云广特高压工程紧急停运及旁路开关操作控制策略研究

Research on control strategy for ESOF & bypass switch operation in Yunnan-Guangdong UHVDC project

紧急停运顺序(ESOF)和旁路开关操作的协调配合是特高压直流输电控制保护策略的关键技术。针对±800kV云广特高压直流输电工程双12脉动阀组串联的接线特点,通过对紧急停运启动因素归纳总结,提出极紧急停运和阀组紧急停运的控制时序,设计了紧急停运过程中旁路开关的控制策略,并增加了特殊硬件回路保证控制系统故障时可靠隔离故障阀组。利用云广工程的功能及动态性能试验,验证了紧急停运顺序动态过程的正确性,最终确定了紧急停运时健康阀组强制移相的时间,优化了两站紧急停运时序,降低了紧急停运时直流电流的突变量。

The coordination between emergency switch off（ESOF） sequence and operation of bypass switch is the key technology of UHVDC protection control strategy. According to the characteristics of series connection of dual 12-pulse converter groups of Yunnan-Guangdong UHVDC transmission system,start factors of ESOF are summarized,control sequences of pole and group ESOF are put forward,and bypass switch control strategy during ESOF is designed. A special hardware loop is adopted to ensure converter groups be isolated reliably when control system fault. Using the function and dynamic performance test of Yunnan-Guangdong project,the correctness of dynamic process of ESOF sequence is validated. And forced phase-shift time of the healthy converter groups is identified,the ESOF sequence of both stations is optimized,and the DC current mutation during ESOF is reduced.