基于Bergeron模型的长线路微分方程算法研究

由于受分布电容作用影响,解微分方程算法应用于长线路阻抗计算时,其计算结果精度降低.针对以上问题,提出一种应用Bergeron模型将长线路进行分段的解决方法.长线路经分段后,利用保护安装处的电流、电压瞬时值应用Bergeron方法计算分段点处的电流、电压瞬时值.利用分段点处电流、电压应用解微分方程算法即可较精确地计算出线路阻抗.新的计算方法对前置低通滤波器滤波特性没有过高要求.仿真计算结果表明,新方法在特高压、长线路情况下仍然可以准确地计算出线路阻抗.

Research on the Application of the Bergeron Model to the Differential Equation Algorithm for Long Transmission Line

The measurement accuracy of the differential equation based distance relay for the long transmission line is deteriorated remarkably due to the influence of the distributed capacitance. In order to solve this problem, a new algorithm, which divides the long transmission line to two sections based on Bergeron method, is presented. The voltage and current at the relay location are used to calculate the instantaneous value of the current and voltage at the splitting point by the electrical-magnetic transient calculation method. The differential equation algorithm can accurately calculate the impedance from the splitting point to the fault point. The new method does not require exact characteristic of the low-pass filter. Simulation results show that this new method can calculate the impedance with high accuracy even for long transmission lines.