Nasser Abdelrahman M, Refky Amr, Shatla Hamdy, Abdel-Hamed Alaa M
Department of Electrical Engineering, Faculty of Engineering, Al-Azhar University, Cairo, Egypt.
Electrical Power and Machines Department, High Institute of Engineering, El-Shorouk Academy, Cairo, Egypt.
Sci Rep. 2024 Mar 25;14(1):7016. doi: 10.1038/s41598-024-57262-0.
The Multilevel inverter (MLI) plays a pivotal role in Renewable Energy (RE) systems by offering a cost-effective and highly efficient solution for converting DC from Photovoltaic (PV) sources into AC at high voltages. In addition, an innovative technology holds immense significance as it not only enables the seamless integration of PV systems into the grid but also ensures optimal power generation, thereby contributing to the widespread adoption of RE and fostering a sustainable future. This paper presents a modified sinusoidal pulse width modulation (SPWM) control scheme for a three-phase half-bridge cascaded MLI-powered PV sources. The selection of the MLI configuration is motivated by its reduced number of switching components, which enhances system reliability and simplifies experimental implementation. Compared to the SPWM schemes which require (m-1) carriers that make the generation of the pulse circuit very complex, the proposed control scheme requires only three signals: a carrier signal, a triangular waveform, and a modulating signal. This approach significantly reduces the complexity of control and facilitates practical implementation. The proposed control scheme simulation is verified using MATLAB/SIMULINK Software. The grey wolf optimization (GWO) algorithm is implemented to determine the optimal switching angles of the proposed control scheme. The Total Harmonic Distortion (THD) objective is selected to be the fitness function to be minimized for improving the quality of the output waveforms. For verification, the results of the proposed GWO-based modified SPWM control scheme are compared with those obtained using both the Particle swarm Optimization (PSO) and Genetic algorithm (GA) used in the literature. Simulation results declared that the proposed control scheme improves performance, especially THD which is minimized to 6.8%. Experimental validation has been conducted by building a laboratory prototype of the proposed system. The experimental and simulation results gave acceptable and limited convergent results considering the experimental difficulties.
多电平逆变器（MLI）在可再生能源（RE）系统中发挥着关键作用，它为将光伏（PV）源的直流电高效转换为高压交流电提供了一种经济高效的解决方案。此外，一项创新技术具有重大意义，因为它不仅能使光伏系统无缝接入电网，还能确保最佳发电效果，从而推动可再生能源的广泛应用，助力实现可持续发展的未来。本文提出了一种用于三相半桥级联MLI供电光伏源的改进型正弦脉宽调制（SPWM）控制方案。选择MLI配置的原因在于其开关元件数量减少，这提高了系统可靠性并简化了实验实施。与需要（m - 1）个载波从而使脉冲电路生成非常复杂的SPWM方案相比，所提出的控制方案仅需要三个信号：一个载波信号、一个三角波形和一个调制信号。这种方法显著降低了控制复杂度并便于实际实施。所提出的控制方案通过MATLAB/SIMULINK软件进行了仿真验证。采用灰狼优化（GWO）算法来确定所提出控制方案的最佳开关角度。选择总谐波失真（THD）目标作为要最小化的适应度函数，以提高输出波形质量。为进行验证，将基于GWO的改进型SPWM控制方案的结果与文献中使用粒子群优化（PSO）和遗传算法（GA）获得的结果进行了比较。仿真结果表明，所提出的控制方案提高了性能，尤其是THD最小化至6.8%。通过构建所提出系统的实验室原型进行了实验验证。考虑到实验困难，实验和仿真结果给出了可接受且有限的收敛结果。
