Vector PWM Research Articles

Direct-Indirect PWM vector controlled of the dual-star asynchronous motor based on a modified winding function approach using the current controller for a six-phase inverter

Direct-Indirect PWM vector controlled of the dual-star asynchronous motor based on a modified winding function approach using the current controller for a six-phase inverter

A novel hybrid discontinuous PWM algorithm for 3L-NPC inverter

Wider linear modulation range, less switching loss and simplicity are the goals pursued by various modulation methods of multilevel inverters. This paper proposes a new hybrid discontinuous pulse width modulation (HDPWM) strategy for 3L-NPC inverter that can achieve the above goals to a certain extent. According to the position of the reference voltage vector and the actual situation of the neutral point voltage, different control modes and clamping types are selected. The neutral point voltage is controlled by DPWM strategy, which cannot only greatly reduce the switch loss, but also maintain the balance of the neutral point voltage and expand the linear modulation range. The implementation of the algorithm combines the advantages of carrier-based PWM (CBPWM) and space vector PWM (SVPWM). There is no need to select the nearest three vectors (NTV) and calculate their dwell time. Only the reference voltage needs to be modified according to the control requirements, and then by comparing the modified reference voltage with the carrier, the driver pulse required by the switching devices can be generated. Compared with the existing PWM methods, it is more simple and easy to implement. Experimental results verify the validity of the method.

The Wavelet-Modulation Technique for , 5-Level, Power Electronic Converters—Part I: Development and Testing

This work extends the wavelet modulation (WM) technique for operating three-phase ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$3\phi$</tex-math></inline-formula> ), five-level (5L) power electronic converters (PECs). The WM technique is extended by resolution segmentation of the synthesis scale-based linearly combined wavelet functions, which are used as switching signals. The resolution segmentation is created based on the dilation property of synthesis scale-based linearly combined wavelet functions. Each leg of the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$3\phi$</tex-math></inline-formula> VS, 5L dc–ac PEC is operated by two sets of resolution-segmented synthesis scale-based linearly combined wavelet basis functions to produce the voltage of one phase. The extended WM technique is implemented for performance testing, when operating <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$3\phi$</tex-math></inline-formula> VS, 5L, diode-clamped and flying-capacitor dc–ac PECs. In this article, Part I, simulation test results are presented and compared with results obtained using the level-shifted pulsewidth modulation, phase-shifted PWM, and space vector modulation. Test results show significant reductions of output harmonics, along with improvements in fundamental components of output voltages and PEC efficiency.

Performance Analysis of Multi-Carrier PWM and Space Vector Modulation Techniques for Five-Phase Three-Level Neutral Point Clamped Inverter

In industries, the demand for multi-phase Multi-Level Inverters (MLIs) increases as they have reduced switching loss, Common Mode Voltage (CMV) and voltage stress across switches. The Multi-Carrier PWM (MCPWM) and Space Vector Modulation (SVM) techniques are predominantly used for controlling the inverter. This paper discusses various PWM techniques like PD, POD, APOD, IC, PSC, VFC PWM and SVM (OFV and SVM with Zero CMV) for 5-phase NPC 3L Inverter. Each PWM techniques gives better results in voltage THD/ dc-link balancing/ CMV. The SVM is significant for obtaining better performances in all these aspects. The Optimized Five Vector (OFV) which has 113 vectors is preferred than normal SVM as it has inequality relationship between 5-phase voltages. Though, OFV gives better results in terms of higher output voltage and lower NPF, the CMV is not eliminated. To eliminate CMV, 51 vectors that generates Zero CMV is selected to drive the inverter where output voltage and NPF is also improved. However, due to the presence of x-y components the distortion is present. The vectors are further reduced to 31 where the x-y components are neglected to reduce the distortion is proposed in this paper. The performance of the inverter drive is enhanced by applying proposed SVM with 31 vectors. The NPF, CMV and losses are calculated for all PWM techniques, also the THD performances of an inverter is found for various techniques. The simulation is carried out for all PWM techniques and the results are verified by experimental results.

A hybrid discontinuous PWM algorithm of balancing neutral point voltage for 3L‐NPC inverter

AbstractWider linear modulation range, less switching loss, and simplicity are the goals pursued by various modulation methods of multilevel inverters. This paper proposes a new hybrid discontinuous pulsewidth modulation (HDPWM) strategy for three‐level neutral‐point‐clamped (3L‐NPC) inverter that can achieve the above goals to a certain extent. According to the position of the reference voltage vector and the actual situation of the neutral point voltage, different control modes and clamping types are selected. The neutral point voltage is controlled by DPWM strategy, which can not only greatly reduce the switch loss but also maintain the balance of the neutral point voltage and expand the linear modulation range. The implementation of the algorithm combines the advantages of carrier‐based PWM (CBPWM) and space vector PWM (SVPWM). There is no need to select the nearest three vectors (NTVs) and calculate their dwell time. Only the reference voltage needs to be modified according to the control requirements, and then by comparing the modified reference voltage with the carrier, the driver pulse required by the switching devices can be generated. Compared with the existing PWM methods, it is more simple and easy to implement. Experimental results verify the validity of the method.

Desain Rangkaian Gate Driver Analog untuk Dual Mosfet Drivers

Switching techniques have been continued to develop, including sinusoidal PWM, space vector PWM, current tracking PWM, harmonic elimination PWM and others. Each method has advantages and disadvantages, but the most commonly used methods are sinusoidal PWM and space vector PWM. PWM that is generated using a microcontroller or analog IC component generally has a maximum voltage value of 5V. To strengthen the PWM wave, a gate-driver circuit is needed, so that the PWM control wave is able to move the IGBT / MOSFET. On this paper, the design of gate driver circuit use An analog IC, which starts from the generation of two waves, namely a sinusoidal wave and a DC source to be compared (Comparator) so that it can produce a PWM wave. Then this PWM wave is isolated using an optocoupler and MOSFET driver IC to limit interference in the switching process on high power supplies. Based on the results, it can be cancluded PWM control wave output from the gate-driver circuit is isolated from the system intended for designing a power converter and other applications.

Voltage boosting capability of three phase current source inverter for standalone system

This paper presents a three-phase current source inverter (CSI) topology with voltage boosting capability for standalone system. Current source inverter (CSI) and voltage source inverter (VSI) are two competitive options to be used as an interfacing unit between variable dc input resource and ac output fed into on-grid, off-grid and industrial used. Among the two topologies, VSI is widely used due to its variable controllable output voltage and ability to operate steadily with open loop V/Hz control. Yet, it suffers circuit complexity due to the need of extra converter stage to meet the required output. On the other hand, CSI has an advantage of voltage boosting capability and better quality of output waveshape, thus no extra converter stage is needed. Most of research works were focusing on studying the suitability and practicality of CSI, along with the advancement using silicon carbide-based power switches and improved modulation techniques to minimize the harmonics suffer by CSI. There is lack of research in investigating the boosting capability particularly on how high CSI able to boost the fundamental output and its impact to overall performance in both open and closedloop standalone system. Thus, this work is intended to highlight in detail the boosting capability of CSI and compare with VSI based on the several circuity and operational features. To support the work, three modulators are implemented namely sinusoidal pulse width modulation (SPWM), third harmonic injection PWM (THIPWM) and space vector modulation (SVM). A dedicated synchronous frame proportional-integral (PI) control in used in closed-loop condition. Result shows that CSI topology able to boost the fundamental output voltage by 52% to 58% by using smaller modulation index as compared to VSI. Interestingly, CSI able to achieve comparable quality and harmonic minimization of output voltage and current as in VSI but with smaller PI control gain. All works are analyzed and verified using MATLAB/Simulink platform.

Research on Generator Side PWM Control of Synchronous Permanent Magnet Wind Power Generation System

This paper mainly studies the generator side converter of permanent magnet synchronous wind power generation system using dual PWM converter as the main circuit. This paper mainly studies and analyzes the control principle and control mode of generator side PWM in wind power generation system, and models and simulates the motor side converter based on rotor field oriented control. According to the control characteristics of the machine side converter, the specific idea of adopting the PWM vector control strategy is analyzed. The vector control strategy based on feedforward decoupling is proposed. The results of MATLAB / Simulink simulation show that: the PMSM Wind power generation system with vector control strategy can achieve stable power generation operation with variable speed and constant frequency, and can effectively adjust the output power of the power generation system, and the output current has good sinusoidal performance and small harmonic.

Investigation of SPWM and SVPWM VSI for Induction Motor Drive

This paper investigates the different modulation techniques of voltage source inverter (VSI) for induction motor drive concerning the harmonic distortion. Two types of PWM strategies are analyzed under various operating conditions regarding total harmonic distortion. Both sinusoidal PWM and space vector PWM strategies have been analyzed. THD has a suitable value that reduces the torque ripple. since the high switching frequency provides high ripple. The system is simulated by using Matlab.

The Implementation of Effective Modulation Schemes to Improve the Power and Harmonic Losses in Grid-Tied Solar NPC Inverter

The growing energy demand, rising fossil fuel prices, and exceeding greenhouse gas emissions require large-scale integration of clean and renewable energy resources. Solar Photovoltaic (PV) system is the potential prospective energy resource to overcome the challenges of conventional grid. Effective power conversion topologies are the prominent need of the PV system to optimize the power and harmonic contents. Three level neutral point clamped (NPC) inverter comparatively produces less harmonics and increases the power delivery compared to the conventional and two-level inverters. Therefore, this research presents the deployment of three level NPC inverter to optimize the switching and power losses in grid connected 250 kW solar PV array. Moreover, power generation, current and voltage characteristics, and fast Fourier transform analysis is performed in MATLAB / Simulink directory with the help of Simpowersystem and Simelectronics toolboxes. To optimize the switching and power losses, sinusoidal PWM and space vector PWM are used to control the duty cycle of IGBT power switches in the proposed NPC inverter. The grid side 3 phase AC output voltage of the proposed inverter is connected to 15 kV grid with the help of 3 phase step up transformer. For 3 phase grid-tied system, the performance evaluation section of the proposed research shows the effectiveness of space vector PWM over sinusoidal PWM.

A Modified Algorithm based on the Equal-Areas PWM for the Extend of Linear Operation of a Microprocessor-Controlled PWM-VSI

A modified algorithm based on the Equal-Areas PWM (EAPWM) is being presented in order to extend the linear operation of the inverter in the overmodulation region, while improving the voltage output in terms of fundamental harmonic component amplitude and Total Harmonic Distortion (THD). EAPWM provides an alternative to Regular Sampling (RS) PWM and Space Vector PWM (SVPWM) strategies. EAPWM is a direct digital PWM method that uses the equal areas theorem to determine the pulse widths. This method maintains the commutations through a complete fundamental cycle, in contrast to naturally and regular sampling PWM techniques, where switched pulses progressively disappear for values of modulation index M greater than unity. In addition, this algorithm reveals several linear operating regions of controlling the output fundamental. Simulation and experimental work carried out using a single-phase voltage source inverter (VSI), showing less harmonic content is present for the first harmonic cluster at the switching frequency, compared to (RS) PWM and Space Vector PWM (SVPWM) strategies. This method is suitable for robotic applications where online control through a microcontroller is needed to drive rotating type loads such us ac motor drives and stepper motors.

A comparative study between methods of detection and localisation of open-circuit faults in a three phase voltage inverter fed induction motor

The present paper focuses on the techniques of detection and localisation of opencircuit faults in a three phase voltage source inverter fed induction motor. First, the paper starts by presenting the impact of an inverter IGBT open-circuit fault on the induction machine performance. A comparative study is then carried out between three different detection techniques: the mean value of the currents method, the measurement of the current drop method and the Park's vectors method. The comparison is to assess each technique in terms of its performance, that is the time detection rapidity and localisation ability, as well as in terms of hardware, that is the number of current sensors required for IGBT open-circuit fault detection. To validate these methods, a test-rig is developed in our diagnostic group laboratory which consists of the realisation of a two-level voltage source inverter controlled by a DSPACE-1104 card to generate the PWM vector control for the induction motor. The obtained simulation and experimental results illustrate well the detection effectiveness of each technique as well as the comparison study merits.

A comparative study between methods of detection and localisation of open-circuit faults in a three phase voltage inverter fed induction motor

The present paper focuses on the techniques of detection and localisation of opencircuit faults in a three phase voltage source inverter fed induction motor. First, the paper starts by presenting the impact of an inverter IGBT open-circuit fault on the induction machine performance. A comparative study is then carried out between three different detection techniques: the mean value of the currents method, the measurement of the current drop method and the Park's vectors method. The comparison is to assess each technique in terms of its performance, that is the time detection rapidity and localisation ability, as well as in terms of hardware, that is the number of current sensors required for IGBT open-circuit fault detection. To validate these methods, a test-rig is developed in our diagnostic group laboratory which consists of the realisation of a two-level voltage source inverter controlled by a DSPACE-1104 card to generate the PWM vector control for the induction motor. The obtained simulation and experimental results illustrate well the detection effectiveness of each technique as well as the comparison study merits.

English

2 ABSTRACT: In home appliances and in small scale industries, single phase induction motors are commonly used. Recently remarkable efforts have been made in adjustable speed - single phase induction motor drives (SPIMD's). Different types of PWM strategies have been used in speed control of SPIMD's, most widely sinusoidal PWM & space vector PWM strategies. Various converters technologies are taking a place in SPIMD's because of its low cost. The proposed project describes the several PWM strategies with an AC chopper to control the speed of single phase induction motor. Asymmetrical PWM technique has been used to operate the power electronics switches (IGBT) of an AC chopper. The main objective of this project is to maintain the speed of the single phase induction motor constant at different load conditions by using Asymmetrical PWM technique, which reduces the harmonic contents in motor current and increasing the motor efficiency. The simulation is carried out in MATLAB/SIMULINK with a Split Phase Induction Motor, where the motor is operated in normal PWM strategy, Hysteresis PWM strategy. The hardware is designed for the Asymmetrical PWM technique and results have been discussed.

Harmonic Evaluation of Z-Source PWM Inverter for Wind Powered Industrial Drive Applications

In this paper, a comparison on Total Harmonic Distortion (THD) by using different pulse width modulation schemes for an industrial drive application is performed. The induction motor drive system driven by a wind energy conversion system is modeled using a Self-Excited Induction Generator. To obtain a constant frequency output an Impedance Source Inverter (ZSI) is connected between the source and the load. The ZSI is selected to avoid the shoot-through limitation which is observed in other conventional PWM inverters. The PWM switching techniques like Trapezoidal PWM, Sinusoidal PWM and Space Vector PWM techniques are mathematically modeled operating at a switching frequency of 10 kHz to control the induction motor drive system though pulse generation. The proposed method is simulated using MATLAB program and the current harmonic levels for driving the IM drive are analyzed. The comparative analysis of current harmonics illustrates the efficient implementation of PWM technique for the drive applications. Based on the simulation evaluation a similar hardware prototype model is setup for a 900W system using Space Vector PWM technique and the results are compared.

Влияние на сеть трёхфазного мостового двухуровневого активного выпрямителя напряжения при различных видах ШИМ

The analysis of influence of PWM boost rectifier with vector control and different types of PWM was made in this scientific article. Comparative analysis of sinusoidal PWM, PWM with Zero Sequence Signal (ZSS) and Space Vector Modulation (SV-PWM) was carried with different magnitudes of modulation factor. Spectrum of harmonic components of the input voltage of the active rectifier was analyzed. The studies were carried out by mathematical modeling in the Matlab/Simulink program. The analysis of the results revealed that a decrease of the modulation factor leads to a slight increase of THD (total harmonic distortion), but magnitude of the harmonics in the low frequency domain grows 2-4 times (11, 15, 17 harmonics). The highest rate of THD was detected with the sinusoidal PWM. Spectrum of harmonic components of phase-to-phase voltage of PWN boost rectifier with Zero Sequence Signal PWM and Space Vector Modulation are virtually identical.

Research on Vector Control and PWM Technique of Six-Phase PMSM

The mathematic model that based on decoupling vector space for six-phase permanent magnet synchronous motor (PMSM) is established. The six-phase PMSM is designed with two sets of Y-connected windings phase shifted by 30 electrical degrees. In the model, the variables of the motor are mapped to the α-β subspace associated with the electromechanical energy conversion and z1-z2 o1-o2 subspace that has nothing to do with the energy conversion subspace in the model. The model implies that different current harmonics have different effects on electromechanical energy conversion. The vector control scheme for six-phase PMSM is presented, in which the currents in the subspace α-β and z1-z2 are controlled in closed loop. A space vector pulse width modulation (SVPWM) algorithm of six-phase voltage-source inverter based on adjacent four largest voltage vectors is discussed. The voltage in α-β and z1-z2 can be modulated simultaneously. Through the simulation and experiment analysis, the vector control method and PWM technique for six-phase PMSM are proved to be feasible and effective.

Dynamically Reconfigurable PWM Controller for Three-Phase Voltage-Source Inverters

This paper presents the design and development of dynamic partially reconfigurable pulsewidth modulation (DPRPWM) controller for three-phase voltage-source inverters (VSI) in a single Xilinx Spartan 3 XCS400PQ208 field programmable gate array (FPGA). The DPRPWM controller is designed such that it switches between the popular PWM techniques like sinusoidal PWM (SPWM) and space vector PWM (SVPWM). The FPGA platform supports the run-time reconfiguration of control functions and algorithms directly in hardware and meets hard real-time performance criteria in terms of timings for PWM generation as well as reconfiguration. The DPRPWM control is simulated and experimentally verified using a low-cost Xilinx Spartan FPGA. The results of SPWM and SVPWM controller are presented and the results prove that the DPRPWM controller for three-phase inverter is highly possible and can be extended to any level/phase PWM controllers.

Energy Conversion Stage Design of Solar Water Pump in a Nanofiltration System

Standalone solar power system provides simple yet flexible solution to certain applications which demand high mobility. This paper introduces the design of a single solar panel powered induction machine-driven water pump system, which is used in an on-board nanofilteration system. The system configuration is evaluated at the first stage to provide high ratio voltage step-up; and complementary PWM and space vector PWM scheme is chosen for dc-dc stage and dc-ac stage respectively; V/F based control scheme is designed and integrated with maximum power point tracking algorithm for the best use of solar panel. The control system is implemented digitally in a TMS320F2812 DSC. Meaningful mode of operation is tested and satisfactory experimental results are collected.

A method for diagnosis of induction machine fed by PWM vector control

In this study, we propose a diagnosis method for the rotor eccentricity in induction machines fed by a PWM converter by considering the harmonics in a transient magnetic phenomenon. The influences of the asymmetrical whirling motions are studied using the back EMF of a search coil, which enables the detection of motor faults. The analysis results of the rotor eccentricity could be obtained by comparing the characteristics of motors fabricated with normal and irregular air gaps, and the validity is verified from the experimental results. The simulation and experimental results can be useful for the online faults detection monitoring system of induction machines.