基于MATLAB仿真的微机保护算法分析

Analysis of Microcomputer Protection Algorithm Based on MATLAB Simulation

电力系统发生短路时故障电流中产生了非周期的衰减直流分量,全波傅氏算法无法将其滤除。对此提出一种全波傅氏改进算法,完全基于故障信号一个半周期的采样值计算衰减直流分量,在故障信号采样值中减去衰减直流分量的离散采样值,再通过全波傅氏算法计算基波幅值和相角。MATLAB/Simulink仿真结果表明改进算法能有效滤除衰减直流分量,与全波傅氏算法相比速度有所降低,但是计算精度得到了有效提高,更易于微机实现且步骤简单。

When a short circuit occurs in a power system,the fault current generates an aperiodic decaying DC component which cannot be removed by the full-wave Fourier algorithm.In this paper,an improved full-wave Fourier algorithm is proposed.The attenuated DC component is calculated based on the sampling value of one and a half cycles of the fault signal,the discrete sampling value of the attenuated DC component is subtracted from the sampling value of the fault signal,and then the fundamental amplitude and phase angle are calculated by the full-wave Fourier algorithm.The MATLAB/Simulink simulation results show that the improved algorithm can effectively filter out the attenuating DC component,and the speed is reduced compared with the full-wave Fourier algorithm,but the calculation accuracy is effectively improved and it is easier for microcomputer implementation and simple steps.