Online control of AC/AC converter based SHEPWM technique

Conventional online control of AC/AC converter controlled by the selective harmonic elimination pulse width modulation technique (SHEPWM) is based on storing the offline calculated switching angle values in a form of lookup table. Then the required switching pattern of certain modulation index (M) is searched through the lookup table. This methodology suffers from limited system flexibility. This paper introduces a novel implementation scheme based on real-time calculation of the required SHEPWM switching pattern with linear control of the fundamental voltage component magnitude based on curve fitting technique for the exact switching angle trajectories. The accuracy of the derived polynomials is evaluated by calculating converter performance parameters using the approximated switching angles solutions obtained from the introduced method and the exact switching angles solutions. Detail of the introduced methodology is presented. Simulation and experimental results have been carried out to confirm the validity of the introduced algorithm

Design of a Partial Resonant Inverter for solar photovoltaic applications

This paper presents a solar-powered Partial Resonant Inverter (PRI) interfaced with an asymmetrical cascaded nine-level inverter. The DC input of the proposed system is obtained using Solar Photovoltaic (SPV) panel. The input DC sources fed to the asymmetrical cascaded nine-level inverter are in the ratio of 1:3. The step modulated nine-level inverter works with a precalculated switching angle for a fixed modulation of 0.7. Compared to the conventional 50 Hz inverter and the multi-output transformer design, the proposed system is more compact because of the high-frequency AC link. The PRI ensures Zero Voltage Switching (ZVS) and reduces the switching losses. The proposed scheme has been validated in the MATLAB/ SIMULINK environment and an experimental prototype is built in the laboratory. Based on the investigations the Selective Harmonic Elimination (SHE) method gives superior performance when compared to the Optimal Harmonic Stepped Modulation (OHSM) method. From the results and comparative analysis, the proposed system uses fewer switches to obtain the nine-level output, uses the PRI setup with the multioutput transformer to make the design compact and improves the power quality of the system

Improved power quality operation of symmetrical and asymmetrical multilevel inverter using invasive weed optimization technique

Low switching frequency pulse width modulation (PWM) technique for modulation and control of multilevel inverter in medium voltage high power applications is preferred in order to reduce the switching losses. In this context, a multilevel inverter operated with Selective harmonics minimization PWM technique offers better quality waveform at reduced switching losses. After the Fourier series analysis, the system of non-linear simultaneous transcendental equations is obtained. These equations are then solved to obtain switching angles to have certain low order harmonics at minimum value and regulation in the fundamental voltage magnitude. In this paper, a novel invasive weed optimization (IWO) technique is proposed to compute switching angles. The proposed technique can compute switching angles for both symmetrical and asymmetrical multilevel inverters. Thus it has superiority over well-known optimization techniques such as GA, PSO, DE, and ACO, etc. Moreover, in certain modulation index ranges, it provides faster convergence and accurate results which have been demonstrated in the paper. The computational results have been verified with the experimental result on the prototype developed in the laboratory. The field programming gate arrays (FPGA) based controller is used to implement the proposed technique. The hardware results have been found in close agreement with the computed results. 2022This publication was made possible by NPRP grant #[ 13S-0108-20008 ] from the Qatar National Research Fund (A member of Qatar Foundation). The statements made herein are solely the responsibility of the authors. The APC of the paper is funded by the Qatar National Library , Doha, Qatar.Scopu

Development and Implementation of Novel Intelligent Motor Control for Performance Enhancement of PMSM Drive in Electrified Vehicle Application

The demand for electrified vehicles has grown significantly over the last decade causing a shift in the automotive industry from traditional gasoline vehicles to electric vehicles (EVs). With the growing evolution of EVs, high power density, and high efficiency of electric powertrains (e–drive) are of the utmost need to achieve an extended driving range. However, achieving an extended driving range with enhanced e-drive performance is still a bottleneck. The control algorithm of e–drive plays a vital role in its performance and reliability over time. Artificial intelligence (AI) and machine learning (ML) based intelligent control methods have proven their continued success in fault determination and analysis of motor–drive systems. Considering the potential of intelligent control, this thesis investigates the legacy space vector modulation (SVM) strategy for wide–bandgap (WBG) inverter and conventional current PI controller for permanent magnet synchronous motor (PMSM) control to reduce the switching loss, computation time and enhance transient performance in the available state–of–the-art e–drive systems. The thesis converges on AI– and ML–based control for e–drives to enhance the performance by focusing in reducing switching loss using ANN–based modulation technique for GaN–based inverter and improving transient performance of PMSM by incorporating ML–based parameter independent controller

Modular Multilevel Converters for Medium Voltage Applications: Low Switching Frequency Modulation Strategies and Circulating Current Control Techniques.

233 p.El objetivo de la presente tesis ha sido el aumento de la eficiencia y la mejora del funcionamiento de convertidores multinivel modulares (MMCs) en aplicaciones de media tensión (drives, STATCOMs, redes de media tensión en DC o colectores de energía en parques eólicos). Para ello se ha propuesto la utilización de una modulación de baja frecuencia de conmutación como la Eliminación Selectiva de Armónicos (SHE-PWM). De esta forma se reducen las pérdidas de conmutación significativamente. Las contribuciones de la tesis son:- Nueva formulación para implementar SHE-PWM: Esta nueva formulación, a diferencia de las existentes, proporciona un sistema único de ecuaciones que es válido para cualquier forma de onda. De esta forma, es posible buscar los ángulos de disparo y los patrones de conmutación, que resuelven el problema de SHE-PWM, sin necesidad de predefinir ninguna forma de onda. Por lo tanto, la búsqueda de ángulos de disparo se simplifica significativamente y se puede encontrar un alto número de soluciones diferentes, pudiendo optimizar el diseño de la forma de onda. Además, esta formulación es válida con simetrías de cuarto de onda y de media onda.- Controles de la corriente circulante en MMCs cuando se utiliza SHE-PWM: estos controles, a diferencia de los existentes, no distorsionan la tensión de fase de salida cuando se utiliza SHE-PWM y permiten mantener equilibradas las tensiones de los condensadores de los sub-módulos del MMC, además de reducir rizado de la corriente circulante. En concreto, se han propuesto dos controles, uno con (N+1) SHE-PWM y otro con (2N+1) SHE-PWM

Modular Multilevel Converters for Medium Voltage Applications: Low Switching Frequency Modulation Strategies and Circulating Current Control Techniques.

233 p.El objetivo de la presente tesis ha sido el aumento de la eficiencia y la mejora del funcionamiento de convertidores multinivel modulares (MMCs) en aplicaciones de media tensión (drives, STATCOMs, redes de media tensión en DC o colectores de energía en parques eólicos). Para ello se ha propuesto la utilización de una modulación de baja frecuencia de conmutación como la Eliminación Selectiva de Armónicos (SHE-PWM). De esta forma se reducen las pérdidas de conmutación significativamente. Las contribuciones de la tesis son:- Nueva formulación para implementar SHE-PWM: Esta nueva formulación, a diferencia de las existentes, proporciona un sistema único de ecuaciones que es válido para cualquier forma de onda. De esta forma, es posible buscar los ángulos de disparo y los patrones de conmutación, que resuelven el problema de SHE-PWM, sin necesidad de predefinir ninguna forma de onda. Por lo tanto, la búsqueda de ángulos de disparo se simplifica significativamente y se puede encontrar un alto número de soluciones diferentes, pudiendo optimizar el diseño de la forma de onda. Además, esta formulación es válida con simetrías de cuarto de onda y de media onda.- Controles de la corriente circulante en MMCs cuando se utiliza SHE-PWM: estos controles, a diferencia de los existentes, no distorsionan la tensión de fase de salida cuando se utiliza SHE-PWM y permiten mantener equilibradas las tensiones de los condensadores de los sub-módulos del MMC, además de reducir rizado de la corriente circulante. En concreto, se han propuesto dos controles, uno con (N+1) SHE-PWM y otro con (2N+1) SHE-PWM