Impact of dynamic load models on transient stability-constrained optimal power flow

Abstract

Load dynamics has a substantial impact on transient stability of a power system, but has not been properly treated in transient stability-constrained optimal power flow (TSCOPF) problems. This paper performs a systematical study of the impact of dynamic load models on the TSCOPF problems. First, based on the extended equal-area criterion (EEAC), the feasibility of the reported TSCOPF solutions in the literature on the benchmark test system (New England 10-machine 39-bus test system) is re-evaluated considering a composite load model. Secondly, the impact of the load model parameters on system dynamics is quantitatively investigated based on trajectory sensitivity analysis. Finally, the impact of the variation in the load model parameters on transient stability margin is examined. Simulation results show that 1) the reported TSCOPF solutions in the literature are not viable if the dynamic load model is considered, 2) the impacts of different load components on system dynamics are varying in both terms of magnitude and direction (positive or negative), and 3) given different contingencies, the impact of the load component may be varied in direction.