Aggregation of different sizes of induction motors (IM) connected to a power system has diverse Precision on the identification of the aggregate model parameters. Earlier work on the aggregation accuracy of various motors sizes has not been extensively identified. Also, IM loads forms the highest component in power system load. Therefore, the paper proposes to compare the accuracy of the aggregate model parameters of a group of IM of different sizes and validate the results by comparing with the individual induction motor parameters. The simulations and the analysis are carried out using Matlab/Simulink-based software package. The performance of the developed model show that, small-scale induction motors gives better accuracy of the aggregate motor parameter when compared with large-scale motor parameters. It is found that the proposed small-scale aggregation model gives acceptably accurate results than the large-scale aggregation model and is good for power system stability analysis.