针对辐射型电网母联死区故障的保护改进设计

Protection Improvement Design for Bus Coupler Dead-zone Fault of Radiation Grid

为确保双母线运行方式下,在母联死区范围内发生故障时,变电站不会全站停电,可以保部分负荷运行,文中对现有母差保护和母联死区保护进行分析研究,对现有母线保护设计方案进行了改进,使其在母线故障时能准确切除故障母线,且在母联死区范围内故障时,也能正确切除母联断路器及与故障相关的母线。最后,通过对母联断路器的动作时间测定,说明此方案可行。

In order to guarantee that no whole transformer substation power outage will occur but partial load is certain to run when the bus coupler dead-zone goes faulty in the double bus operation mode, the differential protection of both the bus and the bus coupler dead-zone is studied. The existing bus protection scheme is improved so that it will act correctly during bus fault. Even though fault should occur in the bus dead-zone, it can still correctly disconnect the bus coupler breaker and the related bus. Finally, by estimating the action time of the bus coupler breaker, the feasibility of the scheme is proved.