Aggregation of induction machines for power system dynamic studies

This paper proposes a method for the aggregation of induction motor loads. Thevenin theorem along with some transient characteristics of induction machine are used in calculating the parameters of the equivalent machine. The dynamic response of the resultant machine differs from the sum of the dynamic responses of the individual machines. For a diversified group of induction machines, at least two separate aggregate machines are needed to represent the overall dynamic performance of the machines. To this end, a handy index for the classification (grouping) of machines is suggested. Comparison between the results obtained from the proposed method and corresponding ones obtained from some of the published methods is also presented. Keywords: Aggregation of Induction machines, Load Modelling, Transient Stability.