Showing papers on "PWM rectifier published in 2012"

Robust Model Predictive Current Control of Three-Phase Voltage Source PWM Rectifier With Online Disturbance Observation

Abstract: This paper presents a robust model predictive current controller with a disturbance observer (DO-MPC) for three-phase voltage source PWM rectifier. The new algorithm is operated with constant switching frequency (CF-MPC). In order to minimize instantaneous d- and q-axes current errors in every sampling period, CF-MPC is implemented by selecting appropriate voltage vector sequence and calculating duty cycles. The fundamental of this algorithm is discussed and the instantaneous variation rates of d- and q-axes currents are deduced when each converter voltage vector is applied in six different sectors. A Luenberger observer is constructed for parameter mismatch and model uncertainty which affect the performance of the MPC. The gains of the disturbance observer are determined by root-locus analysis. Moreover, the stability of the disturbance observer is analyzed when there are errors in the inductor filter parameter. The proposed method has an inherent rapid dynamic response as a result of the MPC controller, as well as robust control performance with respect to the disturbance due to use of the combined observation algorithm. Simulation and experimental results on a 1.1 kW VSR are conducted to validate the effectiveness of the proposed solution.

Switched Control of Three-Phase Voltage Source PWM Rectifier Under a Wide-Range Rapidly Varying Active Load

Abstract: The aircraft electric actuator is one of the most important kind of electric loads of the future more electric aircraft. The power characteristic of an aircraft electric actuator possesses the feature of rapidly varying in a wide range, and it shows constant power load nature in the small-signal sense. In this paper, a novel dc-bus voltage switched control method of three-phase voltage source pulsewidth-modulated rectifiers (VSRs), which aims to solve the problem of flexible voltage regulating under dynamic loads, is proposed under a cascade structure in rotating synchronous coordinates d-q . Several linear controllers are designed on different operating points of the VSR, and one controller is implemented on the VSR system according to certain switching law. The stability of the proposed control approach is guaranteed based on the common Lyapunov function method. Simulation and experimental results show that the desired control performance is obtained in the voltage regulating of a VSR with wide-range rapidly varying load. Compared with a classical PI controller, the derived switched controller can achieve a considerable reduction in the dip of the dc-bus voltage and a certain reduction in the overshoot of the dc-bus voltage during the control process under an aircraft electric actuator load.

A matrix converter-based topology for high power electric vehicle battery charging and V2G application

Abstract: In this paper, a new three-phase converter topology based on a 3x1 matrix converter (MC) is proposed for Plug-in Hybrid or Battery (PHEV/BEV) electric transit buses. In the proposed approach, the MC directly converts the low frequency (50/60 Hz, three-phase) input to a high frequency (6 kHz, one-phase) AC output without a dc-link. The output of the matrix converter (MC) is then processed by a PWM rectifier via a high frequency (HF) isolation transformer to interface with the EV battery system. The MC-PWM rectifier system is made to operate like a dual active bridge (DAB), facilitating bi-directional power flow suitable for charging and Vehicle-to-Grid (V2G) application. The digital control of the system ensures that the input currents are of high quality under both charging and discharging operations. Due to the absence of dc-link electrolytic capacitors, power density of the proposed rectifier is expected to be higher. Analysis, design example and extended simulation results are presented for a three-phase 208 V LL , 50kW charger.

Smart charger for electric vehicles with power quality compensator on single-phase three-wire distribution feeders

Abstract: In this paper, we propose a smart charger for electric vehicles (EVs) with a power quality compensator. The proposed smart charger consists of four-leg IGBTs. Three legs are used for a single-phase full-bridge-based PWM rectifier, which converts power from ac to dc during the battery-charging operation, or from dc to ac during the battery-discharging operation. This PWM rectifier can compensate reactive and unbalanced active currents on single-phase three-wire distribution systems because the third leg is connected to the neutral line of single-phase three-wire distribution feeders. The fourth leg is used as a bidirectional dc-dc converter for battery-charging and discharging operations. The three-leg PWM rectifier uses only constant dc-capacitor voltage control, which is commonly used in active power line conditioners. Thus, the authors have developed the simplest possible control method for a single-phase power quality compensator. The basic principle of the proposed smart charger is discussed in detail, and then confirmed by digital computer simulation using PSIM software. A prototype experimental model is constructed and tested. Experimental results demonstrate that balanced source currents are obtained on the secondary side of the pole-mounted distribution transformer for battery-charging and discharging operations.

MATLAB and SIMULINK for Engineers

Abstract: PREFACE INTRODUCTION TO MATLAB PROGRAMMING 1.1 MATLAB INTRODUCTION 1.2 GETTING STARTED: STEP 1 1.3 GETTING STARTED: STEP 2 1.4 GETTING STARTED: STEP 3 1.5 GETTING STARTED: STEP 4 1.6 SUMMARY KEY TERMS EXERCISES FUNDAMENTALS OF MATLAB PROGRAMMING 2.1 VARIABLES 2.2 ARRAYS 2.3 MATRICES 2.4 MATLAB OPERATORS 2.4.1 ARITHMETIC OPERATORS 2.4.2 RELATIONAL OPERATORS 2.4.3 LOGICAL OPERATORS 2.4.4 OPERATORS PRECEDENCE'S 2.5 MATLAB GRAPHICS 2.5.1 PLOTS 2.5.2 SUB PLOTS 2.5.3 OTHER TYPES OF PLOTS 2.5.3.1 MULTIPLE PLOTS IN A GRAPH 2.5.3.2 LOGARITHMIC PLOTS A GRAPH 2.5.3.3 VARIOUS TYPES OF TWO DIMENSIONAL PLOTS 2.5.3.4 PLOTTING COMPLEX NUMBERSENSIONAL PLOTS 2.5.3.5 THREE DIMENSIONAL PLOTS 2.6 BRANCHING & LOOPING FUNCTIONS 2.6.1 BRANCHING FUNCTIONS 2.6.1.1 IF FUNCTION 2.6.1.2 SWITCH FUNCTION 2.6.1.3 TRY/CATCH FUNCTION 2.6.1.4 THE ERROR FUNCTION 2.6.2 LOOPING FUNCTIONS 2.6.2.1 FOR FUNCTION 2.6.2.2 WHILE FUNCTION 2.6.2.3 BREAK & CONTINUE FUNCTIONS 2.7 MISCELLANEOUS FUNCTIONS 2.7.1 STRING FUNCTIONS 2.7.2 INPUT/OUTPUT FUNCTIONS 2.7.2.1 INPUT FUNCTIONS 2.7.2.2 OUTPUT FUNCTIONS 2.8 PROGRAMMING A THREE PHASE SOURCE 2.9 ADDITIONAL PROGRAMS 2.10 SUMMARY KEY TERMS EXERCISES FUNDAMENTALS OF SIMULINK 3.1 INTRODUCTION 3.2 APPLICATION BLOCK SETS 3.3 APPLICATION TOOLBOXES 3.3.1 POWER SYSTEM TOOLBOX 3.3.2 CONTROL SYSTEM TOOLBOX 3.3.3 THE SIGNAL PROCESSING TOOLBOX 3.3.4 THE SYMBOLIC MATH TOOLBOX 3.4 CONSTRUCTING A SIMULINK MODEL 3.5 TAKING VARIABLES FROM MATLAB 3.6 RUNNING & ANALYZING A SIMULINK MODEL 3.7 DISCRETE TIME SYSTEMS 3.8 SUMMARY KEY TERMS EXERCISES BASIC ELECTRICAL ENGINEERING APPLICATIONS 4.1 ELEMENTARY DEFINITIONS 4.2 PLOTTING OF SINE, COSINE, TRIANGULAR, WAVEFORMS 4.3 ESTIMATION OF AVERAGE, RMS & PEAK VALUES 4.4 OHM'S LAW VERIFICATION 4.5 DEPENDENT & INDEPENDENT VOLTAGE & CURRENT SOURCES 4.6 RLC SERIES PARALLEL CIRCUITS SIMULATION 4.7 RESONANCE PHENOMENON SIMULATION 4.8 SIMULATIONS OF NETWORK THEOREMS 4.8.1 SUPERPOSITION THEOREM 4.8.2 RECIPROCITY THEOREM 4.8.3 THEVENIN'S THEOREM 4.8.4 NORTON'S THEOREM 4.8.5 MAXIMUM POWER TRANSFER THEOREM FOR AC & DC NETWORKS 4.9 MEASUREMENT OF POWER 4.10 THREE PHASE STAR/DELTA SOURCES SIMULATION 4.11 THREE PHASE STAR/DELTA LOAD SIMULATION 4.12 TRANSFORMERS: SINGLE & THREE PHASE 4.13 SIMULATION PROJECTS 4.13 SUMMARY KEY TERMS EXERCISES SIMULATION OF RECTIFIERS 5.1 BASIC TERMS & DEFINITIONS 5.2 POWER ELECTRONIC SWITCHES 5.3 UNCONTROLLED RECTIFIERS 5.4 CONTROLLED RECTIFIERS 5.5 HALF WAVE RECTIFIERS 5.6 FULL WAVE RECTIFIERS 5.7 ANALYSIS OF RECTIFIERS FOR VARIOUS LOADS 5.10 SIMULATION PROJECTS 5.11 SUMMARY KEY TERMS EXERCISES SIMULATION OF INVERTERS 6.1 INTRODUCTION 6.2 BASIC TERMS & DEFINITIONS 6.3 SINGLE PHASE HALF WAVE 6.4 SINGLE PHASE FULL WAVE 6.5 SINGLE PHASE FULL WAVE 6.6 DC TO AC CONVERTERS FOR VARIOUS LOADS 6.7 THREE-PHASE 120 ?& 180 ? CONDUCTION INVERTERS 6.8 ANALYSIS OF DUAL CONVERTERS 6.9 SIMULATION PROJECTS 6.10 SUMMARY KEY TERMS EXERCISES SIMULATION OF CHOPPERS & CYCLOCONVERTERS 7.1 INTRODUCTION 7.2 ELEMENTARY DEFINITIONS 7.3 ANALYSIS OF BUCK CONVERTER 7.4 ANALYSIS OF BOOST CONVERTER 7.5 ANALYSIS OF BUCK-BOOST CONVERTER 7.6 ANALYSIS OF FOUR QUADRANT CHOPPER 7.7 ANALYSIS OF STEP UP CYCLOCONVERTER 7.8 ANALYSIS OF STEP DOWN CYCLOCONVERTER 7.9 SUMMARY KEY TERMS EXERCISES APPLICATIONS TO POWER SYSTEM 8.1 INTRODUCTION 8.2 SIMULATION OF A THREE PHASE POWER SYSTEM 8.3 ANALYSIS OF TRANSMISSION SYSTEM UNDER DIFFERENT FAULTS 8.3.1 VOLTAGE UNBALANCE 8.3.2 VOLTAGE SAG/SWELL 8.3.3 LOAD UNBALANCE 8.3.4 SHORT CIRCUIT/OPEN CIRCUIT 8.3.5 HARMONICS 8.4 LOAD FLOW STUDIES 8.5 POWER SYSTEM STABILITY 8.6 LOAD FREQUENCY CONTROL 8.7 SIMULATION PROJECTS 8.8 SUMMARY KEY TERMS EXERCISES 9.2 APPLICATIONS IN ELECTRICAL MACHINES 9.2.1 SIMULATION OF INDUCTION MOTOR 9.2.2 SIMULATION OF SYNCHRONOUS MOTOR 9.2.3 SIMULATION OF DC SERIES MOTOR 9.2.4 SIMULATION OF DC SHUNT MOTOR 9.3 MOTOR DRIVES 9.4 APPLICATIONS IN CONTROL SYSTEM ENGINEERING 9.4.1 ANALYSIS OF FIRST ORDER SYSTEM 9.4.2 ANALYSIS OF SECOND ORDER SYSTEM 9.4.3 ANALYSIS OF FEEDBACK SYSTEM 9.4.4 BODE PLOT ANALYSIS 9.4.5 STATE VARIABLE MODEL 9.4.6 PERFORMANCE OF FEEDBACK CONTROL SYSTEM 9.5 SUMMARY KEY TERMS EXERCISES OTHER APPLICATIONS 10.1 APPLICATIONS IN COMMUNICATION SYSTEMS 10.1.1 SIMULATION OF AM WAVEFORM 10.1.2 SIMULATION OF FM WAVEFORM 10.1.3 SIMULATION OF PM WAVEFORM 10.1.4 SIMULATION OF DIGITAL TRANSMITTING WAVEFORMS 10.2 APPLICATIONS IN COMPUTER ENGINEERING 10.2.1 INTRODUCTION 10.2.2 ANIMATIONS 10.2.3 SPECIAL FUNCTIONS 10.2.4 RECURSIONS 10.2.5 COMPUTER ARTS 10.3 APPLICATIONS IN MECHANICAL ENGINEERING 10.3.1 INTRODUCTION 10.3.2 MODELLING OF MECHANICAL SYSTEMS 10.3.3 MASS SPRING SYSTEM 10.3.4 OTHER APPLICATIONS 10.4 VARIOUS SIMULATION PROJECTS 10.5 SUMMARY KEY TERMS EXERCISES RECENT DEVELOPMENTS 11.1 INTRODUCTION 11.2 INTRODUCTION TO MATRIX CONVERTER 11.3 BASICS OF MATRIX CONVERTER 11.3.1 BI-DIRECTIONAL SWITCHES 11.3.2 COMMUTATION PROBLEM 10.3.2.1 FOUR STEP CURRENT COMMUTATION 11.3.3 MODULATION TECHNIQUES 11.3.3.1 VENTURINI METHOD 11.3.3.2 SPACE VECTOR MODULATION 11.3.3.3MIN-MID-MAX MODULATION 11.4 PROGRAMMING AND SIMULATIONS OF MATRIX CONVERTERS 11.5 INTRODUCTION TO PWM RECTIFIERS 11.5.1 CONTROL TECHNIQUES 11.5.2 SIMULATION OF PWM RECTIFIER 11.6 SUMMARY KEY TERMS EXERCISES REFERENCES BIBLIOGRAPHY INDEX

A Novel DC-Side Zero-Voltage Switching (ZVS) Three-Phase Boost PWM Rectifier Controlled by an Improved SVM Method

Abstract: A novel active clamping zero-voltage switching three-phase boost pulsewidth modulation (PWM) rectifier is analyzed and a modified minimum-loss space vector modulation (SVM) strategy suitable for the novel zero-voltage switching (ZVS) rectifier is proposed in this paper. The topology of the novel ZVS rectifier only adds one auxiliary active switch, one resonant inductor, and one clamping capacitor to the traditional hard-switched three-phase boost PWM rectifier. With the proposed SVM strategy, the novel ZVS rectifier can achieve ZVS for all the main and auxiliary switches. In addition, the antiparallel diodes can be turned OFF softly, so the reverse recovery current is eliminated. Besides, the voltage stress of all the switches is equal to the dc-link voltage. The operation principle and soft-switching condition of the novel ZVS rectifier are analyzed. The design guidelines of the soft switched circuit parameters are described in detail. A DSP controlled 30 kW prototype is implemented to verify the theory.

An investigation of minimum DC-link capacitance in PWM rectifier-inverter systems considering control methods

Abstract: In this paper, minimum DC-link capacitance in PWM rectifier-inverter systems is investigated. Reduction of DC-link capacitor is one of the most effective issues to realize high power-density PWM rectifier-inverter systems. For the extreme reduction of the DC-link capacitor, the minimum required capacitance should be clarified theoretically, and the improved control method should be developed. Firstly, the calculation method of DC-link voltage variation of the PWM rectifier-inverter systems at a stepwise change in the output power is proposed. Next, based on the proposed calculation method of the DC-link voltage variation and the constraint conditions determined by parameters of the PWM rectifier, the calculation method of the minimum required DC link capacitance at a stepwise change in the output power is proposed. Then, a feed-forward controller based on the output power of the inverter is proposed and the least necessary capacitance is clarified.

A unit power factor DC fast charger for electric vehicle charging station

Abstract: Widely applications of electric vehicle rely on popularization of charging station. With the increase in the number of charging station, the problem of grid pollution becomes worse and worse, and the charging hours must be decreased to raise the utilization rate of electric vehicle. This article proposes a novel unit power factor DC fast charger for electric vehicle charging stations. This DC fast charger, mainly used in fast-charging station, includes two modules: the input module is three-phase PWM rectifier and the output module is the phase-shift full-bridge converter. The two modules are controlled by only one DSP - TMS320F2812. The three-phase PWM rectifier overcomes traditional rectifier's shortcomings of low power factor and large harmonic, and is higher power than three-phase one-switch or two-switch power factor correction circuit. The phase-shift full-bridge converter is the isolated high-frequency DC-DC converter, and apt to be used in high power situation. Furthermore, the volume and weight of the proposed charger are decreased than conventional converter with grid-frequency transformer. A prototype of 10 kW Charger is constructed. The experimental results show that the novel DC fast charger has excellent electrical characteristics, and it can be applied to the electric vehicle charging stations.

Series compensated open-winding PM generator wind generation system

Abstract: This paper presents a new wind power generation system utilizing an open-winding permanent magnet synchronous generator (PMSG). A diode rectifier is used for the major portion of power conversion process. In addition, the proposed system controls the generated power by using an auxiliary voltage source inverter located at the neutral of the generator. The VA rating of the auxiliary inverter is only a fraction of the system rated power. Compared to wind power systems utilizing a PWM rectifier or diode rectifier having a DC/DC boost converter, the converter cost can be considerably reduced. In addition, the generator underutilization issue in a conventional diode rectifier fed wind power system can also be solved.

Hybrid parallel type high-voltage direct current traction power supply current transformer and control method thereof

Abstract: The invention relates to a hybrid parallel type high-voltage direct current traction power supply current transformer and a control method thereof The hybrid parallel type high-voltage direct current traction power supply current transformer is characterized by comprising a set of pulse width modulation (PWM) rectifier units and a set of diode rectifier units, wherein both an input end of the PWM rectifier units and an input end of the diode rectifier units are connected with an alternating current electric network, and an output end of the PWM rectifier units and an output end of the diode rectifier units are connected in parallel to realize high-voltage direct current output Because the PWM rectifier units and the diode rectifier units are connected in series, the direct current output voltage of the entire current transformer is improved, the power supply distance is prolonged, and the contact net loss is reduced Meanwhile, equipment investment is reduced, and the reliability of a system is improved The hybrid parallel type high-voltage direct current traction power supply current transformer and the control method thereof can be widely applied to urban railway transit traction power supply systems

High performance PWM converter control based PMSG for variable speed wind turbine

Abstract: This paper describes the modeling and control of a variable speed wind turbine system for medium power based Permanent Magnet Synchronous Generator (PMSG) which feeds an AC power grid. For that, two Pulse Width Modulated (PWM) voltage converters are connected back to back between the stator terminals of the PMSG and the utility grid via a common DC link, a mathematical modeling of the wind energy conversion system is developed, a distributed generation based on standalone wind energy conversion system (WECS) using a variable speed PMSG is proposed with the Hysteresis Band Current Control (HBCC), Voltage oriented control (VOC) and Flux Oriented Control (FOC). The goal in controlling system is to ameliorate the generated energy quality by regulating DC-link voltage U dc to follow reference value Udc ref . The validity of the developed unified model and the feasibility of the proposed control strategies are all confirmed by the simulated results using SIMULINK/MATLAB software programmes.

Simulation and analysis of a variable speed permanent magnet synchronous generator with flux weakening control

Abstract: Permanent magnet synchronous generator (PMSG) is often linked to a PWM rectifier in order to provide a dc power supply. When such a system is used for variable speed applications, it is desirable to extend the operation speed range. Since the induced voltage of the PMSG increases with the speed, it is proposed in this paper to utilize flux weakening control to restrict the PMSG output voltage at high speed, and consequently increase the maximum operation speed. Implementation and analytical model of the flux weakening control are described, and analysis results obtained in the Matlab/Simulink environment are presented, validating the feasibility of the proposed control strategy.

Start-Up Current Control Method for Three-Phase PWM Rectifiers with a Low Initial DC-Link Voltage

Abstract: When a PWM rectifier has a low DC-link voltage during startup, the output voltage vector cannot be high enough to regulate the input current. This lack of a PWM rectifier output voltage vector can cause an unregulated inrush current when the rectifier operation starts. This paper presents a PWM rectifier start-up current control algorithm for when it starts operation with a lower DC-link voltage than unloaded condition case. To avoid the unregulated inrush current caused by a lack of DC-link voltage, the proposed control scheme regulates the one phase current with one switch chopping and it generates the current command considering the uncontrolled current magnitude information, which is calculated in advance. Simulation and experiment results support the validity of the proposed method.

Study and control of 5-level PWM rectifier-5-level NPC active power filter cascade using feedback control and redundant vectors

Abstract: The purpose of this paper is to develop a control and regulation method for the input DC voltages of a 5-level neutral point clamping (NPC) active power filter (APF). This APF is applied for the enhancement of medium-voltage network power quality by compensation of harmonic currents produced by an induction motor speed variator. In the first part, the authors present a topology of a 5-level NPC voltage source inverter and its simplified space vector pulse width modulation (SVPWM) control strategy. In the second part, the control strategy of the 5-level pulse width modulation current rectifier is presented. In the third part, to remedy to instability problem of the input DC voltages of the APF, the authors propose the feedback control of the 5-level rectifier associated with a simplified SVPWM with the redundant vectors method for the 5-level APF. After that, the sliding mode regulator used to control the APF is developed. The application of the proposed control algorithm offers the possibility of stabilizing the DC voltages of the APF. The stable DC bus supply associated with the sliding regulator of the APF allows the obtainment of low-harmonic content network currents with unity power factor. The instability problem associated with the use of the multilevel APF is solved. The obtained results are full of promise for the use of the multilevel APF in medium-voltage and high-power applications.

Electric vehicle and grid interface with modified PWM rectifier and DC-DC converter with power decoupling and unity power factor

Abstract: In this paper, a configuration with modified single-phase H-bridge AC-DC converter for DC ripple compensation and power decoupling with a DC-DC converter for bidirectional power flow between PHEV (Plug in Hybrid Electric Vehicle) and power grid is proposed. It is well known that single-phase PWM voltage source converter (VSC) suffers from second-order ripple power and subsequent DC-link voltage pulsation. To reduce this low frequency pulsation of DC-link voltage and to obtain the sinusoidal grid current with unity power factor, a modified single-phase H-bridge PWM rectifier consisting of a conventional H-bridge PWM VSC and a pure passive auxiliary circuit is presented with a bidirectional DC-DC converter in order to ensure the bi-directional power flow management between PHEV and power grid at unity power factor and reduced ripple current. The modified H-bridge has the advantage of less number of switches and small DC link capacitor. First 230 V 50 Hz AC supply from source is converted to 400 V DC through single phase VSC and again the battery of EV or PHEV is charge in buck mode and discharge in boost mode with the help of bidirectional DC-DC buck - boost converter. In discharging mode, it delivers energy back to the grid at 230V, 50 Hz. A battery with a charging power of 3.6 kW at 120 V is used in PHEV.

A Novel Double Closed Loops Control of the Three-phase Voltage-sourced PWM Rectifier

Abstract: The double closed loop control strategy, which is composed of inner current loop and outer voltage loop in the d-q synchronous frame, is a relatively common control strategy of the three-phase voltage-sourced PWM rectifier. This strategy is suitable for the digital control system with the digital signal processor (DSP), because of its simple structure. The decoupling part is often ignored without the exact value of the boost inductance. And the nonlinear outer voltage loop is also the limit to improve the control performance. This paper proposed a novel double closed loop control strategy, which consists of decoupling current controller without exact value of the boost inductance in d-q synchronous frame, and the outer voltage linear control strategy with the control amount of the square of the voltage. Both the simulation analysis and experimental results demonstrate the validity of the proposed method and the feasibility of the control strategy.

A modified single-phase h-bridge PWM rectifier with power decoupling

Abstract: It is well known that single-phase PWM rectifiers suffer from second-order ripple power and subsequent dc-link voltage pulsation. To reduce this low frequency fluctuation of dc-link voltage as well as to obtain the sinusoidal grid current with unity power factor, a modified single-phase H-bridge PWM rectifier consisting of a conventional H-bridge rectifier and a pure passive auxiliary circuit is presented. Through utilization of the extra degree of freedom of the H-bridge, the proposed circuit can achieve power decoupling as well as maintaining basic function of a conventional PWM rectifier without additional power devices, which decreases both the product volume and the cost. The corresponding dc-link ripple reduction control method, with the instantaneous power feedforward loop and the dc-link ripple voltage feedback loop, is also provided. The experimental results based on a 1.3kW prototype verified the feasibility of the proposed method.

An FPGA implementation of a voltage-oriented controlled three-phase PWM boost rectifier

Abstract: Voltage-oriented control (VOC) of a three-phase PWM rectifier is one of the widely used structures in active converters. Design, simulation results, an FPGA implementation, and practical results of a VOC based three-phase PWM boost rectifier are presented and explained in this paper. National Instruments CompactRIO programmable automation controller platform is utilized in this application. The developed software and implemented hardware based on this controller are presented for this application.

Research on the field current of a doubly salient electromagnetic generator with a half-controlled PWM rectifier

Abstract: The switched reluctance generation (SRG) mode is widely applied in the doubly salient Electromagnetic machines (DSEMs). A novel half-controlled PWM rectifier (HCPWMR) for DSEM has a promising development prospect in DSEM. With a 12/8-pole DSEM prototype, the finite element method is used in the simulation. The simulation results of HCPWMR are compared with the SRG mode. The working principle of HCPWMR is analyzed. It is concluded that a DSEM with HCPWMR mode can improve the output power.

A summary of current control methods for three-phase voltage-source PWM rectifiers

Abstract: A control technique plays an important role to improve three-phase voltage-source PWM rectifier performance.In this paper,the double closed-loop control mode based on direct current control for three-phase voltage-source PWM rectifier is introduced,the development history and the current situation of three-phase voltage-source PWM rectifier control methods are summarized comprehensively,these control methods are scientifically classified according to the development law of control theory,the development experience of these control methods has three stages that are the traditional linear / nonlinear control,modern nonlinear control and intelligent control,the principles,advantages and disadvantages of these control methods are analyzed,finally,the future development trends of PWM rectifier control strategy are proposed.

Review of Exact Linearization Method Applied to Power Electronics System

Abstract: Power electronic switching converter is a typical nonlinear systems, it is difficult to solve the problem for power electronics system modeling and control by traditional linear control theory. With the development of power electronics and control theory, exact linearization method has been applied to power electronic systems. First, the basic mathematics of differential geometry is introduced. The basic knowledge and implementation conditions for single-input single-output(SISO) system's input- output linearization, single-input single-output system's state feedback linearization, multi-input multi-output (MIMO) system's state feedback linearization is also introduced. Second, the applications of the exact linearization method which is applied in the field for power electronic switching converters, three-phase PWM rectifier, inverter, active power filters(APF), motor control, is introduced. Finally, the exact linearization method in power electronics systems research trends is proposed.

Variable-speed permanent-magnet alternator system and double-port voltage stabilization control method therefor

Abstract: The invention discloses a variable-speed permanent-magnet alternator system and a double-port voltage stabilization control method therefor. The system comprises a permanent-magnet alternator, a PWM (Pulse Width Modulation) rectifier, a DC filtering device and a controller, wherein the controller comprises a rotor position and rotational speed detection module, a DC voltage detection module, a DC current detection module, an AC voltage detection module, an AC current detection module, a coordinate transformation module, a first regulator, a second regulator, a current limit module and a PWM generating module. The method provided by the invention comprises the following steps: acquiring the position, the rotational speed, the DC voltage and current, and the AC voltage and current of the alternator rotor; and acquiring the quadrature-axis and direct-axis currents through coordinate transformation, so as to stabilize the DC and AC voltages for setting values and achieving amplitude limit to quadrature-axis and direct-axis currents generated by a target subjected to closed-loop control and generate PWM trigger pulses to control the PWM rectifier. By adopting the invention, double-port voltage stabilization of a DC and AC output terminal is maintained when the rotational speed of the alternator changes, the cost is low and the reliability is high.

Application research of an electric vehicle DC fast charger in smart grids

Abstract: Popularization of charging station promotes wide applications of electric vehicle (EV). With the increase in the number of charging station, the problem of grid pollution becomes worse and worse. To improve the utilization rate of EV, the charging hours must be decreased. At present, most EVs start charging instantaneously under almost rated power of the charger. Large-scale EVs charging without adjustment will impact the smart grids. The capability of smart grids will restrict the number of charging station; furthermore, it will affect applications of EV. To solve the above problem, it is necessary to design a smart charger, as an important part of charging station, with unit power factor and with the function of fast charging. This article proposes a novel unit power factor DC fast charger for EV charging stations. This DC fast charger includes two modules: the input module is three-phase PWM rectifier and the output module is the phase-shift full-bridge converter. The two modules are controlled by only one DSP - TMS320F2812, which has abundant outside interfaces, to improve cooperating ability of two converters and the dynamic response of the charger. A prototype of 10 kW Charger is constructed. The experimental results show that the novel DC fast charger has excellent electrical characteristics, and it can be applied to the EV charging stations in smart grids.

Two-phase inverted power system and comprehensive control method

Abstract: The invention discloses a two-phase inverted power system and a control method. DC side voltage is obtained by adopting a three-phase power width modulation (PWM) rectifier to realize a high voltage factor of a power grid side and reduce energy loss. Simultaneously, a two-phase inverter only comprises four power switching tubes, and compared with a conventional two-phase inverted power supply, the two-phase inverted power system cancels a switch arm to make the structure of the two-phase power supply simpler, greatly reduce cost and improve system reliability. The three-phase PWM rectifier adopts a double-closed loop control strategy consisting of a voltage outer loop and a current inner loop to realize high-precision control over the voltage of a DC side and the high-power factor controlover the current of the power grid side. The double-closed loop control strategy consisting of voltage sharing outer loop control and output current inner loop control over two series-wound capacitors on the DC side realizes the rapid tracking of output current and the voltage sharing of the two capacitors on the DC side.

Energy-feedback tractive power supply system with high power factor and high cost performance

Abstract: The invention discloses an energy-feedback tractive power supply system with high power factor and high cost performance, relating to an energy-feedback tractive power supply system The system comprises a main substation, a medium-voltage ring network, a first to an Nth energy-feedback tractive substations, a direct-current contact network and a steel rail In the energy-feedback tractive substations, a set of 12-pulse-wave rectifier unit and a set of PWM (Pulse Width Modulation) unit are connected in parallel; by sufficiently utilizing respective advantages of the rectifier unit and the PWM unit, bidirectional flow of energy is realized on the one hand, braking energy of a train is fed back to an alternating-current grid, and electric energy is saved; on the other hand, the energy-feedback tractive power supply system integrates the advantages of simpleness and reliability, low cost and strong overload capability of a diode rectifier unit; beside, certain sensitive and capacitive reactive power is injected into the medium-voltage ring network by utilizing the PWM rectifier unit, and the power factor at the alternating-current incoming line of the main substation can be greatly increased The whole tractive power supply system has higher cost performance

Direct power control method of voltage source PWM (pulse width modulation) rectifier system

Abstract: The invention provides a direct power control method of a voltage source PWM (pulse width modulation) rectifier system. Based on an inner-loop power and outer-loop voltage control method adopted in a DPC (data processing control) method, set values of active power and reactive power are compared with actual values, and a voltage vector is selected by querying a switch list to control the on-off state of the PWM rectifier. According to the control method provided by the invention, a state variable marking the active power and the reactive power is added, the location of a space vector is redefined and a segmented switch list is constructed, thus enhancing the decoupling control on the active power and the reactive power and the response capability, and improving the power factor of the rectifier. The calculation and experiment results show that the grid side input current is sine and the instantaneous power dynamic and static control characteristics of the system are better.

DC voltage balancing control of half-bridge PWM inverter for linear compressor

Abstract: This paper proposes a new single phase back-to-back PWM converter for the power supply of the single phase by using both a full-bridge PWM rectifier and a half-bridge PWM inverter. In addition, the balancing control algorithm of DC voltage for this topology is also proposed by controlling the current of the half-bridge inverter. With the full-bridge PWM rectifier and the half-bridge PWM inverter, AC/DC/AC operation can be carried out by using only a six-pack power module and two series DC capacitors. Since two series connected capacitors are installed at the DC link, each capacitor voltage must be balanced for the safe operation. Using a IP(Integral-Proportional) controller, the DC voltage can be balanced without the current distortion. The proposed algorithm can be easily implemented without much computation and additional hardware circuit. The validity of the proposed algorithm is verified through simulations.

Analysis and optimized design of a distributed multi-stage EMC filter for an interleaved three-phase PWM-rectifier system for aircraft applications

Abstract: Different possible input filter configurations for a modular three-phase PWM rectifier system consisting of three interleaved converter cells are studied. The system is designed for an aircraft application where MIL-STD-461E conducted EMI standards have to be met and system weight is a critical design issue. The importance of a LISN model on the simulated noise levels and the effect of interleaving and power unbalance between the different converter modules is discussed. The effect of the number of filter stages and the degree of distribution of the filter stages among the individual converter modules on the weight and losses of the input filter is studied and optimal filter structures are proposed.

Implementation of high efficiency batteries charger for EV based on PWM rectifier

Abstract: This paper describes a power electronic system used to charge electric vehicle (EV) batteries. To achieve the requirements of high power factor and efficiency, two power converter units are adopted. The PWM rectifier with direct power control based on space vector PWM (DPC-SVM) in the front-end and full-bridge (FB) converter with phase-shifted zero-voltage zero-current-switching (ZVZCS) in the back-end are applied. Decoupling control for instantaneous active and reactive powers of the grid is realized. Experimental results in 8kW prototype show that during the whole charging process, the system efficiency is higher than 85.3% and the input power factor is higher than 99.4%.