Optimization of Generator Reactive Power Dispatch in Restructured Power Systems

Transmission open access has increased the need for reactive power and voltage support in power systems with electricity markets due to the higher requirement for system security and reliability. A Reactive Power Dispatch Optimization (RPDO) method that can be used by the system operator to centralize the scheduling of reactive power from generators is proposed. By centrally scheduling the reactive power outputs of the available generators, the bus voltages in the network can be maintained within the grid code limits while satisfying line flow limits. Given the real power energy schedules that are predetermined by the electricity market, the RPDO method finds a set of generator reactive power schedules that will maintain the bus voltages within acceptable limits, and satisfy generator reactive power and power factor constraints, while minimizing ancillary service payments for reactive power support and for regulating real power. Tests using the IEEE 30-bus system show the effectiveness of the proposed method.