发电机失磁保护的微机实现

Loss-of-Excitation Protection Relaying Based on Microprocessor

本文论述了利用测量机端阻抗以判断大型同步发电机是否失磁的保护原理的微机实现。将直角坐标下的阻抗临界失步曲线映射到极坐标下存贮;采用整周波的Fourier算法;提出了便于在计算机上使用的求相角差的“变间隔法”,给出了装置的动模试验结果。

This paper is concerned with a method for realizing the loss-of-exci-tation protection relaying based on a microprocessor for large synchronous generators.By mapping the critical out-of-step curve on X-R plane to a z-θ plane, the accuracy of sectionalized linearization is improved. The fundamental components of the voltage and current are obtained through Fourier analysis. According to the theory that the phase difference between the fundamental components of the original signals U and I should be fundamental components obtained through Fourier analysis, a new method, the 'Interval-step-in' method, for calculating the phase angle of impedance is developed.