Transmission congestion management with reactive power support in hybrid electricity market

In a competitive power market, the task of an independent system operator (ISO) is to ensure full dispatches of the contracted power are carried out reliably. However, if it threatens the system security then ISO makes decision on the re-dispatch of the contracted power i.e., Congestion Management. This paper proposes an optimal congestion management approach with reactive power support in a deregulated hybrid electricity market. The aim of the proposed work is to minimize deviations from preferred transaction schedules and hence the re-dispatch cost. The values of Transmission Congestion Distribution factors (TCDFs) are used to select re-dispatch of generators then minimization of re-dispatch cost is performed using Particle swarm optimization (PSO) and Particle swarm optimization with Time Varying Accelerating Coefficients (PSO-TVAC). Generator reactive power support is considered to lower the re-dispatch cost. Numerical results on test systems namely South African 18-bus and IEEE 118 bus systems are presented for illustration purpose. The comprehensive experimental results prove that re-dispatch cost is reduced with GENCOS reactive power support and PSO-TVAC is one among the challenging optimization methods which is indeed capable of obtaining higher quality solutions for the proposed problem.