Análise comparativa de métodos de estimação fasorial em linhas de transmissão baseada em com compensação série capacitiva.

Abstract

In this work, five phasor estimation algorithms are evaluated for the usage in distance protection of transmission lines with capacitive series compensation. The capacitor bank’s model considered was a simple one. The phasor estimation techniques analyzed are the Full Cycle Fourier algorithm, the Full Cycle Fourier algorithm with digital Mimic Filter, the Modified Cosine algorithm, and two other algorithms more recently found in the literature. Different types of polarization techniques were used for digital relaying: the self-polarization, the cross polarization, and the positive sequence memory polarization. The fault data considered were generated by ATP - Alternative Transients Program and evaluated with MATLAB. Analytics test functions for use in phasor estimation algorithms were also considered. The evaluation criteria were indexes of time domain performance and the quantity of errors in the determination if the fault is or not in the relay protected zone of the line. The time indexes were the settling time, the rise time and the overshoot of phasor amplitude signals of test functions and time of relay’s protection zone belonging identification for simulated cases. After the analysis, it is possible to conclude that the Modified Cosine algorithm has one of the best performances according to the criteria considered, but without a great superiority compared to other methods.