期刊论文

Capacitor voltage balancing method for MMC based on improved radix-sorting voltage balancing algorithm

中文

电力科学与技术学报

1673-9140

2018

33

1

67-74,80

10.3969/j.issn.1673-9140.2018.01.010

(2016ZK HX308):湖南省重点实验室开放基金

本校为第一机构

现有的子模块电容电压均衡策略一般基于比较类排序算法,存在排序频繁、开关损耗大、运算量大的缺陷,当单个桥臂子模块数较大时,可能使MMC控制器运算时间过长,导致控制失败。针对上述问题,提出一种时间复杂度更低的分配式改进型基数排序均压算法,根据子模块电容电压极差,提出重排序判据,使MMC控制器选择性地排序;在此基础上,优化选取基数排序的关键字,减少不必要数据处理;同时提出降损因子,进一步减少运算量与开关频率。最后,在MATLAB/SIMULINK搭建21电平MMC模型,仿真结果表明:改进型基数MMC均压算法能在较好维持电容电压平衡的基础上,大幅减少运算量,降低开关频率。

Existing voltage balancing strategies are usually based on comparative ranking algorithm,which have disad-vantages,such as complicated sorting,high switching loss and large calculation.When the number of sub-modules (SMs)is excessive,it requires a large amount of computation time,which may result in control failure.To solve these problems,an improved radix-sorting voltage balancing algorithm which has lower time complexity was pro-posed in this paper.First,the maximum voltage difference between the maximum value and minimum value of SMs capacitor voltage was defined as re-sorting criterion,whi...