混合级联九电平逆变器功率均衡调制策略研究  

Research on Power Balance Modulation Strategy of Hybrid Cascaded Nine-level Inverter

作　　者：叶满园 彭瑞凡 童子威 陈子豪 苗志林 YE Manyuan;PENG Ruifan;TONG Ziwei;CHEN Zihao;MIAO Zhilin(School of Electrical and Automation Engineering,East China Jiaotong University,Nanchang 330013,Jiangxi Province,China)

机构地区：[1]华东交通大学电气与自动化工程学院,江西省南昌市330013

出　　处：《中国电机工程学报》2021年第18期6350-6360,共11页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51767007)。

摘　　要：三单元混合级联多电平逆变器可以使用较少的开关器件实现高质量电压输出,但其在传统的混合频率调制策略下存在低压单元开关损耗及级联单元间输出功率不均衡等问题。基于此,首先,提出一种改进型混合调制策略,并推导改进型混合调制策略下级联单元输出电压基波表达式,进而得出各级联单元平均输出功率表达式;然后,对改进型混合调制策略进行功率均衡优化,在保留改进型混合调制策略输出电压谐波性能良好的前提下,通过改造PD调制策略的三角载波,有效均衡低压单元开关损耗,通过控制高压单元输出脉冲宽度实现全幅值调制度下级联单元间输出功率自均衡控制;最后,通过仿真和实验验证所提功率均衡调制策略理论分析的正确性和可行性。The three-unit hybrid cascaded multi-level inverter can use fewer switching devices to achieve high-quality voltage output, but its low-voltage units switching loss under the mixed frequency traditional modulation strategy and the power imbalance problems between cascaded units. Aiming at the above problems, an improved hybrid modulation strategy was proposed, and on the basis of the improved hybrid modulation strategy, the expression of the fundamental wave of the output voltage of the cascade units was derived, and the average output power expressions of the cascade units were obtained. Then the power balance was optimized for the improved hybrid modulation strategy. Under the premise that the improved hybrid modulation strategy has good output voltage harmonic performance, the triangular carrier position of the PD modulation strategy was modified to effectively balance the switching loss of the low-voltage unit and control the output of the high-voltage unit’s pulse width to effectively realizes the power self-equalization between the cascaded units under the full amplitude modulation factor. The correctness of the theoretical analysis and validity of the proposed power balance modulation strategy are confirmed by simulation and experimental results.

关 键 词：混合多电平逆变器 调制策略优化 谐波特性 载波改造 功率均衡 

分 类 号：TM46[电气工程—电器]