Optimal load dispatch based on generator reactive capability curve

Abstract

This paper presents a preliminary study of simultaneous optimal dispatch of both active power and reactive power. In the current economic dispatch practice only optimal active power allocation is considered since all cost functions are characterized as functions of the active power. Reactive power requirements are mostly mandated by utilizing a fixed power factor or based on system operators' judgment. In this proposal we consider making use of generator reactive capability curves to better characterize generation cost. With the new description of the actual generation cost, system dispatchers can achieve further reduction in overall system-wide generation cost while utility companies can make optimized decisions to improve their profit bottom line. Economic dispatch formulations are presented in this paper from both minimizing cost and maximizing profit perspectives. A simple power network is utilized for illustrating the key concept and gaining insight