基于自适应虚拟阻尼控制的并联双向变换器间环流抑制方法  

Circulating Current Suppression Method for Paralleled Bi-directional Power Converters Based on Adaptive Virtual Damping Control

作　　者：李朝阳 张佰富 韩肖清[1] 李鹏[2] 任春光[1] 王弈赫 LI Chaoyang;ZHANG Baifu;HAN Xiaoqing;LI Peng;REN Chunguang;WANG Yihe(Shanxi Key Laboratory of Power System Operation and Control,Taiyuan University of Technology,Taiyuan 030024,China;School of Electrical and Electronic Engineering,North China Electric Power University,Baoding 071003,China)

机构地区：[1]太原理工大学电力系统运行与控制山西省重点实验室,太原030024 [2]华北电力大学电气与电子工程学院,保定071003

出　　处：《高电压技术》2020年第5期1557-1566,共10页High Voltage Engineering

基　　金：国家自然科学基金(51807130);山西省科技重大专项(20181102028);山西省研究生教育创新项目(2019SY149)。

摘　　要：针对双向功率变换器(bidirectional power converters,BPCs)并联运行所引起的零序环流(zero-sequence circulating current,ZSCC)问题,根据变换器功率传输特性建立了零序环流等效数学模型,在分析零序环流的产生机理、抑制原理以及虚拟阻尼对零序环流影响的基础上,提出了一种基于自适应虚拟阻尼的零序环流控制策略。根据由电压波动引起的功率振荡对虚拟阻尼进行实时动态调整,并在功率控制的无功环节中增加积分项,从而实现对电压的无静差追踪,进而实现零序环流的抑制。最后,通过仿真和实验分析对所提控制算法进行验证。研究结果表明,该控制算法可减少变换器间的电压差和等效阻抗差异,提高电流均分效果,实现抑制零序环流的目的。研究结果可为微电网系统多并联双向功率变换器的冗余设计提供参考。The zero-sequence circulating current(ZSCC)is a serious problem in paralleled bidirectional power converters(BPCs)system.To solve the problem,the equivalent mathematical model of the ZSCC is established according to the power transmission characteristics of the converters.Then,a ZSCC control strategy based on adaptive virtual impedance is proposed on the basis of the analysis of the mechanism and suppression principle of the ZSCC and the influence of the virtual impedance on the ZSCC.The virtual impedance is dynamically adjusted over time based on the power oscillation caused by the voltage fluctuations.Moreover,the integral term is added in the reactive link of the power control to realize the tracking of voltage without static error,so the ZSCC is suppressed.Finally,the proposed control algorithm is verified by simulations and experiments.The research results show that the control algorithm can not only reduce the voltage difference and the equivalent impedance difference between the converters,but also improve the current sharing results and achieve the purpose of suppressing the ZSCC.The research results can provide a reference for the redundant design of multi-parallel BPCs in microgrid systems.

关 键 词：交直流混合微电网 不平衡工况 并联变换器 零序环流 零序电压差 自适应虚拟阻尼 

分 类 号：TM46[电气工程—电器]