A New Approach to Loss Minimization in Electric Power Systems

Abstract

In this paper the power losses are studied for an electrical utility. The power and reactive volt-amperes may be specified at the loads. If so, either the voltage or the current vector at the load is also specified. A similar set of specifications may be made for certain of the generator inputs to the electric network. In addition, voltage current vector inputs may be established at other generator nodes. It is presumed that the foregoing restrictions do not preclude the possibility of varying either the voltage or the current vector at several other generator locations. It should be noted that the electric network is assumed to be passive and, if desired, may be grounded at one or more points in addition to those ground connections assumed at the loads and generators. With these restrictions established and the remaining free or manipulative generator voltage or current vectors chosen, loss minimization may be studied. First, the electric network is considered by itself. The necessary and sufficient conditions to be met with the manipulative variables in order to minimize the losses in the electrical network are established. Second, the generator station losses are considered in conjunction with the electric network. This time, the necessary conditions, and also a set of sufficient conditions, are established for the same manipulative variables in order that the over-all loss be minimized. In the latter approach, allowance is made for the fact that the cost per kilowatt-hours is not the same at each station and in the network.