特高压直流输电工程直流分压器动态特性及其引起的误闭锁机理研究  

Mechanism Analysis of Error Block Caused by Dynamic Characteristics of DC Voltage Divider in UHVDC

作　　者：滕予非[1] 汤涌[2] 汪晓华[1] 陈刚 刘耀[2] 张宏图[3] 

机构地区：[1]国网四川省电力公司电力科学研究院,四川省成都市610072 [2]中国电力科学研究院,北京市海淀区100192 [3]国网四川省电力公司,四川省成都市610072

出　　处：《电网技术》2016年第9期2646-2653,共8页Power System Technology

基　　金：国家电网公司科技项目(特高压直流控制封装环节仿真建模处理技术研究与应用)~~

摘　　要：为研究直流分压器暂态特性引发特高压直流误闭锁的机理,首先求取了直流分压器的传递函数。特别地,对其二次侧放电回路击穿后的暂态过程进行理论推导。分析表明,直流分压器二次侧放电回路击穿后即使一次侧直流电压维持不变,电压测量值也需经历一个百毫秒级的暂态过程,方能恢复正常水平。其次,针对某特高压直流因整流站直流分压器异常引发闭锁的实例进行分析,研究了特高压直流整流侧电压指令测量异常的工况下,控制保护系统各环节的响应特性,阐明了该工况下直流电压、电流异常降落的原因,揭示了直流误闭锁机理。第三,基于PSCAD/EMTDC的仿真验证了理论分析的正确性,进而有针对性地提出了反事故措施建议,并利用仿真结果验证了措施的有效性。最后,对逆变站直流分压器二次侧放电回路击穿后暂态特性的分析表明,逆变站直流分压器二次侧放电管击穿短路不会导致直流系统控制保护系统异常响应,甚至发生闭锁事故。In order to conduct mechanism analysis of error block caused by dynamic characteristics of DC voltage divider （DCVD） in UHVDC, transient breakdown process in DCVD secondary side is theoretically derived by means of transfer function derivation in the paper firstly. Theoretical results show that even primary side DC voltage remains unchanged after breakdown in DCVD secondary side, voltage measurement results also experience a transient process of hundred milliseconds before it returns to normal levels. Secondly, an accident of HVDC block caused by DCVD is analyzed. Response characteristics of control and protection system are studied, and HVDC error block mechanism is proposed. Thirdly, correctness of theoretical analysis is verified with PSCAD/EMTDC simulation, and some countermeasures for avoiding the accidents are proposed. Finally, analysis shows that there is no risk of HVDC error block on condition of breakdown in secondary side of inverter DCVD.

关 键 词：高压直流 直流分压器 控制保护系统 VDCOL 欠压保护 

分 类 号：TM721[电气工程—电力系统及自动化]