Space Vector PWM Scheme Research Articles

An Optimized Hybrid SVPWM Strategy Based on Multiple Division of Active Vector Time (MDAVT)

This paper presents a new advanced bus-clamped space vector pulsewidth modulation (SVPWM) technique to reduce line current harmonic distortion as well as switching loss. The proposed sequence introduces multiple division of active vector time (MDAVT) in a subcycle. An analysis of optimal subdivision of active vector dwell time is presented. Existing bus-clamping pulsewidth modulation techniques use double-switching clamping sequences, which use only one zero state and apply an active vector twice in a subcycle. The proposed MDAVT-based SVPWM technique presents a hybrid SVPWM technique. The additional switching is added when the fundamental voltage crosses zero. The switching patterns for the other two phases are not changed. The harmonic performance and switching loss characteristics of the proposed hybrid SVPWM techniques over the existing SVPWM is verified with experimental results on a 415-V, 2.2-kW induction motor drive.

A Switching Frequency Optimized Space Vector Pulse Width Modulation (SVPWM) Scheme for Cascaded Multilevel Inverters

This paper presents a novel switching frequency optimized space vector pulse width modulation (SVPWM) scheme for cascaded multilevel inverters. The proposed SVPWM is developed in a α′β′ coordinate system, in which the voltage vectors have only integer entries and the absolute increment of coordinate values between adjacent vectors is equal to dc-bus voltage of power cells (1 pu). The new SVPWM scheme is built with three categories of switching paths. During each switching path, the change of one phase voltage is limited in 1 pu. This contributes to decrease the number of commutations of switches. The proposed SVPWM scheme is validated on a 7-level cascaded inverter and the results show that it significantly outperforms traditional SVPWM schemes in terms of decreasing the number of switch commutations.

Improvised SVPWM Strategies for an Enhanced Performance for a Four-Level Open-End Winding Induction Motor Drive

A four-level open-end winding induction motor drive (OEWIMD) is obtained when an induction motor with open windings is fed from either side with two two-level 3-Ph voltage-source inverters (VSIs) with unequal dc-link voltages, which are in the ratio of 2:1. This drive principally suffers from two problems namely: the circulation of zero sequence current in motor phases and overcharging of the lower dc-link capacitor by its counterpart with higher dc-link voltage. It has been reported earlier, that the decoupled space vector pulse width modulation (SVPWM) control strategies avoid both of these problems. This paper proposes an improvised SVPWM scheme that achieves a better harmonic performance compared to the decoupled SVPWM scheme without altering either the power circuit configuration or the voltage ratings of the devices. The proposed PWM strategy clamps the inverter with lower dc-link voltage with an active state, while the other inverter is switched around it. It has been shown that the proposed SVPWM scheme results in an overall reduction of losses for the drive system while resulting in a considerably lower d <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">v</sub> /d <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</sub> compared to the decoupled SVPWM schemes. The four-level OEWIMD employing the proposed SVPWM scheme is simulated and is validated with experimental results.

A Random Forest Regression Based Space Vector PWM Inverter Controller for the Induction Motor Drive

This paper presents a random forest (RF) regression based implementation of space vector pulse width modulation (SVPWM) for a two-level inverter to improve the performance of the three-phase induction motor (TIM) drive. The RF scheme offers the advantage of rapid implementation and improved prediction for the SVPWM algorithm to improve the performance of a conventional space vector modulation scheme. In order to show the superiority of the proposed RF technique to other techniques, an adaptive neuro fuzzy inference system (ANFIS) and artificial neural network (ANN) based SVPWM schemes are also used and compared. The proposed speed controller uses a backtracking search algorithm to search for the best values for the proportional-integral controller parameters. The robustness of the RF-based SVPWM is found superior to the ANFIS and ANN controllers in all tested cases in terms of damping capability, settling time, steady-state error, and transient response under different operating conditions. The prototype of the optimal RF-based SVPWM inverter controller of induction motor drive is fabricated and tested. Several experimental results show that there is a good agreement of the speed response and stator current with the simulation results which are verified and validated the performance of the proposed RF-based SVPWM inverter controller.

A Neutral-Point Voltage Balance Controller for the Equivalent SVPWM Strategy of NPC Three-Level Inverters

Based on the space vector pulse width modulation (SVPWM) theory, this paper realizes an easier SVPWM strategy, which is equivalently implemented by CBSPWM with zero-sequence voltage injection. The traditional SVPWM strategy has no effect on controlling the neutral-point voltage balance. In order to solve the neutral-point voltage unbalance problem for neutral-point-clamped (NPC) three-level inverters, this paper proposes a neutral-point voltage balance controller. The proposed controller realizes controlling the neutral-point voltage balance by dynamically calculating the offset superimposed to the three-phase modulation waves of an equivalent SVPWM strategy. Compared with the traditional SVPWM strategy, the proposed neutral-point voltage balance controller has a strong ability to balance the neutral-point voltage, has good steady-state performance, improves the output waveforms quality and is easy for digital implementation. An experiment has been carried out on a NPC three-level inverter prototype based on a digital signal processor-complex programmable logic device (DSP-CPLD). The obtained experimental results verify the effectiveness of the proposed neutral-point voltage balance controller.

Research on Synchronized SVPWM Strategies Under Low Switching Frequency for Six-Phase VSI-Fed Asymmetrical Dual Stator Induction Machine

In high-power traction drive systems, the switching frequency of the inverter is strictly limited owing to the restrictions on switching losses and cooling conditions. In this case, the multimode modulation strategy is usually adopted. Based on the analysis of a modified 24-sector space vector pulse width modulation (SVPWM) technique, several synchronous modulation strategies with different pulse numbers are proposed in this paper, which can be applied to the two-level six-phase voltage-inverter-fed asymmetrical dual-stator induction machines. By comparing the harmonic performance of the synchronized modulations, the authors present a set of multimode SVPWM strategy, which is suitable for the high-power traction drive systems under low switching frequency. At the same time, the switching strategy for transitions between different modulation modes is proposed as well. Simulation and experimental results verify the validity and effectiveness of the proposed synchronized modulation strategies and the switching strategy between different modulation modes.

Comparison of Two SVPWM Control Strategies of Five-Phase Fault-Tolerant Permanent-Magnet Motor

Five-phase fault-tolerant permanent-magnet motors incorporate the merits of high-efficiency and high fault-tolerant capability. By adopting the fault-tolerant control technique, these motors can continue operating even fault occurs. This paper proposes two space vector pulse-width modulation (SVPWM) control strategies, namely the symmetric one and the asymmetric one. The novelty of the proposed SVPWM control strategies includes two parts. One is that voltage vector locations in both SVPWM strategies are reconfigured based on a new vector space diagram. Another is that the process of switching vector calculation under fault is similar to that under healthy condition. A five-phase fault-tolerant permanent-magnet motor drive is developed and the proposed fault-tolerant control strategies are evaluated in terms of the torque, voltage, current waveforms, and total harmonic distortion. Simulated and experimental results are provided to verify the effectiveness of the theoretical analysis.

Investigation of the Common Mode Voltage for a Neutral-Point-Clamped Multilevel Inverter Drive and its Innovative Elimination through SVPWM Switching-State Redundancy

The purpose of this paper is to provide a comprehensive Investigations and its control on the common mode Voltage (CMV) of the three-phase three-level neutral-point diode-clamped (NPC) multilevel inverter (MLI). A widespread space-vector pulse width modulation (SVPWM) technique to mitigate the perpetual problem of the NPC-MLI, the CMV, proposed. The proposed scheme is an effectual blend of nearest three vector (NTV) and selected three vector (STV) techniques. This scheme is capable to reduce the CMV without compromise the inverter output voltage and Total harmonics distraction (THD). CMV reduction achieved less than +Vdc/6 using the proposed vector selection procedure. The theoretical Investigations, the MATLAB software based computer simulation and Field Programmable Gate Array (FPGA) supported hardware corroboration have shown the superiority of the proposed technique over the conventional SVPWM schemes.

An Equivalent Carrier-based Implementation of a Modified 24-Sector SVPWM Strategy for Asymmetrical Dual Stator Induction Machines

A modified space vector pulse width modulation (SVPWM) strategy based on vector space decomposition and its equivalent carrier-based PWM realization are proposed in this paper, which is suitable for six-phase asymmetrical dual stator induction machines (DSIMs). A DSIM is composed of two sets of symmetrical three-phase stator windings spatially shifted by 30 electrical degrees and a squirrel-cage type rotor. The proposed SVPWM technique can reduce torque ripples and suppress the harmonic currents flowing in the stator windings. Above all, the equivalent relationship between the proposed SVPWM technique and the carrier-based PWM technique has been demonstrated, which allows for easy implementation by a digital signal processor (DSP). Simulation and experimental results, carried out separately on a simulation system and a 3.0 kW DSIM prototype test bench, are presented and discussed.

EXPERIMENTAL INVESTIGATION OF A SIX-PHASE VARIABLE FREQUENCY DRIVE / ŠEŠIŲ FAZIŲ DAŽNINĖS PAVAROS EKSPERIMENTINIS TYRIMAS

Experimental results of a variable frequency drive, consisting of a six-phase voltage source inverter and six-phase asynchronous AC motor are presented in this paper. Frequency converter uses a six-phase space vector PWM scheme created by the author. The voltage forming scheme is implemented in Matlab/Simulink, and logical signals for inverter control are transferred from PC via the National instruments PCI-6024E data acquisition card. Voltages, at which the experimental motor operates at maximum efficiency, were determined experimentally. Motor transitions, when it is operating with one, two, and three failed phase windings are presented, confirming that a six-phase motor can operate with up to three failed windings. Darbe pateikiami dažninės pavaros, sudarytos iš šešių fazių dažnio keitiklio ir šešių fazių asinchroninio elektros variklio, eksperimentinių tyrimų rezultatai. Šešių fazių įtampai formuoti taikomas autoriaus sukurtas erdvinių vektorių moduliacijos algoritmas, naudojantis vidutinio ilgio vektorius. Algoritmas realizuotas asmeniniu kompiuteriu Matlab/Simulink terpėje. Signalams inverterio raktų valdymui iš kompiuterio gauti panaudotas National Instruments PCI-6024E duomenų įvesties/ išvesties įrenginys. Atlikti inverterio įtampos, kuriai esant šešių fazių variklis dirba maksimaliu naudingumo koeficientu, tyrimai. Pateikiami šešių fazių variklio greičio ir sukimo momento pereinamųjų procesų tyrimo rezultatai, esant vienos, dviejų ir trijų variklio apvijų gedimams, patvirtinantys, kad šešių fazių variklis gali ribotai veikti sugedus iki trijų apvijų.

An SVPWM Scheme for the Suppression of Zero-Sequence Current in a Four-Level Open-End Winding Induction Motor Drive With NestedRectifier–Inverter

A four-level open-end winding induction motor (OEWIM) drive is known to suffer from two perennial problems. One is the problem of zero-sequence currentin the motor phases, which is caused by the existence of zero-sequence voltage in them. The other is the overcharging of the dc-link capacitor of theinverter operated with lower dc-link voltage by its counterpart operated with a higher dc-link voltage. This paper investigates the applicability of aspecial variant of space vector pulse width modulation (SVPWM) scheme for a recently proposed power circuit configuration, in which arectifier–inverter combination is nested within the conventional two-level inverter configuration to achieve four-level inversion. This PWM schemeis named as the sample-averaged zero-sequence elimination (SAZE) SVPWM scheme, wherein the zero sequence voltage is suppressed in each sampling timeperiod in the average sense. Both of the aforementioned problems encountered in this drive are successfully overcome for this power circuit configurationby resorting to the proposed SVPWM strategy.

A New SVPWM for the Phase Current Reconstruction of Three-Phase Three-level T-type Converters

This paper presents a new space vector pulsewidth modulation scheme to reconstruct phase currents using neutral-point current sensing in three-level T-type converters (TLTTCs). For this purpose, zero vector and offset vectors are replaced with complementary active vectors. These active vectors do not affect the resultant output voltage and the voltage balance at the neutral point of TLTTCs. Hence, the pulsewidths of corresponding active vectors can be adjusted even at low speeds without much additional switching losses and low-frequency noise in the inverter. The modified switching patterns can easily be generated without significant computational complexity. The proposed method is experimentally verified using Texas Instruments TMS320F28335 and Spartan 6 controllers, on a custom designed T-type converter based on Fuji IGBT modules.

Modified DC-Bus Voltage-Balancing Algorithm Based Three-Level Neutral-Point-Clamped IPMSM Drive for Electric Vehicle Applications

A modified dc-link voltage-balancing scheme for a three-level neutral-point-clamped inverter with an interior permanent magnet synchronous machine is presented with a wider range of machine operation including field weakening. It uses two dc-link voltage sensors to take care of the voltage differences and keeps it to a required tolerance level. A switching control strategy is developed using a space vector pulsewidth modulation scheme. The number of vectors per switching cycle is optimized to five, and changes in the control strategy depending on the two capacitor voltage differences are only allowed to take place at the start of each switching cycle. This helps in reducing the switching losses. A detailed analysis on the larger capacitor voltage deviation at high modulation index and leading power factor is analyzed, and four control strategies are developed to reduce it. Simulation studies are carried out in MATLAB/Simulink platform, and an experimental setup is developed using a DSpace®-based real-time emulator. Simulation and experimental results show the effectiveness of the proposed system.

DC link current simulation of voltage source inverter with random space vector pulse width modulation

Aiming at analysis complexity, a simulation model is built and presented to analyze and demonstrate the characteristics of the direct current (DC) link current of the three-phase two-level inverter with the random space vector pulse width modulation (SVPWM) strategy. The developing procedure and key subsystems of the simulation model are given in detail. Several experiments are done using the simulation model. The results verify the efficiency and convenience of the simulation model and show that the random SVPWM scheme, especially the random switching frequency scheme, can efficiently suppress the harmonic peaks of the DC link current.

Three‐mode pulse‐width modulation of a three‐phase four‐wire inverter

In order to reduce the switching frequencies of power semiconductors and then to increase the efficiency in a three-phase four-wire inverter, the state controllability of a system is investigated by considering the inverter as a switched linear system. It is found that a three-phase four-wire inverter is a three-mode controllable, therein, only three non-zero vectors are required to make the system completely state controllable. With the three operating modes, a novel control strategy, called a three-mode pulse-width modulation (3-MPWM), is proposed in this study. There are three types of 3-MPWMs, that is, 3-MPWM(I), 3-MPWM(II) and 3-MPWM(III). Compared with the conventional space-vector pulse width modulation strategy, the switching frequencies of the proposed 3-MPWMs are significantly reduced by two-thirds, hence, the switching losses of the power semiconductors can be reduced and the efficiency of the inverter can be improved. In addition, the number of operating modes used in 3-MPWM(I) and 3-MPWM(II) is reduced by a half. Finally, simulation and experimental results are conducted to verify the effectiveness of the 3-MPWM strategies.

SVPWM Performance of PMSM Variable Speed and Impact of Diagnosis Sensors Faults

In this paper, the performances of a permanent magnet synchronous motor and impact of the control method on the diagnosis strategy are presented. First, permanent magnet synchronous motor and two level three phase inverter with space vector PWM strategy is developed. The PMSM speed is controlled by sliding mode control. A comparative study between standard and symmetric SVPWM methods is used. Latest part is devoted to treat fault detection on the sensors by a state estimation method. In our case, the sensors to monitor are those of the phase currents. Simulation results in superposition for both SVPWM methods have been compared, and fault detection diagnoses are presented.

Modelling and Simulation of the 150° Conduction Mode Quasi Space Vector PWM Inverter Fed Permanent Magnet Brushless DC Motor

This paper presents an alternative space vector pwm scheme of 150o conduction mode for the three phase voltage source inverter (3PVSI) with the switching periods, of six switches, determined by the Quasi Space Vector (QSV) relevant to the rotor of the three phase Permanent Magnet Brushless DC(3PPMBLDC) Motor. Performance can be delineated through the dynamic model of 3PPMBLDC motor with the simulations of torque and speed characteristics when applied by 3PVSI with this modulation scheme.

Space‐vector pulse width modulation scheme for open‐end winding induction motor drive configuration

This study proposes a novel space-vector pulse width modulation scheme for an induction motor with open-end windings. The proposed PWM scheme requires two two-level inverters with isolated power supplies. This PWM scheme uses instantaneous phase reference voltages for the generation of gating signals. Open-end winding induction motor (OEWIM) offers significant switching redundancy. Thus, with the proposed scheme the required gating pulses can be generated to reduce the voltage stress on the switching devices. In addition, the switching scheme is capable of equalising the junction temperature rise during the switching and conduction state of the devices. In the present switching scheme when one inverter is switching while the other inverter is clamped and vice versa. The proposed scheme is simulated using MATLAB/Simulink. The PWM scheme is experimentally validated on dSPACE for a three-level OEWIM.

A New Active Fault-Tolerant SVPWM Strategy for Single-Phase Faults in Three-Phase Multilevel Converters

Multilevel converters have been well studied for high-voltage high-power renewable energy applications. Owing to the multibranch structure, these converters can be operated under fault conditions in case of a loss of a branch or voltage cell. In this regard, this paper proposes a new active fault-tolerant space vector pulsewidth modulation strategy for single-phase faults in three-phase multilevel converters. The proposed modulation strategy treats the multilevel converter as a two-level converter by introducing an offset vector. A generalized approach is proposed to search for the offset vector and to adjust the modulation of the converter online under different fault operation conditions. Several short- and open-circuit faults have been demonstrated on a seven-level hybrid input-switched converter to prove the effectiveness of the proposed fault-tolerant scheme.

Space-vector PWM Techniques for a Two-Phase Permanent Magnet Synchronous Motor Considering a Reduction in Switching Losses

Two PWM techniques using space vector pulse-width modulation (SVPWM) are proposed for a two-phase permanent magnet synchronous motor (PMSM) driven by a two-phase eight- switch inverter. A two-phase motor with two symmetric stator windings is usually driven by a two- phase four-, six-, or eight-switch inverter. Compared with a four- and six-switch inverter, a two-phase eight-switch inverter can achieve larger power output. For two-phase motor drives, the SVPWM technique achieves more efficient DC bus voltage utilization and less harmonic distortion of the output voltage. For a two-phase PMSM fed by a two-phase eight-switch inverter under a normal SVPWM scheme, each of the eight PWM trigger signals for the inverter have to be changed twice in a cycle, causing a higher PWM frequency. Based on the normal SVPWM scheme, two effective SVPWM schemes are investigated in order to reduce the PWM frequency by rearranging four comparison values, while achieving the same function as the normal PWM scheme. A detailed explanation of the normal and two proposed SVPWM schemes is illustrated in the paper. The experimental results demonstrate that the proposed schemes achieve a better steady performance with lower switching losses compared with the normal scheme.