Voltage-based reactive power pricing in deregulated environment using hybrid multi-objective particle swarm optimisation

Reactive power market management along with voltage stability is needed to maintain system reliability and to meet the required security levels in deregulated power system. This paper explores the technical and economic issues of reactive power pricing mechanism along with improvement in voltage stability in deregulated system. The algorithm proposes a multi-objective optimisation problem for minimising reactive power pricing and cost of energy loss along with voltage stability improvement using Hybrid Multi-Objective Particle Swarm Optimization. The voltage magnitude of generators, reactive power settings of shunt capacitors and the transformer tap settings are taken as the control variables. The proposed problem uses a well-defined reactive power-bid structure based on long-term capacity bids provided by the generators and capacitors to the system operator to ensure voltage security. The proposed cost-based pricing strategy along with stability enhancement has been implemented in IEEE 30-bus test system under normal and stressed system conditions.