A comparative analysis of dynamic load models for voltage stability studies

Due to the significant impact of load characteristics on power system stability, it is necessary to obtain accurate load models that can be applied in digital simulations. This paper is concerned with the analysis of two dynamic load models: Exponential recovery load model and composite load model, obtained with measurement-based load modeling approach. Both of them describe the dynamic characteristics of loads using mathematical expressions in the state space or differential equation form. Therefore, the question naturally is under what conditions can be used each one of them. This paper reports our work on the analysis and comparison of both load models used in voltage stability studies in an IEEE 30 bus power system. The results indicate that several factors must be analyzed in the load model structure selection, which can influence the quality of the model obtained.