Darvish Falehi Ali
Department of Electrical Engineering, Islamic Azad University, Shadegan Branch, Shadegan, Iran.
Heliyon. 2020 Mar 18;6(3):e03585. doi: 10.1016/j.heliyon.2020.e03585. eCollection 2020 Mar.
In this paper, a novel Asymmetrical Multi-Level Inverter (AMLI) is suggested to solve the voltage quality problem. The suggested AMLI has been constructed based on series connection of sub-AMLIs to create a high-step quasi-sinusoidal voltage with considering few semiconductor switches. The ladder capacitors of sub-AMLI have been clamped to the H-bridge structure via several bi-directional switches. Based on an innovative geometric progression for DC power supplies of AMLI, it can operate as so-called odd-nary AMLI. It has effectually created a quasi-sinusoidal with high steps i.e., low Total Harmonic Distortion (THD) with respect to low number of switches. The performance of suggested AMLI has been thoroughly compared with other inventive asymmetrical and symmetrical multilevel inverters. Following that, scission-style harmonic elimination based on Pulse Width Modulation (PWM) is introduced to enhance voltage quality of AMLI. Three prominent criterions related to voltage quality i.e., desired fundamental component, elimination of third harmonic and reduction of THD have been assigned as objective functions of optimization problem. Considering the multi-objective nature of the optimization problem, non-dominated sorting Multi-Objective Grey Wolf Optimizer (MOGWO) has been implemented to solve the optimization problem, and then compared with Non-dominated Sorting Genetic Algorithm II (NSGA-II). To sum up, the relevant analytical studies along with both the simulation and experimental results have transparently validated the performance of suggested AMLI. Also, the voltage quality problem using MOGWO-based scission-style harmonic elimination strategy has been well approved.
本文提出了一种新型非对称多电平逆变器（AMLI）来解决电压质量问题。所提出的AMLI基于子AMLI的串联构建，以在考虑较少半导体开关的情况下创建高电平准正弦电压。子AMLI的梯形电容通过几个双向开关钳位到H桥结构。基于一种创新的AMLI直流电源几何级数，它可以作为所谓的奇进制AMLI运行。它有效地创建了具有高电平的准正弦波，即相对于较少数量的开关具有低总谐波失真（THD）。所提出的AMLI的性能已与其他创新的非对称和对称多电平逆变器进行了全面比较。随后，引入了基于脉宽调制（PWM）的分裂式谐波消除方法来提高AMLI的电压质量。与电压质量相关的三个突出标准，即期望的基波分量、三次谐波的消除和THD的降低，已被指定为优化问题的目标函数。考虑到优化问题的多目标性质，已采用非支配排序多目标灰狼优化器（MOGWO）来解决优化问题，然后与非支配排序遗传算法II（NSGA-II）进行比较。总之，相关的分析研究以及仿真和实验结果都清楚地验证了所提出的AMLI的性能。此外，基于MOGWO的分裂式谐波消除策略的电压质量问题也得到了很好的验证。
