特高压奉贤换流站最后断路器保护调试异常原因及改进建议

Abnormal Causes and Improved Suggestions of Last Circuit Breaker Protection during Test Process in Fengxian UHVDC Converter Station

鉴于高压直流输电系统逆变站最后断路器跳闸装置是非常重要的换流站直流系统控制设备,介绍了奉贤特高压换流站最后断路器保护的基本原理,针对系统调试期间该保护未正常动作的异常情况,通过分析现场故障录波图中各参数变化曲线得出调试时最后断路器保护未正确动作的原因是由于系统输送功率过小所致,并提出了相应的改进建议,使得在低功率系统调试时能起到测试最后断路器保护的作用,同时避免了设备损坏。

The tripping equipment of the last circuit breaker is an important control device of the DC system in HVDC converter station.Firstly,this paper introduces the basic principle of the last circuit breaker protection in Fengxian HVDC converter station.Then,aiming at the abnormal condition of protection failure in system operation period,we analyze parameters variation curves in the field fault recording figure,and it is concluded that protection failure is caused by too small transmitted power.Based on the analysis,we propose an improved suggestion to test the last circuit breaker protection during system operation under low power condition,which can also help to avoid device damage.