Optimum coordination of overcurrent relays using the modified Jaya algorithm

Application of modified Jaya algorithm for determining the optimum time multiplier setting (TMS) and plug setting (PS) of overcurrent relays (OCRs) is presented in this paper. The OCR time coordination is of great importance as it reduces the power outages by avoiding the backup relays to mal-operate. For this, the OCRs should have PS and TMS values set to their optimum values. Setting the PS and TMS of OCRs to their optimum values can be formulated as a constrained nonlinear optimization problem. The objective is to find the value of PS and TMS of OCRs so as to make the time of operation of relays as minimum as possible. This is to be achieved under the constraint of maintaining the coordination of relays. Jaya algorithm is a recently proposed simple optimization technique which can be used for solving the constrained optimization problems. The main contribution of this paper is modification in the original Jaya algorithm and application of modified Jaya algorithm to determine the values of PS and TMS of OCRs, which are optimum. The results are compared with the results obtained using genetic algorithm (GA). It has been shown that the modified Jaya algorithm outperforms the GA. Also it is shown that the problem can be decomposed in parts to reduce the complexity without loss of accuracy.