Implementation of advanced DSP techniques in distance protection scheme

This paper presents the impact of changes in distance protection algorithm when performing simplifications in certain calculations. Advancements in digital technology have allowed relay manufacturers to include more and more relay functions within a single hardware platform. This paper presents digital power system protection implementation using dsPIC33F microcontroller using Fast Fourier Transform technique. The analog input signal is converted to its digital equivalent through a suitable 16-bit ADC and is further processed using complex Fast Fourier Transform algorithm to extract the fundamental frequency magnitude. Once this magnitude is obtained, it is fed to the internal relay algorithm to initiate appropriate actions. In this paper, implementation of distance relay using mho characteristic is explained.