摘要
PWM变流器载波移相并联可以增大系统容量,减小入网电流谐波,但存在环流问题。首先分析了三相PWM变流器环流的等效数学模型,讨论了零序环流(ZSCC)产生原因。对零序电压注入式SVPWM调制算法所产生的环流进行傅里叶分析,针对零序环流的直流分量和3、9、15次谐波分量,提出一种基于准比例谐振(QPR)和比例积分(PI)结合的零序环流抑制方法,对4个模块并联的变流器环流抑制方法仿真。搭建了实际微网系统并进行了并网和离网实验。仿真和实验结果表明该策略可以有效地减小入网电流谐波和环流。
Parallel PWM converters with carrier phase shifting can increase system capacity, reduce current harmonics into the grid, whereas lead to the problem of circulating current. Consequently, we established and analyzed the equivalent and average mathematic models of the zero-sequence circulating current(ZSCC). Based on space vector pulse width modulation(SVPWM) of zero sequence injecting to sinusoidal pulse width modulation(SPWM), the frequency characteristics and mathematic expression of ZSCC were researched. Aiming to reduce the dc and 3, 9 and 15 harmonic components of ZSCC, we proposed a suppression method for the ZSCC based on QPR and PI, and simulated ZSCC for a converter which consists of 4 parallel modules. A microgrid platform was built to perform experiments of grid-connected mode and island mode. Results indicate that the control strategy is effective in reducing harmonic current and ZSCC.
作者
夏岩
邹见效
李凯
徐纯科
石方舟
XIA Yan;ZOU Jianxiao;LI Kai;XU Chunke;SHI Fangzhou(School of Automation Engineering,University of Electronic Science and Technology of China,Chengdu 611731,China;Power Electronics Department of Dongfang Electric Corporation,Chengdu 611731,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2019年第3期855-862,共8页
High Voltage Engineering
关键词
三相PWM变流器
载波移相并联
零序环流
PI+QPR控制器
微网
three phase PWM converters
carrier shifting parallel
zero-sequence circulating current
PI+QPR controller
microgrid
