A Reactive Power Reserve Constrained Optimum Reactive Power Dispatch Using Coronavirus Herd Immunity Optimizer

Abstract

The Optimal Reactive Power Dispatch (ORPD) is a very important study in planning the power system operation. The conventional ORPD formulations focus only on driving the objective functions toward optima and ignore the benefits to retain adequate Reactive Power Reserve (RPR) in the system. Studies show that inadequate RPR can jeopardize the power system voltage security under stressed conditions. In view of this, a Reserve Constrained ORPD (RC-ORPD) is proposed in this paper and solved using the recently developed, Coronavirus Herd Immunity Optimizer (CHIO). For this purpose, the minimum required Effective Reactive Reserve (ERR) is devised and introduced as a constraint in the ORPD problems. Here, the minimization of power loss and L-index are taken as objective functions, and the problem is formulated as a non-linear constrained optimization problem. The proposed problem is tested on standard IEEE 30 bus and IEEE 57 bus systems. To assess the impact of the proposed strategy, the same problems are also solved by relaxing the ERR constraint. Comparisons reveal that the added constraint improves voltage stability linked parameters and offers more RPR in the system without sacrificing much on the optimum solution. Further, the proficiency of CHIO is verified through various case studies and comparisons.