基于模型识别的串补线路方向元件

Directional Element for Series Compensated Lines Based on Model Identification

提出了一种基于模型识别的串补线路方向元件的方向判别原理。采用时域算法,通过2种模型的模型误差、识别的电感值和电容值与实际值的差异构成方向判据。大量仿真验证表明,该方法不受衰减直流分量、故障类型、过渡电阻以及故障点位置影响,与传统工频量方向元件相比,不仅避免了电容器容抗大于背侧系统阻抗时引起的方向误判问题,而且提高了方向判别的准确性。

A novel directional protective scheme based on model identification method for series compensated transmission lines is proposed. The scheme detects transmission line fault by comparing the model error, inductance and capacitance calculated in two different models. Comparing with the traditional directional protection in frequency domain, instead, the proposed method calculates the parameters in time domain, and real-operation caused by the compensated capacitor is avoided. Simulation results show that the proposed method is not affected by DC component, fault type, fault location and transition resistance, and it has high accuracy.