HVDC换相失败暂态特性及其对差动保护的影响分析和对策  

Transient characteristic of HVDC system during commutation failure,its effect on differential protection and countermeasures

作　　者：申洪明[1] 黄少锋[1] 费彬[1] 

机构地区：[1]华北电力大学新能源电力系统国家重点实验室,北京102206

出　　处：《电力自动化设备》2015年第4期109-114,120,共7页Electric Power Automation Equipment

基　　金：国家重点基础研究发展计划(973计划)资助项目(2012-CB215206)~~

摘　　要：通过CIGRE HVDC标准测试模型,获取了直流系统换相失败时的等值工频电流与换流母线电压之间的关系曲线。推导了交直流互联系统中电流差动保护的判据表达式,并对与直流系统直接相连的输电线路的差动保护进行了分析。分析结果表明,交直流互联运行环境下发生区内故障有可能引发差动保护的拒动。提出了基于幅值判据来识别内部故障。PSCAD/EMTDC仿真结果验证了理论分析的正确性和所提判据的有效性。The relation between equivalent power-frequency current and converter bus voltage during the commutation failure of DC system is obtained based on the CIGRE HVDC benchmark model. The criterion expression of current differential protection for AC-DC interconnected system is deduced and the differential protection connected to DC power system for transmission line is analyzed. The analytical results indicate that,the differential protection may reject to act when in-zone fault occurs in AC-DC interconnected operation. It is proposed to detect the internal fault based on the amplitude criterion. Simulative results by PSCAD / EMTDC validate the correctness of theoretical analysis and the effectiveness of proposed criterion.

关 键 词：高压直流输电 换相失败 暂态 暂态特性 等值工频电流 差动保护 继电保护 幅值判据 

分 类 号：TM72[电气工程—电力系统及自动化]