基于异构边界的串补输电线路单端量全线速动保护原理

针对串补给线路距离保护带来的超越误动问题，提出了一种基于异构边界的串补输电线路单端量全线速动保护原理。该原理将安装于线路一侧的串补装置作为线路保护范围的异构边界，利用单端测量信息构建R-L微分方程求解故障距离，并采用最小二乘算法对故障距离进行拟合估计，根据测距结果的拟合误差可以判断故障点与串补电容之间的相对位置关系，从而实现串补线路的全线速动保护。所提方法应用等传变理论克服了电容式电压互感器暂态传变误差以及线路分布电容对故障测距精度的干扰，仿真表明能够在40 ms内快速切除串补线路的内部故障。

Heterogeneous Boundary Based Principle of Full-line Accelerated Protection Applying Single-terminal Information for Series Compensated Transmission Lines

In order to solve the mal-operation problem of the distance protection on the series compensated line, this paper proposes a principle of full-line accelerated protection for the series compensated transmission lines based on the heterogeneous boundary. This principle takes the series compensated capacitor that located on the terminal of the transmission line as a heterogeneous boundary of the protected zone. The R-L differential equation is utilized to solve the fault location with single-terminal measurement information. The least square method is used to fit and estimate the fault distance. The calculated fitting error of the location results can be used to judge the relative position relationship between the fault point and the series capacitor. Hence, the protection can achieve the full-line accelerated protection. The theory of equal transfer process of transmission lines is used to eliminate the adverse impacts on the accuracy of fault location, which are caused by the transient transfer error of capacitor voltage transformer and the distributed capacitor of transmission line. The simulation verifies that the proposed protection can quickly trip within 40 ms when fault occurs inside the series compensated transmission line.