Reactive Power Control in Electrical Power Transmission System

In this paper, an understanding of reactive power associated with power transmission networks is developed. To make transmission networks operate within desired voltage limits, methods of making up or taking away reactive power— hereafter called reactive-power control—are discussed. Before proceeding further, however, a thorough understanding of the reactive power in ac systems is necessary. This paper is not intended to provide a comprehensive analysis of transmission lines. Rather, its objective is to examine those aspects that enhance the understanding of the interplay between voltages on the line and the resulting reactive-power flows.