基于最优三次谐波注入的改进APOD调制  

Improved APOD Modulation Based on Optimal Third Harmonic Injection

作　　者：武亮亮[1] 唐芬[2] 陈鹏飞[1] 梁家志[1] 王玮[1] Poh Chiang Loh WU Liangliang;TANG Fen;CHEN Pengfei;LIANG Jiazhi;WANG Wei;Poh Chiang Loh(National Active Distribution Network Technology Research Center(Beijing Jiaotong University),Haidian District,Beijing 100044,China;Collaborative Innovation Center of Electric Vehicles in Beijing(Beijing Jiaotong University),Haidian District,Beijing 100044,China)

机构地区：[1]国家能源主动配电网技术研发中心(北京交通大学),北京市海淀区100044 [2]北京电动车辆协同创新中心(北京交通大学),北京市海淀区100044

出　　处：《电网技术》2020年第4期1257-1266,共10页Power System Technology

基　　金：国家重点研发计划项目(2018YFB0905200)。

摘　　要：在采用高阶滤波器的三电平变流器中,载波同相层叠调制(phase disposition,PD)产生的开关频率次边带谐波易扩散到高阶滤波器固有谐振点附近,引起输出电流谐波增加或振荡,而载波交替反相层叠(alternative phase opposition disposition,APOD)所需滤波器总电感量较大。针对以上问题,在定量分析比较PD和APOD两种调制方式谐波分布及边带谐波扩散特点的基础上,给出了两种调制方式总电感量约束方程。为保有APOD调制谐波分布集中优点的同时减小APOD总电感量需求,研究了一种基于最优三次谐波注入的改进APOD调制策略,分析了不同三次谐波注入量对APOD电压谐波分布及总电感量需求的影响,进而给出了以总电感量需求最小为目标的三次谐波最优注入量的计算方法,该方法可以实时根据当前调制度自动计算需要注入的三次谐波最优幅值,实现最优三次谐波的在线注入。最后,仿真和实验结果表明,所提策略不仅可以有效地避开高阶滤波器的谐振点,而且可有效降低主导谐波电压幅值,从而减小所需滤波器总电感量。In a three-level converter with high-order filters, the side-band harmonics around switching frequency generated with phase disposition(PD) modulation may spread near the inherent resonance points of high-order filters, resulting in increase or oscillation of harmonics of output current, while large total inductance of the filter is required if alternative phase opposition disposition(APOD) modulation is employed. To address these issues, harmonic distribution and the side-band harmonic spread characteristics of PD and APOD modulations are firstly quantitatively analyzed and compared. On this basis, the total inductance constraint equations of both modulations are presented. In order to reduce the total inductance requirement of APOD while retaining the advantage of concentrated harmonic distribution of APOD modulation, an improved APOD modulation strategy based on optimal third harmonic injection is studied. The influences of different third harmonic injections on voltage harmonic distribution and the total inductance requirement are analyzed. The calculation method of the optimal third harmonic injection value aiming at minimum total inductance requirement is presented, which could automatically calculate the injected optimum amplitude of the third harmonic according to current modulation degree, and realize online injection of the optimum third harmonic. Finally, simulation and experimental results show that the proposed strategy can effectively avoid the resonant points of high-order filters and reduce the amplitude of dominant harmonic voltage. Therefore, the required total inductance could be effectively reduced.

关 键 词：APOD调制 三次谐波注入 谐波分布 LCL滤波器 

分 类 号：TM721[电气工程—电力系统及自动化]