INTERACTIVE SOFTWARE FOR EVALUATING RELAY ALGORITHMS

Abstract

Recent advances in microelectronics have made available low cost micro-processors with enhanced capabilities. This has increased the interest for using micro-processors in power system protection. Several relay algorithms proposed in the past can be implemented on a micro-procesor to produce numerical estimates of operating parameters of a power system. These estimates form the basis of relaying decisions. The relay algorithms are designed assuming the nature of the waveforms of the inputs. The estimates provided by an algorithm are not correct when the waveform of an input is not similar to that used in the design of the algorithm. The accuracy of the estimates is further reduced by the words of the digital processors being of finite sizes. Therefore, a relay algorithm is chosen after studying its characteristics and investigating its performance. This thesis is concerned with the development of a software that provides an interactive approach for the evaluation of relay algorithms. The software incorporates several algorithms that are designed by using the trigonometric, correlation and least error squares techniques. The software also includes facilities for generating data that can be used for testing the performance of the algorithms in situations that a relay might encounter in a power system.