Dead-Time Analysis in Three-Phase Two-Level Inverters using the SVPWM Technique

The space vector pulsewidth modulation (SVPWM) techniques enhance the performance of multilevel multiphase inverters. With multilevel (three-phase) inverters and with (two-level) multiphase inverters, it is widely accepted that the typical SVPWM strategies have an equivalent carrier-based pulsewidth modulation (CBPWM) counterpart, which produces identical results. However, the conclusions reached in the articles that show these cannot be applied, nor even extended, to SVPWM techniques with more than two levels and three phases. This article shows that the most widely accepted multilevel multiphase SVPWM techniques have a fully equivalent CBPWM counterpart, which consists of a phase disposition pulsewidth modulation with an appropriate zero-sequence injection scheme. Closed-form expressions to calculate the zero sequences are provided. The proposed modulation techniques are simulated and then implemented in a field-programmable gate array, showing that the equivalent CBPWM techniques produce identical results as the original SVPWM ones, but with a significant reduction of hardware requirements. The proposed methodology can be generalized to other multilevel multiphase SVPWM techniques.

This paper presents a modified space vector pulse width modulation (MSVPWM) technique for nine-level cascaded H-bridge (CHB) inverter. Based on a modular structure and absence of capacitor balancing problems, CHB inverter topology is preferred. Nowadays, space vector PWM (SVPWM) control scheme has achieved higher attention among different PWM techniques. In general, SVPWM method is realized based on disintegrating higher-level hexagons into a number of two-level hexagons. Compared to conventional SVPWM technique, the proposed MSVPWM technique reduces the computational burden and memory requirement involved in the realization of nine-level SVPWM. This is achieved by reducing the number of two-level hexagons without losing the inverter output voltage profile. Also a further modified space vector pulse width modulation technique is presented, which greatly reduces the computation efforts. The proposed SVPWM techniques are applied to a nine-level CHB inverter by using MATLAB/SIMULINK software tool and are compared with carrier-based sinusoidal pulse width modulation (SPWM) technique to validate the proposed techniques. The proposed SVPWM schemes produce lower harmonic distortion and higher DC bus utilization compared to SPWM technique. To verify the practicality of the proposed SVPWM techniques, experimental results are presented on nine-level CHB inverter.

The inverters and control methods are applied in more and more fields with power electronics development. The technology of current hysteretic band PWM is a kind of easy and reliable control method. But the harmonic distortion of load current is big amplitude around switching frequency side band. The paper introduce a Varied Hysteretic-band Current control technique(VHBCC), this method can spreads the spectrum contents of load current around switching frequency side band, reduces the harmonic distortion of load current . At last, The results of simulation prove the method feasible and effective.

Four-dimensional 24-sector space vector pulse width modulation (SVPWM) techniques result in good harmonic performance in split-phase induction motor (SPIM) drives, but have high computational burden. Per-phase analysis of two such SVPWM techniques is reported in this paper. Though the switching sequences used and the harmonic spectra are different for the two techniques, the waveshape of average pole voltage is identical for both PWM techniques at a given operating point. Consequently, common mode voltage (CMV) of a given inverter is also identical for the two methods. Analysis of CMV gives a method to derive the zero-sequence signal for each inverter from its three-phase sinusoidal modulating signals. Addition of the zero-sequence signal, thus derived, to the sinusoidal modulating signals results in a computationally-efficient method for generating the equivalent modulating signal. Equivalent carrier waves are derived for the two PWM techniques based on the corresponding switching sequences employed. The resulting carrier-based implementation reduces the computation time from $52.9\mu \mathrm{s}$ to $26.7\mu \mathrm{s}$ on a TMS320F28377S DSP platform. Simulation and experimental results of stator current waveform and total harmonic distortion (THD) in stator current from a 6-kW, 200-V, 50-Hz SPIM drive are presented for the two proposed methods and an existing carrier-based PWM.

Due to its advantages, the asymmetrical dual three-phase induction motor drive is a strong choice in high-power applications. However, the common-mode voltage produced by the voltage source inverters affects the winding insulation and damages the bearings. Common-mode voltage is also responsible for electromagnetic interference and leakage currents. This paper, therefore, analyses the common-mode voltage produced by the inverter supplying a dual three-phase induction motor drive and proposes a novel modified space vector decomposition-based Space Vector Pulse Width Modulation (SVPWM) technique for common mode reduction. The vector space decomposition-based space vector modulation technique offers excellent flexibility as it reduces the common-mode voltage (CMV) by exploiting the additional degree of freedom in a dual three-phase system. The common-mode voltage (CMV) can be reduced to one-sixth of the DC link voltage compared to the highest CMV, i.e. half of the DC-link voltage produced in conventional space vector modulation. The proposed method is also validated experimentally to demonstrate the effectiveness of the proposed scheme in terms of the amplitude of CMV, pulsations, and total harmonic distortion(THD) in current.

A review of the sinusoidal pulse-width-modulation (SPWM) and the space vector PWM (SVPWM) techniques for AC motor drives is reported, taking into account secondary effects such as the digital quantization, the dead time, and the dwell time. Simulation results show close agreement with the measured harmonics caused by an experimental digital-signal-processor (DSP)-controlled inverter operating in the same conditions. The SPWM waveforms have cleaner spectra than the SVPWM, but the quality factors are higher with respect to the SVPWM, having the same peak value of the voltage reference. As a consequence, if the switching frequency is high enough, the losses due to the harmonics can be almost neglected, and the SVPWM seems to be the best solution in terms of output voltage, harmonic losses, and number of switchings per cycle.

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. DOI: http://dx.doi.org/10.11591/ijpeds.v5i1.6038

The Doubly Fed Induction Motor (DFIM) is essential in Wind Energy Conversion Systems (WECS) for efficient wind energy harvesting. Conventional power converters in WECS often result in high Total Harmonic Distortion (THD) in output voltage and current, affecting wind energy economy. This research proposes replacing conventional converters with Modular Multi-level Converters (MMC) due to their scalable topology, low harmonic distortion, high efficiency, and the elimination of DC link capacitors. The MMC is connected in a back-to-back configuration between the rotor of the DFIM and the grid to enable four-quadrant operation. Circulating current in the MMC is minimized using a Modified Deer Hunting Optimization (MDHO) based Fractional Order PID (FOPID) controller and a Mexican Axolotl Optimization (MAO) based FOPID. Capacitor voltage balancing is achieved using Level-Shifting PWM (LSPWM) and Three-Dimensional Space Vector PWM (3D-SVPWM) techniques with voltage sorting algorithms. The impact of these control and modulation techniques on the DFIM is analyzed in terms of reduced THD, and steady state and transient performance. Simulations are conducted in MATLAB/R2022a, and experimental validation is performed using a 7-level 0.5 kW MMC in a Hardware-In-Loop (HIL) setup.

Multi-phase induction motor drives are being considered for various high power applications because of their superiority over three-phase counterparts. Space vector pulse width modulation (SVPWM) schemes can be utilized to improve output voltage spectrum of the inverter thus reducing stator harmonic currents and torque pulsation. Different SVPWM techniques are analyzed for a dual three-phase induction motor (DTIM) supplied from two three-phase inverters. Harmonic component in the phase current and phase voltage is analyzed for four different SVPWM schemes. A detailed modeling of DTIM along with SVPWM strategies are is presented in the paper. Simulation results are provided to verify the analysis proposed.

Phase current is crucial for closed-loop control and system monitoring of a T-type three-level inverter (TThLI). However, the traditional space vector pulse width modulation (SVPWM) method cannot fully meet the minimum sampling time, which leads to the emergence of unobservable areas (UAs) in the neutral current sensor (NCS) phase current reconstruction system of TThLI. Moreover, the current zeropoint drift (ZPD) caused by temperature drift, aging, and noise affects the accuracy of NCS sampling. Regarding the issues above, this paper investigates the impact of UAs and ZPD on the NCS phase current reconstruction system and proposes an asymmetric SVPWM and error suppression (APES) phase current reconstruction method. The proposed method comprises two links: asymmetric SVPWM (ASVPWM) and ZPD error suppression. Firstly, the ASVPWM regulates the PWM waveforms according to composite zero vector and volt-second balancing principles and then generates three observable vectors whose dwell time is greater than the minimum sampling time to eliminate the UAs. Secondly, the ZPD errors are obtained and suppressed through the dynamic current triple sampling mechanism to improve reconstruction accuracy. Finally, experimental results show that the proposed APES method achieves an accuracy of 3.51% at the expense of a slight increase in total harmonic distortion.

the Simulation model of DDPMSG 10KW grid Connected are developed using MATLAB 2013(a) and FAST Simulator. In addition to it SVPWM technique has been applied for 10KW grid connected model. Space vector pulse width modulation has been used for obtaining the output voltage with less distortion. An interface has also been developed between FAST and SIMULINK with MATLAB, enabling users to implement advanced turbine controls in SIMULINK convenient block diagram . The FAST subroutines have been linked with a MATLAB standard gateway subroutine in order to Generator torque control, nacelle yaw control, and pitch control modules can be designed in the SIMULINK environment. The fully controlled converter has been used to provide separate control for active and reactive powers. The simulation results in MATLAB SIMULINK 2013a showing the model have good dynamic and static performance. Index Terms: Direct drive permanent magnet synchronous generator, space vector pulse width modulation, fully controlled converters. I. Introduction The aim of this research is to model an autonomous control wind turbine driven permanent magnetic synchronous generator.(PMSG) which feeds alternating current (AC) power to the utility grid. Furthermore, this research also demonstrates the effects and the efficiency of PMSG wind turbine which is integrated by autonomous controllers. In order for well autonomous control, two voltage source inverters are used to control wind turbine connecting with the grid. The generator-side inverter is used to adjust the Synchronous generator as well as separating the generator from the grid when necessary. The grid-side inverter controls the power flow between the direct current (DC) bus and the AC side. Both of them are oriented control by space vector pulse width modulation (SVPWM) with back-to-back frequency inverter. Moreover, the proportional-integral (PI) controller is enhanced to control both of the of the converters and the pitch angle of the wind turbine. II. Inverters And The Pitch Angle Of The Wind Turbine According to the continuous development of wind power technology, the efficiency of inverter device is facing some tough issues and plays a vital role in the improvement of wind power generation system performance. They need to be enhanced by controller (3) to improve the efficiency and the reliability. Inside them, MPPT integrating with the back to back space vector Pulse width modulation (4) is the advantage of controller (3), which is used to measure the rotor speed and compare with the calculated optimal rotor speed. On the other hand, not only does the inverter take an advantage in efficiency control but also the pitch angle controller takes another important part of wind turbine. It is integrated to adjust the aerodynamic torque of the wind turbine when this study rates wind speed

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.

In an isolated mode operation of wind power generating system (WPGS), operating voltage and frequency are affected under sudden change of load because of more transient time, higher total harmonic distortion. To minimize the effects, the WEGS should be operated with suitable controller and the inverter should be operated with required pulse width modulation (PWM) technique. In this paper, the proposed WPGS is simulated using MATLAB/Simulink with adaptive voltage controller (AVC) and load current observer (LCO) and the inverter is operating with Unified voltage Space Vector PWM (USVPWM) technique to improve the transient behaviour of the system. The same proposed system is also simulated with conventional space vector pulse width modulation (SVPWM) techniques. The simulation results will be analyzed in various load conditions. The conventional SVPWM results compared with the USVPWM results like transient time, load voltage and load current total harmonic distortion under balanced three-phase load.

This study proposed a novel method to eliminate the pulse width modulation (PWM) harmonics at a quite low switching frequency for the two‐segment three‐phase motor. Due to the PWM technique and considerations of switching losses, acoustic noise <20 kHz in the motor drive system is common. By using modified space vector PWM (MSVPWM) technique and interleaved topology with magnetically coupled inductors (MCIs), the proposed novel method is able to remove the first, second, and third order carrier frequency noises from the motor. The MSVPWM is used to eliminate the first and third order carrier frequency harmonics and second order harmonics are reduced by interleaved topology. With this method, the unpleasant acoustic noise <20 kHz could be removed when the switching frequency is selected near 6.7 kHz. The size of MCIs mainly depends on the PWM current harmonics and it is very small compared with inductor‐capacitor/inductor‐capacitor‐inductor filter. Moreover, this method remains to be the control dynamics of the motor without additional inductance for fundamental frequency currents. Finally, the effectiveness of the proposed method is verified by detailed simulation and experimental results.

In this work, the direct torque control (DTC) is applied to the five-phase permanent magnet synchronous motor (FP-PMSM). The DTC method based on classical space vector pulse width modulation (SVPWM) is a common solution used to overcome traditional problems; such as stator flux ripple, electromagnetic torque ripple and gives more total harmonic distortion (THD) of the stator current. The actual paper is based on improving the performance of DTC-SVPWM by using the feedforward neural networks (FNNs) instead of the proportional-integral (PI) regulators and hysteresis comparators (HCs) of the conventional SVPWM strategy. This algorithm can solve the traditional PI regulators and HCs problems which are represented in responses dynamic and reduce the torque ripple, flux ripple, and the THD of stator current of FP-PMSM drives. The proposed strategy was tested in different tests with simulation using Matlab software.