Current trend indicate that there has been increase on power outage frequency. This has partly been as a result of unstable power system with very small security margin of operation. Therefore, this paper focusses on the voltage stability of aggregation of multiple induction motors (IM) connected in parallel on the same bus of a power system into a single equivalent model using two methods of aggregations. This has been necessitated by the strong effects that the nonlinear loads have on power system characteristics and therefore erroneous modeling of these devices continues to be an area of greater uncertainty and may cause voltage instability. Though various methods of aggregations have been used, comparison on their suitability and accuracy has not been extensively explored. Appropriate dynamic load model aggregation reduces the computation time and provides a faster and efficient model derivation and parameters identification that are most sensitive to load dynamics. The simulations and analysis are carried out using MATLAB/SIMULINK. The accuracy of these methods is compared to identify the most suitable parameters aggregation method of IM model. Their performance is validated by evaluating the results obtained from industrial and standard individual IM and the aggregation model on IEEE 16 Bus standard system found in literature. Further, the transient characteristics due to voltage disturbances of the aggregate IM and that of original IM group are simulated and compared to check the effectiveness of the aggregation methods on power system. The results obtained are suitable and practical.