基于多种群遗传算法的多电平逆变器输出电压THD最小化调制策略  

Research on THD Minimization Modulation Strategy of Multilevel Inverter Output Voltage Based on Multiple Population Genetic Algorithm

作　　者：叶满园 凌袁学 肖兆军 罗振远 陶振宇 YE Manyuan;LING Yuanxue;XIAO Zhaojun;LUO Zhenyuan;TAO Zhenyu(School of Electrical and Automation Engineering,East China Jiaotong University,Nanchang 330013,China)

机构地区：[1]华东交通大学电气与自动化工程学院,南昌330013

出　　处：《高电压技术》2024年第10期4671-4679,共9页High Voltage Engineering

基　　金：国家自然科学基金(52267014);江西省自然科学基金(20242BAB26071)。

摘　　要：多电平逆变器具有低谐波含量,电磁干扰小,高压大容量,输出波形质量好等特点,被广泛用于中高压大功率系统当中。特定谐波消除技术SHEPWM是在多电平逆变器中的一种常用开关策略,相比于高频调制,SHEPWM技术能够消除某特定次谐波,而且具有更低的开关频率和开关损耗等优点。针对传统SHEPWM技术中THD不能达到最优的问题,推导出了输出电压谐波总含量的解析表达式,并采用多种群遗传算法对解析表达式进行求解,在得到最优开关角度的同时求出全调制度下输出电压的最小THD值。文中以三单元7电平级联H桥为例,给出了THD解析式模型及其开关角度轨迹图,和传统多波段SHE进行了对比,发现谐波总含量THD得到很大程度上的降低,同时也解决了其存在电流倒灌的问题。仿真分析和实验结果验证了方法的可行性和优势。Multi-level inverters are widely used in medium-and high-voltage high-power systems due to their low harmonic content,small electromagnetic interference,high voltage and large capacity,and good output waveform quality.Selective harmonic elimination pulse width modulation(SHEPWM)is a common switching strategy in multilevel inverters,which can eliminate a specific harmonic compared to high-frequency modulation,and has the advantages of lower switching frequency and switching losses.Aiming at the problem that total harmonic distortion(THD)cannot be optimized in traditional SHEPWM technology,we derived an analytical expression of the total harmonic content of the output voltage,used the multiple population genetic algorithm to solve the analytic expression,and obtained the minimum THD value under the full modulation index while obtaining the optimal switching angles.Taking the three-unit 7-level cascaded H-bridge as an example,we presented the analytical model of THD and its switching angle trajectory diagram,and compared with the traditional multi-band SHE.It is found that the total harmonic content THD is greatly reduced.At the same time,the problem of current backflow in traditional multi-band SHE can also be solved.Simulation analysis and experimental results verify the feasibility and advantages of the proposed method.

关 键 词：多电平逆变器 遗传算法 总谐波失真(THD) THD最小化 电流倒灌 低频调制 

分 类 号：TM464[电气工程—电器] TP18[自动化与计算机技术—控制理论与控制工程]