Sinewave PWM Research Articles

Analysis and assessment of electrical and thermal performance of five‐phase voltage source inverter under different modulation strategies: Comparative study under balanced and unbalanced load

SummaryThis paper compares four modulation strategies applied to five‐phase voltage source inverters (5PH‐VSI). The modulation strategies under investigation are sine wave pulse width modulation (S‐PWM), fifth‐harmonic injection PWM (FH‐PWM), space vector‐PWM using two large vectors (2V‐SVPWM), and space vector‐PWM using two medium and two large vectors (4V‐SVPWM). The study utilizes simulations to analyze the results based on four performance criteria: low‐order harmonics (LOH), maximum modulation index (MMI), common mode voltage (CMV), and total harmonic distortion (THD) under balanced and unbalanced load. To validate the simulation results for these criteria, an experimental test‐bench is employed, which includes a 5PH‐VSI feeding an R‐L load, and controlled by a low‐cost STM32F4‐DISCOVERY microcontroller board. Additionally, a mathematical approach is used to calculate the total thermal losses (TTL) then simulations are performed using Piecewise Linear Electrical Circuit Simulation (PLECS) software to assess the modulation schemes based on additional thermal performance criteria: conduction losses (CL), switching losses (SL), TTL, the efficiency, and the maximum permissible heat sink thermal resistance (MPHTR) at the steady‐state regime. The results indicate that the 4V‐SVPWM method demonstrates superior efficiency in terms of THD. Furthermore, it showcases the lowest TTL at high switching frequencies, allowing for the best efficiency and minimizing MPHRT, therefore providing the largest margin for the heat sink thermal resistance design. On the other hand, the 2V‐SVPWM offers the highest MMI, but this comes at the cost of high TTL and some LOHs appearing. In addition, it exhibits the highest CMV for unbalanced load. S‐PWM and FH‐PWM offer the advantage of simpler implementation.

High gain coupled inductor SEPIC based boost inverter using extended SPWM

This research work designs a high gain coupled inductor SEPIC (CI-SEPIC) based boost inverter. This topology presents low switching voltage stress, high output DC and AC voltage and highly efficient system, which makes it suitable for renewable energy applications. A seventh order system is obtained through dynamic modelling of the CI-SEPIC converter for which PID controller is designed to track the reference value. The extended sine-wave pulse width modulation (ESPWM) has maintained the high gain without compromising the efficiency and ensured low voltage stress on the switching devices. Simulation and experimental results validated that CI-SEPIC based boost inverter with ESPWM achieved high dc gain of 15.98, boost factor of 25, exceptional dc-ac coupling with minimum possible capacitance of 3.3uF, decreased device stress by 33% and smaller size of the complete system.

Stability analysis of improved combined-mode power converter and power flow control using FPGA

ABSTRACT An improved combined-mode power converter (CMPC) for a solar photovoltaic (SPV) system is presented in this paper. Ten-power electronic switches are utilised for the functioning of the converter. The proposed converter has four modes of operation: buck, boost, inverter, and mixed mode. The new CMPC topology provides a unique and complex switching sequence for implementing the mixed-mode operation. This work uses a field-programmable gate array (FPGA) for mode selection and to create PWM (MS-PWM) signals. A digital MS-PWM controller is configured to switch between improved stepped perturb and observe (ISPO) maximum-power point tracking (MPPT) and sine wave PWM (SPWM). The ISPO provides the appropriate duty cycle for buck/boost operation, while the SPWM controls the inverter operation. This work’s new digital PWM control algorithm supports mode selection, PWM generation, and reconfiguring PWM generation timings. The whole framework for constructing the MS-PWM controller employs a very high-speed integrated circuit hardware description language (VHDL). Simulation and experimental results are presented, proving that the digital MS-PWM controller uses fewer resources with improved accuracy.

An SVPWM Algorithm for a Novel Multilevel Rectifier with DC-Side Capacitor Voltage Balance

The recently proposed novel unidirectional multilevel rectifier, a three single-phase star-connected multilevel rectifier, has the characteristic of having a large number of DC-side capacitors and a complex capacitor voltage balancing control structure under conventional carrier-based phase-shift sine wave pulse-width modulation (SPWM). Hence, a space vector pulse-width modulation (SVPWM) algorithm for the novel multilevel rectifier is proposed in this paper, which can quickly balance the capacitor voltage without an additional voltage balancing control structure. Firstly, it divides the space vectors of the rectifier, then it determines the two basis voltage vectors that synthesize the output reference voltage. After that, based on the analysis of the relationship between switching states and the charge–discharge of capacitors, the final action sequences of redundant vectors are determined according to the principle of keeping the capacitor charge–discharge time consistent. Thus, the capacitor voltages can be automatically balanced without an additional voltage balancing control structure. Finally, simulation and experimental results validated the feasibility and effectiveness of the proposed SVPWM algorithm. The results also show improvements in current quality, capacitor voltage balance and the fluctuation of the neutral point voltage on the DC-link, allowing for further reduction in the overall volume and cost of the rectifier.

An Efficient Asymmetric Direct Current (DC) Source Configured Switched Capacitor Multi-level Inverter

This paper is dealing about Switched Capacitor Multi-Level Inverter (SCMLI) circuit which is controlled by triangular multicarrier Sinewave Pulse Width Modulation (SPWM) technique. The proposed SCMLI is powered from asymmetric DC source configuration to obtain multi-level output voltage by applying switching pulse to the main circuit from control circuit for switching operation. Fourteen switches and four capacitors are employing to do the proposed inversion operation in an effective way. Switching capacitors can perform boost operation to enhance voltage from the source level to the required level. Input DC from the asymmetric sources is converted to AC voltage for the application of consumers. This proposed conversion system is applicable for mainly in industrial and renewable energy-based energy conversion system because it can carry high output voltages. This proposed method gives about more efficiency. Also reduces switching losses in lower value, low conduction losses and capacitor ripple losses. The simulation model is analyzed in MATLAB/SIMULINK platform and the same validated in hardware results. The developed SCMLI structure is witness over other topologies for the power inversion process in the multi-level.

Mitigation of common mode voltage in five phase multilevel inverter

This paper exhibits the new modified sine wave pulse width modulation technique in a multilevel inverter to a decrement in the common mode voltage. It focuses on different schemes for decrease of CMV to reduce the circulating bearing current in poly phase induction motor drive. There are two different topologies considered for analysing the value of circulating bearing current in motor drives such as Neutral Point Clamped Inverter (NPC) topology and Cascaded inverter topology. The identified better topology to reduce circulating bearing current is cascaded topology. The simulation model of the proposed five phase five level inverter circuits are developed under the MATLAB-SIMULINK. The use of five phases in this technique is to enhance the productivity of machine and to reduce the losses in the machine unlike the three- phase machine which accounts for more losses compared to five phases. Simulation results are contrasted to those of theoretical calculations to examine the common mode voltage. Total Harmonic Distortion (THD) comparison is also done under Fast Fourier Transform (FFT) analysis between NPC inverter topology and cascaded inverter topology.

The Design of SVPWM Waveform Generator Based on CPLD_DSP

Space vector pulse width modulation (SVPWM) control technology could obtain quasi circular rotating magnetic field by switching the space voltage vector of the inverter. Under the condition of low switching frequency, the performance of AC motor was better than that of sine wave pulse width modulation. When this technology was applied to inverter control system, better output voltage waveform could be obtained than conventional six step waveform. And in order to further improve the control performance of the motor, it was very necessary to design SVPWM waveform generator. The design of SVPWM waveform generator based on Complex Programmable Logic Device and Digital Signal Processing (CPLD_DSP) was introduced in the article. The main idea of SVPWM was to synthesize reference voltage vector by switching space voltage vector of inverter. Time holding data and sector number could be calculated from coordinate switch of Voltage gathered from inverter by DSP. And the data was sent into CPLD. SVPWM waveform was generated by state machine programed in VHDL. Finally program was download in CPLD chip named EPM1270T144C5N. The transformation from time signal to SVPWM switch signal was finished successfully. The three phrase output signal had good coherence. Thus the controlling function of the motor control system was improved in a certain extent.

3-Phase Induction Motor Control using Space Vector and Sinusoidal Pulse Width Modulation Technique

This paper deals with the control of the induction motor using two different control methods: Space Vector and Sine wave pulse width modulation technique. The objective of the project is to find the most appropriate technique for induction motor control for industrial application. The scalar v/f method offers good performance only in the course of the steady-state and not under transient conditions. This important downside may be rectified by the vector control technique. The method provides high dynamic performance for velocity and torque-controlled AC machines.

A Unidirectional Single-Stage Three-Phase Soft-Switched Isolated DC–AC Converter

This paper presents a novel single-stage soft-switched high-frequency-link three-phase dc–ac converter topology. The topology supports unidirectional dc to ac power flow and is targeted for applications like grid integration of photovoltaic sources, fuel cell, etc. The high frequency magnetic isolation results in reduction of system volume, weight, and cost. Sine-wave pulsewidth modulation is implemented in dc-side converter. Though high-frequency switched, dc-side converter is soft switched for most part of the line cycle. The ac-side converter active switches are line frequency switched incurring negligible switching loss. The line frequency switching of ac-side converter facilitates use of high voltage blocking inherently slow semiconductor devices to generate high voltage ac output. In addition, a cascaded multilevel structure is presented in this paper for direct medium-voltage ac grid integration. A detailed circuit analysis considering nonidealities like transformer leakage and switch capacitances, is presented in this paper. A 6-kW three-phase laboratory prototype is built. The presented simulation and experimental results verify the operation of the proposed topologies.

Coupled‐inductor based diode assisted boost inverter for achieving highgain

A high-gain single-stage three-phase coupled-inductor diode-assisted boost inverter (CL-DABI) is presented for energy applications. A new scheme has been proposed which is simple, has less number of energy storage components and uses non-shoot-through pulse-width modulation (PWM) techniques such as sine-wave PWM and space vector modulation to get the maximum gain from a low-voltage dc source. During simulation and hardware implementation, it was observed that the SPWM method resulted in a lower conversion rate and higher device stress. To improve the shortcomings, extended sine-wave PWM (ESPWM) method is proposed to achieve high gain without compromising the conversion efficiency and putting devices under stress. Mathematical analysis, simulations results and experimental verifications are presented here. Hardware results prove the validity of the proposed CL-DABI with ESPWM by achieving high intermediate dc gain, excellent dc-ac coupling, less device stress, comparable power quality and smaller size.

Integral‐series Fourier analysis of chaotic PWM patterns for common mode voltage stresses

In this study, the theory of pulse width modulation (PWM) is developed for both sine-wave PWM (SPWM) and chaotic sine-wave PWM (CSPWM). In SPWM, power spectra are analysed by an analytical method such as double Fourier series (DFS) technique, and the integral-series Fourier method is fully devised and analytically theorised for CSPWM. It is shown that the root-mean-square value of inverter's zero-sequence voltage does not rely on carrier and reference frequency in fixed-frequency SPWM, while in CSPWM, this depends on frequency modulating gain and chaotic sequence of numbers. Also, the computation time of purely numerical harmonic analysis can be much heavier than analytical ones. Furthermore, the DFS and integral-series Fourier methods are applied to SPWM and CSPWM with two different frame sizes of squirrel cage motors for the shaft voltage and the electro-magnetic interference (EMI). The numerical and experimental results show that CSPWM can have positive effect on the shaft voltage while it definitely weakens the EMI problems.

A Bridge Modular Switched-Capacitor-Based Multilevel Inverter With Optimized SPWM Control Method and Enhanced Power-Decoupling Ability

Microinverters operating into the single-phase grid from new energy source with low-voltage output face the challenges of efficiency bottleneck and twice-line-frequency variation. This paper proposed a multilevel inverter based on bridge modular switched-capacitor (BMSC) circuits with its superiority in conversion efficiency and power density. The topology is composed of dc–dc and dc–ac stages with independent control for each stage, aiming to improve system stability and simplify the control method. The BMSC dc–dc stage, which can be expanded to synthesize more levels, not only features multilevel voltage gain but also partially replaces the original bulk input capacitor and functions as an active energy buffer to enhance power-decoupling ability between dc and ac sides. In dc–ac stage, the control strategy of optimized unipolar frequency doubling sine-wave pulse width modulation is proposed to improve the quality of output waveform. Meanwhile, the multilevel voltage phase has been optimized to further reduce the power loss. Finally, a prototype has been built and tested. Associated with the simulation, the experimental results validate the practicability of these analyses.

Flux-controlled memristor equivalent circuit based on SPWM control

This paper provides a practical two-terminal implementation circuit model of a flux-controlled memristor based on the SPWM (Sine-wave Pulse-Width Modulation) control algorithm. The model can be divided into two parts: the main circuit and the control circuit. The main circuit includes a passive low pass filter and an equivalent variable resistor regulated by the control circuit based on the SPWM method. The components that constitute the main circuit are passive devices, such as resistors, inductors and capacitors, as well as power switching devices. Thus, the memristor implementation circuit can be used to handle electrical signals with higher power levels. Detailed theoretical analysis and verification of the proposed memristor circuit are presented. Both the simulated and experimental results demonstrate that the input impedance of the proposed circuit has the typical characteristics of a flux-controlled memristor, which is in accordance with the theoretical analysis. Furthermore, the circuit can handle signals with power up to several hundred watts. Additionally, the proposed circuit has the advantages of simple topology and low cost, which may promote applications of the memristor in the real world.

Maximum Efficiency per Torque Control of Permanent-Magnet Synchronous Machines

High-efficiency permanent-magnet synchronous machine (PMSM) drive systems need not only optimally designed motors but also efficiency-oriented control strategies. However, the existing control strategies only focus on partial loss optimization. This paper proposes a novel analytic loss model of PMSM in either sine-wave pulse-width modulation (SPWM) or space vector pulse width modulation (SVPWM) which can take into account both the fundamental loss and harmonic loss. The fundamental loss is divided into fundamental copper loss and fundamental iron loss which is estimated by the average flux density in the stator tooth and yoke. In addition, the harmonic loss is obtained from the Bertotti iron loss formula by the harmonic voltages of the three-phase inverter in either SPWM or SVPWM which are calculated by double Fourier integral analysis. Based on the analytic loss model, this paper proposes a maximum efficiency per torque (MEPT) control strategy which can minimize the electromagnetic loss of PMSM in the whole operation range. As the loss model of PMSM is too complicated to obtain the analytical solution of optimal loss, a golden section method is applied to achieve the optimal operation point accurately, which can make PMSM work at maximum efficiency. The optimized results between SPWM and SVPWM show that the MEPT in SVPWM has a better effect on the optimization performance. Both the theory analysis and experiment results show that the MEPT control can significantly improve the efficiency performance of the PMSM in each operation condition with a satisfied dynamic performance.

IMPLEMENTATION OF AC INDUCTION MOTOR CONTROL USING CONSTANT V/HZ PRINCIPLE AND SINE WAVE PWM TECHNIQUE WITH TMS320F28027

This paper presents the hardware implementation of V/f control of induction motor using sine wave PWM method. Because of its simplicity, the V/F control also called as the scalar control, is the most widely used speed control method in the industrial applications. In this method the ratio between stator voltage to frequency is maintained constant so that the stator flux is maintained constant. As the stator flux is maintained constant, the torque developed by the motor depends only on the slip speed and is independent of the supply frequency. Thus we can control the speed and torque of induction motor by simply controlling the slip speed of induction motor. The complete control is achieved with the help of TMS320F28027 Development Board. One of the basic requirements of this scheme is the PWM inverter. The gating signals are generated using sine wave PWM technique. Implementation issues such as PWM signal generation, ramp control, v/f control, inverter design are discussed. The results are discussed based on the various waveforms.

A Problem with IFOC and a New PWM Based 180 Degree Conduction Mode for Three Phase Inverter

Three Phase Inverters being used today are based on Field Orientation Control (FOC) and Sine Wave PWM (SPWM) techniques because 120 degree or 180 degree conduction methods produce high value of THD (Total Harmonic Distortion) in the power system. The Indirect Field Orientation Control (IFOC) method is difficult to implement in real systems due to speed sensor accuracy issue. This paper discusses the problem with IFOC and a PWM based 180 degree conduction mode for the three phase inverter. The modified control method improves THD and this paper also compares the results obtained using modified control method with the conventional 180 degree conduction mode.

Stable V/F Control of Open Winding Surface Mounted Permanent Magnet Synchronous Motor Drives with SPWM Strategy

This paper presents dual inverter power supply open-end winding of surface mounted permanent magnet synchronous motor (OW-SPMSM) drive system for fans and pumps energy saving by V/f control. On the principle of OW-SPMSM drive system, this paper puts forward a unified Sine wave pulse width modulation strategy (SPWM) of dual inverter, which is easy to real time implementation for the calculation of this method is less than SVPWM, its performance is as good as the SVPWM in terms of harmonic power balance. Accordingly, a power factor closed loop control was introduced into the drive system to achieve stable volts/hertz (V/F) control. The system simulation model was investigated in detail; its results show that the proposed drive system has greatly improved the system dynamic performance.

Phase‐shifted pulse‐width‐amplitude modulation for quasi‐Z‐source cascade multilevel inverter‐based photovoltaic power system

A phase-shifted pulse-width-amplitude modulation (PS-PWAM) is proposed for a quasi-Z-source cascade multilevel inverter (qZS-CMI)-based photovoltaic power system. The switching actions of each power device of the qZS-CMI in the PS-PWAM technique are greatly reduced when compared with that in the phase-shifted sinewave pulsewidth modulation, so the qZS-CMI's power loss is reduced when using the PS-PWAM. The PS-PWAM principle and the qZS-CMI's loss analysis are presented. The simulation and experimental results verify the proposed PS-PWAM and the resultant efficiency improvement.

The SPWM Pulse Width Signal Spectrum Analysis Based on MATLAB

Based on the analysis of the characteristics of sine-wave pulse-width modulation (SPWM) and space vector pulse width modulation (SVPWM) [, the key points are the algorithm of various sampling methods of PWM signals and the analysis of those signals spectrum with MATLAB[4]. The foundational features of the harmonic distributions and advantages and disadvantages of various sampling methods are obtained. According to the analysis, some suggest can be given for the evaluation of pulse width modulation scheme. In the same time, some methods of optimization of pulse wave are advised to provide theoretical guidance for the system design.

A Voltage Controller in Photo-Voltaic System with Battery Storage for Stand-Alone Applications

This paper proposes the new voltage controller in photo-voltaic system for Stand-Alone Applications with battery energy storage. The output of the PV array is unregulated DC supply due to change in weather conditions. The maximum power is tracked with respect to temperature and irradiance levels by using DC-DC converter. The perturbation and observes algorithm is applied for maximum power point tracking (MPPT) purpose. This algorithm is selected due to its ability to withstand against any parameter variation and having high efficiency. The solar cell array powers the steady state energy and the battery compensates the dynamic energy in the system. The aim of the control strategy is to control the SEPIC converter and bi-direction DC-DC converter to operate in suitable modes according to the condition of solar cell and battery, so as to coordinate the two sources of solar cell and battery supplying power and ensure the system operates with high efficiency and behaviors with good dynamic performance. The output of DC-DC converter is converted to AC voltage by using inverter. The AC output voltage and frequency are regulated. A closed loop voltage control for inverter is done by using unipolar sine wave pulse width modulation (SPWM). The regulated AC voltage is fed to AC standalone loads or grid integration. The overall system is designed, developed and validated by using MATLAB-SIMULINK. The simulation results demonstrate the effective working of MPPT algorithm, control strategy and voltage controller with SPWM technique for inverter in AC standalone load applications. DOI: http://dx.doi.org/10.11591/ijpeds.v2i1.127