关于输电线路光纤电流差动保护的若干问题讨论

Discussions on several problems about the optical fiber differential protection of the transmission line

针对电力系统实际运行中影响输电线路光纤差动保护正确动作的诸多因素,以RCS-931光纤差动保护为例,从光纤差动保护的动作原理和特定运行方式的角度出发,深入细致地讨论分析了诸如线路电容电流、重负荷状态下发生高阻接地故障、CT饱和、线路两侧CT特性不一致、光纤通道数据采样同步等问题对光纤差动保护的影响,从运行管理、设计选型和保护软件算法等方面提出了具体的解决方法和措施,消除了这些因素对光纤电流差动保护的不利影响。

This paper indicates a number of factors which affect the normal action of current differential protection for transmission line in power system in actual operation.And it takes the principle and certain operating mode of differential protection for optical fiber as a view and the RCS-931 differential protection for optical fiber as an example to discuss and analyze intensively the influence over the differential protection for optical fiber from the line capacitance and current,high-impedance grounding fault under heavy load,CT saturation on the transmission line,disparity of CT on two sides of the transmission line,and the data sampling in step of the optical fiber line.Then it brings in some solutions in detail from the operational guidance,selection of design,and protection of software algorithm to remove the adverse effect brought by those problems above for the differential protection for optical fiber.