EQUIVALENT LOAD MODEL OF INDUCTION MACHINES

ABSTRACT A load model, based on combining two or more induction machines connected to a common bus or substation, either directly or through feeders-, is presented. The model is developed by combining the transient equations in the 0-d-q axes of N-induction machines into that of a single equivalent machine. The parameters of the equivalent machine are then derived from the combined equations. An equivalent mechanical load is also found by combining the loads and the inertias of the various machines. The equivalent is validated by simulating its response to severe voltage and frequency disturbances and comparing the results with the sum of the responses of the individual machines to the same distucbances. For a diversified group of induction machines, this paper illustrates grouping them into two or three equivalent machines would be adequate for modeling the net dynamic response of all the machines