An elegant approach to optimal real and reactive power dispatch

Abstract

This paper presents a new reactive VAR and real power dispatch method for the economic operation of a power system. The analysis is twofold, involving successive evaluation of the optimum voltage and the real power generation. The former is obtained by reactive VAR control, avoiding non-linear programming techniques, and the latter by a closed-form expression of λ, a linear function of the penalty factors. Transmission losses are considered as a function of the system voltage and are minimized by adjusting the transformer tap positions, the reactive power injection of VAR sources, and the generator voltage magnitude dependent on excitation. The feasibility of the technique is demonstrated by means of a standard system.