基于SVPWM补偿优化的三电平NPC并网逆变器容错控制  

Fault tolerant control of three-level NPC grid-connected inverter based on SVPWM compensation optimization

作　　者：杨清 黄景涛 关海平 YANG Qing;HUANG Jingtao;GUAN Haiping(College of Information Engineering,Henan University of Science and Technology,Luoyang 471023,China;Tongliao SPIC Power Generation Co.,Ltd.,Tongliao 028001,China)

机构地区：[1]河南科技大学信息工程学院,河南洛阳471023 [2]通辽电投发电有限责任公司,内蒙古通辽028001

出　　处：《电力工程技术》2024年第2期199-209,共11页Electric Power Engineering Technology

基　　金：国家自然科学基金资助项目(62172142);教育部产学合作协同育人项目(202101222007)。

摘　　要：为保证并网系统中三电平中点箝位(neutral point clamped,NPC)型并网逆变器单相桥臂短路或断路故障后持续运行,提出一种基于空间矢量脉宽调制(space vector pulse width modulation,SVPWM)的优化补偿型低共模电压容错控制策略。首先,通过分析故障后八开关三相逆变器(eight switch three phase inverters,ESTPI)拓扑开关状态对应的共模电压大小,确定参考电压矢量合成规则;然后,通过一个基波周期内中点电流情况分析中点电位波动机理,进而对空间矢量合成进行调节补偿;最后,设计低通滤波器和滞环控制器进一步对补偿进行优化调整,保证并网电流质量的同时有效抑制了直流母线中点电位偏移。仿真结果表明,该容错控制策略能够实现三电平NPC并网逆变器单相桥臂故障后并网系统的稳定可靠运行,每个基波周期有三分之一时间的共模电压得到改善,优化补偿后的并网电流质量显著提高,且在并网电流突变时具备良好的控制特性。To ensure the three-level neutral point clamped(NPC)grid-connected inverter in a grid-connected system continuous operation after a single-phase bridge arm short circuit or open circuit failure,an optimal compensation fault-tolerant control strategy with low common-mode voltage is proposed in this paper,which is based on space vector pulse width modulation(SVPWM).Firstly,the reference voltage vector synthesis rule is determined by analyzing the common mode voltage corresponding to the switch state of the eight-switch three-phase inverters(ESTPI),which is the topology of the three-level NPC inverter with one phase failure.Then,the mechanism of neutral point potential fluctuation is analyzed by the neutral point current change in a fundamental wave period.Further,the space vector synthesis is compensated based on this mechanism.Finally,the low-pass filter and hysteresis controller are designed to optimize vector synthesis compensation,so as to ensure the quality of grid-connected current and effectively restrain the neutral point potential offset of the DC bus.The simulation results show that the proposed fault-tolerant control strategy can realize the stable and reliable operation of the grid-connected system after single-phase bridge arm failure,and the common-mode voltage can be reduced for one-third of the period time.The quality of grid-connected current is improved significantly.The proposed controller has good control characteristics when the grid-connected current changes.

关 键 词：三电平逆变器 中点箝位(NPC) 容错控制 中点电位波动 空间矢量脉宽调制(SVPWM)优化补偿 滞环控制器 

分 类 号：TM464[电气工程—电器]