三相PWM逆变器直接并联系统零序环流分析与抑制  

Analysis and Suppression of Zero Sequence Circulating Currentin a Direct Parallel System of Three-phase PWM Inverters

作　　者：崔巍[1] 奚磊 Cui Wei;Xi Lei(State Grid NARI Technology Co.,Ltd.,Nanjing Jiangsu 211106,China)

机构地区：[1]国电南瑞科技股份有限公司,江苏南京211106

出　　处：《电气自动化》2024年第3期20-23,共4页Electrical Automation

基　　金：国网总部科技项目(524608180194)。

摘　　要：环流抑制是实现三相PWM逆变器直接并联系统重要关键技术之一。首先在同步旋转坐标下建立了三相PWM逆变器直接并联系统的零序环流数学模型,结合逆变器空间矢量调制算法详细分析了环流抑制原理。在此基础之上,提出一种基于比例谐振与非零矢量占空比前馈控制的环流抑制策略。该策略可通过调整逆变器空间矢量中的零矢量,在减小环流幅值/有效值的同时,可进一步抑制并联零序环流中的工频波动。最后通过试验给出了不同控制策略下的环流抑制波形,充分证明了所提策略的有效性,为三相PWM逆变器直接并联系统可靠稳定运行提供技术支持。Circulating current suppression is one of the important key technologies for achieving a direct parallel system of three-phase PWM inverters.Firsty,establish a zero-sequence circulating current mathematical model of a three-phase PWM inverter directly parallel system in synchronous rotating coordinates,and then analyze the circulating current suppression principle in detail combined with the inverter space vector modulation algorithm.On this basis,a circulating current suppression strategy based on proportional resonance and non-zero vector duty cycle feedforward control was proposed.The strategy can further suppress power frequency fluctuations in the parallel zero-sequence circulating current by adjusting the zero vector in the inverter space vector,while reducing the amplitude/effective value of the circulating current.Finally,comparative experimental waveforms under different suppression strategies were provided through prototype experiments,which can fully demonstrate the effectiveness of the proposed strategy.The research achievement can provide technical support for the reliable and stable operation of three-phase PWM inverter direct parallel systems.

关 键 词：环流分析 变换器并联 电感不平衡 比例谐振控制 环流抑制策略 

分 类 号：TM76[电气工程—电力系统及自动化]