非对称负载下逆变器电压不平衡度抑制策略  

Suppression Strategy for Inverter Voltage Imbalance Degree under Asymmetric Load

作　　者：张家祥[1] 刘素芳[2] 海方 ZHANG Jiaxiang;LIU Sufang;HAI Fang(School of Electrical Engineering,Zhengzhou Railway Vocational&Technical College,Zhengzhou 451460,China;School of Electronic Engineering,Zhengzhou Railway Vocational&Technical College,Zhengzhou 450052,China;Rolling Stock Academy,Zhengzhou Railway Vocational&Technical College,Zhengzhou 450052,China)

机构地区：[1]郑州铁路职业技术学院电气工程学院,郑州450052 [2]郑州铁路职业技术学院电子工程学院,郑州450052 [3]郑州铁路职业技术学院机车车辆学院,郑州451460

出　　处：《电力系统及其自动化学报》2021年第10期138-144,共7页Proceedings of the CSU-EPSA

摘　　要：为解决多逆变器并联系统输出端电压出现三相不对称的问题,本文提出一种基于主从控制的多逆变器并联系统输出级电压不平衡度改善策略。首先,分析非对称负载导致多逆变器并联系统输出级电压出现三相不对称的原因。其次,采用基波旋转坐标变换的方法将负载电流中的正负序分量分离出来,利用其余从逆变器可用容量来补偿负载电流中的全部负序分量,而主逆变器仅提供负载电流中的基波分量,并维持逆变器输出端电压稳定。所提控制策略将电能质量治理功能嵌入到从逆变器控制策略中,有效降低了输出端电压的不平衡度。最后,基于PSCAD仿真对本文所提控制算法的有效性进行了验证。To solve the problem of three-phase imbalance in the output voltage from a multi-inverter parallel system,a strategy for improving the output voltage imbalance degree of the system is proposed in this paper,which is based on the master-slave control.First,the reason for three-phase asymmetry in the output voltage from the system under asymmetric load is analyzed.Then,the positive-and negative-sequence components in load current are separated by means of fundamental rotating coordinate transformation,and the available capacity of the slave inverters is used to compensate all the negative-sequence components in the load current,while the master inverter only provides the fundamental component of the load current and maintains the output voltage stability of the inverter.The proposed control strategy embeds the power quality control function into the control strategy for the slave inverter,thus effectively reducing the imbalance degree of output voltage.Finally,the effectiveness of the proposed control algorithm is verified by simulations using PSCAD.

关 键 词：多逆变器并联系统 非对称负载 电压不平衡 主从控制 

分 类 号：TM727[电气工程—电力系统及自动化]