摘要
已有一体化变流器存在无法同时进行无功补偿和故障抑制、各桥臂两端承受电压高、动态响应速度慢以及电弧接地故障抑制难等问题,故提出集成无功补偿和故障抑制功能的一体化变流器新型拓扑结构及其控制策略。首先,分析一体化变流器的拓扑结构及其工作原理,提出四桥臂级联H桥变流器的新型拓扑结构,三相桥臂星型连接用于无功功率补偿,在星型连接点与大地间增设一条由单相级联H桥变流器构成的接地桥臂,为变流器直流侧电压控制提供支撑,实现接地故障电流快速全补偿。其次,在分析无功补偿、故障抑制和直流侧电压稳定控制原理和相互作用机理的基础上,提出三者的协同控制策略。最后,利用PSCAD/EMTDC软件对所提一体化变流器及控制策略进行仿真验证,结果表明在直流侧无独立电源的情况下,可同时进行无功补偿和故障抑制。
The existing integrated converters have had such problems as being unable to perform reactive power compensation and fault suppression at the same time,having high voltage at both ends of the bridge arms,reacting slowly in dynamic response,and being hard to suppress the arc ground faults,and so on.Therefore,a new structure of the integrated converter with fault suppression and reactive power compensation functions and its control strategy are proposed.Firstly,by analyzing the topology and working principle of the integrated converter,a new topology of four-leg cascaded H-bridge converter is proposed.In this structure,its three-phase bridge arms are star-connected for reactive power compensation.A grounding bridge arm composed of a single-phase cascaded H-bridge converter is added between the star connection point and the earth to provide support for the DC side voltage control of the converter,realizing the quick and complete compensation of the ground fault current.Secondly,based on the analysis of the principle and interaction mechanism of the reactive power compensation,the fault suppression and the DC side voltage stability control,a cooperative control strategy is proposed.Finally,the simulation verification of the proposed integrated converter and control strategy is carried out with the PSCAD/EMTDC software.The results show that the fault suppression and reactive power compensation can be performed at the same time when there is no independent power supply on the DC side.
作者
游建章
郭谋发
YOU Jianzhang;GUO Moufa(College of Electrical Engineering and Automation,Fuzhou University,Fuzhou 350108,Fujian Province,China)
出处
《电网技术》
EI
CSCD
北大核心
2022年第6期2241-2248,共8页
Power System Technology
基金
国家自然科学基金项目(51677030)。
关键词
配电网
无功补偿
故障抑制
一体化变流器
多功能控制策略
distribution networks
reactive power compensation
fault suppression
integrated converter
multi-function control strategy
