Abstract
For the evaluation of voltage stability of electric power systems using power vs voltage curve (P-V curve) in a real time voltage monitoring system, many cases of load flow calculation are required. To reduce computing time, parts of network in lower voltage level are required to be reduced into small equivalent networks. This paper describes a new method reducing parts of power system in lower voltage level maintaining the same voltage characteristics as those in whole network before reduction. Thus, P-V curve obtained at the network where some parts are reduced, corresponds to the one obtained at the whole network.
A new procedure to formulate an equivalent network is shown. Especially, in order to make the two P-V curves correspondent as accurate as possible, the reactive power of load in the equivalent network is determined as the function of active power of load and a new procedure compensating the resistance of the equivalent network is also introduced.
