Comparative Study of Phasor Estimation Techniques Applied on Distance Protection

In this paper, a comparative analysis of phasor estimation techniques applied to distance protection in electric power transmission lines is presented in order to highlight their main characteristics under different fault situations. Phasor estimation is one of the primary steps in analyzing electromagnetic transients and protecting electrical power systems. Therefore, high performance is crucial for better system operation. Three techniques are implemented and analyzed in this paper: the Full-Cycle Discrete Fourier Transform (FCDFT), Half-Cycle Discrete Fourier Transform (HCDFT), and Full-Cycle Cosine. In order to compare the performance of the implemented techniques, a 230 kV electrical power system with a 180 km transmission line is simulated under different fault situations. The simulation results showed that the FCDFT presented the best performance compared to HCDFT and Full-Cycle Cosine. However, the FullCycle Cosine technique achieved a higher speed to detect changes in the circuit's behavior, implying a faster response to the distance protection.