新型并联交错型多电平变换器的桥臂统一脉宽调制策略  

Leg-unified Pulse Width Modulation Strategy for Novel Parallel Interleaved Multilevel Converters

作　　者：公铮[1] 张海军[1] 戴鹏[1] 李明[1] GONG Zheng;ZHANG Haijun;DAI Peng;LI Ming(China University of Mining and Technology,Xuzhou 221008,Jiangsu Province,China)

机构地区：[1]中国矿业大学

出　　处：《中国电机工程学报》2018年第23期7026-7034,共9页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51707086);中国博士后科学基金资助项目(2017M621864)~~

摘　　要：并联交错型变换器(parallel interleaved multilevel converter,PIMC)是在多变换器并联结构基础上发展而来的新型大功率变换拓扑。目前,PIMC通常采用耦合式桥臂电感以便于均衡各桥臂电流,对电感设计的要求高且扩展性较差,因此考虑采用分立式桥臂电感,但现有调制策略存在难以均衡桥臂电流、算法实现较为复杂等问题。针对这些问题,推导PIMC各桥臂输出电流变化量与桥臂开关函数的动态表达式,进而从保证电流动态平衡的角度出发,提出易于实现的桥臂输出电流排序均衡方法,并结合其实现方式设计了桥臂统一脉宽调制策略。该策略能够有效控制PIMC各桥臂输出电流均衡,在占用较少控制器资源的情况下获得良好的输出谐波特性,易于向任意电平数扩展。最后,基于大功率MATLAB/Simulink仿真及小功率平台实验结果,详细分析了PIMC的内、外部特性,验证所提调制策略的正确性和有效性。Parallel interleaved multilevel converter(PIMC) is a novel high-power conversion topology family derived from the structure of parallel-connected converters. The coupled inductors are commonly adopted in PIMC for the convenience of leg output current balancing, which requires high-difficulty inductor design and lacks expansibility, thus the isolated inductors are considered in PIMC. However, the existing modulation strategies are not satisfied for current balancing. To address this matter, the dynamic expression relates the leg current variation and switching function is firstly derived. A leg output current balancing method based on a simple sorting algorithm is proposed with the aim of maintain the currents balanced dynamically. Then a leg-unified pulse width modulation(LUPWM) strategy is designed by considering the implementation of the proposed current balancing method. The LUPWM not only achieves a satisfied effectiveness in current balancing, but also obtains a good output harmonic performance with low-cost controller resources; hence it is easy to be applied for systems with arbitrary voltage levels. Finally, the internal and external characteristics are evaluated by high-power MATLAB/Simulink simulation and low-power experimental results, respectively, which validates the proposed LUPWM strategy.

关 键 词：并联交错型多电平变换器 桥臂电感设计 电流均衡 脉宽调制 脉冲模式 

分 类 号：TM46[电气工程—电器]