Dynamic load modelling and aggregation in power system simulation studies

Effects of modelling and aggregation of composite loads on power system dynamic performance are investigated. Interconnected induction motors and static loads are aggregated to yield a single equivalent model seen at the boundary bus. Comparison is made of the system performance in the following three cases: (i) original detailed model of the power system, (ii) reduced model with the aggregated dynamic load model, and (iii) reduced model with the load conventionally represented by constant impedance. Simulation results are presented to demonstrate the superiority of the aggregated dynamic load representation in both small and large disturbance studies. The results include system responses to sudden load changes, three phase faults, and line outage, in addition to eigenvalue analysis.