waveforms, reduced Total Harmonic Distortion (THD and reduced EMI problems by reducing the switching dv/dt. In this paper, a three phase CMLI is controlled with Sinusoidal PWM strategy with Phase Disposition PWM (PDPWM, Phase Opposition and Disposition PWM (PODPWM, Alternative Phase Opposition and Disposition PWM (APODPWM, Phase Shift PWM (PSPWM and hybrid modulation strategy and the variation of THD in their outputs are observed by varying the modulation index. Simulations are performed using MATLAB-SIMULINK. It is observed that APODPWM and PSPWM provide output with relatively low distortion. It is also seen that PS, APOD and hybrid PWM are found to perform better since they provide relatively higher fundamental RMS output voltage. From hardware results it is seen that POD PWM provides output with relatively low distortion. It is also observed that PSPWM is found to perform better since it provide relatively higher fundamental RMS output voltage.
High flexibility and low cost digital implementation for modern PWM strategies
DEFF Research Database (Denmark)
Mathe, Laszlo; Sera, Dezso; Kerekes, Tamas
2011-01-01
like AZSPWM, NSPWM, or ACRPWM. By using a conventional PWM unit from a microcontroller, these modern modulation techniques are often difficult, or even impossible, to implement. The proposed method can be used to implement PWM strategies even for those microcontrollers which are not equipped...
Influence of PWM Modes on Commutation Torque Ripples in Sensorless Brushless DC Motor Control System
Institute of Scientific and Technical Information of China (English)
ZHANGXiang－jun; CHENBo－shi; 等
2001-01-01
This paper introduces four PWM modes used in the sensorless brushless DC motor control system,analyzes their different influences on the commutation torque ripple in detail,and selects the best PWM mode in four given types to reduce commutation torque ripple of Brushless OC( BLDC) motors,Simulation and experimental results show that the selection is correct and practical.
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...... is presented, and a dual voltage control strategy is then proposed, which comprises one voltage loop implemented in the synchronous reference frame for active power balancing, and another one implemented in the harmonic reference frame for ripple power compensation. Special attention is given to the bandwidth...
Energy Technology Data Exchange (ETDEWEB)
Bolognesi, P.; Carrara, G.; Casini, D.; Taponecco, L. [Pisa Univ. (Italy). Dipt. di Sistemi Elettrici e Automazione
1995-12-31
A possible way to extend a previously theoretically examined local spectral approximation strategy to the case of three-phase inverters is reported, and the first results obtained from a theoretical research concerning the elimination of entire harmonic families by imposing simple structural properties to the output waveforms are then presented. 1 ref, 10 figs, 1 tab
DEFF Research Database (Denmark)
Kouchaki, Alireza; Niroumand, Farideh Javidi; Haase, Frerk;
2015-01-01
circuit is used to provide the inductor current harmonic spectrum. Therefore, using the harmonic spectrum, the low and high frequency copper losses are calculated. The high frequency minor B-H loops in one switching cycle are also analyzed. Then, the loss map provided by the measurement setup is used...
High flexibility and low cost digital implementation for modern PWM strategies
DEFF Research Database (Denmark)
Mathe, Laszlo; Sera, Dezso; Kerekes, Tamas
2011-01-01
In this paper a new low cost technique for PWM strategy implementation is presented. The proposed technique does not require dedicated hardware PWM units, thus offering higher flexibility of use. Furthermore, the aforementioned method eases the digital implementation of modern modulation methods ...... with hardware PWM unit. The experimental results show that this new technique is suitable to replace traditional implementation methods with minimum computational overhead, with the benefit of high flexibility, lower cost and faster code development.......In this paper a new low cost technique for PWM strategy implementation is presented. The proposed technique does not require dedicated hardware PWM units, thus offering higher flexibility of use. Furthermore, the aforementioned method eases the digital implementation of modern modulation methods...
High-Feedback Operation of Power Electronic Converters
Directory of Open Access Journals (Sweden)
Gennady Y. Mikhal'chenko
2013-03-01
Full Text Available The purpose of this review is to provide a survey of some of the most important bifurcation phenomena that one can observe in pulse-modulated converter systems when operating with high corrector gain factors. Like other systems with switching control, electronic converter systems belong to the class of piecewise-smooth dynamical systems. A characteristic feature of such systems is that the trajectory is “sewed” together from subsequent discrete parts. Moreover, the transitions between different modes of operation in response to a parameter variation are often qualitatively different from the bifurcations we know for smooth systems. The review starts with an introduction to the concept of border-collision bifurcations and also demonstrates the approach by which the full dynamics of the piecewise-linear, time-continuous system can be reduced to the dynamics of a piecewise-smooth map. We describe the main bifurcation structures that one observes in three different types of converter systems: (1 a DC/DC converter; (2 a multi-level DC/DC converter; and (3 a DC/AC converter. Our focus will be on the bifurcations by which the regular switching dynamics becomes unstable and is replaced by ergodic or resonant periodic dynamics on the surface of a two-dimensional torus. This transition occurs when the feedback gain is increased beyond a certain threshold, for instance in Electronics 2013, 2 114 order to improve the speed and accuracy of the output voltage regulation. For each of the three converter types, we discuss a number of additional bifurcation phenomena, including the formation and reconstruction of multi-layered tori and the appearance of phase-synchronized quasiperiodicity. Our numerical simulations are compared with experimentally observed waveforms.
The General Technique of Selected Harmonics Elimination for Multilevel Converters
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
For high power applications, multilevel converters have many advantages in comparison with other circuit topologies with output transformers. Cascaded inverters are one type of multilevel converters, they are easy to implement, very suitable for modularized layout and packaging. Their manufacturing cost is low. A multilevel PWM technique, called as General Technique of Selected Harmonics Elimination(GTSHE), is proposed in the paper. A general harmonic elimination equation for N cells, M pulses per half cycle, nth harmonic is derived, and verified by simulation results.
Pulsewidth Modulation of Neutral-Point-Clamped Indirect Matrix Converter
DEFF Research Database (Denmark)
Blaabjerg, Frede; Poh Chiang, Loh; Gao, Feng
2008-01-01
discussed in the existing literature. Addressing the previously described issues, this paper focuses on the operational mode analysis of a three-level indirect matrix converter implemented using a neutral-point-clamped inversion stage and the design of a number of PWM and modulation ratio compensation...... schemes for controlling the converter with improved waveform quality. The 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 this paper....
Robust DC/DC converter control for polymer electrolyte membrane fuel cell application
Wang, Ya-Xiong; Yu, Duck-Hyun; Chen, Shi-An; Kim, Young-Bae
2014-09-01
This study investigates a robust controller in regulating the pulse width modulation (PWM) of a DC/DC converter for a polymer electrolyte membrane fuel cell (PEMFC) application. A significant variation in the output voltage of a PEMFC depends on the power requirement and prevents a PEMFC from directly connecting to a subsequent power bus. DC/DC converters are utilized to step-up or step-down voltage to match the subsequent power bus voltage. In this study, a full dynamic model, which includes a PEMFC and boost and buck DC/DC converters, is developed under MATLAB/Simulink environment for control. A robust PWM duty ratio control for the converters is designed using time delay control (TDC). This control enables state variables to accurately follow the dynamics of a reference model using time-delayed information of plant input and output information within a few sampling periods. To prove the superiority of the TDC performance, traditional proportional-integral control (PIC) and model predictive control (MPC) are designed and implemented, and the simulation results are compared. The efficacies of TDC for the PEMFC-fed PWM DC/DC converters are validated through experimental test results using a 100 W PEMFC as well as boost and buck DC/DC converters.
Enhanced control of DFIG-used back-to-back PWM VSC under unbalanced grid voltage conditions
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
This paper presents a unified positive- and negative-sequence dual-dq dynamic model of wind-turbine driven doublyfed induction generator (DFIG) under unbalanced grid voltage conditions. Strategies for enhanced control and operation of a DFIG-used back-to-back (BTB) PWM voltage source converter (VSC) are proposed. The modified control design for the grid-side converter in the stationary αβ frames diminishes the amplitude of DC-link voltage ripples of twice the grid frequency, and the two proposed control targets for the rotor-side converter are alternatively achieved, which, as a result, improve the fault-ride through (FRT) capability of the DFIG based wind power generation systems during unbalanced network supply. A complete unbalanced control scheme with both grid- and rotor-side converters included is designed. Finally, simulation was carried out on a 1.5 MW wind-turbine driven DFIG system and the validity of the developed unified model and the feasibility of the proposed control strategies are all confirmed by the simulated results.
Transformerless DC-DC Converter Using Cockcroft-Walton Voltage Multiplier to Obtain High DC Voltage
Directory of Open Access Journals (Sweden)
Meghana G Naik,
2014-11-01
Full Text Available In the present scenario the use of transformer for high voltages in converter circuit reduces the overall operating efficiency due to leakage inductance and use of transformer also increases the operational cost. . Therefore the proposed system is implemented with transformer less DC-DC converter so as to obtain high DC voltage with the use of nine stage Cockcroft-Walton (CW voltage multiplier. The proposed converter operates in CCM (continuous conduction mode, so that the converter switch stress, the switching losses are reduced. The DC voltage at the input of the proposed model is low and is boosted up by boost inductor (Ls in DC-DC converter stage and performs inverter operation. The number of stages in CW-voltage multiplier circuit is applied with low input pulsating DC (AC Voltage voltage where it is getting converted to high DC output voltage. The proposed converter switches operates at two independent frequencies, modulating (fsm andalternating (fsc frequency. The fsm operates at higher frequency of the output while the fsc operates at lower frequency of the desired output voltage ripple and the output ripples can be adjusted by the switch Sc1 and Sc2. The regulation of the output voltage is achieved by controlling the Duty ratio.The simulation is carried over by the MATLABSIMULINK.
Pengaruh Penambahan PWM (Pulse Width Modulation Pada Generator HHO Tipe Dry Cell
Directory of Open Access Journals (Sweden)
Fungky Dyan Pertiwi
2013-09-01
Full Text Available Generator HHO memanfaatkan proses elektrolisis air agar mendapatkan gas H2. Namun, pada praktiknya pemakaian arus dari aki yang besar dan temperatur tinggi membuat bejana generator menjadi cepat rusak, sehingga dibutuhkan tambahan rangkaian elektronika PWM pada pengujian generator HHO guna mengatasi permasalahan tersebut. Penelitian menggunakan elektroda plat berjumlah 9 berdimensi 120mm 120mm, tebal 1mm dan dibatasi oleh o-ring dengan diameter 126mm, tebal 3mm. Pengujian dilakukan secara eksperimen dengan 2 kelompok yaitu kelompok control yang mana pengujian tanpa menggunakan PWM serta kelompok uji dimana pengujian menggunakan PWM dengan variasi duty cycle 30%, 50% dan 70%. Pengujian dilakukan hingga temperatur elektrolit 93oC. Hasil uji didapatkan bahwa arus, laju produksi dan efisiensi terbesar didapatkan pada pengujian tanpa PWM yang mencapai 60,6A, 6,033 10-6kg/s dan 25,69%. Namun, pada pengambilan data kedua efisiensi turun menjadi 19,74%. Penambahan PWM pada pengujian berpengaruh pada arus dan temperatur yang stabil meskipun laju produksi dan efisiensi lebih kecil daripada pengujian tanpa PWM. Pengujian dengan PWM pada duty cycle 70% menghasilkan laju produksi dan efisiensi terbesar yang mencapai 1,843 10-6 kg/s dan 15,19%.
Novel Full-bridge ZVS DC-DC Converter with an Clamp Diodes
Guangqun, Nan; Xue, Hu
The two arms of this converter all work at zero-voltage switching condition, that bring many advantages, such as little loss of power, simple control, etc. But these also exists some problems, such as parasitic oscillation on the output rectifier diodes. A novel full-bridge ZVS PWM DC-DC converter which adopts two clamping diodes in the first side of the transformer is proposed to reduce the parasitic oscillation in this paper. In this paper, It heavily analyzes the realization process of their soft-switching and the reason of related issues and solution, we establishes simulation model and simulates using orCAD. Finally,a 5 kW ZVS PWM DC-DC converter Prototype in that TMS320F2812 is the core controlled chip has been set up, and the experiments showed us the validation of the correlative theory.
A study of DC-DC converters with MCT's for arcjet power supplies
Stuart, Thomas A.
1994-01-01
Many arcjet DC power supplies use PWM full bridge converters with large arrays of parallel FET's. This report investigates an alternative supply using a variable frequency series resonant converter with small arrays of parallel MCT's (metal oxide semiconductor controlled thyristors). The reasons for this approach are to: increase reliability by reducing the number of switching devices; and decrease the surface mounting area of the switching arrays. The variable frequency series resonant approach is used because the relatively slow switching speed of the MCT precludes the use of PWM. The 10 kW converter operated satisfactorily with an efficiency of over 91 percent. Test results indicate this efficiency could be increased further by additional optimization of the series resonant inductor.
Parallel Interleaved VSCs: Influence of the PWM Scheme on the Design of the Coupled Inductor
DEFF Research Database (Denmark)
Gohil, Ghanshyamsinh Vijaysinh; Bede, Lorand; Maheshwari, Ram Krishan;
2014-01-01
-linkage in the CI is presented in this paper. The maximum flux density and the core losses, being the most important parameters for the CI design, are evaluated for continuous PWM and discontinuous pulsewidth modulation (DPWM) schemes. The effect of these PWM schemes on the design of the CI is discussed....... To limit the circulating current, magnetic coupling between the interleaved legs of the corresponding phase is provided by means of a Coupled Inductor (CI). The design of the CI is strongly influenced by the Pulsewidth Modulation (PWM) scheme used. The analytical model to evaluate the flux...
Research on Passivity Based Controller of Three Phase Voltage Source PWM Rectifier
Directory of Open Access Journals (Sweden)
Yin Hongren
2012-09-01
Full Text Available Euler-Lagrange (EL model of voltage source PWM rectifier is set up based on its model in synchronous dq coordinates. Passivity based controller is designed on the basis of passivity and EL model of voltage source PWM rectifier. Three switching function are educed by passivity based controller. A switching function is only realized in engineering consequently. Voltage source PWM rectifier using passivity based controller has many advantages, such as simpler structure, low total harmonic distortion, and good disturbance rejection performance. Passivity based control law is proved feasible by simulink simulation.
Directory of Open Access Journals (Sweden)
1V.Chaitanya,P.G.scholar,
2015-10-01
Full Text Available : Even though electrical vehicle concept is introduced in early 1800’s, it gained importance in past couple of decades due to growing conscience on environmental aspects. Different types of electrical vehicles are manufactured in the past centuries and now onboard generation is seems to be promising by fulfilling the needs of a vehicle. Fuel cells or fuel cell stack produces typically 32-68V of EMF, which has to be conditioned before it fed to motor. The conditioning involves two stages DCDC conversion and then to DC-AC conversion .DC-AC conversion is done through inverter. For DC-DC to conversion various topologies are proposed such as fly back, forward, buck-boost are proposed. This paper deals with the front end DC-DC converter and inverter switching. A hybrid modulation scheme is used to produce pulses to switch the source end full bridge rectifier and inverter at load end. In this modulation scheme high frequency pulses given to full bridge rectifier and 33% modulation scheme based pulses are produced for inverter switching.
Architecture for a High-to-Medium-Voltage Power Converter
Vorpenian, Vatche
2008-01-01
A power converter now undergoing development is required to operate at a DC input potential ranging between 5.5 and 10 kV and a DC output potential of 400 V at a current up to 25 A. This power converter is also required to be sufficiently compact and reliable to fit and operate within the confines of a high-pressure case to be lowered to several miles (approx.5 km) below the surface of the ocean. The architecture chosen to satisfy these requirements calls for a series/ parallel arrangement of 48 high-frequency, pulse-width-modulation (PWM), transformer-isolation DC-to-DC power converter blocks. The input sides of the converter blocks would be connected in series so that the input potential would be divided among them, each of them being exposed to an input potential of no more than 10 kV/48 . 210 V. The series connection of inputs would also enforce a requirement that all the converter blocks operate at the same input current. The outputs of the converter blocks would be connected in a matrix comprising 6 parallel legs, each leg being a cascade of eight outputs wired in series (see figure). All the converter blocks would be identical within the tolerances of the values of their components. A single voltage feedback loop would regulate the output potential. All the converter blocks would be driven by the same PWM waveform generated by this feedback loop. The power transformer of each converter block would have a unity turns ratio and would be capable of withstanding as much as 10 kVDC between its primary and secondary windings. (Although, in general, the turns ratio could be different from unity, the simplest construction for minimizing leakage and maximizing breakdown voltage is attained at a turns ratio of unity.)
Directory of Open Access Journals (Sweden)
Rui Melício
2007-01-01
Full Text Available En el presente trabajo se hace un análisis actual de la capacidad instalada de producción de energía eléctrica utilizando fuentes de energía renovable en Portugal y se analiza la situación actual relacionada con convertidores electrónicos de potencia. Además el trabajo aporta información sobre la simulación de topologías de convertidores de potencia en los sistemas de energía eólica, los convertidores usuales de dos niveles, el convertidor multinivel y el convertidor matricial. Se usa el método de la modulación de los pulsos de disparo mediante vectores espaciales de tensión y el control por modo de deslizamiento. Esta simulación permite concluir que las ondas de tensión y corriente en los convertidores de dos etapas AC/DC/AC se presentan con mejor comportamiento armónico que en el convertidor de una etapa AC/AC.This paper presents an analysis of the present installed electric power capacity of renewable energy power systems in Portugal, and analyzes the present state of power converters applied to wind farms. Also, this paper presents a simulation of a wind energy system with the usual topology for power converters, a two-levels converter, a multi-level converter and a matrix converter, using pulse modulation by space vector modulation. The simulation allows concluding that the waves for the electric voltage and the current in the converters AC/DC/AC have better performance than in the matrix converter AC/AC.
Stator insulation systems for medium voltage PWM drives fed motors
Energy Technology Data Exchange (ETDEWEB)
Gao, G.; Chen, W. [TECO-Westinghouse Motor Co., Round Rock, TX (United States)
2005-07-01
Adjustable speed drives (ASD) are commonly used in power electronics and control systems. It is estimated that more than 15 per cent of medium voltage motors are currently fed by such drives worldwide. A research project was conducted to examine the influence of medium voltage pulse width modulated (PWM) ASD on motor stator insulation systems. The findings, based on accelerated laboratory tests, have helped designers to improve the capabilities of the insulation system used for ASD-fed motors. Repetitive, high magnitude voltage spikes with fast rise time create significant stress on insulation systems. Gradual deterioration and premature failure of the motor insulation can result from surge voltages which generate surface discharges between phase windings/end windings, or partial discharges between stator turns. However, there is no industrial standard to evaluate motor insulation life under ASD-cable-motor conditions. Several material manufacturers have developed their own version of corona resistant material. However, the insulation life of ASD-fed motors does not depend solely on the raw materials. Rather, it depends on the complete insulation system, including the stator manufacturing process. In order to address this problem, TECO-Westinghouse Motor Company has developed special design criteria and manufacturing practices in order to reduce winding insulation temperature and to compensate for the additional heat generated by high frequency contents in the PWM voltage waveform. A patent pending new cooling system should reduce winding temperature by 15 to 20 degrees C. This paper presented design considerations for turn insulation, groundwall insulation, and a voltage stress grading system. A new thermal class H insulation system was also described. 6 refs., 2 tabs., 5 figs.
A Dual-Mode Step-up DC/DC Converter IC with Current-Limiting and EMI Reduction Techniques
Institute of Scientific and Technical Information of China (English)
Wan-Rone Liou; Chun-Ting Kuo; Mei-Ling Yeh; Ping-Hsing Chen; Marynelle L. Z. Rosales
2008-01-01
This paper presents a novel dual-modestep-up (boost) DC/DC converter. Pulse-frequencymodulation (PFM) is used to improve the efficiency atlight load. This converter can operate betweenpulse-width modulation (PWM) and pulse-frequencymodulation. The converter will operate in PFM mode atlight load and in PWM mode at heavy load. Themaximum conversion efficiency of this converter is 96%.The conversion efficiency is greatly improved when loadcurrent is below 100 mA. Additionally, a soft-startcircuit and a variable-sawtooth frequency circuit areproposed in this paper. The former is used to avoid thelarge switching current at the start up of the converterand the latter is utilized to reduce the EMI of theconverter.
a microprocessor-based control, scheme for a pwm voltage-fed ...
African Journals Online (AJOL)
Dr Obe
Department of Electrical Engineering ... integral controllers constitute the main control program while the application of thyristor gating ... PWM strategies depend on application .... Figure 3(a) shows the basic principle of gating signal.
PWM Switching Frequency Effects on Eddy Current Sensors for Magnetically Suspended Flywheel Systems
Jansen, Ralph; Lebron, Ramon; Dever, Timothy P.; Birchenough, Arthur G.
2003-01-01
A flywheel magnetic bearing (MB) pulse width modulated power amplifier (PWM) configuration is selected to minimize noise generated by the PWMs in the flywheel position sensor system. Two types of noise are addressed: beat frequency noise caused by variations in PWM switching frequencies, and demodulation noise caused by demodulation of high order harmonics of the switching voltage into the MB control band. Beat frequency noise is eliminated by synchronizing the PWM switch frequencies, and demodulation noise is minimized by selection of a switching frequency which does not have harmonics at the carrier frequency of the sensor. The recommended MB PWM system has five synchronized PWMs switching at a non-integer harmonic of the sensor carrier.
Directory of Open Access Journals (Sweden)
O. Malik
2013-02-01
The internal PWM signal conversion occurs by the use of non-equilibrium physical processes in the semiconductor substrate of the MOS-C. The 10-20 V amplitude limited square PWM output signal is obtained by the amplification of the sensor signal with a standard 60 dB transimpedance amplifier. The amplified output signal presents positive and negative PWM waveforms that can be easily separated using diodes. The duty of the positive part is proportional to the light intensity, whereas the negative part is inversely proportional to the intensity. The frequency operating range of this proposed instrument varies from 1 Hz to a few kilohertz. The duty cycle of the PWM output signal varies from 2% to 98% when the incident light intensity varies in the microwatts range. These new transducers or sensors could be useful for automatic control, robotic applications, dimmer systems, feedback electronic systems, and non-contact optical position sensing for nulling and centering measurements.
Design of a High Performance Green-Mode PWM Controller IC with Smart Sensing Protection Circuits
National Research Council Canada - National Science Library
Shen-Li Chen; Shih-Hua Hsu
2014-01-01
A design of high performance green-mode pulse-width-modulation (PWM) controller IC with smart sensing protection circuits for the application of lithium-ion battery charger is investigated in this article...
Energy Technology Data Exchange (ETDEWEB)
Silva Junior, Pedro A. da; Selinke, Rubens A.; Martins, Denizar Cruz [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Eletrica. Inst. de Eletronica de Potencia
1996-12-31
This paper presents the analysis and implementation of an algorithm for numerical simulation applied to static converter, using PWM modulation and PID (Proportional Integral Derivative) controller. A buck converter prototype is designed and the experimental results are compared to those of the simulation. (author) 5 refs., 7 figs.; e-mail: inep at inep.ufsc.br
Analysis of VCO based noise shaping ADCs linearized by PWM modulation
Hernandez, Luis; Prefasi, , Enrique; Paton , Susana; Rombouts, Pieter
2012-01-01
Nonlinearity is one of the main problems associated with VCO based noise shaping ADCs. Their open loop architecture does not permit correction of the nonlinear voltage to frequency response of the VCO by feedback. Recently, linearization of a VCO ADC by Pulse Width Modulation (PWM) precoding has been proposed. Here, the input signal is encoded by a PWM modulator to drive the VCO with a 2-level signal, thus eliminating the nonlinearity of the VCO. This paper analyzes the remaining inherent dis...
Positioning Error of Optoelectronic Telescope Compensated by Bipolar PWM Driving Mode
Institute of Scientific and Technical Information of China (English)
LI Xiao-yan; ZHOU Hui; FU Hong; HOU Yun-hai
2005-01-01
The optoelectronic telescope has two sets of control systems: azimuth one and elevation one, and both are driven by PWM power amplifier with high efficiency and wide speed regulation range. The diagram of the azimuth control system is demonstrated, the nonlinear factors is analyzed at low speed, and some related experiments are carried out. The results show that the positioning error with unipolar is 86 codes(106.21″),while 18 codes (22. 23″) is with bipolar PWM driver.
A New Method for Maintaining Constant Dither Amplitude in Low Frequency PWM
Directory of Open Access Journals (Sweden)
KANG, H.
2017-02-01
Full Text Available Various controls for fluid flow and pressure are now required in related industries, and the pulse width modulation (PWM and dithering techniques have become essential for the proportional control of solenoids. However, there is a fatal drawback when the dither current signals are generated as a by-product of low frequency PWM. That is, the average current and the dither amplitude in low frequency PWM cannot be controlled independently. Therefore, a new method for maintaining constant dither amplitudes is proposed in this paper. Throughout the mathematical analysis, the effect of PWM frequency and duty cycle on the average current and dither amplitude was investigated, and the analysis result was validated by electrical experiments. Based on the mathematical analysis, a new method that properly varies both the duty cycle and the PWM frequency to obtain the desired average current and constant dither amplitude was established and verified. This method requires only the calculations for determining the proper PWM frequency and duty cycle, so it is possible to improve the performance of a proportional solenoid valve without additional devices or cost.
Indian Academy of Sciences (India)
A Ramachandran; M Channa Reddy; Ranjan Moodithaya
2008-10-01
The recent increase in the use of speed control of ac induction motor for variable speed drive using pulse width modulation (PWM) inverter is due to the advent of modern power electronic devices and introduction of microprocessors. There are many advantages of using ac induction motor for speed control applicatons in process and aerospace industries, but due to fast switching of the modern power electronic devices, the parasitic coupling produces undesirable effects. The undesirable effects include radiated and conducted electromagnetic interference (EMI) which adversely affect nearby computers, electronic/electrical instruments and give rise to the ﬂow of bearing current in the induction motor. Due to the ﬂow of bearing current in the induction motor, electrical discharge machining takes place in the inner race of the bearing which reduces the life of the bearing. In high power converters and inverters, the conducted and radiated emissions become a major concern. In this paper, identiﬁcation of bearing current due to conducted emission, the measurement of bearing current in a modiﬁed induction motor and to minimize the bearing current are discussed. The standard current probe, the standard line impedance stabilization network (LISN)), the electronics interface circuits are used to measure high frequency common mode current, bearing current and to minimize the conducted noise from the system. The LISN will prevent the EMI noise entering the system from the supply source by conductive methods, at the same time prevents the EMI generated if any due to PWM, fast switching in the system, will not be allowed to enter the supply line. For comparing the results with Federal Communications Commission (FCC) and Special Committee on Radio Interference (CISPR) standards, the graphs are plotted with frequency Vs, line voltage in $dB{_\\mu} V$, common mode voltage in $dB{_\\mu} V$ and the bearing current in $dB_{\\mu} A$ with out and with minimizing circuits.
Compherensive Design of a 100 kW/400 V High Performance AC-DC Converter
2015-01-01
In this paper, a comprehensive design for a 100kW/400V, three-phase pulse-width modulated (PWM) AC-DC converter is presented that serves as the front-end power supply for wide-range varying active load. This power supply includes two series stages; a six-switch AC-DC boost converter and a DC-DC buck converter to regulate 400VDC at load side. The design of all inductors and capacitors is fulfilled using mathematical expressions. In addition, small signal modelling and controller design are pre...
DEFF Research Database (Denmark)
Kloch, Allan; Hansen, Peter Bukhave; Wolfson, David;
1999-01-01
at 2.5 Gbit/s, the regeneration causes a reduction of the required input power to an in-line EDFA of ~6 dB for a power penalty of 1 dB at a bit error rate of 10-9. If two converters are concatenated the power requirement is reduced ~8 dB. Obviously, the power reduction allows for longer spans between....... It is predicted that jitter accumulation can be minimised by using a 9-10 dB ratio between the signal and CW power also assuring a high extinction ratio. Using this guideline simulations show that 20 cross-gain modulation converters can be cascaded at 10 Gbit/s with only ~20 ps of accumulated jitter...... and an extinction ratio of ~10 dB.The regenerative capabilities of the cross-phase converters are described and verified experimentally at 20 Gbit/s, where the noise redistribution and improvement of the signal-to-noise ratio clearly is demonstrated by controlling the input power to an EDFA. In a similar experiment...
Hybrid Voltage-Multipliers Based Switching Power Converters
Rosas-Caro, Julio C.; Mayo-Maldonado, Jonathan C.; Vazquez-Bautista, Rene Fabian; Valderrabano-Gonzalez, Antonio; Salas-Cabrera, Ruben; Valdez-Resendiz, Jesus Elias
2011-08-01
This work presents a derivation of PWM DC-DC hybrid converters by combining traditional converters with the Cockcroft-Walton voltage multiplier, the voltage multiplier of each converter is driven with the same transistor of the basic topology; this fact makes the structure of the new converters very simple and provides high-voltage gain. The traditional topologies discussed are the boost, buck-boost, Cuk and SEPIC. They main features of the discussed family are: (i) high-voltage gain without using extreme duty cycles or transformers, which allow high switching frequency and (ii) low voltage stress in switching devices, along with modular structures, and more output levels can be added without modifying the main circuit, which is highly desirable in some applications such as renewable energy generation systems. It is shown how a multiplier converter can become a generalized topology and how some of the traditional converters and several state-of-the-art converters can be derived from the generalized topologies and vice-versa. All the discussed converters were simulated, additionally experimental results are provided with an interleaved multiplier converter.
OW式永磁直驱风电系统不连续脉宽调制∗%Open Winding PMSG for Discontinuous PWM
Institute of Scientific and Technical Information of China (English)
殷杰; 向铁元; 杨瑶
2015-01-01
Permanent Magnet Synchronous Generator current ripple in the operation proposed an open winding type permanent magnet direct drive wind power system for discontinuous PWM modulation. Open winding pair was established equivalent switch model PMSG inverter drive system, clarify the decoupled nature of PWM modulation current ripple causes by introducing a“valid” by properly offset voltage vector time effectively solved PMSG machine side of the stator current ripple, realized the optimization of PMSG were converters power quality improvement. Finally, 110kW wind drag and experimental platform for the open winding PMSG continuous PWM modulation method for performance verification, verified the validity of the method in the optimization of PMSG on-grid power quality.%针对中压永磁直驱风电系统( PMSG)运行中存在的电流脉动问题，提出一种OW式永磁直驱风电系统不连续PWM调制方法。建立了OW双逆变器PMSG驱动系统等效开关模型，阐明了解耦PWM调制电流脉动问题的本质原因，引入“有效时间”概念，通过合理地偏移有效电压矢量作用时间，解决了PMSG机侧定子电流脉动问题，实现了PMSG变流器发电品质的优化提高。最后，基于110 kW风力发电对拖试验平台对所提OW PMSG不连续PWM调制方法进行性能验证，验证了该方法对优化PMSG并网电能品质的有效性。
Analysis of Single Phase PWM Rectifier for Different Applications
Mitra, Arkendu; Chowdhuri, Sumana
2017-04-01
This research work investigates the various applications of a PWM rectifier based on its input power factor. Most of the cases, the papers describe the operation of the rectifier used for unity power factor (UPF) operation. Beside this mode of operation, this paper compiles the application of the rectifier as STATCOM also, where the rectifier deals only with reactive power exchange. In this work, the controller is implemented by inserting a loop for reference input of phase angle which will be compared with the actual one, so that user can operate the rectifier at any power factor. Some basic formulae are derived for the input current, active power and reactive power based on which the control circuit is to be designed. Here two Proportional-Integral (PI) controllers are used. A brief description of tuning these two PI controllers is incorporated in this paper. Also some calculations are given to determine the harmonic factors of the input line current from which it is found that the rectifier when operated in each mode operation, the order of the harmonics are very low.
Analysis of Single Phase PWM Rectifier for Different Applications
Mitra, Arkendu; Chowdhuri, Sumana
2016-06-01
This research work investigates the various applications of a PWM rectifier based on its input power factor. Most of the cases, the papers describe the operation of the rectifier used for unity power factor (UPF) operation. Beside this mode of operation, this paper compiles the application of the rectifier as STATCOM also, where the rectifier deals only with reactive power exchange. In this work, the controller is implemented by inserting a loop for reference input of phase angle which will be compared with the actual one, so that user can operate the rectifier at any power factor. Some basic formulae are derived for the input current, active power and reactive power based on which the control circuit is to be designed. Here two Proportional-Integral (PI) controllers are used. A brief description of tuning these two PI controllers is incorporated in this paper. Also some calculations are given to determine the harmonic factors of the input line current from which it is found that the rectifier when operated in each mode operation, the order of the harmonics are very low.
Institute of Scientific and Technical Information of China (English)
张伟龙; 谢新胜; 李帅
2013-01-01
With the continuous development of power electronics technology and mature, As the importance of power electronics technology and simulation applications. PWM and SPWM technology and PSIM software will certainly be with the power electronics technology development is recognized by more and more people. This paper simply introduces the technology of the most basic concepts, with PSIM software to deepen the understanding of them, Let us in the future life and work have a basic understanding of and cognition, also make a foundation for future learning.%随着电力电子技术的不断发展与成熟，电力电子在各个方面都得到了广泛的应用。而作为电力电子技术的重要技术和仿真应用软件，PWM与SPWM技术及PSIM软件必然会随着电力电子技术的发展被越来越多的人所认识。本文通过简单地介绍这项技术的最基本概念，并用PSIM软件来加深对它们的理解，让大家在日后的生活和工作有一个基本的了解和认识，也为今后的学习打一个基础。
PWM-Statcom system additionally having active filter function
Energy Technology Data Exchange (ETDEWEB)
Matsui, K.; Kojima, H.; Yamamoto, I.; Hasegawa, M. [Chubu Univ., Kasugai Aichi (Japan); Ando, K. [Nitto Kogyo Corp., Nagakute, Aichi (Japan)
2006-07-01
The harmonic characteristics of static synchronous compensators (Statcom) were discussed with particular reference to the difference between symmetrical and asymmetrical modulation strategies that influence a quality of output waveform. The asymmetrical modulation strategy is the better approach in higher power factor applications such as alternating current (AC) motor drives. It was noted that in cases requiring a passive filter with a very large scale Statcom, a symmetrical modulation strategy is superior. Therefore, in this study, a symmetrical modulation was preferred for a neutral point clamped (NPC) pulse width modulation (PWM) inverter. Due to switching in a limited narrow frequency band, such output harmonics can be eliminated using a simple passive filter and harmonics such as the fifth and the seventh, can be suppressed using the proposed Statcom scheme in which the feedback signals for the fifth and seventh harmonics are injected into the Statcom. Using these feedback signals, the harmonics in the power system were significantly reduced. This result was also confirmed by simulation. It was concluded that, in addition to the proper operation of the Statcom, it is possible to perform an active filtering function . 10 refs., 1 tab., 9 figs.
Cao, Dong
Due the energy crisis and increased oil price, renewable energy sources such as photovoltaic panel, wind turbine, or thermoelectric generation module, are used more and more widely for vehicle and grid-connected applications. However, the output of these renewable energy sources varies according to different solar radiation, wind speed, or temperature difference, a power converter interface is required for the vehicle or grid-connected applications. Thermoelectric generation (TEG) module as a renewable energy source for automotive industry is becoming very popular recently. Because of the inherent characteristics of TEG modules, a low input voltage, high input current and high voltage gain dc-dc converters are needed for the automotive load. Traditional high voltage gain dc-dc converters are not suitable for automotive application in terms of size and high temperature operation. Switched-capacitor dc-dc converters have to be used for this application. However, high voltage spike and EMI problems exist in traditional switched-capacitor dc-dc converters. Huge capacitor banks have to be utilized to reduce the voltage ripple and achieve high efficiency. A series of zero current switching (ZCS) or zero voltage switching switched-capacitor dc-dc converters have been proposed to overcome the aforementioned problems of the traditional switched-capacitor dc-dc converters. By using the proposed soft-switching strategy, high voltage spike is reduced, high EMI noise is restricted, and the huge capacitor bank is eliminated. High efficiency, high power density and high temperature switched-capacitor dc-dc converters could be made for the TEG interface in vehicle applications. Several prototypes have been made to validate the proposed circuit and confirm the circuit operation. In order to apply PV panel for grid-connected application, a low cost dc-ac inverter interface is required. From the use of transformer and safety concern, two different solutions can be implemented, non
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...... applications. Spectral measurements on prototypes of a pulse width modulator (PWM), a -modulator and a hysteretic self-oscillating modulator are shown, which are verifying their simulations, with respect to different EMI challenges....
Push-pull with recovery stage high-voltage DC converter for PV solar generator
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.
Directory of Open Access Journals (Sweden)
F. J. De la Hidalga-W
2013-01-01
Full Text Available This work shows that the direct PWM output electric signal, with a duty cycle controlled by light intensity, can beobtained using a circuit containing a saw-tooth voltage generator connected in series with a dc voltage source and ametal (semitransparent gate oxide semiconductor capacitor (MOS-C.The internal PWM signal conversion occurs by the use of non-equilibrium physical processes in the semiconductorsubstrate of the MOS-C. The 10-20 V amplitude limited square PWM output signal is obtained by the amplification ofthe sensor signal with a standard 60 dB transimpedance amplifier. The amplified output signal presents positive andnegative PWM waveforms that can be easily separated using diodes. The duty of the positive part is proportional tothe light intensity, whereas the negative part is inversely proportional to the intensity. The frequency operating rangeof this proposed instrument varies from 1 Hz to a few kilohertz. The duty cycle of the PWM output signal varies from2% to 98% when the incident light intensity varies in the microwatts range. These new transducers or sensors couldbe useful for automatic control, robotic applications, dimmer systems, feedback electronic systems, and non-contactoptical position sensing for nulling and centering measurements.
Logic Pulse Width Modulation Method for Converter%变换器的逻辑脉冲宽度调制方法
Institute of Scientific and Technical Information of China (English)
魏毅立; 周金生; 罗家涛; 张自雷
2014-01-01
分析了单相半桥DC-AC变换器的逻辑脉冲宽度调制（ LPWM）控制方法，阻感负载电流为正和为负情形下IGBT的导通状态，进而分别给出了等效电路。其方法是根据负载的电流的正负而开放或封锁对应的IGBT的门极脉冲。在单相半桥DC-AC变换器的LPWM基础上，分析了三相桥式DC-AC变换器的LPWM控制方法和SVPWM的LPWM控制方法， LPWM控制方法的优点是减少了一半的门极驱动损耗，除电流过零点以外无需再加死区，提高了开关频率，增强了系统的安全性。然后再通过Matlab仿真软件对LPWM仿真，验证了LPWM控制方法正确性。%The logic pulse width modulation ( LPWM) control method for single-phase half bridge DC-AC convert-er, and the on-off state of IGBT under the circumstance of inductive load with the load current as positive and nega-tive respectively have been analyzed in this paper, so as to present the equivalent circuits.This method is to open or close the corresponding IGBT trigger pulse according to the load current being positive or negative.In addition, based on the LPWM control method for the single-phase half bridge DC-AC converter, LPWM control methods for the three-phase bridge DC-AC converter and SVPWM control method have been also analyzed.The advantage of LP-WM control method is to reduce half of the switching loss.No dead zone is need to add up except for the current pass-ing through the zero point, so as to improve the switch frequency and enhance the system safety.Simulation results based on Matlabverify the correctness of LPWM control method.
EVALUATION OF VARIOUS UNIPOLAR MULTICARRIER PWM STRATEGIES FOR FIVE LEVEL FLYING CAPACITOR INVERTER
Directory of Open Access Journals (Sweden)
B. SHANTHI
2012-06-01
Full Text Available This paper presents the comparison of unipolar multicarrier Pulse Width Modulation (PWM techniques for the Flying Capacitor Multi Level Inverter (FCMLI. Due to switch combination redundancies, there are certain degrees of freedom to generate the five level AC output voltage. This paper presents the use of Control Freedom Degree (CFD combination. The effectiveness of the PWM strategies developed using CFD are demonstrated by simulation and experimentation. The results indicate that the multilevel inverter triggered by the developed USHPWM strategy exhibits reduced harmonics. PWM strategies developed are implemented in real time using dSPACE/Real Time Interface (RTI. The simulation and experimental output closely match with each other validating the strategies presented.
A novel PWM scheme to eliminate the diode freewheeling In the Inactive phase in BLDC motor
Institute of Scientific and Technical Information of China (English)
WEI Kun; HU Chang-sheng; ZHANG Zhong-chao
2006-01-01
The brushless DC motor (BLDCM) with trapezoidal electromotive force (back-EMF) waveform is used widely.In principle,when the motor runs in the 120°conduction mode,two of the three phases are active while the other phase is inactive at all times.However,a ripple current occurs in the inactive phase due to the diode freewheeling during the non-commutation period in the traditional pulse width modulation (PWM) methods,which aggravates the torque ripples.A new PWM method is proposed in this paper to eliminate the diode freewheeling during the non-commutation period in the inactive phase.As a result,the torque ripple is suppressed using the proposed method.The simulation and experimental results are demonstrated to verify the validity of the proposed PWM method.
Design hardware calculator in PWM peripherals of nios Ⅱ with verilog HDL
Institute of Scientific and Technical Information of China (English)
XU Yang; XIANG Min
2009-01-01
The Plus Width Module (PWM) in microprocessors is commonly used in motor control field. If the ordinary PWM peripherals output PWM waveform, the software must calculate the period and duty cycle number based on the microprocessor's system clock cycle first, and then write them into the registers. As all known, the microprocessor without hardware calculator consume very long time in multiplication and division. In order to reduce the CPU's running time, a calculation hardware unit was designed to calculate the waveform parameters. The software only need to write the period (Hz units) to the period register and the duty cycle (% units)to its register. This hardware unit was designed with Verilog HDL and running in the Nios II system successfully.
Institute of Scientific and Technical Information of China (English)
刘海涛; 陈涛
2012-01-01
In order to guarantee the performance of converter, it needs to select the appropriate intermediate DC support capacitor. According to the analysis of the circuit topology and the switch modulation mode of converter and referring to the existing literature, it summerizes a method to calculate current of the capacitor. The theory and simulation results demonstrate that this method has good accuracy.%为了使变频器满足性能要求，需选择合适的中间直流支撑电容。根据对变频器电路拓扑与开关调制方式的分析，并借鉴已有文献资料，归纳出计算电容器电流的方法。理论与仿真证明，该方法有较好的准确性。
Control Strategy for Three Phase Voltage Source PWM Rectifier Based on the Space Vector Modulation
Directory of Open Access Journals (Sweden)
MILOUD, Y.
2010-08-01
Full Text Available This paper proposes the space vector pulse width modulation (SVPWM control scheme for three-phase voltage source PWM rectifier. The control system based on SVPWM includes two PI controllers which are used to regulate the AC currents and DC-link voltage. The proposed control can stabilize the minimum of the systems storage function at the desired equilibrium point determined by unity power factor and sinusoidal current on the AC side, and constant output voltage on the DC side. So the stable state performance and robustness against the load�s disturbance of PWM rectifiers are both improved. The simulation result shows feasibility of this strategy.
Synchronized Scheme of Continuous Space-Vector PWM with the Real-Time Control Algorithms
DEFF Research Database (Denmark)
Oleschuk, V.; Blaabjerg, Frede
2004-01-01
This paper describes in details the basic peculiarities of a new method of feedforward synchronous pulsewidth modulation (PWM) of three-phase voltage source inverters for adjustable speed ac drives. It is applied to a continuous scheme of voltage space vector modulation. The method is based...... on a representation of the pulse patterns as a function of the fundamental and switching frequencies of the drive system. Accurate trigonometric algorithms of vector PWM have been analysed, and also compared with the algebraic ones based on linear approximation of the durations of active switching states from...
Energy Technology Data Exchange (ETDEWEB)
Abdoulin, E. [International Rectifier France, 91 - Saint Michel sur Orge (France)
2000-03-01
Power MOSFETs used as synchronous rectifiers in isolated DC to DC converters allow to design energy efficient power supplies. In order to improve the efficiency of the isolated DC-DC converter of about 5%, the synchronous controller rectifier designed by International Rectifier is based on a predictive method in order to generate the appropriate signals for the driving of the secondary stage MOSFETs. In addition, the PWM architecture of the primary stage is not modified. (J.S.)
Directory of Open Access Journals (Sweden)
G. Sridhar Babu
2013-11-01
Full Text Available This paper presents the design and implementation of power converters for wind conversion systems. The power converter can not only transfer the power from a wind generator, but also improve the stability and safety of the system. The proposed system consists of a Permanent magnet synchronous generator (PMSG; a DC/DC boosts converter, a bi-directional DC/DC converter and a full-bridge DC/AC inverter. The wind generator is the main power source of the system, and the battery is used for energy storage and power compensation to recover the natural irregularity of the wind power. In this paper presents a new system configuration of the front-end rectifier stage for a hybrid wind or photo voltaic energy system. The configuration allows the two sources to supply the load separately or simultaneously, depending on the availability of energy sources. The inherent nature of this cuk-scpic fused converter, additional input filters are not necessary to filter out high frequency harmonic content is determinant for the generator life span, heating issue and efficiency. The fused multi-input rectifier stage also allows maximum power from the wind and sun. When it is available an adaptive MPPT algorithm will be used for photo voltaic (PV system. Operational analysis of the roposed system, will discoursed in this paper simulation results are given to highlight the merit of the proposed circuit.
Dual PWM Wind Power Grid System Based on DSP%基于DSP双PWM风力发电并网系统的研究
Institute of Scientific and Technical Information of China (English)
吕振; 孟祥海; 林振杨; 高爽
2011-01-01
The double PWM wind power grid systems theory was analyzed. The basic theory of the wind power generator system was elaborated based on DSP TMS320LF2407, while the system machine-side converter and the network-side converter were analyzed. And by controlling the inverter output, the parallel running with the grid is realized under the premise of ensuring the quality of the output power. And to ensure that the harmonic content fed into the grid should be as small as possible while still meet the power requirements. Finally, the whole system was verified by experiment, experiment results show that the dual PWM wind power grid system has good stability and reliability.%详细分析了风力发电双PWM并网系统的原理,阐述了基于DSP TMS320LF2407风力发电并网系统的基本理论,同时对系统的机侧变流器和网侧变流器进行了分析,并通过控制逆变器的输出,在保证输出电能质量的前提下实现与电网的并行运行；并且保证馈入电网的谐波含量要尽可能小的同时还要符合功率要求.最后,对整个系统进行了实验验证,实验结果表明,双PWM风力发电并网系统具有良好的稳定性和可靠性.
A New Zero Voltage Switching Buck-Boost Type DC-DC Converter
Directory of Open Access Journals (Sweden)
Majid Delshad
2010-03-01
Full Text Available In this paper, a new zero voltage switching isolated buck-boost DC-DC converter with active clamp circuit is proposed. The active clamp circuit in this converter not only absorbs voltage spikes across the main switch but also provides soft switching conditions for all switches. All switches are PWM controlled which simplifies the control implementation. One of the main advantages of this converter is the that it operating can operate at high power levels while soft switching conditions exist in both buck and boost modes of converter operation. Since this converter can operate over a wide input voltage range, it can be employed in power factor correction. The experimental results obtained from a 150W prototype circuit operating at 100KHz are presented to confirm the integrity of the proposed circuit.
EMC Specific Problems of Frequency Converters Used at Interlocking Device
Directory of Open Access Journals (Sweden)
J. Novak
2009-12-01
Full Text Available The paper deals with problems of electromagnetic compatibility (EMC of frequency control drive of electromotive switch actuator of railway switch. The frequency converter with Pulse Width Modulation (PWM and the output sinus filter are used for feeding of the asynchronous motor of the switch actuator. This drive is operated in an insulated system of feeding voltages. The drive is fed by a frequency converter with an unshielded cable with length up to 1.2 km. The EMC problems occurring at development and operating of the drive are analyzed in this paper. The used solution of these problems and experience with EMC of the given system from real operation are described in this paper as well.
Feedforward Synchronised PWM for Adjustable Speed AC Drives with Different Control Modes
DEFF Research Database (Denmark)
Oleschuk, Valentin; Blaabjerg, Frede; Jensen, Flemming Buus
2002-01-01
This paper presents a novel method of direct synchronised pulswidth modulation (PWM) for three-phase voltage source inverters, feeding induction motors with different control regimes. It is based on the universal algorithm with either simplified algebraic or accurate trigonometric control functions...
Active and reactive power control of a current-source PWM-rectifier using space vectors
Energy Technology Data Exchange (ETDEWEB)
Salo, M.; Tuusa, H. [Tampere University of Technology (Finland). Department of Electrical Engineering, Power Electronics
1997-12-31
In this paper the current-source PWM-rectifier with active and reactive power control is presented. The control system is realized using space vector methods. Also, compensation of the reactive power drawn by the line filter is discussed. Some simulation results are shown. (orig.) 8 refs.
DEFF Research Database (Denmark)
Mathe, Laszlo; Cornean, Horia; Sera, Dezso
2011-01-01
of the transfer ratio. The difference between most of the proposed modulation methods like sine-triangular, SVM, and 120 - 60 - 30 Discontinuous PWM consists in the redistribution of the time-length applied for the zero voltage vectors during a fundamental frequency period. This paper presents a unified...
Three Phase Six-Switch PWM Buck Rectifier with Power Factor Improvement
DEFF Research Database (Denmark)
Zafar Ullah Khan, M; Mohsin Naveed, M.; Hussain, Dil Muhammad Akbar
2013-01-01
Conventional Phase Controlled Rectifier injects low order current harmonics into the AC mains. Large size filtering components are required to attenuate these harmonics. In this paper, Three Phase Six-Switch PWM Buck Rectifier[1] is presented which operates at nearly unity power factor and provides...
Three Phase Six-Switch PWM Buck Rectifier with Power Factor Improvement
DEFF Research Database (Denmark)
Zafar Ullah Khan, M; Mohsin Naveed, M.; Hussain, Dil Muhammad Akbar
2013-01-01
Conventional Phase Controlled Rectifier injects low order current harmonics into the AC mains. Large size filtering components are required to attenuate these harmonics. In this paper, Three Phase Six-Switch PWM Buck Rectifier[1] is presented which operates at nearly unity power factor and provid...
PWM Flow Rate Control of ER Valve and its Application to ER Actuator Control
Nakano, Masami; Minagawa, Shuji; Hagino, Katsuya
The PWM (Pulse Width Modulation) control of ER valve consisting of two parallel electrodes has been investigated to continuously control the flow rate of an electrorheological (ER) suspension containing sulfonated polymer particles in silicone oil. PWM wave voltages are applied to the electrodes of the ER valve. It is possible to control continuously the flow rate by changing the duty ratio of the PWM wave from 1 to 0, where the duty ratio of 1 corresponds to the state to stop the flow. A miniature bellows actuator driven by a pair of PWM controlled ER valves has been developed, and the control characteristics of the actuator have been investigated. The duty ratios of both ER valves have been proposed to be changed alternately in proportion to the control voltage V to control the flow rate into and out of the bellows chamber, and also an overlap duty ratio Dov at V=0V has been introduced. The introduction of the overlap duty ratio Dov was found to be very important to smoothly control the actuator and to improve the control performance.
Six-Phase Vehicular Drive with Renewable DC Sources and Hybrid PWM Control of Four Inverters
DEFF Research Database (Denmark)
Oleschuk, Valentin; Ermuratskii, Vladimir; Blaabjerg, Frede
2015-01-01
The paper presents results of research of quad-inverter-based automotive system with combined scheme of PWM control of inverters, supplied by two renewable dc sources (by fuel cells and by battery). It has been shown, that hybrid switching techniques can be used successfully for control of vehicle...
New DC/DC High Step Up Isolated Converter with ZVS
Directory of Open Access Journals (Sweden)
Ehsan Movahedi
2014-10-01
Full Text Available In this paper we presents a soft switch sepic, flyback converter. At first the converter have hard switching in main switch and completely analysis then added auxiliary circuit for soft switching Auxiliary circuit in the converter is not only soft switching condition for the main switch but also prevents the spike voltage across the main switch when turned off that because leakage inductance. Therefore, the proposed converter efficiency in comparison with the previous converters increased and voltage stress on the main switch is reduced. Also the auxiliary switch in the converter have soft switching and thereby decrese losses. this converter Control with pwm.These converter have higher efficiency than the similar converters and the cost is low. Auxiliary circuit in the converter is not only soft switching condition for the main switch but also prevents the spike voltage across the main switch when turned off that because leakage inductance. Therefore, the proposed converter efficiency in comparison with the previous converters increased and voltage stress on the main switch is reduced.
Design of Single-Phase AC Converter With Trans-Z Source%具有 Trans-Z 源的单相交流变换器设计
Institute of Scientific and Technical Information of China (English)
王毅; 曹茂永; 张刘春; 房绪鹏; 仲崇旭
2016-01-01
1Due to drawbacks of low voltage transfer ratio and dead time control complexity of traditional single-phase AC-DC-AC converter, a novel single-phase AC-DC-AC converter transformer-based Z-source is presented. Based on analysis of topology, working principle and steady-state characteristics of the converter, boost formula is derived. The paper established small signal model, studied effect of circuit parameters on system performance, further analyzed effect of coupled inductor turn ratio and shoot-through duty cycle of inverter-bridge on output voltage. Performance of the proposed converter is verified with simulation and a laboratory prototype of 200V/50Hz. Results of simulation and experiment show that the converter is feasible.%针对传统单相电压源 AC-DC-AC 变换器存在电压传输比低、死区控制复杂的不足，提出了一种具有Transformer-based Z-source(Trans-Z 源)的新型单相交流变换器。通过研究该变换器的拓扑结构和工作原理，分析了其稳态升压特性，并推导了变换器的升压公式；建立了变换器的小信号模型，分析了电路参数对系统性能的影响，进一步研究了耦合电感匝数比与逆变桥直通占空比对输出电压的影响。通过系统仿真和搭建200 V/50 Hz 样机模型来验证变换器的性能。仿真与实验结果表明了所提变换器的可行性。
Directory of Open Access Journals (Sweden)
Jami Rajesh
2014-02-01
Full Text Available This paper deals with a novel type soft switching utility frequency AC- high frequency AC converter using asymmetrical PWM bidirectional active switches which can be defined as high frequency resonant matrix converter.This power frequency changer can directly convert utility frequency AC power to high frequency AC power ranging more than 20kHz up to 100kHz. Only one active edge resonant capacitor-assisted soft switching high frequency load resonant cyclo-converter is based on asymmetrical duty cycle PWM strategy. This high frequency cyclo-converter uses bidirectional IGBTs composed of anti-parallel one-chip reverse blocking IGBTs. This high frequency cycloconverter has some remarkable features as electrolytic capacitorless DC busline link, unity power factor correction and sinewave line current shaping, simple configuration with minimum circuit components and low cost, high efficiency and downsizing. This series load resonant cycloconverter incorporating bidirectional active power switches is developed and implemented for high efficiency consumer induction heated food cooking appliances. Its operating principle is described by using equivalent circuits. Its operating performances as soft switching operating ranges and high frequency effective power regulation characteristics are discussed on the basis of simulation and experimental results.
Ohyama, Kazuhiro; Sakamoto, Tsuyoshi; Arinaga, Shinji; Yamashita, Yukio
This paper proposes variable-speed wind generation system using the boost converter. The proposed system has three speed control modes for the wind velocity. The control mode of low wind velocity regulates the armature current of the generator with the boost converter to control the speed of wind turbine. The control mode of middle wind velocity regulates the DC link voltage with the vector controlled inverter to control the speed of wind turbine. The control mode of high wind velocity regulates the pitch angle of the wind turbine with the pitch angle control system to control the speed of wind turbine. The hybrid of three control modes extends the variable-speed range. The proposed system simplifies the maintenance and improves the reliability and reduces the cost in compare with the variable-speed wind generation system using PWM converter. This paper describes the control strategy and modeling for simulation using Matlab Simulink of the proposed system. Also this paper describes the control strategy and modeling of variable-speed wind generation system using PWM converter. The steady state and transient responses for wind velocity changes are simulated using the Matlab Simulink. This paper verifies the fundamental performance of the system using boost converter by discussing the simulation results of the both systems.
CCLIBS: The CERN Power Converter Control Libraries
AUTHOR|(SzGeCERN)404953; Lebioda, Krzysztof Tomasz; Magrans De Abril, Marc; Martino, Michele; Murillo Garcia, Raul; Nicoletti, Achille
2015-01-01
Accurate control of power converters is a vital activity in large physics projects. Several different control scenarios may coexist, including regulation of a circuit’s voltage, current, or field strength within a magnet. Depending on the type of facility, a circuit’s reference value may be changed asynchronously or synchronously with other circuits. Synchronous changes may be on demand or under the control of a cyclic timing system. In other cases, the reference may be calculated in real-time by an outer regulation loop of some other quantity, such as the tune of the beam in a synchrotron. The power stage may be unipolar or bipolar in voltage and current. If it is unipolar in current, it may be used with a polarity switch. Depending on the design, the power stage may be controlled by a firing angle or PWM duty-cycle reference, or a voltage or current reference. All these cases are supported by the CERN Converter Control Libraries (CCLIBS). These open-source C libraries include advanced reference generati...
DEFF Research Database (Denmark)
Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.
2013-01-01
A new pulse width modulation (PWM) strategy which is an alternative approach of discontinuous PWM (DPWM) for a three-level neutral point clamped (NPC) inverter is developed and presented in this paper. The proposed PWM scheme not only takes advantage of the special properties available in NPC...... can be simplified. The salient features of the proposed scheme, as compared with the existing carrier-based DPWM strategies, are: 1) its reduced computational processing time, 2) its capability to balance the DC-link voltage without any additional control and 3) its reduced complexity e.g. only one...
Realization of PWM Velocity Modulation in Hydraulic Elevator%PWM调速在液压电梯中的实现
Institute of Scientific and Technical Information of China (English)
唐国兴; 恽源世; 徐鸣谦
2001-01-01
This paper introduces the realization of velocity modulation control in hydraulic elevator by using PWM technology. It mainly includes two parts, one is about how to send out PWM signal via computer to perform the velocity modulation, and the other is about the design of manual PWM velocity modulation device.%介绍了运用PWM技术实现液压电梯的调速控制，主要包括两部分，一是用工控机发送PWM信号进行调速，二是手动PWM调速装置的设计。
Directory of Open Access Journals (Sweden)
Vengadeshwaran Velu
2016-01-01
Full Text Available Three-phase system has numerous advantages over the single-phase system in terms of instantaneous power, stability, and cost. Three-phase systems are not available in every location particularly in remote rural areas, hill stations, low voltage distribution homes, and so forth. Having a system that is capable of converting directly the readily available single-phase system to three phases will have greater usability in various applications. The routine techniques adopted in the direct ac-ac single-phase-to-three-phase converters do not yield the best desired outputs because of their complexity in the segregation process and bidirectional nature of the input signal. Other initiatives use ac-dc-ac converters which are huge and costly due to dc link energy storage devices. Further, none of these systems provide a convincing result in producing the standard three-phase output voltages that are 120° away from each other. This paper proposes an effective direct ac-ac single-phase-to-three-phase conversion technique based on space vector pulse width modulation based matrix converter system that produces a convincing three-phase output signals from a single-phase source with balanced modulation index characteristics. The details of the scientific programming adopted on the proposed technique were presented.
National Research Council Canada - National Science Library
Hsin-Jang Shieh; Ying-Zuo Chen
2017-01-01
To efficiently supply wide-range DC voltage from a pulse-width modulation (PWM) rectifier, this paper presents a single-phase, full-wave, diode-bridge, single-ended primary-inductor converter-type (SEPIC-type...
Kohara, Tatsuya; Noguchi, Toshihiko; Kondo, Seiji
In recent years, parallel-operation of inverters is employed to increase reliability and capacity in an uninterruptible power supply (UPS) system. A phase error in PWM carrier-signals of each inverter causes high frequency loop current between inverters. Therefore, the PWM carrier-signal of each inverter should be adjusted in phase. This paper proposes a detection method of phase error in PWM carrier-signal and its application to synchronization control for parallel-connected inverters. A simple definite-integral circuit achieves the detection of carrier phase error from high frequency loop current using no signal line between inverters. The detected carrier phase error is applied to synchronize the PWM carrier-signal through a PI-compensator, and then the high frequency loop current can be suppressed. Several experimental test-results show the validity of the proposed detection method and synchronization control.
New zero voltage switching DC converter with flying capacitors
Lin, Bor-Ren; Shiau, Tung-Yuan
2016-04-01
A new soft switching converter is presented for medium power applications. Two full-bridge converters are connected in series at high voltage side in order to limit the voltage stress of power switches at Vin/2. Therefore, power metal-oxide-semiconductor field-effect transistors (MOSFETs) with 600 V voltage rating can be adopted for 1200 V input voltage applications. In order to balance two input split capacitor voltages in every switching cycle, two flying capacitors are connected on the AC side of two full-bridge converters. Phase-shift pulse-width modulation (PS-PWM) is adopted to regulate the output voltage. Based on the resonant behaviour by the output capacitance of MOSFETs and the resonant inductance, active MOSFETs can be turned on under zero voltage switching (ZVS) during the transition interval. Thus, the switching losses of power MOSFETs are reduced. Two full-bridge converters are used in the proposed circuit to share load current and reduce the current stress of passive and active components. The circuit analysis and design example of the prototype circuit are provided in detail and the performance of the proposed converter is verified by the experiments.
Analysis of Discontinuity Induced Bifurcations in a Dual Input DC-DC Converter
Giaouris, Damian; Banerjee, Soumitro; Mandal, Kuntal; Al-Hindawi, Mohammed M.; Abusorrah, Abdullah; Al-Turki, Yusuf; El Aroudi, Abdelali
DC-DC power converters with multiple inputs and a single output are used in numerous applications where multiple sources, e.g. two or more renewable energy sources and/or a battery, feed a single load. In this work, a classical boost converter topology with two input branches connected to two different sources is chosen, with each branch independently being controlled by a separate peak current mode controller. We demonstrate for the first time that even though this converter is similar to other well known topologies that have been studied before, it exhibits many complex nonlinear behaviors that are not found in any other standard PWM controlled power converter. The system undergoes period incrementing cascade as a parameter is varied, with discontinuous hard transitions between consecutive periodicities. We show that the system can be described by a discontinuous map, which explains the observed bifurcation phenomena. The results have been experimentally validated.
A AC-DC Inversion Power Design Based on PWM IC Controller%基于PWM IC芯片控制的开关电源设计
Institute of Scientific and Technical Information of China (English)
王玉德; 韩翠玲; 陈春廷; 孙洪海
2008-01-01
介绍了SG3525 PWM IC芯片的内部结构,基于该芯片设计了15V/36V的开关电源.设计中给出具体的设计电路和参数.经过实验验证该系统控制可靠,稳定性好,纹波系数低,能够很好地适应电源电压10%和负载20%的变化,具有一定的实际应用价值.
Theory of multi-phase PWM DC/DC converter%多相PWM控制DC/DC变换器
Institute of Scientific and Technical Information of China (English)
陈小明
2001-01-01
@@ 概述 近年来,随着一些高性能CPU的出现,如Pentium 4、Athlon等,需要输出电压更小,更大电流的DC/DC变换器,对热性能、EMI及负载瞬变应答(Load Transient)的要求也不断提高.传统的单相DC/DC变换器日益显示出局限性.多相DC/DC变换器以其独特的性能,为高性能CPU电源的解决方案开辟的一条新路.
Step-by-Step Design Procedure for a Grid-Connected Three-Phase PWM Voltage Source Converter,
DEFF Research Database (Denmark)
Liserre, Marco; Blaabjerg, Frede; Aquila, Antonio Dell
2004-01-01
The voltage source active rectifier is one of the most interesting solutions to interfacing dc power systems to the grid. Many elements are responsible for the overall system behaviour, such as value of the passive elements, sensors position, analog/digital filters and ac current/dc voltage...... controllers. In this paper a step-by-step design procedure, taking into account all these elements, is proposed and validated through the tests on an experimental prototype. The reported results are particularly relevant to evaluate the influence on the grid current harmonic content of the grid sensor...... position and of the use of analog filters in the feedback signals....
Step-by-Step Design Procedure for a Grid-Connected Three-Phase PWM Voltage Source Converter,
DEFF Research Database (Denmark)
Liserre, Marco; Blaabjerg, Frede; Aquila, Antonio Dell
2004-01-01
controllers. In this paper a step-by-step design procedure, taking into account all these elements, is proposed and validated through the tests on an experimental prototype. The reported results are particularly relevant to evaluate the influence on the grid current harmonic content of the grid sensor...
Indian Academy of Sciences (India)
Manoj Kumar Modi; S Venugopal; G Narayanan
2013-06-01
The equivalence of triangle-comparison-based pulse width modulation (TCPWM) and space vector based PWM (SVPWM) during linear modulation is well-known. This paper analyses triangle-comparison based PWM techniques (TCPWM) such as sine-triangle PWM (SPWM) and common-mode voltage injection PWM during overmodulation from a space vector point of view. The average voltage vector produced by TCPWM during overmodulation is studied in the stationary (a–b) reference frame. This is compared and contrasted with the average voltage vector corresponding to the well-known standard two-zone algorithm for space vector modulated inverters. It is shown that the two-zone overmodulation algorithm itself can be derived from the variation of average voltage vector with TCPWM. The average voltage vector is further studied in a synchronously revolving (d-q) reference frame. The RMS value of low-order voltage ripple can be estimated, and can be used to compare harmonic distortion due to different PWM methods during overmodulation. The measured values of the total harmonic distortion (THD) in the line currents are presented at various fundamental frequencies. The relative values of measured current THD pertaining to different PWM methods tally with those of analytically evaluated RMS voltage ripple.
Microcontroller based PWM controlled four switch three phase inverter fed induction motor drive
Directory of Open Access Journals (Sweden)
Mohanty Kant Nalin
2010-01-01
Full Text Available This paper presents PIC microcontroller based PWM inverter controlled four switch three phase inverter (FSTPI fed Induction Motor drive. The advantage of this inverter that uses of 4 switches instead of conventional 6 switches is lesser switching losses, lower electromagnetic interference (EMI, less complexity of control algorithms and reduced interface circuits. Simulation and experimental work are carried out and results presented to demonstrate the feasibility of the proposed approach. Simulation is carried out using MATLAB SIMULINK and in the experimental work a prototype model is built to verify the simulation results. PIC microcontroller (PIC 16F877A is used to generate the PWM pulses for FSTPI to drive the 0.5 hp 3-phase Induction Motor.
Moment Stability of the Critical Case of PWM Feedback Systems with Stochastic Perturbations
Directory of Open Access Journals (Sweden)
Zhong Zhang
2012-01-01
Full Text Available This paper further studies the moment stability of pulse-width-modulated (PWM feedback system which is subjected to multiplicative and additive random disturbance modeled by the derivative of Wiener process. Different from the existing investigation, we focus on its critical case. The linear plant considered herein is assumed to be critically stable; that is, the plant has one and only one pole at the origin, and the rest of the poles are left half of complex plane. We establish several globally asymptotically stability criteria for such PWM feedback systems and then propose an algorithm to calculate the stability bound effectively. Furthermore, we present two numerical examples to show the effectiveness of the theoretical results.
OPTIMAL PWM BASED ON REAL—TIME SOLUTION WITH NEURAL NETWORK
Institute of Scientific and Technical Information of China (English)
ShenZhongting; YanYangguang
2002-01-01
A novel concept of neural network based control in pulse-width modulation(PWM)voltage source inverters is presented.On the one hand,the optimal switching an-gles are obtained in real time by the neural network based controller；on the other hand,the output voltage is ad-justed to fit the expected value by neural network when input voltage or loads change.The structure of neural network is simple and easy to be realized by DSP hard-ware system.No large memory used for the existing opti-mal PWM schemes is required in the system.Theoreticalanlysis of the proposed so-called sparse neural network is provided,and the stability of the system is proved.Un-der the control of neural network the error of output volt-age descends sharply,and the system outputs ac voltage with high precision.
Shunt PWM advanced var compensators based on voltage source inverters for Facts applications
Energy Technology Data Exchange (ETDEWEB)
Barbosa, Pedro G.; Misaka, Isamu; Watanabe, Edson H. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia
1994-12-31
Increased attention has been given to improving power system operation. This paper presents modeling, analysis and design of reactive shunt power compensators based on PWM-Voltage Source Inverters (Pulse Width Modulation -Voltage Source Inverters). (Pulse Width Modulation - Voltage Source Inverters). The control algorithm is based on new concepts of instantaneous active and reactive power theory. The objective is to show that with a small capacitor in the side of a 3-phase PWM-VSI it is possible to synthesize a variable reactive (capacitive or inductive) device. Design procedures and experimental results are presented. The feasibility of this method was verified by digital simulations and measurements on a small scale model. (author) 9 refs., 12 figs.
Conversor Boost PWM Entrelaçado com Comutação Suave
Directory of Open Access Journals (Sweden)
Lúcio dos Reis Barbosa
2002-01-01
Full Text Available Este artigo apresenta uma topologia aprimorada de um conversor Boost PWM com comutação suave. O circuito proposto, tendo duas chaves ativas entrelaçadas, opera com chaveamento suave, sob odulação PWM (pulse-width-modulation. Além disso, este conversor fornece alta rendimento sob as condições de operação, para uma larga variação de carga, e operando à altas freqüências. Para ilustrar o princípio de operação deste novo conversor apresenta-se um estudo pormenorizado, incluindo simulações e resultados. A validade deste novo conversor é confirmada por meio dos resultados obtidos.
Nongrounded Common-Mode Equivalent Circuit for Brushless DC Motor Driven by PWM Inverter
Maetani, Tatsuo; Isomura, Yoshinori; Watanabe, Akihiko; Iimori, Kenichi; Morimoto, Shigeo
This paper describes nongrounded common-mode equivalent circuit for a motor driven by a voltage-source PWM inverter. When the capacitance of the rotor was small, the phenomenon that polarity of the common mode voltage and shaft voltage reversed was observed. In order to model this phenomenon, the bridge type equivalent circuit is proposed. It is verified with the calculation and experiment that shaft voltage values and polarity are accurately calculated with the proposed equivalent circuit.
High-Frequency Link Inverter for Fuel CellsBased on Multiple-Carrier PWM
Institute of Scientific and Technical Information of China (English)
无
2005-01-01
A similar circuit as Fig. 12 can be realized with MOSFET or IGBT devices configured as bi-directional pairs in the output bridge. In this case, the complete process in Fig. 8 would be needed to generate the complete 50% gate drive pulses. The 50% gate pulses still support pulse transformer coupling, retaining the simplicity of the gate drive isolation. The PWM cycloconverter process scales directly to higher switching speeds possible with these devices.
Modelling of a double star induction motor for space vector PWM control
Energy Technology Data Exchange (ETDEWEB)
Hadiouche, D.; Razik, H.; Rezzoug, A. [Groupe de Recherche en Electrotechnique et Electronique de Nancy, G.R.E.E.N. - CNRS UPRES, University H. Poincare, Vandoeuvre-les-Nancy (France)
2000-08-01
In this paper, we present the analysis and the modelling of a Double-Star Induction Motor (DSIM). A steady-state model is first established in order to analyse its harmonic behaviour. Then, a new transformation matrix is proposed in order to develop a suitable dynamic model. In both cases, the study is made using an arbitrary shift angle between the two stars. At last, a space vector Pulse Width Modulation (PWM) control or the DSIM is simulated. (orig.)
Modeling and Design of Five Level Cascaded H-Bridge Multilevel Inverter with DC/DC Boost Converter
Directory of Open Access Journals (Sweden)
Vinayaka B.C
2014-06-01
Full Text Available Power electronic converters, especially DC/AC Sinusoidal Pulse Width Modulation inverters have been extending their range of use in industry because of their numerous advantages. They typically synthesize the stair –case voltage waveform (from several dc sources which has reduced harmonic content. This paper aims to extend the knowledge about the performance of Five level Cascaded H-Bridge MLI topology with DC/DC Boost Converter using SPWM for fixed DC Source. The output voltage is the sum of the voltage that is generated by each bridge. The switching angles can be chosen in such a way that the total harmonic distortion is minimized. This topology incorporates Boost Converter in the input side which magnifies the fundamental output voltage with reduction in total harmonic distortion. It also incorporates LC filter and hence output is drawn near the sine wave because of more levels. Results of experiments proved efficiency of 95%.The performance of the proposed SPWM strategy in terms of output voltage and THD has studied successfully and shown using MATLAB/Simulink.
Nonlinear Control of an Open-Loop Open-Winding Motor System with Modulated Converters
Directory of Open Access Journals (Sweden)
Oleschuk V.I.
2017-04-01
Full Text Available Purpose of this work - to provide wider control opportunities for multiphase open-end winding motor drive by modification of basic scheme of space-vector pulse-width modulation (PWM. It has been shown, that the proposed development of basic PWM scheme insures available solutions for realization of specific control dependences and modes of operation of adjustable speed ac drives with different types and kinds of loads. Suitable algorithms of PWM of converters of multiphase drive have been analyzed and compared. Extensive simulation studies have been executed for evaluation of performance and effectiveness of the proposed control strategy. Assessment of harmonic composition of the phase voltages of drive system with modified scheme of space-vector modulation has been done. Results of the executed simulations proved the fact, that the developed techniques of space-vector pulse-width modulation allow providing quarter-wave or half-wave symmetry of waveforms of the output voltage of six-phase adjustable speed drive systems during the analyzed non-standard modes and regimes of its operation.
A New PWM Modifying Technique for Reconstructing Three-phase Currents from DC Bus Current
Aoyagi, Shigehisa; Iwaji, Yoshitaka; Tobari, Kazuaki; Sakamoto, Kiyoshi
Vector control is used to drive a DC brushless motor and generally needs current information. DC bus current detection is often adopted as a low cost method for reconstructing three-phase currents. PWM modifying techniques increase the DC pulse duration, thereby enabling easy detection of the DC bus current. However, these techniques have two problems: reducing a noise frequency and making the reconstructed current waveforms distorted by current ripple. In the techniques, modification signals are added to the three-phase voltage commands; the sum of the signals over a single cycle is zero. The authors examined several PWM modifying techniques from the points of view of noise and current distortion performance. One of the techniques had a good noise performance, and the frequency component of the noise was the same as the carrier frequency (fc). However, the reconstructed current waveforms were distorted. The total harmonic distortion (THD) varied from 1.7% to 4.1%. Another technique had a very poor noise performance, and the frequency component on the noise was one-fourth of fc. The authors developed a new PWM modifying method called “Half Pulse Shift”, which achieves the optimum noise and current distortion performance. The frequency component of the new method was two-thirds of fc, and the current waveforms were not distorted; the THD in the simulations and experiments was 0.5%-1.4% and 3.4%-3.6%, respectively.
Analysis of Discontinuous Space Vector PWM Techniques for a Seven-Phase Voltage Source Inverter
Directory of Open Access Journals (Sweden)
Mohd. Arif Khan
2012-03-01
Full Text Available This paper presents discontinuous space vector PWM (DPWM techniques for a seven-phase voltage source inverter (VSI. Space vector model of a seven-phase VSI shows that there exist 128 space vectors with different lengths and maps into fourteen sided polygons. A number of possibilities could arise to implement modulation of inverter legs due to large number of available space voltage vectors. Two strategies are adopted here; one utilising large and two middle sets of space vectors to implement discontinuous space vector PWM. Clamping of legs of inverter to either positive or negative dc bus leads to discontinuity in the switching and consequently offers reduced switching loss modulation strategy. A significant reduction in switching losses can be achieved while employing DPWM in a seven-phase VSI. A generalised method is also proposed to realize the DPWM in a seven-phase VSI. Comparison of continuous and discontinuous PWM is presented in terms of switching current ripple. The experimental set-up is illustrated and the experimental results are presented.
Chunhong, Zhang; Haigang, Yang; Shi, Richard
2013-06-01
A synchronous buck DC—DC converter with an adaptive multi-mode controller is proposed. In order to achieve high efficiency over its entire load range, pulse-width modulation (PWM), pulse-skip modulation (PSM) and pulse-frequency modulation (PFM) modes were integrated in the proposed DC—DC converter. With a highly accurate current sensor and a dynamic mode controller on chip, the converter can dynamically change among PWM, PSM and PFM control according to the load requirements. In addition, to avoid power device damage caused by inrush current at the start up state, a soft-start circuit is presented to suppress the inrush current. Furthermore, an adaptive slope compensation (SC) technique is proposed to stabilize the current programmed PWM controller for duty cycle passes over 50%, and improve the degraded load capability due to traditional slope compensation. The buck converter chip was simulated and manufactured under a 0.35 μm standard CMOS process. Experimental results show that the chip can achieve 79% to 91% efficiency over the load range of 0.1 to 1000 mA
Institute of Scientific and Technical Information of China (English)
Zhang Chunhong; Yang Haigang; Richard Shi
2013-01-01
A synchronous buck DC-DC converter with an adaptive multi-mode controller is proposed.In order to achieve high efficiency over its entire load range,pulse-width modulation (PWM),pulse-skip modulation (PSM)and pulse-frequency modulation (PFM) modes were integrated in the proposed DC-DC converter.With a highly accurate current sensor and a dynamic mode controller on chip,the converter can dynamically change among PWM,PSM and PFM control according to the load requirements.In addition,to avoid power device damage caused by inrush current at the start up state,a soft-start circuit is presented to suppress the inrush current.Furthermore,an adaptive slope compensation (SC) technique is proposed to stabilize the current programmed PWM controller for duty cycle passes over 50％,and improve the degraded load capability due to traditional slope compensation.The buck converter chip was simulated and manufactured under a 0.35μm standard CMOS process.Experimental results show that the chip can achieve 79％ to 91％ efficiency over the load range of 0.1 to 1000 mA.
Institute of Scientific and Technical Information of China (English)
胡跃伟; 鲁明; 田利梅; 武登云
2014-01-01
控制力矩陀螺框架电机驱动电路采用的脉宽调制方式不同,所产生的电机转矩脉动也会不同.针对无刷直流电机驱动的控制力矩陀螺框架系统,从换相期间转矩脉动、非换相期间转矩脉动及脉宽调制方式的应用改进3个方面对不同脉宽调制方式进行分析,得出采用PWM_ON PWM方式的转矩脉动最小,适用于控制力矩陀螺框架系统的高精度控制要求.通过仿真验证了分析的正确性.
Lorenzo, J., Jr.; Espiritu, J. C.; Mediavillo, J.; Dy, S. J.; Caldo, R. B.
2017-06-01
This paper aims to develop and implement a Sugeno-style fuzzy inference system using a microcontroller for buck and boost DC-to-DC converter. The buck converter circuit is given an input voltage range of 4-5V and expected to have an output voltage of 1.5V, while the boost converter has an input voltage range of 2-3V and expected to have an output voltage of 15V. A microcontroller will be used for the input values, PWM signal, which is supplied through the MOSFET. The constants in the program in the microcontroller were manipulated to acquire desired accurate output voltages wherein the concept of fuzzy logic was applied. The proponents achieved less than 2.5% tolerance in the buck converter and less than 5% in the boost 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.
Distributed control system for parallel-connected DC boost converters
Energy Technology Data Exchange (ETDEWEB)
Goldsmith, Steven
2017-08-15
The disclosed invention is a distributed control system for operating a DC bus fed by disparate DC power sources that service a known or unknown load. The voltage sources vary in v-i characteristics and have time-varying, maximum supply capacities. Each source is connected to the bus via a boost converter, which may have different dynamic characteristics and power transfer capacities, but are controlled through PWM. The invention tracks the time-varying power sources and apportions their power contribution while maintaining the DC bus voltage within the specifications. A central digital controller solves the steady-state system for the optimal duty cycle settings that achieve a desired power supply apportionment scheme for a known or predictable DC load. A distributed networked control system is derived from the central system that utilizes communications among controllers to compute a shared estimate of the unknown time-varying load through shared bus current measurements and bus voltage measurements.
Grid converter for LED based intelligent light sources
DEFF Research Database (Denmark)
Török, Lajos
to reduce the size of the magnetic components. A description of different grid regulations was given followed by a set of converter topologies and controllers. Different control techniques were pointed out. Among the listed topologies and control solutions few were selected for further analysis, design...... controllers can be designed. The controller design was interconnected with the hardware design and control platform. Thus two dfferent prototypes were designed and built with two dierent digital controllers and the controller design, analysis and implementation was based on these two case studies. The first...... of the PI controller. All four control loops were implemented in a 16 bitfixed point dsPIC33FJ32GS406 microcontroller driving at the same time 8 PWM channels. Finally a brief analysis was done on the eect of the grid disturbances, especially voltage sags on the digital controller. Dierent grid codes...
A novel single phase buck PFC converter in discontinuous capacitor voltage mode operation
Institute of Scientific and Technical Information of China (English)
邓超平; 凌志斌; 叶芃生
2003-01-01
A novel single-phase Buck converter for power factor correction is proposed. It features simple control due to the constant duty ratio PWM used. It can obtain unity power factor by selecting a suitable LC filter at its input to force the voltage of capacitor to operate in discontinuous capacitor voltage mode. And by using another resonant LC filter at its output, it can not only eliminate the input current distortion at the vicinity of the zero crossing of the supply but also drastically reduce the 100 Hz output voltage ripple. The validity of analysis is confirmed by simulation results and experimental results.
Device Loading and Efficiency of Modular Multilevel Converter under Various Modulation Strategies
DEFF Research Database (Denmark)
Liu, Hui; Ma, Ke; Blaabjerg, Frede
2016-01-01
Modular Multilevel Converter (MMC) has been becoming a very important solution for high power and medium power applications, where the efficiency and reliability performance are crucial design considerations. In this paper, three widely used modulation methods for MMC, Phase Shift PWM (PSPWM...... of the power devices in terms of power loss and thermal profiles, which are critical issues in terms of efficiency and reliability of the MMC. Special attention is given to the performance comparison of MMC under various modulation indexes as well as different switching frequencies when applying those...
DC-link voltage balancing in cascaded H-Bridge converters
Directory of Open Access Journals (Sweden)
Lewicki Arkadiusz
2014-09-01
Full Text Available In this paper a DC-link voltage balancing strategy for multilevel Cascaded H-Bridge (CHB converter is proposed. Presented solution bases on optimal choice of active vector durations in Space-Vector Pulse Width Modulation (SV-PWM. It makes it possible to DC-link voltages control and to properly generate the output voltage vector in the case of DC-link voltage unbalance. Results of simulation and experimental researches on proposed control strategy are presented in the paper
汽车 ABS 电机 PWM 控制方法研究%Research on ABS motor PWM control
Institute of Scientific and Technical Information of China (English)
初亮; 祁富伟; 王彦波; 蔡健伟
2014-01-01
通过对ABS工作过程中制动液流量的分析，确定了ABS电机的基本工作要求。结合ABS电机的工作特性，采用基于逻辑门限值的PWM控制方法控制电机。运用DSpace搭建快速原型试验台，对比在不同电机工作转速、PWM控制频率下的噪声和制动踏板感觉，优化逻辑门限值大小，得出合理的工作方式，使电机既能满足控制要求，又有较长的寿命。通过在不同路面的试验结果对该控制方法的两个关键参数进行了优化。最后进行不同工况的试验，结果表明：通过优化控制参数的PWM 控制方法，具有较强的鲁棒性，能够满足ABS在任何工作条件下对电机的要求。%T hrough the characteristics of the flow of brake fluid during ABS (anti-lock braking sys-tem) working process ,the basic requirements of ABS motor was determined and the PWM (pulse width modulation) control based logic threshold was adapted .A rapid prototyping test bench with DSpace was built .The logic threshold values were optimized by comparing the noise and the pedal stroke when various motor speed and PWM frequency were used .Then a much more reasonable con-trol method can be got w hich makes the motor to meet the control requirements and also has a longer life .After a lot of tests on different test track ,the key control parameters were optimized .Finally , the control method was tested under different road conditions and various load conditions .The results show that the control method is robust and meet the ABS requirements to the motor under any work conditions .
Wavelength converter technology
DEFF Research Database (Denmark)
Kloch, Allan; Hansen, Peter Bukhave; Poulsen, Henrik Nørskov;
1999-01-01
Wavelength conversion is important since it ensures full flexibility of the WDM network layer. Progress in optical wavelength converter technology is reviewed with emphasis on all-optical wavelength converter types based on semiconductor optical amplifiers....
Wavelength converter technology
DEFF Research Database (Denmark)
Kloch, Allan; Hansen, Peter Bukhave; Poulsen, Henrik Nørskov;
1999-01-01
Wavelength conversion is important since it ensures full flexibility of the WDM network layer. Progress in optical wavelength converter technology is reviewed with emphasis on air-optical wavelength converter types based on semiconductor optical amplifiers....
Technologies for converter topologies
Energy Technology Data Exchange (ETDEWEB)
Zhou, Yan; Zhang, Haiyu
2017-02-28
In some embodiments of the disclosed inverter topologies, an inverter may include a full bridge LLC resonant converter, a first boost converter, and a second boost converter. In such embodiments, the first and second boost converters operate in an interleaved manner. In other disclosed embodiments, the inverter may include a half-bridge inverter circuit, a resonant circuit, a capacitor divider circuit, and a transformer.
Power Converters for Accelerators
Visintini, R
2015-01-01
Particle accelerators use a great variety of power converters for energizing their sub-systems; while the total number of power converters usually depends on the size of the accelerator or combination of accelerators (including the experimental setup), the characteristics of power converters depend on their loads and on the particle physics requirements: this paper aims to provide an overview of the magnet power converters in use in several facilities worldwide.
Optimized MPPT algorithm for boost converters taking into account the environmental variables
Petit, Pierre; Sawicki, Jean-Paul; Saint-Eve, Frédéric; Maufay, Fabrice; Aillerie, Michel
2016-07-01
This paper presents a study on the specific behavior of the Boost DC-DC converters generally used for powering conversion of PV panels connected to a HVDC (High Voltage Direct Current) Bus. It follows some works pointing out that converter MPPT (Maximum Power Point Tracker) is severely perturbed by output voltage variations due to physical dependency of parameters as the input voltage, the output voltage and the duty cycle of the PWM switching control of the MPPT. As a direct consequence many converters connected together on a same load perturb each other because of the output voltage variations induced by fluctuations on the HVDC bus essentially due to a not insignificant bus impedance. In this paper we show that it is possible to include an internal computed variable in charge to compensate local and external variations to take into account the environment variables.
DEFF Research Database (Denmark)
Isidori, Andrea; Rossi, Fabio Mario; Blaabjerg, Frede
2012-01-01
. Furthermore, the increment of the wind roughness class causes a larger dispersion of the mean values and the variation of the junction temperatures, also affecting the lifetime of the converter. Hence, the cycles lifetime largely decreases considering variable wind speed profile. In fact, the results show......This paper focuses on the design, thermal loading and reliability of a three-level Neutral Point Clamped (3-L NPC) back-to-back full scale converter for a 10 MW direct-drive wind turbine equipped with a Permanent Magnet Synchronous Generator (PMSG). The reliability performance of the three...... the dynamics of the system using different kinds of modulation strategies and analyzing different wind load conditions dependent on roughness classes. It is concluded that 60° discontinuous PWM modulation strategies show better thermal performance and increase the estimated lifetime of the converter...
A Color LED Driver Implemented by the Active Clamp Forward Converter
Directory of Open Access Journals (Sweden)
C. H. Chang
2013-03-01
Full Text Available Because light emitting diodes (LEDs have the advantages of dc working voltage, high luminescent efficiency, shortignition time, high reliability and pollution free, they have substituted for incandescent bulbs and fluorescent lampsgradually. In order to simplify circuit complexity, an active clamp forward converter with the sequential color display(SCD control is proposed to drive red, green and blue (RGB LED arrays. The proposed converter has zero-voltageswitching (ZVS operations of both the main switch and the auxiliary switch, resulting in high system efficiency. DrivingRGB LED arrays sequentially by one converter can save components and reduce cost significantly. Additionally, thepulse-width modulation (PWM control is applied to achieve a large chromaticity variation. The circuit operations areanalyzed in detail and the circuit parameters are designed based on the practical considerations. Finally, an illustrativeexample is implemented to demonstrate the feasibility and validity of the proposed LED driver.
Highly Sensitive and Wide-Dynamic-Range Multichannel Optical-Fiber pH Sensor Based on PWM Technique.
Khan, Md Rajibur Rahaman; Kang, Shin-Won
2016-11-09
In this study, we propose a highly sensitive multichannel pH sensor that is based on an optical-fiber pulse width modulation (PWM) technique. According to the optical-fiber PWM method, the received sensing signal's pulse width changes when the optical-fiber pH sensing-element of the array comes into contact with pH buffer solutions. The proposed optical-fiber PWM pH-sensing system offers a linear sensing response over a wide range of pH values from 2 to 12, with a high pH-sensing ability. The sensitivity of the proposed pH sensor is 0.46 µs/pH, and the correlation coefficient R² is approximately 0.997. Additional advantages of the proposed optical-fiber PWM pH sensor include a short/fast response-time of about 8 s, good reproducibility properties with a relative standard deviation (RSD) of about 0.019, easy fabrication, low cost, small size, reusability of the optical-fiber sensing-element, and the capability of remote sensing. Finally, the performance of the proposed PWM pH sensor was compared with that of potentiometric, optical-fiber modal interferometer, and optical-fiber Fabry-Perot interferometer pH sensors with respect to dynamic range width, linearity as well as response and recovery times. We observed that the proposed sensing systems have better sensing abilities than the above-mentioned pH sensors.
A Three Phase Multi Level Converter For grid Connected PV System
Directory of Open Access Journals (Sweden)
S. Srikanth
2014-07-01
Full Text Available Photovoltaic energy is a wide kind of green energy. A high performance on these systems is needed to make the most of energy produced by solar cells. Also, there must be a constant adaptation due to the continuous variation of power production. Control techniques for Power Converters like the MPPT algorithm (Maximum Power Point Tracking present very good results on photovoltaic chains. Nevertheless, losses on power elements reduce global performance and the voltage/current adaptation is not always possible. This paper presents a single-phase 11-level (5 H-bridges cascade multilevel DC-AC grid-tied inverter. Each inverter bridge is connected to a 200 W solar panel. OPAL-RT lab was used as the hardware in the loop (HIL real-time control system platform where a Maximum Power Point Tracking (MPPT algorithm was implemented based on the inverter output power to assure optimal operation of the inverter when connected to the power grid as well as a Phase Locked Loop (PLL for phase and frequency match. A novel SPWM scheme is proposed in this paper to be used with the solar panels that can account for voltage profile fluctuations among the panels during the day. Simulation and experimental results are shown for voltage and current during synchronization mode and power transferring mode to validate the methodology for grid connection of renewable resources.
FPGA-based real-time simulation of power converters of renewable energy sources
Energy Technology Data Exchange (ETDEWEB)
Kokenyesi, Tamas; Varjasi, Istvan [Budapest University of Technology and Economics, Department of Automation and Applied Informatics (Hungary)], e-mail: kokenyesi.tamas@gmail.com, email: varjasi@aut.bme.hu
2011-07-01
This paper presents a hardware-in-the-loop testing (HIL) approach based on a field programmable gate array (FPGA) real-time simulation with real measured signals designed to reduce the cost and time for testing the main circuit of a power converter significantly. This method allows the control unit to measure its outputs on the same signal level in a completely transparent way, unlike other computer based simulation methods. As an example, a simulator for a three-phase inverter used for DC/AC conversion or frequency control is described and the simulated network illustrated. The calculation procedure and relative equations are also detailed, with simulation parameters and some measurement results being presented. It was found that the main advantage of this method is speed, which was only limited by the actual capabilities of the FPGA used. This method can be applied to a wide variety of analog circuits, reducing time to market. More complex circuits and higher frequencies could be simulated in the future with the evolution of FPGAs.
General analytical solutions for DC/AC circuit network analysis
Rubido, Nicolás; Baptista, Murilo S
2014-01-01
In this work, we present novel general analytical solutions for the currents that are developed in the edges of network-like circuits when some nodes of the network act as sources/sinks of DC or AC current. We assume that Ohm's law is valid at every edge and that charge at every node is conserved (with the exception of the source/sink nodes). The resistive, capacitive, and/or inductive properties of the lines in the circuit define a complex network structure with given impedances for each edge. Our solution for the currents at each edge is derived in terms of the eigenvalues and eigenvectors of the Laplacian matrix of the network defined from the impedances. This derivation also allows us to compute the equivalent impedance between any two nodes of the circuit and relate it to currents in a closed circuit which has a single voltage generator instead of many input/output source/sink nodes. Contrary to solving Kirchhoff's equations, our derivation allows to easily calculate the redistribution of currents that o...
Directory of Open Access Journals (Sweden)
Eduardo Pérez Lobato
2006-08-01
Full Text Available This paper presents the use of a microcontroller to demodulate two Pulse Width Modulated (PWM signals which are being generated by a digital accelerometer, to obtain their pulse widths and transmit them serially to a parallel port of a general purpose computer.Esta publicación presenta el uso de un microcontrolador para demodular dos señales PWM que están siendo generadas por un acelerómetro digital, obtener sus anchos y enviarlas en forma serial al puerto paralelo de un computador de propósitos generales.
Modelling and Controller Design of Electro-Pneumatic Actuator Based on PWM
Directory of Open Access Journals (Sweden)
Behrouz Najjari
2012-07-01
Full Text Available In this paper, a nonlinear model associated to the fast switching on-off solenoid valve and pneumatic cylinder was dynamically presented. Furthermore, an investigation into the electrical, magnetic, mechanical and fluid subsystems are made. Two common control policies to track valve position, a Proportional Integrator (PI based on Pulse Width Modulation (PWM and hysteresis controllers, are investigated. To control cylinder position, a Programmable Logic Controller (PLC on a simulated unit and an experimental setup regulated with AVR microcontroller are carried out. Experimental results show effective validation to the simulation results from PLC.
Filtro paso bajo discreto de operación directa sobre señales PWM
López Batres, Sergio
2010-01-01
Este proyecto aborda la construcción y diseño de un filtro de paso bajo que opera sobre señales moduladas en anchura de impulsos (PWM). Utiliza componentes analógicos y un microprocesador que efectúa el control del sistema. Su función es servir de atenuador de los armónicos en amplificadores de clase D que podrían usarse en sistemas de audio, sin necesidad de un filtro paso bajo analógico de orden elevado. Ingeniería Técnica en Electrónica
High-Frequency Link Inverter for Fuel Cells Based on Multiple-Carrier PWM
Institute of Scientific and Technical Information of China (English)
无
2004-01-01
HIGH-FREQUENCY (I-IF) ac link inverter topologies, with or without soft switching, have important practical advantages compared to more conventional dc link inverters in terms of isolation, size of magnetics, and other properties. It is possible to obtain these basic advantages directly in a conventional PWM inverter with trans former-coupled output, but only if the transformer can handle the low modulating frequency. HF link topologies have not been common for medium power (1 to 20kW), largely because of the number of power stages and control complexity.
A COMPREHENSIVE ANALYSIS OF SPACE VECTOR PWM TECHNIQUE BASED ON PLACEMENT OF ZERO-SPACE VECTOR
Directory of Open Access Journals (Sweden)
G.SAMBASIVA RAO,
2011-04-01
Full Text Available In this paper, the effect of placement of zero-space vector for the implementation of space vector based Pulse Width Modulation techniques for 3-phase Voltage Source Inverter is presented. Several pulse width modulation (PWM control strategies have been proposed for 3-phase voltage source inverter (VSI in the past. It is known that space vector modulation (SVM offers a degree of freedom in its implementation with regard to the placement of the zero-space vector. Apart from constructing a consistent theoretical framework, simulation results with conventional continuous SVM and various discontinuous SVM techniques are presented and all the cases are compared in this paper.
Control of a PWM Rectifier with Extended Functions in a Signal Digital Processor
Directory of Open Access Journals (Sweden)
C. Núñez–Gutiérrez
2009-01-01
Full Text Available This work presents the application of a digital signal processor (DSP for the control of a three–phase PWM rectifier for industrial applications, to which are extended their functions to have capacity to compensate voltage sags. The study stands out the advantages that the DSP offers to control, based on the system transformation from fix reference frame to synchronous reference frame (D–Q theory and classical controllers. The analysis of the system is presented, as well as simulation and experimental results to validate the operation of the DSP as system element controller.
Design of a ZVS PWM inverter for a brushless DC motor in an EMA application
Bell, J. Brett; Nelms, R. M.; Shepherd, Michael T.
1993-01-01
The Component Development Division of the Propulsion Laboratory at Marshall Space Flight Center (MSFC) is currently investigating the use of electromechanical actuators for use in space transportation applications such as Thrust Vector Control (TVC). These high power servomechanisms will require rugged, reliable, and compact power electronic modules capable of modulating several hundred amperes of current at up to 270 Vdc. This paper will discuss the design and implementation of a zero-voltage-switched PWM (Pulse Width Modulation) inverter which operates from a 270 Vdc source at currents up to 100 A.
The PWM strategies of grid-connected distributed generation active NPC inverters
DEFF Research Database (Denmark)
Ma, Lin; Xinmin, Jin; Kerekes, Tamas
2009-01-01
The Neutral Point Clamped topology due to high efficiency, low leakage current and EMI, its integration is widely used in the distributed generation (DG) systems. However the main disadvantage of the NPC inverter is given by an unequal distribution of the losses in the semiconductor devices, which...... leads to an unequal distribution of temperature. By using the Active NPC topology, the power losses distribution problem is alleviated. The modulation strategy is a key issue for losses distribution in this topology. In this paper two known strategies are discussed and a new proposed PWM strategy...
Directory of Open Access Journals (Sweden)
R. Arulmurugan
2012-10-01
Full Text Available This paper proposes a new dc to dc boost converter using closed loop control proportional Integral and Derivative mechanism for photovoltaic (PV standalone high voltage applications. The boost converter is composed of MOSFETs which are driven by closed loop PWM control. Many advantages including high efficiency, minimum number of switch, high voltage and power, low cost. This converter is attractive for high voltage and high power applications. The analysis and design considerations of the converter are presented. A prototype was implemented for an application requiring a 410W output power, input voltage range from 17.1-V, and a 317-V output voltage. The proposed system efficiency is about 90%.
Directory of Open Access Journals (Sweden)
R. Arulmurugan
2013-07-01
Full Text Available This paper proposes a new dc to dc boost converter using closed loop control proportional Integral and Derivative mechanism for photovoltaic (PV standalone high voltage applications. The boost converter is composed of MOSFETs which are driven by closed loop PWM control. Many advantages including high efficiency, minimum number of switch, high voltage and power, low cost. This converter is attractive for high voltage and high power applications. The analysis and design considerations of the converter are presented. A prototype was implemented for an application requiring a 410W output power, input voltage range from 17.1-V, and a 317-V output voltage. The proposed system efficiency is about 90%.
ASIC and FPGA based DPWM architectures for single-phase and single-output DC-DC converter: a review
Chander, Subhash; Agarwal, Pramod; Gupta, Indra
2013-12-01
Pulse width modulation (PWM) has been widely used in power converter control. This paper presents a review of architectures of the Digital Pulse Width Modulators (DPWM) targeting digital control of switching DC-DC converters. An attempt is made to review the reported architectures with emphasis on the ASIC and FPGA implementations in single phase and single-output DC-DC converters. Recent architectures using FPGA's advanced resources for achieving the resolution higher than classical methods have also been discussed. The merits and demerits of different architectures, and their relative comparative performance, are also presented. The Authors intention is to uncover the groundwork and the related references through this review for the benefit of readers and researchers targeting different DPWM architectures for the DC-DC converters.
Directory of Open Access Journals (Sweden)
Zheng Wang
2016-01-01
Full Text Available Three-port isolated (TPI bidirectional DC/DC converters have three energy ports and offer advantages of large voltage gain, galvanic isolation ability and high power density. For this reason this kind of converters are suitable to connect different energy sources and loads in electric and hybrid vehicles. The purpose of this paper is to propose chaotic modulation and the related control scheme for TPI bidirectional DC/DC converters, in such a way that the switching harmonic peaks can be suppressed in spectrum and the conducted electromagnetic interference (EMI is reduced. Two chaotic modulation strategies, namely the continuously chaotic modulation and the discretely chaotic modulation are presented. These two chaotic modulation strategies are applied for TPI bidirectional DC/DC converters with shifted-phase angle based control and phase-shifted PWM control. Both simulation and experiments are given to verify the validity of the proposed chaotic modulation-based control schemes.
Energy Technology Data Exchange (ETDEWEB)
Aime, M.
2003-11-15
Thanks to the technological progress achieved in the field of power electronics, the use of static converters has spread to new applications. In particular, some applications such as active filtering or the supply of special AC machines require power converters having good dynamic performances. The subject of this thesis is to evaluate systematically the dynamic performances of multi-cell converters, and then to optimize these performances. This document is organized in four chapters. The first one summarizes the main multilevel converter structures, and some control strategies dedicated to these structures. The second chapter presents the evaluation criteria chosen to quantify the dynamic performances of static converters. These criteria are then used to compare the performances obtained with two different PWM strategies. An optimized strategy which results from a trade-off between the two former strategies is then introduced. The third chapter shows a new control strategy of multi-cell voltage source converters. This new strategy enables to control the peak current at a fixed switching frequency. The operation of this controller is explained, and the results obtained by digital simulations are presented and discussed. The fourth chapter deals with the experimental achievement of the peak current control. In particular, the implementation of the control algorithm within a FPGA is demonstrated. Finally, the conclusion of this thesis presents some orientations for further developments, in order to improve the current control strategy and to widen its field of applications. (author)
High Efficiency Reversible Fuel Cell Power Converter
Pittini, Riccardo; Andersen, Michael A. E.; Zhang, Zhe
2014-01-01
Den store integration af vedvarende energikilder kræver egnede energioplagringssystemer for at balancere energi-produktion og -efterspørgsel i elnettet. Tovejs brændselsceller er en attraktiv teknologi til energilagringssystemer på grund af den høje energitæthed af brændstof. Sammenlignet med traditionel envejs brændselscelle, har tovejs brændselsceller øget driftsspænding og strømområder. Dette kendetegn øger belastningen på dc-dc- og dc-ac-omformere i det elektriske system, som kræver et or...
The photoelectric displacement converter
Dragoner, Valeriu V.
2005-02-01
In the article are examined questions of constructing photoelectric displacement converter satisfying demands that are stated above. Converter has channels of approximate and precise readings. The approximate reading may be accomplished either by the method of reading from a code mask or by the method of the consecutive calculation of optical scale gaps number. Phase interpolator of mouar strips" gaps is determined as a precise measuring. It is shown mathematical model of converter that allow evaluating errors and operating speed of conversion.
Bi-Frequency Modulated Quasi-Resonant Converters: Theory and Applications
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
Directory of Open Access Journals (Sweden)
Juarez B. Silva
2012-01-01
Full Text Available Remote experiments may be an important tool to implement new technologies in the teaching/learning process, since it enables experimenting with real plants, essential to consolidate the concepts acquired in the theoretical classes, especially in technical and scientific disciplines.This article presents the “modulator PWM” remote experiment, its operational architecture and construction. It seeks to demonstrate its integration with theory and the use of the 3G cellular network as a communications channel for remote experimenting. The PWM modulators are often used in disciplines of higher education courses in electrical engineering, telecommunications and electronics. This article shows that it is possible to perform the practical activity completely remotely, via 3G cellular networks or through the internet to access the experiment and perform the experiments needed to fully understand the theories of the PWM modulator.This article is a further initiative for remote experiments in the world of different engineering specialties, involving the cellular networks that are rapidly expanding at this time.
Directory of Open Access Journals (Sweden)
P. Ribereau
2008-12-01
Full Text Available Since the pioneering work of Landwehr et al. (1979, Hosking et al. (1985 and their collaborators, the Probability Weighted Moments (PWM method has been very popular, simple and efficient to estimate the parameters of the Generalized Extreme Value (GEV distribution when modeling the distribution of maxima (e.g., annual maxima of precipitations in the Identically and Independently Distributed (IID context. When the IID assumption is not satisfied, a flexible alternative, the Maximum Likelihood Estimation (MLE approach offers an elegant way to handle non-stationarities by letting the GEV parameters to be time dependent. Despite its qualities, the MLE applied to the GEV distribution does not always provide accurate return level estimates, especially for small sample sizes or heavy tails. These drawbacks are particularly true in some non-stationary situations. To reduce these negative effects, we propose to extend the PWM method to a more general framework that enables us to model temporal covariates and provide accurate GEV-based return levels. Theoretical properties of our estimators are discussed. Small and moderate sample sizes simulations in a non-stationary context are analyzed and two brief applications to annual maxima of CO_{2} and seasonal maxima of cumulated daily precipitations are presented.
A high efficiency PWM CMOS class-D audio power amplifier
Institute of Scientific and Technical Information of China (English)
朱樟明; 刘帘曦; 杨银堂; 雷晗
2009-01-01
Based on the difference close-loop feedback technique and the difference pre-amp, a high efficiency PWM CMOS class-D audio power amplifier is proposed. A rail-to-rail PWM comparator with window function has been embedded in the class-D audio power amplifier. Design results based on the CSMC 0.5 μm CMOS process show that the max efficiency is 90%, the PSRR is -75 dB, the power supply voltage range is 2.5-5.5 V, the THD+N in 1 kHz input frequency is less than 0.20%, the quiescent current in no load is 2.8 mA, and the shutdown current is 0.5 μA. The active area of the class-D audio power amplifier is about 1.47 × 1.52 mm2. With the good performance, the class-D audio power amplifier can be applied to several audio power systems.
A high efficiency PWM CMOS class-D audio power amplifier
Energy Technology Data Exchange (ETDEWEB)
Zhu Zhangming; Liu Lianxi; Yang Yintang [Institute of Microelectronics, Xidian University, Xi' an 710071 (China); Lei Han, E-mail: zmyh@263.ne [Xi' an Power-Rail Micro Co., Ltd, Xi' an 710075 (China)
2009-02-15
Based on the difference close-loop feedback technique and the difference pre-amp, a high efficiency PWM CMOS class-D audio power amplifier is proposed. A rail-to-rail PWM comparator with window function has been embedded in the class-D audio power amplifier. Design results based on the CSMC 0.5 mum CMOS process show that the max efficiency is 90%, the PSRR is -75 dB, the power supply voltage range is 2.5-5.5 V, the THD+N in 1 kHz input frequency is less than 0.20%, the quiescent current in no load is 2.8 mA, and the shutdown current is 0.5 muA. The active area of the class-D audio power amplifier is about 1.47 x 1.52 mm{sup 2}. With the good performance, the class-D audio power amplifier can be applied to several audio power systems.
Full-Circle Resolver-to-Linear-Analog Converter
Alhorn, Dean C.; Smith, Dennis A.; Howard, David E.
2005-01-01
A circuit generates sinusoidal excitation signals for a shaft-angle resolver and, like the arctangent circuit described in the preceding article, generates an analog voltage proportional to the shaft angle. The disadvantages of the circuit described in the preceding article arise from the fact that it must be made from precise analog subcircuits, including a functional block capable of implementing some trigonometric identities; this circuitry tends to be expensive, sensitive to noise, and susceptible to errors caused by temperature-induced drifts and imprecise matching of gains and phases. These disadvantages are overcome by the design of the present circuit. The present circuit (see figure) includes an excitation circuit, which generates signals Ksin(Omega(t)) and Kcos(Omega(t)) [where K is an amplitude, Omega denotes 2(pi)x a carrier frequency (the design value of which is 10 kHz), and t denotes time]. These signals are applied to the excitation terminals of a shaft-angle resolver, causing the resolver to put out signals C sin(Omega(t)-Theta) and C cos(Omega(t)-Theta). The cosine excitation signal and the cosine resolver output signal are processed through inverting comparator circuits, which are configured to function as inverting squarers, to obtain logic-level or square-wave signals .-LL[cos(Omega(t)] and -LL[cos(Omega(t)-Theta)], respectively. These signals are fed as inputs to a block containing digital logic circuits that effectively measure the phase difference (which equals Theta between the two logic-level signals). The output of this block is a pulse-width-modulated signal, PWM(Theta), the time-averaged value of which ranges from 0 to 5 VDC as Theta ranges from .180 to +180deg. PWM(Theta) is fed to a block of amplifying and level-shifting circuitry, which converts the input PWM waveform to an output waveform that switches between precise reference voltage levels of +10 and -10 V. This waveform is processed by a two-pole, low-pass filter, which removes
Modified Multiport Dc-Dc Converter Topology For Smart Grid
Directory of Open Access Journals (Sweden)
Dhamodharan Shanmugam
2013-10-01
Full Text Available The development of a Solid State Transformer (SST that incorporates a DC-DC multiport converter to integrate both photovoltaic (PV power generation and battery energy storage is presented in this dissertation. The DC-DC stage is based on a quad active-bridge (QAB converter which not only provides isolation for the load, but also for the PV and storage. The AC-DC stage is implemented with a pulse-widthmodulated (PWM single phase rectifier. A unified gyrator-based average model is developed for a general multi-active-bridge (MAB converter controlled through phase-shift modulation (PSM. Expressions to determine the power rating of the MAB ports are also derived. The developed gyrator-based average model is applied to the QAB converter for faster simulations of the proposed SST during the control design process as well for deriving the state-space representation of the plant. Both linear quadratic regulator (LQR and singleinput-single-output (SISO types of controllers are designed for the DC-DC stage. A novel technique that complements the SISO controller by taking into account the cross coupling characteristics of the QAB converter is also presented herein. Cascaded SISO controllers are designed for the AC-DC stage. The QAB demanded power is calculated at the QAB controls and then fed into the rectifier controls in order to minimize the effect of the interaction between the two SST stages. The dynamic performance of the designed control loops based on the proposed control strategies are verified through extensive simulation of the SST average and switching models.
Ali, Ahmed MA
2016-01-01
This book covers high speed data converters from the perspective of a leading high speed ADC designer and architect, with a strong emphasis on high speed Nyquist A/D converters. For our purposes, the term 'high speed' is defined as sampling rates that are greater than 10 MS/s.
Ferreira, J.A.
2014-01-01
Electrical power converter for converting electrical power of a power source connected or connectable at an input to electrical DC-power at an output, wherein between the input and the output a first circuit of submodules is provided, wherein said first circuit of submodules and the power source for
2015-01-01
This paper presents a buck-boost converter which is modified to utilize new 600 V gallium nitride (GaN) power semiconductor devices in an application requiring 1200 V devices. The presented buck-boost converter is used as a part of a dc/dc stage in an all-GaN photovoltaic (PV) inverter and it provides a negative voltage for the 3-level neutral-point-clamped (NPC) PWM inverter which is connected to the utility grid. Since in this application the transistor and the diode of ...
DEFF Research Database (Denmark)
Mira Albert, Maria del Carmen; Zhang, Zhe; Knott, Arnold
2017-01-01
This paper presents the design, modeling, and control of an isolated dc-dc three-port converter (TPC) based on an interleaved-boost full-bridge converter with pulsewidth modulation (PWM) and phase-shift control for hybrid renewable energy systems. In the proposed topology, the switches are driven......, a prototype is constructed and tested under the various modes, depending on the availability of the renewable energy source and the load consumption. The experimental results show that the two decoupled control variables achieve effective regulation of the power flow among the three ports....
Institute of Scientific and Technical Information of China (English)
窦亚力; 乔海强; 钱帆; 李龙光; 李子久
2016-01-01
In order to meet the inverter of trigger requirements applied to the power electronic , this paper primarily presents a novel method of using OMAPL 138 and FPGA to implement multi-channel PWM pulse generator with three-level PWM inverters .The pulse generator receives the PWM pattern parameters and setting parameters from OMA-PL138 processor through a built-in parallel interface , and produces the three-phase PWM driven signals by FPGA without the OMAPL138 intervention .The hardware architecture , basic principles , implementation method of the pulse generator described in this paper is verified by simulation and experiment .Three phase PWM generators have the fea-tures of simplifying circuit-design, improving reliability of system and guaranteeing concurrent triggering of power de-vices.%为了满足一种新能源发电领域的电力电子变换装置上逆变器触发的要求，研制了利用OMAPL138和FP-GA实现的多路PWM脉冲发生器。该脉冲发生器利用接口单元接收OMAPL138写入的PWM脉冲占空比和设置参数等数据，利用FPGA产生PWM波形，达到其工作不受OMAPL138影响的效果。同时介绍了脉冲发生器的硬件架构、基本原理和实现方法，并通过仿真和实验得到验证。该PWM发生器既简化了电路的设计，提高了系统的可靠性，又可保证逆变器功率元件触发的同步。
Analysis of Peak-to-Peak Current Ripple Amplitude in Seven-Phase PWM Voltage Source Inverters
Directory of Open Access Journals (Sweden)
Gabriele Grandi
2013-08-01
Full Text Available Multiphase systems are nowadays considered for various industrial applications. Numerous pulse width modulation (PWM schemes for multiphase voltage source inverters with sinusoidal outputs have been developed, but no detailed analysis of the impact of these modulation schemes on the output peak-to-peak current ripple amplitude has been reported. Determination of current ripple in multiphase PWM voltage source inverters is important for both design and control purposes. This paper gives the complete analysis of the peak-to-peak current ripple distribution over a fundamental period for multiphase inverters, with particular reference to seven-phase VSIs. In particular, peak-to-peak current ripple amplitude is analytically determined as a function of the modulation index, and a simplified expression to get its maximum value is carried out. Although reference is made to the centered symmetrical PWM, being the most simple and effective solution to maximize the DC bus utilization, leading to a nearly-optimal modulation to minimize the RMS of the current ripple, the analysis can be readily extended to either discontinuous or asymmetrical modulations, both carrier-based and space vector PWM. A similar approach can be usefully applied to any phase number. The analytical developments for all different sub-cases are verified by numerical simulations.
Cascaded resonant bridge converters
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.
A Novel Algorithm of PWM Using Virtual Flux Model Prediction%一种采用虚拟磁链模型预测的新型PWM算法
Institute of Scientific and Technical Information of China (English)
杜少通; 伍小杰; 周娟; 王福均; 杨宇
2015-01-01
In allusion to pulse-width modulation (PWM), a novel algorithm of pulse width modulation (NPWM) was proposed based on virtual flux model prediction. The virtual flux models consisting of sinusoidal modulation voltage and converter output voltage were established. The cost function was built aiming at making the flux error minimum. And the optimal objective voltage vector was obtained by using model prediction. On the basis of single target predictive method, a type of multi-target predictive method was put forward whi’ch ensures that the device’s average switching frequency was reduced under the premise of certain range of flux errors . The algorithm flow was analyzed according to the established cost function. The control effect of NPWM and space vector pulse width modulation was compared by simulations and experiments, which verifies the effectiveness of NPWM in the two predictive methods.%针对变流器脉宽调制(pulse-width modulation，PWM)，基于虚拟磁链的模型预测，提出一种新型脉宽调制算法(novel algorithm of pulse-width modulation，NPWM)。建立由正弦调制电压和变流器输出电压构成的虚拟磁链模型，以磁链误差最小为优化目标建立价值函数，采用模型预测获取最优目标电压矢量。基于单一目标预测方法，提出一种多目标预测方案，确保在磁链误差范围一定的前提下降低器件平均开关频率，依据建立的价值函数分析算法流程。仿真和实验比较两种预测算法下NPWM调制和空间矢量脉宽调制的控制效果，验证两种预测方法下NPWM算法的有效性。
电流谐波最优PWM开关角计算及数字实现%The Current Harmonic Optimal PWM (CHOPWM) Method and Its Digital Implementation
Institute of Scientific and Technical Information of China (English)
王从刚; 何凤有; 邓庆伟; 刘战; 曹晓冬
2012-01-01
介绍了三电平变频器在低开关频率运行下的电流谐波最优PWM(CHOPWM)方法,对其基本原理及开关角的求解进行了深入分析和研究.对三电平变频器输出电压、电流进行傅里叶级数分析,求出电流畸变率的表达式；令电流总畸变率作为目标函数,令电压基波幅值等于参考电压幅值作为非线性约束条件,进而利用MATLAB优化工具箱中的ga函数和fmincon函数求解出CHOPWM开关角.用MATLAB软件搭建了仿真模型,对开关频率为250Hz时的开关角求解结果进行仿真验证.对基于TMS320F2812的CHOPWM数字实现进行分析.最后,通过实验验证了开关角求解方法的有效性.%The current harmonic Optimal PWM (CHOPWM) method for three level converters operating at low switching frequency is introduced. Its basic principle and the solution of the switching angle is researched. The three -level inverter output voltage and current is analyzed using fourier series and the expression of current distortion rate is calculated. The expression of current distortion rate is regarded as a nonlinear transcendental equation and the voltage fundamental amplitude is equal to the reference voltage amplitude seen as nonlinear constraints. Then the switching angle of CHOPWM is solved by using the function of ga and fmincon function in MATLAB optimization toolbox. A simulation model was built using MATLAB software. Results of the switching angle at 250Hz switching frequency are verified. CHOPWM digital implementation is analyzed based on the TMS320F2812. The experimental results verify the availability of the scheme.
Suppression technology research of PWM inverter EMI%PWM 变频器的 EMI抑制技术研究
Institute of Scientific and Technical Information of China (English)
郭攀锋; 李欣; 张红
2015-01-01
In view of the application of PWM inverter which commonly used in present market, we analyze the mecha-nism of electromagnetic interference ( EMI) from some aspects, including rectifier and inverter side and overvoltage. In this paper, the electromagnetic interference filter is introduced, and the parameters of the RLC filter are designed. The final LC-RLC cascade filter topology structure is put forward.Finally, simulation model is established by Matlab/Simulink, to verify the effectiveness of the electromagnetic interference suppression technique.%针对目前市场上常用的功率变频器———PWM变频器的应用，从几个方面分析了的其电磁干扰（ EMI）产生机理，包括整流测、逆变侧和过电压产生。然后，介绍了几种常见滤波器，并对RLC滤波器参数进行设计，并提出了LC-RLC级联滤波器的拓扑结构。最后，利用Matlab／Simulink建立了相应的几种滤波器仿真模型，验证所设计的滤波器对了EMI抑制技术的有效性。
A Nonlinear Digital Control Solution for a DC/DC Power Converter
Zhu, Minshao
2002-01-01
A digital Nonlinear Proportional-Integral-Derivative (NPID) control algorithm was proposed to control a 1-kW, PWM, DC/DC, switching power converter. The NPID methodology is introduced and a practical hardware control solution is obtained. The design of the controller was completed using Matlab (trademark) Simulink, while the hardware-in-the-loop testing was performed using both the dSPACE (trademark) rapid prototyping system, and a stand-alone Texas Instruments (trademark) Digital Signal Processor (DSP)-based system. The final Nonlinear digital control algorithm was implemented and tested using the ED408043-1 Westinghouse DC-DC switching power converter. The NPID test results are discussed and compared to the results of a standard Proportional-Integral (PI) controller.
Low-temperature operation of a Buck DC/DC converter
Ray, Biswajit; Gerber, Scott S.; Patterson, Richard L.; Myers, Ira T.
1995-01-01
Low-temperature (77 K) operation of a 42/28 V, 175 W, 50 kHz PWM Buck DC/DC converter designed with commercially available components is reported. Overall, the converter losses decreased at 77 K compared to room temperature operation. A full-load efficiency of 97 percent was recorded at liquid-nitrogen temperature, compared to 95.8 percent at room temperature. Power MOSFET operation improved significantly where as the output rectifier operation deteriorated at low-temperature. The performance of the output filter inductor and capacitor did not change significantly at 77 K compared to room temperature performance. It is possible to achieve high-density and high efficiency power conversion at low-temperatures due to improved electronic, electrical and thermal properties of materials.
Isolated single-stage high power factor AC/DC converter
Institute of Scientific and Technical Information of China (English)
王卫; 贲洪奇; 高国安
2001-01-01
The problem of harmonic pollution has brought wide attention with the increase of power customers. The adoption of the technology of active power factor correction (APFC) with advanced high frequency power converter is a more efficient solution to the problem of harmonic pollution. A single-stage isolated high power factor AC/DC converter, which features wide range DC output, high power factor, lower harmonic pollution in input current, and phase-shift PWM full-bridge circuit can achieve soft switching. The principle of the circuit topology and the reasons of voltage surges across the power switch are analyzed. Experiment results illustrate that this circuit has the advantages of high power factor and lower harmonic distortion.
Optimal Control with Complete Load-Decoupled Design for the Buck DC-DC Switching Converter
Institute of Scientific and Technical Information of China (English)
Fei-Hu; Hsieh; Yau-Tarng; Juang
2002-01-01
This paper describes a new controller design procedure and turning method for the buck PWM DCDCswitching converter taking into consideration the equivalent series resistance of components. First, the linearoptimal feedback is designed by the LQR approach. Then the designed control law is implemented by aphase-lag lead controller incorporated with a complete load-decoupled PD compensator. The phase-lag lead controlleris tuned to achieve the optimal design based on the output error voltage directly, instead of using an estimator.With the proposed PD compensator, the converter is robust with respect to the load changes and parameterperturbations. We also provide the conditions for the robust stability assurance of the closed-loop system.
Design of high efficiency dual-mode buck DC-DC converter
Xinquan, Lai; Huali, Zeng; Qiang, Ye; Huisen, He; Shasha, Zhang; Yuqing, Sun
2010-11-01
A buck DC—DC switching regulator with high efficiency is implemented by automatically altering the modulation mode according to load current, and it can operate with an input range of 4.5 to 30 V. At light load current, the converter operates in skip mode. The converter enters PWM mode operation with increasing load current. It reduces the switching loss at light load and standby state, which results in prolonging battery lifetime and stand-by time. Meanwhile, externally adjustable soft-start minimizes the inrush supply current and avoids the overshoot of output voltage at initial startup. The regulator is fabricated by a 0.6 μm CDMOS process. The test results show that, under the condition of 3.3 V output, the efficiency is up to 64% at 5 mA and the maximum efficiency is 95.5%.
Design of high efficiency dual-mode buck DC-DC converter
Energy Technology Data Exchange (ETDEWEB)
Lai Xinquan; Zeng Huali; Ye Qiang; He Huisen; Zhang Shasha; Sun Yuqing, E-mail: zenghuali4213@126.com, E-mail: xqlai@mail.xidian.edu.cn [Institute of Electronic CAD, Xidian University, Xi' an 710071 (China)
2010-11-15
A buck DC-DC switching regulator with high efficiency is implemented by automatically altering the modulation mode according to load current, and it can operate with an input range of 4.5 to 30 V. At light load current, the converter operates in skip mode. The converter enters PWM mode operation with increasing load current. It reduces the switching loss at light load and standby state, which results in prolonging battery lifetime and stand-by time. Meanwhile, externally adjustable soft-start minimizes the inrush supply current and avoids the overshoot of output voltage at initial startup. The regulator is fabricated by a 0.6 {mu}m CDMOS process. The test results show that, under the condition of 3.3 V output, the efficiency is up to 64% at 5 mA and the maximum efficiency is 95.5%.
Highly Sensitive and Wide-Dynamic-Range Multichannel Optical-Fiber pH Sensor Based on PWM Technique
Directory of Open Access Journals (Sweden)
Md. Rajibur Rahaman Khan
2016-11-01
Full Text Available In this study, we propose a highly sensitive multichannel pH sensor that is based on an optical-fiber pulse width modulation (PWM technique. According to the optical-fiber PWM method, the received sensing signal’s pulse width changes when the optical-fiber pH sensing-element of the array comes into contact with pH buffer solutions. The proposed optical-fiber PWM pH-sensing system offers a linear sensing response over a wide range of pH values from 2 to 12, with a high pH-sensing ability. The sensitivity of the proposed pH sensor is 0.46 µs/pH, and the correlation coefficient R2 is approximately 0.997. Additional advantages of the proposed optical-fiber PWM pH sensor include a short/fast response-time of about 8 s, good reproducibility properties with a relative standard deviation (RSD of about 0.019, easy fabrication, low cost, small size, reusability of the optical-fiber sensing-element, and the capability of remote sensing. Finally, the performance of the proposed PWM pH sensor was compared with that of potentiometric, optical-fiber modal interferometer, and optical-fiber Fabry–Perot interferometer pH sensors with respect to dynamic range width, linearity as well as response and recovery times. We observed that the proposed sensing systems have better sensing abilities than the above-mentioned pH sensors.
Push-Pull Converter Fed Three-Phase Inverter for Residential and Motor Load
Directory of Open Access Journals (Sweden)
Samuel Rajesh Babu
2015-06-01
Full Text Available The proposed paper is an new approach for power conditioning of a PV (photo-voltaic cell array. The main objective is to investigate an approach to provide and improve the delivered electric energy by means of power conditioning structures with the use of alternative renewable resources (ARRs for remote rural residential or industrial non-linear loads. This approach employs a series-combined connected boost and buck boost DC-DC converter for power conditioning of the dc voltage provided by a photo-voltaic array. The input voltage to the combined converters is 100 V provided from two series connected PV cells, which is converted and increased to 200 V at the dc output voltage. Series-combined connected boost and buck-boost DC-DC converters operate alternatively. This helps to reduce the input ripple current and provide the required 400 Vdc on a sinusoidal PWM three-phase inverter. Analysis of the two series-combined DC-DC converters is presented along with simulation results. Simulations of the series-combined DC-DC converters are presented with an output DC voltage of 200 V and a maximum output load of Po = 600 W.
Indian Academy of Sciences (India)
ANIL KUMAR ADAPA; D VENKATRAMANAN; VINOD JOHN
2017-08-01
A PWM converter is the prime component in many power electronic applications such as static UPS, electric motor drives, power quality conditioners and renewable-energy-based power generation systems. While there are a number of computer simulation tools available today for studying power electronic systems,the value added by the experience of building a power converter and controlling it to function as desired is unparalleled. A student, in the process, not only understands power electronic concepts better, but also gains insights into other essential engineering aspects of auxiliary subsystems such as start-up, sensing, protection, circuit layout design, mechanical arrangement and system integration. Higher levels of protection features are critical for the converters used in a laboratory environment, as advanced protection schemes could prevent unanticipated failures occurring during the course of research. This paper presents a laboratory-built General-Purpose IGBT Stack (GPIS), which facilitates students to practically realize different power converter topologies. Essential subsystems for a complete power converter system is presented covering details of semiconductor device driving, sensing circuit, protection mechanism, system start-up, relaying and critical PCB layout design, followed by a brief comparison to commercially available IGBT stacks. The results show the high performance that can be obtained by the GPIS converter.
Chen, Jiaxin; Guo, Youguang; Zhu, Jianguo; Wei Lin, Zhi
2012-04-01
This paper presents a finite element analysis (FEA) based method for analyzing and controlling the bias magnetic state of the transformer of a pulse-width-modulation (PWM) switching full bridge dc-dc converter. A field-circuit indirect coupling method for predicting the transient bias magnetic state is introduced first. To increase flexibility of the proposed method, a novel transformer model which can address not only its basic input-output characteristic, but also the nonlinear magnetizing inductance, is proposed. Both the asymmetric characteristic and the variable laws of the current flowing through the two secondary windings during the period of PWM switching-off state are highlighted. Finally, the peak magnetizing current controlled method based on the on-line magnetizing current computation is introduced. Analysis results show that this method can address the magnetic saturation at winding ends, and hence many previous difficulties, such as the start-up process and asymmetry of power electronics, can be easily controlled.
Directory of Open Access Journals (Sweden)
A.S. Oshaba
2013-05-01
Full Text Available This study presents an approach for the speed control of a permanent magnet DC motor drive via Pulse Width Modulation (PWM technique and a DC/DC converter. The Particle Swarm Optimization (PSO technique is used to minimize a time domain objective function and obtain the optimal controller parameters. The performance of the proposed technique has been evaluated using various types of disturbances including load torque variations. Simulation results illustrate clearly the robustness of the controller and validity of the design technique for controlling the speed of permanent magnet motors.
Al-Naseem, Osama Abdulrahman
-quadrant switches used in a conventional matrix converter. This increase in power handling capability is due to the doubling of the number of devices in a multilevel matrix converter switch cell. Scaling up the power handling capability is accomplished by cascading more than one switch cell per branch. Control of the new converter is achieved through space vector modulation in which three-phase ac voltages are transformed to the d-q reference frame and compared with a set of space vectors prior to modulation. Since it has 19683 different switching combinations, control can be difficult and complex. Nevertheless, the multilevel matrix converter has been modeled and controlled through simulation. Simulation results show the possibility of operating the converter to produce the desired voltage waveforms with universal input and output power factors and maintain constant capacitor voltages simultaneously. Also in this dissertation is the derivation of an analytical averaged equivalent circuit model of a PWM converter. This model reveals how dominant loss mechanisms vary with converter operating point. The model is based on the operational characteristics of power diodes and IGBTs. Laboratory experiments support the derived model and confirm that IGBT current tailing and diode reverse-recovery are indeed the most critical losses in a PWM converter. These losses are more significant at light load, hence reducing the energy capture capability of converters used in wind generation. The results suggest that multilevel conversion, which has been employed in the novel multilevel matrix converter, could improve the low-wind converter efficiency.
Directory of Open Access Journals (Sweden)
Wenzhou Lu
2016-01-01
Full Text Available This paper analyzes the general properties of IMP-based controller and presents an internal-model-principle-based (IMP-based specific harmonics repetitive control (SHRC scheme. The proposed SHRC is effective for specific nk±m order harmonics, with n>m≥0 and k=0,1,2,…. Using the properties of exponential function, SHRC can also be rewritten into the format of multiple resonant controllers in parallel, where the control gain of SHRC is n/2 multiple of that of conventional RC (CRC. Therefore, including SHRC in a stable closed-loop feedback control system, asymptotic disturbance eliminating, or reference tracking for any periodic signal only including these specific harmonic components at n/2 times faster error convergence rate compared with CRC can be achieved. Application examples of SHRC controlled three-phase/single-phase grid-connected PWM inverters demonstrate the effectiveness and advantages of the proposed SHRC scheme.
Directory of Open Access Journals (Sweden)
Nirban Chakraborty
2014-04-01
Full Text Available This paper presents the speed control scheme of direct vector control of Induction Motor drive (IM drive. The Fuzzy logic controller is (FLC used as the controller part here for the direct vector control of Induction Motor using Sinusoidal PWM Inverter (SPWM. Fuzzy logic controller has become a very popular controlling scheme in the field of Industrial application. The entire module of this IM is divided into several parts such as IM body module, Inverter module, coordinate transformation module and Sinusoidal pulse width modulation (SPWM production module and so on. With the help of this module we can analyze a variety of different simulation waveforms, which provide an effective means for the analysis and design of the IM control system using FLC technique.
Partially resonant active filter using the digital PWM control circuit with the DSP
Energy Technology Data Exchange (ETDEWEB)
Matsuo, Hirofumi; Kurokawa, Fujio; Luo, Zongxin; Makino, Yutaka; Ishizuka, Yoichi [Nagasaki Univ. (Japan); Oshikata, Tetsuya [Shindengen Elect. Mfg. Co. Ltd. (Japan)
2000-07-01
The partially resonant active filter, as a pre-regulator, using the digital PWM control circuit with the DSP is proposed to improve the power factor and input current harmonic distortion factor. The steady-state and dynamic characteristics of this active filter are analysed and the relationship among the circuit parameters, variables and performance characteristics such as the pre-regulation of the output voltage, input power factor, input current harmonic distortion, boundaries of stability and so forth are defined. Using the partially resonant active filter, the high power efficiency over 91% is obtained and the high frequency switching noise is suppressed. Also, the digital control with the DSP is versatile and consequently, the power factor over 0.99 and total harmonic distortion factor less than 1% are easily realized. (orig.)
Microcontroller based PWM Inverter for Speed Control of a Three Phase Induction Motor
Directory of Open Access Journals (Sweden)
M. A. Latif
2013-04-01
Full Text Available Three phase induction motor has proven to be an extremely reliable electromechanical energy conversion device for over 100 years. The speed control of induction motor is a crying need for the real world industrial applications. However, there are so many options available for the precise speed control of induction motor except by changingthe frequency. Therefore to achieve the goal of speed control of induction motor, there is no alternative of inverters. With the availability of high speed power semiconductor devices, the three phase inverters play the key role for variable speed ac motor drives. In addition to the speed control, the inverter can also provide some unique features, like voltage control, torque control, power factor correction, auto breaking, built in protection system and so forth.In this paper, a three phases PWM inverter using MC3PHAC microcontroller with computer interface is proposed to run a squirrel case induction motor. Some results of the proposed inverter are presented.
Converting Nonclassicality into Entanglement
Killoran, N.; Steinhoff, F. E. S.; Plenio, M. B.
2016-02-01
Quantum mechanics exhibits a wide range of nonclassical features, of which entanglement in multipartite systems takes a central place. In several specific settings, it is well known that nonclassicality (e.g., squeezing, spin squeezing, coherence) can be converted into entanglement. In this work, we present a general framework, based on superposition, for structurally connecting and converting nonclassicality to entanglement. In addition to capturing the previously known results, this framework also allows us to uncover new entanglement convertibility theorems in two broad scenarios, one which is discrete and one which is continuous. In the discrete setting, the classical states can be any finite linearly independent set. For the continuous setting, the pertinent classical states are "symmetric coherent states," connected with symmetric representations of the group S U (K ). These results generalize and link convertibility properties from the resource theory of coherence, spin coherent states, and optical coherent states, while also revealing important connections between local and nonlocal pictures of nonclassicality.
Improving Power Converter Reliability
DEFF Research Database (Denmark)
Ghimire, Pramod; de Vega, Angel Ruiz; Beczkowski, Szymon
2014-01-01
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...... 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...... 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...
Converting Nonclassicality into Entanglement.
Killoran, N; Steinhoff, F E S; Plenio, M B
2016-02-26
Quantum mechanics exhibits a wide range of nonclassical features, of which entanglement in multipartite systems takes a central place. In several specific settings, it is well known that nonclassicality (e.g., squeezing, spin squeezing, coherence) can be converted into entanglement. In this work, we present a general framework, based on superposition, for structurally connecting and converting nonclassicality to entanglement. In addition to capturing the previously known results, this framework also allows us to uncover new entanglement convertibility theorems in two broad scenarios, one which is discrete and one which is continuous. In the discrete setting, the classical states can be any finite linearly independent set. For the continuous setting, the pertinent classical states are "symmetric coherent states," connected with symmetric representations of the group SU(K). These results generalize and link convertibility properties from the resource theory of coherence, spin coherent states, and optical coherent states, while also revealing important connections between local and nonlocal pictures of nonclassicality.
Thermionic photovoltaic energy converter
Chubb, D. L. (Inventor)
1985-01-01
A thermionic photovoltaic energy conversion device comprises a thermionic diode mounted within a hollow tubular photovoltaic converter. The thermionic diode maintains a cesium discharge for producing excited atoms that emit line radiation in the wavelength region of 850 nm to 890 nm. The photovoltaic converter is a silicon or gallium arsenide photovoltaic cell having bandgap energies in this same wavelength region for optimum cell efficiency.
Comparative Analysis of PWM Techniques for Three Level Diode Clamped Voltage Source Inverter
Directory of Open Access Journals (Sweden)
Zulkifilie Bin Ibrahim
2014-07-01
Full Text Available Multilevel inverters are increasingly being used in high-power medium voltage industrial drive applications due to their superior performance compared to conventional two-level inverters. Thre are a number of Pulse width modulation (PWM techniques applied in recent years. The most widely applied PWM techniques are Sine Pulse Width Modulation (SPWM and Space Vector Pulse Width Modulation (SVPWM. SPWM is the most simple modulation technique that can realize easily in analog circuit. However, it has some drawbacks such as higher total harmonic distortion (THD, lower effective DC utilization and lower switching frequency. Space vector pulse width modulation (SVPWM is widely used because of their easier digital realization and better DC bus utilization and lower THD. The complexity is due to the difficulty in determining the reference vector location, on times calculation, and switching states selection. This paper presents a simple SVPWM algorithm for diode clamped three level inverters based on standard two-level SVPWM which can easily determine the location of reference vector, calculate the on-times, the selection of switching states. Three level diode clamped inverter (3LDCI using space vector modulation technique has been modeled and simulated using MATLAB/SIMULINK and Origin 6.1 with a passive R-L load that can be extended to any level. Simulation results are presented to verify the proposed SVPWM control in terms of THD. The results are compared with conventional sinusoidal pulse width modulation (SPWM where SVPWM shows better performance than SPWM in terms of THD.
Directory of Open Access Journals (Sweden)
Nittala S K Sastry
2012-06-01
Full Text Available This paper presents a new PWM Multi phase DC-DC converter under current mode control with an auxiliary circuit which provides zero voltage switching in order to meet the power supply requirements of the processors of modern electronic equipments like laptops, mobiles, and PDAs etc which require more than 70 A current, lower voltage and better transient response.The multi phase topology benefits in high current, good efficiency and better current transient response. High current multi phase buck converters found applications in advanced data control, solid state lasers, communication equipment and Pentium processors etc. In this paper designed of three phase DC-DC converter 100W, 12V/1V under current mode control is discussed in detail and the simulation results are presented to support the theoretical analysis.
Directory of Open Access Journals (Sweden)
Bogimi Sirisha
2012-03-01
Full Text Available In this paper, a three-phase two leg neutral point clamped (NPC converter is presented for power factor correction and dc-link voltage regulation. The adopted converter has simpler circuit configuration and less number of power switches compared to three-level PWM converter. In this circuit configuration, only eight power switches and four clamping diodes with voltage stress of half the dc bus voltage are used. A simplified space vector pulse width modulation scheme (SVPWM is also adopted to track the line current commands. A reference voltage vector is generated on the ac terminal for drawing the sinusoidal line currents with unity power factor. This algorithm reduces the time required to calculate the switching time durations of voltage vectors. The simulation results have been presented to verify the validity and effectiveness of the proposed control strategy.
Institute of Scientific and Technical Information of China (English)
无
2005-01-01
Performance evaluation on ZCS-PFM series-resonant DC-DC converter with high-frequency high-voltage transformer for magnetron drive，Power supply with high insulation capability to feed electronics on the high potential side in power distribution networks，Series-parallel resonant UPS with capacitive output DC bus filter for powering HFC networks，Soft-switching phase-shifted PWM full-bridge DC-DC converter with reduced conduction losses novel soft-switching DC-DC converter using tapped inductor type filter，Synthesis and Modulation of a Single Phase DC/AC Converter with High-Frequency Isolation in Photovoltaic Energy Applications， Transformer Parasitic Parameters and Lossless Inductive Snubber Assisted Zero Current Soft Switching DC-DC Converter for High Power Magnetron Drive。
基于FPGA的空间矢量PWM的实现%A Realization of FPGA-based Space-vector PWM
Institute of Scientific and Technical Information of China (English)
孙文焕; 程善美; 秦忆
2000-01-01
本文详述了空间矢量SVPWM的算法，并提出用FPGA实现SVPWM的方法，最后分析了使用FPGA的优点。%This paper reviews an arithmetic of the space-vector PWM in detail,and advances a realization of FPGA-based space-vector PWM ,finally analyses the merit of FPGA-based strategy.
Compherensive Design of a 100 kW/400 V High Performance AC-DC Converter
Directory of Open Access Journals (Sweden)
Ghasem Esfandiari
2015-01-01
Full Text Available In this paper, a comprehensive design for a 100kW/400V, three-phase pulse-width modulated (PWM AC-DC converter is presented that serves as the front-end power supply for wide-range varying active load. This power supply includes two series stages; a six-switch AC-DC boost converter and a DC-DC buck converter to regulate 400VDC at load side. The design of all inductors and capacitors is fulfilled using mathematical expressions. In addition, small signal modelling and controller design are presented in order to raise the design efficiency of the proposed converter. Also, due to the high power application, improved soft-switching techniques are applied. Furthermore, systematic approach to design an input EMI filter for DC-DC converter is explained. The simulation results performed by PSCAD software show that high performance of the proposed power supply is obtained in terms of stability, high power factor, high efficiency and low total harmonic distortion (THD.
A nine-level hybrid symmetric cascaded multilevel converter for induction motor drive
Indian Academy of Sciences (India)
INDRAJIT SARKAR; B G FERNANDES
2017-08-01
A nine-level hybrid symmetric cascaded multilevel converter (MLC) fed induction motor drive is proposed in this paper. The proposed converter is capable of producing nine output voltage levels by using the same number of power cells as that of conventional five-level symmetric cascaded H-bridge converter. Eachphase in this configuration consists of one five-level transistor-clamped H-Bridge (TCHB) power cell and one three-level H-bridge power cell with equal dc link voltages, and they are connected in cascade. Due to cascade connection and equal dc link voltage, the power shared by each power cell is nearly equal. Near-equal power sharing enables the feature of improving input current quality by using an appropriate phase-shifting multiwinding transformer at the converter input. In this paper, the operation of the converter is explained using staircase and hybrid multi-carrier sine PWM techniques. Further, a detailed analysis for the variations in the dc link capacitor voltages and the dc link mid-point voltage in TCHB power cell is carried out, and the analytical expressions thus obtained are presented. The performance of proposed system is analysed by simulating a 500 hp induction motor drive system in MATLAB/Simulink environment. A laboratory prototype is also developed to validate the claims experimentally.
Institute of Scientific and Technical Information of China (English)
王剑; 李永东
2012-01-01
4象限H桥级联型多电平变换器的功率单元中,由于单相H桥逆变器的输出功率中含有2倍于输出电压频率的脉动分量,如果输入级的PWM整流器采用传统的控制策略,直流母线电压也将会含有该频率的脉动.在PWM整流器电压定向控制中,使用比例-积分-谐振(PIR)调节器控制电压环和电流环,抑制了直流母线电压的脉动,在小功率平台上的实验证明了该控制策略的有效性.%In power cells of the four-quadrant cascaded H-bridge multilevel converters,the output power of H-bridge single-phase inverters contains component whose frequency is twice the output voltage frequency. This component will cause the DC-link voltage to pulsate if the PWM rectifier in the input stage is controlled with the conventional method. Proportional-integral-resonant (PIR) regulator was proposed for the DC-link voltage loop and the AC current loop of the voltage-oriented control of the PWM rectifier. Experimental result shows that the DC-link voltage is well-controlled even with a very small DC-link capacitor,which confirms the effectiveness of proposed control strategy.
DEFF Research Database (Denmark)
Sørensen, P G; Rømer, F K; Cortes, D
1984-01-01
In order to evaluate bleomycin-associated lung damage in humans, lung function parameters and serum levels of the endothelial-bound angiotensin-converting enzyme (ACE) were determined by serial measurements in 11 patients who were treated for testicular cancer. None developed clinical or radiolog......In order to evaluate bleomycin-associated lung damage in humans, lung function parameters and serum levels of the endothelial-bound angiotensin-converting enzyme (ACE) were determined by serial measurements in 11 patients who were treated for testicular cancer. None developed clinical...
Institute of Scientific and Technical Information of China (English)
ESMAELI Abdolreza; SUN Li
2007-01-01
Modeling and simulation of induction motor drive system to investigate and mitigate the adverse effects of PWM inverter based on analysis, modeling and simulation are presented. The estimation of conducted disturbances and other adverse effects of PWM inverter by simulation offer a considerable gain from the economic point of view. For an accurate model of the motor drive system including mains, rectifier, inverter, motor and its long cables, the high frequency parasitic current paths are taken into account. The novel model and its parasitic values for three-phase induction motor system are presented. Finally a new solution for suppressing EMI, common mode voltage, leakage current, bearing current and shaft voltages is proposed and the results show the excellent performances of proposed solution including active and passive filters.
A Novel Electronically Controllable of Current-mode Level Shifted Multicarrier PWM Based on MO-CFTA
Directory of Open Access Journals (Sweden)
W. Kongnun
2013-09-01
Full Text Available This paper proposes the application of an electronically controlled current-mode for a level shifted multicarrier PWM generator. The proposed circuit consists of two multiple-output current follower transconductance amplifiers (MO-CFTAs for the multiple-output triangular generator and four current follower transconductance amplifiers (CFTAs for the signal comparator. The characteristics of the circuit are as follows: the current output can be controlled by bias current, the maximum amplitude deviation due to temperature variation is less than 1.37% and the power consumption is approximately 0.744 microwatt, at ±1.5V supply voltages. The proposed PWM has been verified through PSpice simulation results which are in consistent with the theoretical analysis.
Energy Technology Data Exchange (ETDEWEB)
Ludwiczak, Bogna, E-mail: bogna.ludwiczak@zumtobelgroup.com [Zumtobel Lighting GmbH, Schweizerstr.30, 6851 Dornbirn (Austria); Jantsch, Wolfgang [Institut für Halbleiter- und Festkörperphysik, Johannes Kepler Universität, 4040 Linz (Austria)
2015-02-15
We investigate experimentally the color stability of high power phosphor converted InGaN LEDs under pulse width modulation (PWM) and continuous current reduction (CCR) dimming modes and for varied operation temperatures. Our measurements reveal that the chromaticity coordinate pathways of the warm white and the cold white LED's differ for the same operation conditions. The color deviation- minimizing phenomenon of opposite peak wavelength shifts appears only for a cold white LED under CCR driving mode. This favorable effect does not occur for warm white LEDs. This type of LED exhibits the best color stability under PWM driving mode. The experimental results are consistently explained in terms of the quantum confined Stark effect and temperature induced changes of the LED emission. - Highlights: • Cold and warm white LEDs reacts colorimetrically unlike in different driving modes. • For cold white emission driving conditions are crucial. • Opposite peak wavelength shifts reduces color deviations for cold white emission. • For warm white emission rather phosphor properties determines color deviations.
Khan, Md Rajibur Rahaman; Kang, Shin-Won
2016-07-09
In this paper, we propose a temperature/thermal sensor that contains a Rhodamine-B sensing membrane. We applied two different sensing methods, namely, fiber-optic pulse width modulation (PWM) and an interdigitated capacitor (IDC)-based temperature sensor to measure the temperature from 5 °C to 100 °C. To the best of our knowledge, the fiber-optic PWM-based temperature sensor is reported for the first time in this study. The proposed fiber-optic PWM temperature sensor has good sensing ability; its sensitivity is ~3.733 mV/°C. The designed temperature-sensing system offers stable sensing responses over a wide dynamic range, good reproducibility properties with a relative standard deviation (RSD) of ~0.021, and the capacity for a linear sensing response with a correlation coefficient of R² ≈ 0.992 over a wide sensing range. In our study, we also developed an IDC temperature sensor that is based on the capacitance variation principle as the IDC sensing element is heated. We compared the performance of the proposed temperature-sensing systems with different fiber-optic temperature sensors (which are based on the fiber-optic wavelength shift method, the long grating fiber-optic Sagnac loop, and probe type fiber-optics) in terms of sensitivity, dynamic range, and linearity. We observed that the proposed sensing systems have better sensing performance than the above-mentioned sensing system.
Hoogland, J.K.; Neumann, C.D.D.; Bloch, D.
2001-01-01
We give a simple algorithm to incorporate the effects of resets in convertible bond prices, without having to add an extra factor to take into account the value of the reset. Furthermore we show that the effect of a notice period, and additional make-whole features, can be treated in a straightforwa
An Electromagnetic Beam Converter
DEFF Research Database (Denmark)
2009-01-01
The present invention relates to an electromagnetic beam converter and a method for conversion of an input beam of electromagnetic radiation having a bell shaped intensity profile a(x,y) into an output beam having a prescribed target intensity profile l(x',y') based on a further development...
Definition of Power Converters
Bordry, F
2015-01-01
The paper is intended to introduce power conversion principles and to define common terms in the domain. The concept s of sources and switches are defined and classified. From the basic laws of source interconnections, a generic method of power converter synthesis is presented. Some examples illustrate this systematic method. Finally, the commutation cell and soft commuta tion are introduced and discussedd.
Convertible Proxy Signcryption Scheme
Institute of Scientific and Technical Information of China (English)
李继国; 李建中; 曹珍富; 张亦辰
2004-01-01
In 1996, Mambo et al introduced the concept of proxy signature. However, proxy signature can only provide the delegated authenticity and cannot provide confidentiality. Recently, Gamage et al and Chan and Wei proposed different proxy signcryption schemes respectively, which extended the concept of proxy signature.However, only the specified receiver can decrypt and verify the validity of proxy signcryption in their schemes.To protect the receiver' s benefit in case of a later dispute, Wu and Hsu proposed a convertible authenticated encryption scheme, which carn enable the receiver to convert signature into an ordinary one that can be verified by anyone. Based on Wu and Hsu' s scheme and improved Kim' s scheme, we propose a convertible proxy signcryption scheme. The security of the proposed scheme is based on the intractability of reversing the one-way hash function and solving the discrete logarithm problem. The proposed scheme can satisfy all properties of strong proxy signature and withstand the public key substitution attack and does not use secure channel. In addition, the proposed scheme can be extended to convertible threshold proxy signcryption scheme.
The Convertible Arbitrage Strategy Analyzed
Loncarski, I.; Ter Horst, J.R.; Veld, C.H.
2006-01-01
This paper analyzes convertible bond arbitrage on the Canadian market for the period 1998 to 2004.Convertible bond arbitrage is the combination of a long position in convertible bonds and a short position in the underlying stocks. Convertible arbitrage has been one of the most successful strategies
Directory of Open Access Journals (Sweden)
P.Sathya
2013-02-01
Full Text Available this paper presents the design and implementation of high performance closed loop Boost converter for solar powered HBLED lighting system. The proposed system consists of solar photovoltaic module, a closed loop boost converter and LED lighting module. The closed loop boost converter is used to convert a low level dc input voltage from solar PV module to a high level dc voltage required for the load. To regulate the output of the converter, closed loop voltage feedback technique is used. The feedback voltage is compared with a reference voltage and a control signal is generated and amplified. The amplified signal is fed to 555 Timer which in turn generates a PWM signal which controls the switching of MOSFET. Thus by switching of MOSFET it would try to keep output as constant. Initially the boost converter, timer circuit, amplifier circuit and LED light circuits are designed, simulated and finally implemented in printed circuit board. The simulation studies are carried out in MULTISIM. Theexperimental results for solar PV and boost converter obtained in both software and hardware are presented here.
一种PWM/LDO双模同步降压型稳压器的设计%Design of a PWM/LDO Dual-Mode Synchronous Buck Regulator
Institute of Scientific and Technical Information of China (English)
常昌远; 郑烁锐; 王青
2011-01-01
A PWM/LDO dual-mode system controlled by external synchronous signal was designed, which improved the system performance at light load. Architecture of the entire system and its functions were described, and a detailed analysis was made on the switchover circuit The circuit was simulated based on CSMC 0. 5 μm CMOS process. Results showed that the system had an input voltage ranging from 3. 5 V to 6 V, an output voltage of 3. 3 V,and an operating frequency of 1. 2 MHz. The ripple of the output voltage was less than 30 mV in PWM mode, while the ripple voltage was less than 10 μV and the max load current was 50 mA in LEX) mode. The circuit had a conversion efficiency above 80% over the load range from 20 mA to 1. 2 A, and the PWM/LDO switchover time was less than 60 μs.%设计了一种新颖的外部同步信号控制PWM/LDO双模系统,用来提高系统在轻载下的性能.介绍了整个系统的整体框架和功能,并对切换电路进行了详细的分析与设计.在此基础上,基于华润上华0.5 μm CMOS工艺,使用Cadence对整体电路进行仿真验证.结果表明,系统输入电压Vin的范围为3.6～6 V,输出电压Vo为3.3V,PWM信号工作频率为1.2 MHz,PWM模式下纹波小于30 mV,LDO模式下最大负载电流为50 mA、纹波电压小于10μV,在20 mA～l.2 A负载范围内,系统效率保持在80％以上,PWM/LDO双模切换稳定时间小于60μs.
Reactive power compensation capacity tuning method based on PWM rectifier%基于 PWM 整流器的无功补偿容量整定方法
Institute of Scientific and Technical Information of China (English)
甘伟; 冀红超; 杨兴武
2016-01-01
为了充分利用PWM整流器的容量，实现对电网无功功率的调节及电网电压的稳定控制，深入分析了一种基于PWM整流器的无功补偿容量整定方法。重载情况下，PWM整流器在其容量范围内向电网不补偿或少量补偿无功功率，无功功率补偿量由PWM整流器的额定容量和直流负载功率共同决定；轻载情况下，PWM整流器能够补偿电网所缺的所有无功功率。文章还详细分析了直流电容参数的选取方法。最后通过MATLAB／Simulink仿真进行了验证，仿真结果表明该整定方法能够实现无功功率的动态补偿。%In order to fully employ the capacity of the PWM rectifier , and realize the regulation of reactive power and the stable control of voltage in the grid , a deep analysis of a reactive power compensation capacity tuning method based on PWM rectifier has been presented in this paper .In heavy load situations , the PWM rectifier does not com-pensate or compensate a small amount of reactive power , that is to say , the reactive power compensation amount is de-termined by the rated capacity of the PWM rectifier and the DC load power;in light load situations , the PWM rectifier can compensate the whole reactive power in the grid .This paper also analyzes the selection method of the DC capaci-tor parameter in detail.At last, it validates the system through the MATLAB/Simulink, the simulation results show that the tuning method can realize dynamic reactive power compensation .
Luo, Fang Lin
2003-01-01
INTRODUCTIONHistorical ReviewMultiple Quadrant ChoppersPump CircuitsDevelopment of DC/DC Conversion TechniqueCategorize Prototypes and DC/DC Converters Family TreeVOLTAGE-LIFT CONVERTERSIntroductionSeven Self-Lift ConvertersPositive Output Luo-ConvertersNegative Output Luo-ConvertersModified Positive Output Luo-Converters Double Output Luo-ConvertersPOSITIVE OUTPUT SUPER-LIFT LUO-CONVERTERS IntroductionMain SeriesAdditional SeriesEnhanced Series Re-Enhanced Series Multiple-Enhanced Series Summary of Positive Output
Simulation of Multi-level Cascade Boost PWM Rectifer-Inverter%升压型PWM整流器-逆变器多级串联仿真
Institute of Scientific and Technical Information of China (English)
陈婕; 姜建国
2011-01-01
Many problems should be considered in design of high-voltage power converter, especially the current control at the AC main and the output voltage waveform. Traditional non-controlled rectifier is non-linear, which is not conducive to optimizing the design of high-vokage transformer. Traditional VSI with single-phase inverter structure is not conductive to the improvement of the power hierarchy. In addition, the problem of common-mode voltage suppression exists in the rectifier and inverter. To solve the above problems, the PWM rectifier with power factor close to 1 and cascade inverters is proposed. All control principles are tested by MATLAB/SIMULINK.%高压大功率变频器的设计包括多个方面，其中网侧电流控制、输出电压波形控制是至关重要的两个方面。传统不控整流器本身是非线性的．不利于高压变压器的优化设计。传统电压源逆变器采用单一的单相逆变器结构，不利于功率等级的提高。文中采用单周期控制PWM整流器，并采用逆变器多级串联来提高功率等级，并采用MATLAB／SIMuLINK进行了仿真研究。
Analysis of Current Source PWM Inverter for Different Levels with No-Insulating Switching Device
Directory of Open Access Journals (Sweden)
Kumar Abhishek
2013-04-01
Full Text Available This paper gives the new set-up of inverter having DC current source (CSI having no insulated switching device. In the proposed new CSI topology every switching device are connected across a common-source level, thus a single power supply gate drive circuit is required and no insulated power supply and the customary bootstrap circuit is applied. This CSI topology is even legitimate for utmost level of current waveform output, where the power switches number increases. As a turn up, gate drive complexity is reduced, and it also eliminates the cost of capacitors and transformers in switching devices, driver circuits. In addition, this new topology of current-source PWM inverter (CSI can operate even at utmost switching frequency, as every switches will be connected across a common source level. In this paper the different level of proposed CSI operation principle, its design using computer simulation (MATLAB with its total harmonic distortion (THD is analyzed. The computer simulation using MATLAB determines the feasibility of this topology with the analysis of different level which results in reduction of its complexity and the physical size.
Inverter Output Filter Effect on PWM Motor Drives of a Flywheel Energy Storage System
Santiago, Walter
2004-01-01
NASA Glenn Research Center (GRC) has been involved in the research and development of high speed flywheel systems for small satellite energy storage and attitude control applications. One research and development area has been the minimization of the switching noise produced by the pulsed width modulated (PWM) inverter that drives the flywheel permanent magnet motor/generator (PM M/G). This noise can interfere with the flywheel M/G hardware and the system avionics hampering the full speed performance of the flywheel system. One way to attenuate the inverter switching noise is by placing an AC filter at the three phase output terminals of the inverter with the filter neutral point connected to the DC link (DC bus) midpoint capacitors. The main benefit of using an AC filter in this fashion is the significant reduction of the inverter s high dv/dt switching and its harmonics components. Additionally, common mode (CM) and differential mode (DM) voltages caused by the inverter s high dv/dt switching are also reduced. Several topologies of AC filters have been implemented and compared. One AC filter topology consists of a two-stage R-L-C low pass filter. The other topology consists of the same two-stage R-L-C low pass filter with a series connected trap filter (an inductor and capacitor connected in parallel). This paper presents the analysis, design and experimental results of these AC filter topologies and the comparison between the no filter case and conventional AC filter.
隔离式SEPIC三电平AC-AC变换器的研究%Research of Isolated SEPIC Three-level AC - AC Converter
Institute of Scientific and Technical Information of China (English)
周振军; 李磊
2011-01-01
电力电子装置已在电力系统中得到了越来越广泛的应用,代表之一就是交流调压稳压装置.但是目前的交流调压稳压器多数采用AC-DC-AC的变换方式,这种调压稳压器不仅体积大、噪音大,而且开关管的电压应力大、输出电压波形质量低.提出了一种新型的隔离式交-交变换器,它是在sepic变换器(单端初级电感转换器)的基础上引入了推挽式变压器实现电气隔离.分析了工作原理,给出了控制策略,并通过仿真论证了变换器开关管电压应力小、输出电压波形质量高等特点.%Power electronics have been more widely used in power systems. One representative of power electronics is AC voltage regulator. But the AC - DC - AC conversion type is widely used for voltage regulator now. These AC voltage regulator not only have big bulk and high noise,but also with high power switch voltage stress and low quality of output waveform. To solve these problems)an isolated three-level AC - AC direct converter was proposed. It joined the push-pull transformer to achieve electrical isolation based on sepic AC -AC converter. Its operation principle and control strategies of the converter were investigated. By modeling and simulation,the performances of the AC - AC converter were verified, such as low switch voltage stress, high quality of output waveform and so on.
Microprocessor controlled static converter
Directory of Open Access Journals (Sweden)
Stefan Szabo
2005-10-01
Full Text Available This paper wants to demonstrate a way of implementing a microcontroller into an DC motor speed control loop. The static power converter is a fully controlled rectifier bridge, using standard SCR's. The bridge's control signals are supplied by the microcontroller and are phase-angle or burst types. The automation loop contains a software PI-style regulator. All the experimental results shows that this aproach is flexibile enough to be used on a large scale.
DEFF Research Database (Denmark)
Margheritini, Lucia; Vicinanza, Diego; Frigaard, Peter
2008-01-01
head hydroturbines are converting the potential energy of the stored water into power. A key to success for the SSG will be the low cost of the structure and its robustness. The construction of the pilot plant is scheduled and this paper aims to describe the concept of the SSG wave energy converter...... and the studies behind the process that leads to its construction. The pilot plant is an on-shore full scale module in 3 levels with an expected power production of 320 MWh/y in the North Sea. Location, wave climate and laboratory tests results will be used here to describe the pilot plant and its characteristics.......The SSG (Sea Slot-cone Generator) is a wave energy converter of the overtopping type. The structure consists of a number of reservoirs one on the top of each others above the mean water level, in which the water of incoming waves is stored temporary. In each reservoir, expressively designed low...
A Novel Four-Step Commutation for Bidirectional Switch Cells of AC-AC Matrix Converter
DEFF Research Database (Denmark)
Guo, Yougui; Zeng, Ping; Blaabjerg, Frede
2012-01-01
sector ones and active switching time PWM ones synchronize. Second, the required switching states are flexibly realized in the form of the look-up table by programming in VHDL language for 36 switching combinations of input sectors with output ones. Third, the obtained switching states are judged whether...... on or off of output current happens on the second and third steps. Here the second step is equal to the third one. This method is implemented with four steps by programming in VHDL language. First, the special flip-flop, 74AHC16373, is obtained by programming so as to make input sector signals, output......A novel four-step commutation is proposed with unequal step for each bidirectional switch cell on the basis on analysis of many proposed commutation methods of matrix converter in this paper. The first and fourth step can be shorter than the second or third one because the actual switching...
Dynamic Performance of a Back-to-Back HVDC Station Based on Voltage Source Converters
Khatir, Mohamed; Zidi, Sid-Ahmed; Hadjeri, Samir; Fellah, Mohammed-Karim
2010-01-01
The recent developments in semiconductors and control equipment have made the voltage source converter based high voltage direct current (VSC-HVDC) feasible. This new DC transmission is known as "HVDC Light or "HVDC Plus by leading vendors. Due to the use of VSC technology and pulse width modulation (PWM) the VSC-HVDC has a number of potential advantages as compared with classic HVDC. In this paper, the scenario of back-to-back VSC-HVDC link connecting two adjacent asynchronous AC networks is studied. Control strategy is implemented and its dynamic performances during disturbances are investigated in MATLAB/Simulink program. The simulation results have shown good performance of the proposed system under balanced and unbalanced fault conditions.
DSP implementation of Fuzzy based Power Quality enhancement strategy for IPOS converter fed drive
Directory of Open Access Journals (Sweden)
N.Radhakrishnan
2012-03-01
Full Text Available The paper attempts to develop a Fuzzy based Pulse Width Modulation (PWM scheme through the use of a Digital Signal Processor (DSP with a view to improve the input power factor of a drive system. It corners to exploit the merits of an inherent decision making mechanism to construct a control algorithm and there from articulate a methodology to reshape the input current wave to a sinusoidal form. The procedure forges to facilitate an increase in the fundamental component of the current through the entire operating range. The scheme, investigated using a prototype model envisages to enhance the power quality indices of the AC-DC converter fed drive system, in addition to regulating its speed
Hysteresis Current Control Based Shunt Active Power Filter for Six Pulse Ac/Dc Converter
Directory of Open Access Journals (Sweden)
Rakesh Kumar Pandey
2017-02-01
Full Text Available In this paper the simulation of Shunt Active power Filter using P-Q theory and PI controller has been presented. This SAPF compensates the harmonic currents drawn by three phase six pulse AC/DC converter. The process of compensation is done by calculating the instantaneous reactive power losses using p-q theory and the PI controller to reduce the ripple voltage of the dc capacitor of the PWM-VSI. This approach is different from conventional approach and provides very effective solution. In this simulation we use hysteresis band current controller (HCC for switching the VSI inverter. The simulation has been done for both steady state and transient conditions
Improved direct power control of a grid-connected voltage source converter during network unbalance
Institute of Scientific and Technical Information of China (English)
Peng ZHOU; Wei ZHANG; Yi-kang HE; Rong ZENG
2010-01-01
This paper deals with an improved direct power control(DPC)strategy for the pulse width modulation(PWM)voltage source converter(VSC)under unbalanced grid voltage conditions.In order to provide enhanced control performance for the VSC,the resonant controllers tuned at the double grid frequency are applied in the DPC design to eliminate the power pulsations and dc link voltage ripples produced by the transient unbalanced grid faults.In this way,the output power and dc link voltage of the VSC can be directly regulated without positive and negative sequential decomposition.As a result,and as has been verified by experiment,the proposed method can provide fast dynamic response with easy implementation.
Battery pack state of charge balancing algorithm for cascaded H-Bridge multilevel converters
DEFF Research Database (Denmark)
Máthé, Lászlo; Burlacu, Paul Dan; Schaltz, Erik
2016-01-01
For most of the Multilevel Converter (MC) applications a commonly discussed issue is the maintenance of balance between the energy storage elements from the SubModules (SM). In applications where a battery pack is also part of the SM storage, such as STATCOMs or motor drives, the SM voltage...... is not in linear relation with the State Of Charge (SOC) of the entire battery; thus, the balancing becomes more cumbersome. A method to balance the SOC of the battery packs in a system using cascaded H-Bridge is proposed in this paper. The method uses nearest level control followed by sorting and selection based...... on the SOC of the battery packs. Based on the simulation results the number of switching is reduced considerably compared to the method where the phase shifted PWM is used. In addition, the time needed to achieve the balanced SOC is also reduced. The proposed method has been verified through experiments...
Quadrant Cascaded Multilevel Converter and Rectifier Control%4象限级联型多电平变换器及其整流器控制
Institute of Scientific and Technical Information of China (English)
孙炳海; 李永东; 王剑
2011-01-01
In the power units of cascaded multilevel converters, replacing the diode rectifier with PWM rectifier can make the converter have the regenerative ability; using the leak inductance as the filter reactor of the PWM rectifier can reduce the volume and cost of the converter; the phase-shift secondary side of the transformer can eliminate the current harmonics caused by the single power unit, restraining the grid side harmonic especially the low order harmonic. In the control scheme PLL is employed to track the grid voltage's phase and frequency. The PIR control strategy of the PWM rectifier is used to maintain the DC-link voltage stable when feeding the single-phase inverter. The mathematic model of the PWM rectifier, its orientation method and the PIR current control strategy were introduced. The experiment results verify that the converter can achieve the regenerative ability when operating in the accelerating and decelerating of electrical machines.%在级联型多电平变换器的功率单元中,用PWM整流器替代二极管整流器,可以实现能量的双向流动;利用隔离变压器的副边漏抗代替整流器的输入电抗器,可以减少变换器的体积和成本;隔离变压器的副边绕组移相消除了由单个功率单元所引起的谐波电流,抑制了网侧谐波尤其是低次谐波的产生.在整流器控制中使用锁相环对电网的相位和频率跟踪,采用PWM整流器的PIR电流控制策略,有利于在整流器接单相逆变负载的情况下维持母线电压的稳定.给出了PWM整流器的数学模型、定向策略及PIR控制策略,通过实验验证了新型整流器及其控制策略在电机加速减速过程中能够实现能量回馈.
Institute of Scientific and Technical Information of China (English)
Jia-bing HU; Wei ZHANG; Hong-sheng WANG; Yi-kang HE; Lie XU
2009-01-01
This paper proposes a current control scheme for a grid-connected pulse width modulator (PWM) voltage source converter (GC-VSC) under imbalanced and distorted supply voltage conditions. The control scheme is implemented in the positive synchronously rotating reference frame and composed of a single proportional integral (PI) regulator and multi-frequency resonant controllers tuned at the frequencies of 2ω and 6ω, respectively. The experimental results, with the target of eliminating the active power oscillations and current harmonics on a prototype GC-VSC system, validate the feasibility of the proposed current control scheme during supply voltage imbalance and distortion.
DEFF Research Database (Denmark)
Mira Albert, Maria del Carmen; Zhang, Zhe; Knott, Arnold;
2016-01-01
This paper presents the design, modelling and control of a three-port (TPC) isolated dc-dc converter based on interleaved-boost-full-bridge with pulse-width-modulation and phase-shift control for hybrid renewable energy systems. In the proposed topology, the switches are driven by phase-shifted PWM...... of the proposed ac inductor based TPC is investigated by performing state-space modelling. Moreover, the derived mathematical models are validated by simulation and measurements. In order to verify the validity of the theoretical analysis, design and power decoupling control scheme, a prototype is constructed...
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...
Institute of Scientific and Technical Information of China (English)
孙炳海; 王剑; 李永东
2011-01-01
研究了回馈式H桥级联型多电平变换器,利用移相变压器的二次侧漏抗代替PWM整流器的输入电抗器,采用比例积分加谐振（PIR）的调节方法,设计了电网电压定向控制的PWM整流器双闭环控制策略。同时,文中给出了H桥的功率单元拓扑结构、PWM整流器的数学模型及控制策略,对PIR调节器原理、功率单元及网侧电流谐波进行了分析阐述。通过实验,验证了移相变压器消除谐波的作用,以及控制策略对直流母线电压稳定的有效性,实验结果表明PWM整流器及其控制策略在电动机加速、减速过程中,表现出良好的四象限运行性能。%Regenerative H-bridge multi-level cascade converter is studied in this paper.The secondary leakage reactance of phase-shifting transformer have been used to replace the input reactor for rectifier,and the PIR regulator is adopted in the design of grid voltage oriented double-loop control stragety.In this paper,the topology of H-bridge power converter unit,the mathematical model and control strategy of PWM rectifier,the principle of the PIR regulator and the current harmonics of power unit and grid are analyzed and discussed.The experimental results validate the function of phase-shifting transformer in harmonic current suppression and the effectiveness of control stagey for DC-bus voltage stability.The experimental results show good performance of PWM rectifier under the acceleration and deceleration of the motor four-quadrant operation.
Kazimierczuk, Marian K
2012-01-01
This book is devoted to resonant energy conversion in power electronics. It is a practical, systematic guide to the analysis and design of various dc-dc resonant inverters, high-frequency rectifiers, and dc-dc resonant converters that are building blocks of many of today's high-frequency energy processors. Designed to function as both a superior senior-to-graduate level textbook for electrical engineering courses and a valuable professional reference for practicing engineers, it provides students and engineers with a solid grasp of existing high-frequency technology, while acquainting them wit
Cycloidal Wave Energy Converter
Energy Technology Data Exchange (ETDEWEB)
Stefan G. Siegel, Ph.D.
2012-11-30
This program allowed further advancing the development of a novel type of wave energy converter, a Cycloidal Wave Energy Converter or CycWEC. A CycWEC consists of one or more hydrofoils rotating around a central shaft, and operates fully submerged beneath the water surface. It operates under feedback control sensing the incoming waves, and converts wave power to shaft power directly without any intermediate power take off system. Previous research consisting of numerical simulations and two dimensional small 1:300 scale wave flume experiments had indicated wave cancellation efficiencies beyond 95%. The present work was centered on construction and testing of a 1:10 scale model and conducting two testing campaigns in a three dimensional wave basin. These experiments allowed for the first time for direct measurement of electrical power generated as well as the interaction of the CycWEC in a three dimensional environment. The Atargis team successfully conducted two testing campaigns at the Texas A&M Offshore Technology Research Center and was able to demonstrate electricity generation. In addition, three dimensional wave diffraction results show the ability to achieve wave focusing, thus increasing the amount of wave power that can be extracted beyond what was expected from earlier two dimensional investigations. Numerical results showed wave cancellation efficiencies for irregular waves to be on par with results for regular waves over a wide range of wave lengths. Using the results from previous simulations and experiments a full scale prototype was designed and its performance in a North Atlantic wave climate of average 30kW/m of wave crest was estimated. A full scale WEC with a blade span of 150m will deliver a design power of 5MW at an estimated levelized cost of energy (LCOE) in the range of 10-17 US cents per kWh. Based on the new results achieved in the 1:10 scale experiments these estimates appear conservative and the likely performance at full scale will
Institute of Scientific and Technical Information of China (English)
梁双全; 李岚
2011-01-01
建立了三相电压型PWM变换器的数学模型,详细分析了PWM变换器电网电压定向控制的两种实现方式,并重点根据电网电压和线电压间的矢量关系,确定了双馈发电励磁系统网侧PWM变换器电网电压定向的实现方法.以TMS320F2812为主控制芯片,搭建了三相电压型PWM变换器控制实验所需的平台,设计了过零比较电路和相应的软件实现程序.实验结果验证了该电网电压定向控制方法的有效性和可行性.%A mathematical model of three-phases voltage PWM converter was established, two implementation methods of grid voltage orientation control of PWM converter were analyzed in details. According to vector relation of grid voltage and line voltage, an implementation method of grid voltage orientation of grid side PWM converter of doubly-fed power excitation system was determined. An experimental platform of three-phase voltage PWM converter was built by taking TMS320F2812 as main control chip, and zero-crossing comparator and software were designed. The experimental result indicated that the control method is correct and valid.
Bidirectional buck boost converter
Esser, Albert Andreas Maria
1998-03-31
A bidirectional buck boost converter and method of operating the same allows regulation of power flow between first and second voltage sources in which the voltage level at each source is subject to change and power flow is independent of relative voltage levels. In one embodiment, the converter is designed for hard switching while another embodiment implements soft switching of the switching devices. In both embodiments, first and second switching devices are serially coupled between a relatively positive terminal and a relatively negative terminal of a first voltage source with third and fourth switching devices serially coupled between a relatively positive terminal and a relatively negative terminal of a second voltage source. A free-wheeling diode is coupled, respectively, in parallel opposition with respective ones of the switching devices. An inductor is coupled between a junction of the first and second switching devices and a junction of the third and fourth switching devices. Gating pulses supplied by a gating circuit selectively enable operation of the switching devices for transferring power between the voltage sources. In the second embodiment, each switching device is shunted by a capacitor and the switching devices are operated when voltage across the device is substantially zero.
Gallium phosphide energy converters
Energy Technology Data Exchange (ETDEWEB)
Sims, P.E.; Dinetta, L.C.; Goetz, M.A.
1995-10-01
Gallium phosphide (GaP) energy converters may be successfully deployed to provide new mission capabilities for spacecraft. Betavoltaic power supplies based on the conversion of tritium beta decay to electricity using GaP energy converters can supply long term low-level power with high reliability. High temperature solar cells, also based on GaP, can be used in inward-bound missions greatly reducing the need for thermal dissipation. Results are presented for GaP direct conversion devices powered by Ni-63 and compared to the conversion of light emitted by tritiarated phosphors. Leakage currents as low as 1.2 x 10(exp {minus}17) A/sq cm have been measured and the temperature dependence of the reverse saturation current is found to have ideal behavior. Temperature dependent IV, QE, R(sub sh), and V(sub oc) results are also presented. These data are used to predict the high-temperature solar cell and betacell performance of GaP devices and suggest appropriate applications for the deployment of this technology.
Directory of Open Access Journals (Sweden)
Z.A. Jaffery
2012-10-01
Full Text Available The authors present the design, simulation and analysis of a single phase voltage source inverter using soft switching techniques. The performance of the inverter has been compared in terms of harmonic contents present in output voltage and current. The research works for a PWM inverter along with a LLCC filter has been investigated. This paper also investigated the performance of the same inverter with a feedback controller with a closed loop feedback path to maintain rated output voltage. This work is helpful for the inverter used in application where high quality ac wave is prime requirement
Directory of Open Access Journals (Sweden)
Ayse KOCALMIS BILHAN
2013-01-01
Full Text Available A space vector PWM method for a two level inverter is proposed in this paper. A two level inverter using space vector modulation strategy has been modeled and simulated with a passive R-L load. Photovoltaic cells are used as DC source for input of two-level inverter. Simulation results are presented for various operation conditions to verify the system model. In this paper, MATLAB/Simulink package program has been used for modeling and simulation of PV cells and two-level space vector pulse width modulation (SVPWM inverter.
Convertidor Matricial CA-CA Trifásico PWM: Simulación e Implementación
Ortega Gutiérrez, Daniel
2006-01-01
En el presente trabajo se estudian los principios básicos de un Convertidor Matricial (CM). Para ello se implementó un prototipo y se realizaron simulaciones previas en Matlab-Simulink. Se estudian los conceptos básicos para su operación así como las diferentes técnicas de modulación PWM utilizadas para su control. El CM es un convertidor CA-CA trifásico que se considera de la nueva generación de variadores de velocidad integrados, dado que no requiere de componentes qu...
Manufacturing method of photoelectric converter
Energy Technology Data Exchange (ETDEWEB)
Yamazaki, Shunpei; Suzuki, Kunio; Fukada, Takeshi; Kanehana, Mikio
1987-06-25
This is a photoelectric converter wherein a photoelectromotive force is generated by utilizing the shorter wavelength side by the 1st converter and by utilizing the longer wavelength side by the 2nd converter; as a whole, wider wavelength range of light can be converted into electricity. In the 1st. converter, an electrode on the side of semi-incident surface is made transparent as well as an electrode equipped on the back of a non-mono-crystalline semiconductor. Light which passed this is introduced into the 2nd converter to generate an electromotive force. This invention especially relates with a method of forming this 2nd converter. In preparing I-type non-mono-crystalline semiconductor among the semiconductors having PIN junction, PCVD method is used by means of ECR (Electron Cyclotron Resonance) by using a hydrogen- or halogen- added Si-semiconductor instead of using expensive Ge, etc, which are common in the conventional method. (3 figs)
Institute of Scientific and Technical Information of China (English)
王宝忠; 孙健涛; 要丹
2011-01-01
Exactly detecting of rotor position was required during the control of brushless DC motor, and back EMF detecting method was a simple, effective way to detect the position-sensorless rotor position of brushless DC motor. A back EMF detecting method based on the H_PWM-L_PWM modulation model by analyzing the freewheeling condition of a non-conducted phase of this model was raised. This back EMF detecting method needed not to detect the center voltage of the three-phase winding, and gained a two times of the back EMF of a non-conducted phase. The simulation under MATLAB software environment and experimental results showed that this method had good performance in low speed control of brushless DC motor.%无刷电机的控制需要准确检测到转子的位置,反电动势法是检测无位置传感器无刷直流电机转子位置的一种简单、有效的方法.采用二相导通星形三相六状态的控制模式,通过分析在H_PWM-L PWM调制方式下不导通相的续流情况,提出了基于该调制方式的反电动势检测方法.该反电动势检测法不需要检测三相绕组中点电压,所获得的是不导通相的两倍的反电动势.MATLAB仿真和试验结果证明,该检测方法具有良好的低速控制性能.
Directory of Open Access Journals (Sweden)
Abdelkrim Thameur
2015-01-01
Full Text Available This paper proposes a regulation method of back-to-back connected two-level PWM rectifier-five-level Voltage Source Inverter (VSI in order to reduce the torque ripple in induction motor. First part is dedicated to the presentation of the feedback control of two-level PWM rectifier. In the second part, five-level Neutral Point Clamped (NPC voltage source inverter balancing DC bus algorithm is presented. A theoretical analysis with a complete simulation of the system is presented to prove the excellent performance of the proposed technique.
PWM调制下无刷直流电机的转矩脉动抑制%Torque Ripple Reduction of Brushless DC Motors by PWM Modes
Institute of Scientific and Technical Information of China (English)
孟光伟; 李槐树; 熊浩
2011-01-01
分析无刷直流电机在PWM调制下稳态时的换相过程,通过在换相期间的PWM调制来实现高、低速条件下的换相转矩脉动补偿控制,确定了保持换相期间非换相相电流幅值不变的换相时间.分析PWM调制方式对三相六状态二二导通无刷直流电机控制系统的影响,提出了在PWM-ON-PWM调制方式下的换相转矩脉动补偿控制,不但能够完全消除非换相期间由于关断相出现电流而引起的电磁转矩脉动,而且能够完全补偿由于换相而引起的转矩脉动,实现电机在低速和高速时的无转矩脉动控制.%The steady commutation process of brushless DC motor by PWM modes was analyzed, and realized phase conversion torque ripple compensation control under both low speed and high speed operation by PWM control in commutation period,and confirmed commutation time to hold amplitude of current in commutation period. The effect by PWM modes on a three-phase six-state 120°conduction brushless DC motor was analyzed,and proposed torque ripple compensation control in PWM_ON_PWM mode, which can not only entirely eliminate torque ripple resulted from the current emerging in the turn-off phase during non-commutation period but also compensate torque ripple caused by the commutation current during commutation period. The torque ripple can be effectively reduced under both low speed and high speed operation using torque ripple compensation control in PWM ON PWM mode.
Wester, Gene W. (Inventor)
1980-01-01
A unity power factor converter capable of effecting either inversion (dc-to-dc) or rectification (ac-to-dc), and capable of providing bilateral power control from a DC source (or load) through an AC transmission line to a DC load (or source) for power flow in either direction, is comprised of comparators for comparing the AC current i with an AC signal i.sub.ref (or its phase inversion) derived from the AC ports to generate control signals to operate a switch control circuit for high speed switching to shape the AC current waveform to a sine waveform, and synchronize it in phase and frequency with the AC voltage at the AC ports, by selectively switching the connections to a series inductor as required to increase or decrease the current i.
Electromagnetic wave energy converter
Bailey, R. L. (Inventor)
1973-01-01
Electromagnetic wave energy is converted into electric power with an array of mutually insulated electromagnetic wave absorber elements each responsive to an electric field component of the wave as it impinges thereon. Each element includes a portion tapered in the direction of wave propagation to provide a relatively wideband response spectrum. Each element includes an output for deriving a voltage replica of the electric field variations intercepted by it. Adjacent elements are positioned relative to each other so that an electric field subsists between adjacent elements in response to the impinging wave. The electric field results in a voltage difference between adjacent elements that is fed to a rectifier to derive dc output power.
PWM型DC/DC变换器的Washout滤波器混沌控制方法%Controlling Chaos in PWM DC/DC Converter with Washout Filter
Institute of Scientific and Technical Information of China (English)
汪剑鸣; 许镇琳
2005-01-01
研究如何利用Washout滤波器控制技术来控制PWM型DC/DC变换器中的混沌现象.首先分析了利用Ott-Grebogi-Yorke(OGY)方法对DC/DC变换器进行混沌控制存在的不足,然后以Henon系统为例说明了如何利用Washout滤波器进行混沌控制.最后,应用Washout滤波器对两种采用不同控制策略的DC/DC变换器实施控制,将其从混沌状态控制到周期状态.理论分析和计算机仿真表明,该控制技术不但可以很好用于DC/DC变换器中的混沌控制,而且能够克服OGY方法的不足.
Development of PWM Control Technology in Multilevel Converters%多电平变换器PWM控制技术发展现状
Institute of Scientific and Technical Information of China (English)
李永东; 高跃
2006-01-01
多电平PWM控制技术一直是多电平变换器研究的核心内容之一.基于传统两电平PWM技术研究的经验,经过近十几年的发展,多电平PWM控制技术已形成了几类不同的实现方法,同时新的控制方法还在涌现.与两电平相比,多电平PWM方法需要面对一些新出现的问题,并拓展PWM控制的内涵,进而形成新的PWM控制思路.按照目前的发展情况,多电平PWM控制方法一般有多电平载波PWM方法、多电平空间矢量PWM方法,以及其他优化的PWM方法.本文对已有多电平PWM控制技术进行了归纳和分析,最后指出多电平空间矢量法和载波调制法在一定条件下具有内在的一致性.
Integrated power electronic converters and digital control
Emadi, Ali; Nie, Zhong
2009-01-01
Non-isolated DC-DC ConvertersBuck ConverterBoost ConverterBuck-Boost ConverterIsolated DC-DC ConvertersFlyback ConverterForward ConverterPush-Pull ConverterFull-Bridge ConverterHalf-Bridge ConverterPower Factor CorrectionConcept of PFCGeneral Classification of PFC CircuitsHigh Switching Frequency Topologies for PFCApplication of PFC in Advanced Motor DrivesIntegrated Switched-Mode Power ConvertersSwitched-Mode Power SuppliesThe Concept of Integrated ConverterDefinition of Integrated Switched-Mode Power Supplies (ISMPS)Boost-Type Integrated TopologiesGeneral Structure of Boost-Type Integrated T
Directory of Open Access Journals (Sweden)
Zamratul Fuadi
2014-03-01
Full Text Available Inverter merupakan perangkat elektronika daya yang berfungsi mengonversi sumber searah menjadi bolak-balik. Full bridge inverter adalah satu jenisnya yang mampu menghasilkan tegangan tiga tingkat jika menggunakan teknik modulasi unipolar. Penambahan sirkuit dual buck converter pada full bridge inverter mampu menghasilkan tegangan dalam lima tingkat. Dua saklar pada rangkaian dual buck converter switching pada frekuensi tinggi 20 kHz, sedangkan empat saklar pada full bridge inverter switching pada frekuensi rendah 50 Hz. Teknik modulasi in phase disposition PWM (PDPWM digunakan untuk mengatur penyalaan saklar dual buck converter. Keluaran inverter lima tingkat dibandingkan dengan tiga tingkat. Total harmonic distortion tegangan (THDV dan arus (THDi inverter lima tingkat bernilai 23.2281 % dan 23.0975 %, sedangkan inverter tiga tingkat sebesar 51.9302 % dan52.2458 %. Ketika daya 1004.08 watt disumbangkan ke jala-jala, inverter lima tingkat menghasilkan power factor senilai 0.99 dan THDi 4.1 %. Pada sumbangan daya yang sama, inverter tiga tingkat menghasilkan power factor sebesar 0.919 dan THDi bernilai 45.64 %.
Energy Technology Data Exchange (ETDEWEB)
Machado, Ricardo Q.; Pomilio, Jose A. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Engenharia Eletrica e de Computacao], e-mail: ricardom@dsce.fee.unicamp.br; Buso, Simone [Universidade de Padova, Padua (Italy). Dept. de Engenharia da Informacao], e-mail: simone.buso@dei.unipd.it
2004-07-01
This paper describes a line-interactive single-phase to three-phase converter. The typical application is in rural areas supplied by the single-wire with earth return. The traditional objective of feeding a three-phase induction motor is not anymore the main concern for such conversion. Due to the evolution of the agro business, some of the local load (as electronic power converters, computers, communication equipment, etc.) requires high quality power, intended as sinusoidal, symmetrical and balanced three-phase voltage. Additionally, to maximize the power got from the feeder, the system provides a unitary power factor to the feeder. A three-phase PWM converter is used for this purpose. The power converter does not process all the load power, as in the conventional solutions, but only the fraction necessary to regulate the three-phase bus voltage. The control strategy, design highlights and experimental results are presented. (author)
Zhang, Jiyan; Dong, Jinxin
2016-09-01
The color discrimination is a powerful tool for detection of eye diseases, and it is is necessary to produce different kinds of color rapidly and precisely for testing color discrimination thresholds of human eyes. Three channels' pulse-width modulation (PWM) and light-mixing technology is a new way to mixing color, and a new measurement method for color discrimination thresholds of human eyes based on PWM light-mix technology can generate kinds of color stimuli. In this study, 5 youth volunteers were measured via this equipment after the test for the stability of the device's illumination and chrominance. Though the theory of Macadam ellipses and the interleaved staircase method, a psychophysical experiment was made to study the color discrimination threshold of the human eyes around a basic color center. By analyzing the data of the chromatic ellipse and the color discrimination threshold, the result shows that each color is not uniform in a single color region and the color difference threshold of normal human is around the third Macadam ellipses. The experimental results show that the repeatability and accuracy of the observer can meet the accuracy requirements of the relevant experiments, and the data is reliable and effective, which means the measurement method is an effective way to measure the color discrimination thresholds of human visual system.
Nanostructure Neutron Converter Layer Development
Park, Cheol (Inventor); Sauti, Godfrey (Inventor); Kang, Jin Ho (Inventor); Lowther, Sharon E. (Inventor); Thibeault, Sheila A. (Inventor); Bryant, Robert G. (Inventor)
2016-01-01
Methods for making a neutron converter layer are provided. The various embodiment methods enable the formation of a single layer neutron converter material. The single layer neutron converter material formed according to the various embodiments may have a high neutron absorption cross section, tailored resistivity providing a good electric field penetration with submicron particles, and a high secondary electron emission coefficient. In an embodiment method a neutron converter layer may be formed by sequential supercritical fluid metallization of a porous nanostructure aerogel or polyimide film. In another embodiment method a neutron converter layer may be formed by simultaneous supercritical fluid metallization of a porous nanostructure aerogel or polyimide film. In a further embodiment method a neutron converter layer may be formed by in-situ metalized aerogel nanostructure development.
Impedance source power electronic converters
Liu, Yushan; Ge, Baoming; Blaabjerg, Frede; Ellabban, Omar; Loh, Poh Chiang
2016-01-01
Impedance Source Power Electronic Converters brings together state of the art knowledge and cutting edge techniques in various stages of research related to the ever more popular impedance source converters/inverters. Significant research efforts are underway to develop commercially viable and technically feasible, efficient and reliable power converters for renewable energy, electric transportation and for various industrial applications. This book provides a detailed understanding of the concepts, designs, controls, and application demonstrations of the impedance source converters/inverters. Key features: Comprehensive analysis of the impedance source converter/inverter topologies, including typical topologies and derived topologies. Fully explains the design and control techniques of impedance source converters/inverters, including hardware design and control parameter design for corresponding control methods. Presents the latest power conversion solutions that aim to advance the role of pow...
A thermochemical energy converter
Energy Technology Data Exchange (ETDEWEB)
Toyeguti, K.; Indzima, T.
1982-08-09
Mercury is used as the active mass of the anode in the converter and 0/sub 2/ is used as the active cathode material. The reaction of Mercury + 1/2 0/sub 2/-Hg0 occurs with a discharge. With heating to 500/sup 0/C the regeneration of the Mercury, Hg0 yields Mercury + 1/2 0/sub 2/, occurs. The device for performing the thermochenical conversion of energy contains an element body, an oxygen chamber, an oxygen electrode, a chamber with an alkaline liquid electrolyte, a separator, an auxiliary separator, an electrode and a chamber with the Mercury. The thermochemical reaction occurs in the reactor to which the Hg0 is transported along a pipe which has a refrigerator and a valve. The Mercury is fed into the element from a reservoir. The Mercury reduced in the reactor and in a reaction tower is fed into it through a closed cycle. The bellows is connected with the reactor by a pipe with a refrigerator. Through it the 0/sub 2/ goes in a closed cycle to the chamber. The current forming reactions are Hg + 20H-anion yields Hg0 + H/sub 2/0 + 2e and 1/2 0/sub 2/ + H/sub 2/0 + 2e yields 20H-anion. The voltage on the outleads of the element is approximately 0.3 volts.
Directory of Open Access Journals (Sweden)
SRDIC, S.
2015-08-01
Full Text Available This paper presents a buck-boost converter which is modified to utilize new 600 V gallium nitride (GaN power semiconductor devices in an application requiring 1200 V devices. The presented buck-boost converter is used as a part of a dc/dc stage in an all-GaN photovoltaic (PV inverter and it provides a negative voltage for the 3-level neutral-point-clamped (NPC PWM inverter which is connected to the utility grid. Since in this application the transistor and the diode of the buck-boost converter need to block the sum of the PV string voltage (which is normally in the range from 150 to 350 V and the dc bus voltage (which is in the order of 400 V, the 1200 V devices or series connection of 600 V devices need to be employed. Currently, 1200 V GaN power semiconductor devices are not commercially available. Therefore, the standard buck-boost converter is modified to enable the use of 600 V GaN devices in this particular application. Based on the proposed converter topology, a PSpice simulation model and a 600 W converter prototype were developed. Both simulation and experimental results show successful operation of the converter.
An Integrated Inductor for Parallel Interleaved VSCs and PWM Schemes for Flux Minimization
DEFF Research Database (Denmark)
Gohil, Ghanshyamsinh Vijaysinh; Bede, Lorand; Teodorescu, Remus;
2015-01-01
The interleaving of the carrier signals of the parallel Voltage Source Converters (VSCs) can reduce the harmonic content in the resultant switched output voltages. As a result, the size of the line filter inductor can be reduced. However, in addition to the line filter, an inductive filter is oft...
Proposed electromagnetic wave energy converter
Bailey, R. L.
1973-01-01
Device converts wave energy into electric power through array of insulated absorber elements responsive to field of impinging electromagnetic radiation. Device could also serve as solar energy converter that is potentially less expensive and fragile than solar cells, yet substantially more efficient.
Impedance Source Power Electronic Converters
DEFF Research Database (Denmark)
Liu, Yushan; Abu-Rub, Haitham; Ge, Baoming
Impedance Source Power Electronic Converters brings together state of the art knowledge and cutting edge techniques in various stages of research related to the ever more popular impedance source converters/inverters. Significant research efforts are underway to develop commercially viable...... and technically feasible, efficient and reliable power converters for renewable energy, electric transportation and for various industrial applications. This book provides a detailed understanding of the concepts, designs, controls, and application demonstrations of the impedance source converters/inverters. Key...... control methods. Presents the latest power conversion solutions that aim to advance the role of power electronics into industries and sustainable energy conversion systems. Compares impedance source converter/inverter applications in renewable energy power generation and electric vehicles as well...
Institute of Scientific and Technical Information of China (English)
辛德环
2011-01-01
分析了基于零阶保持器( ZOH)原理的传统数模转换器(DAC)和线性功率放大器的优点和缺点,以及基于脉冲宽度调制( PWM)技术的D类功率放大器在节能方面的优势和性能上的不足.详细分析了数字PWM调制器( PWM- DAC)的基本原理并推导其算法,进行了性能仿真分析计算,证明了用PWM-DAC同时完成数模转换和PWM调制的可行性,结果表明,这种转换性能优良.