Minimisation of reactive-power installation in a power system

Reactive-power installations at suitable points become necessary in most modern high-voltage networks, to prevent excessive voltage drops at load busbars. In the paper, the minimisation of the total required reactive-power installation is formulated as a nonlinear-programming problem. Based on certain specific features of this problem, a new solution technique, which results in a considerable reduction of computational effort, as compared with general optimisation techniques, is developed. An additional feature of this technique is that it can be used in conjunction with any standard a.c. load-flow program. The technique is applied to a typical network to bring out the advantages of this approach. An extension of this technique for cases where the voltage restrictions have to be satisfied for two or more loading conditions is also presented.