故障电流中衰减直流分量的滤波算法研究

Research of decaying DC removal algorithms in fault current

在电力系统中,任何故障或扰动都会使得系统中出现衰减直流分量,它将影响继保装置的测量精度。该文通过引入一组滤波算子,实现了衰减直流分量参数的在线计算,并在此基础上说明了信号基波和谐波分量的计算方法。该算法的数据窗只需要一个基波周期,具有很好的快速性,理论上是一种精确算法。对传统DFT算法和本文算法的仿真结果表明了这种算法的有效性。

Decaying DC offsets are generated following any faults or disturbances in an electric power system, and the measure accuracy of digital relay devices is affected. In this paper, a group of filter operator is introduced to estimate the parameter of decaying DC component online. A technique to calculate the fundamental frequency and harmonics component in the signal is proposed based on evaluation of the decaying DC offsets. The data windows just need one fundamental cycle, so this technique has high speed. In theory, the proposed technique is an accurate algorithm. Simulation results adopted traditional DFT and the proposed technique show the effectiveness of the proposed technique.