The algorithm for the detection of loss of excitation of synchronous generators based on a digital-phase comparator

Abstract

The paper presents an algorithm that is used to detect the loss of excitation (LOE) of synchronous generators. The algorithm is implemented on the principle of a digital phase comparison in the time domain. The digital phase comparator calculates the integral of the instantaneous power of the input signals. The algorithm uses the currents and corresponding line voltages obtained by the measurements available at the terminal of the generator as their input signals. The input signals are phase-compared on the basis of the value of loss of excitation index after which the LOE is detected. The software package MATLAB/Simulink includes the test power system along with the synchronous generator which simulates the phenomenon of LOE. The algorithm has been tested for total and partial LOE and stability power swing for different operating modes of a synchronous generator. The test results show good properties of the proposed algorithm.