Impact of composite dynamic load on the dynamic security region of power systems

Dynamic security region (DSR) is one of the direct methods focusing on the transient stability of power system. This paper explores the impact of composite dynamic load (CDL) characteristic on the DSR, which including the load model consisting of constant impedance load and induction motor load (ZM), the load model consisting of constant current load and induction motor load (IM) and the load model consisting of constant power load and induction motor load (PM). As the introduction of the composite dynamic load could lead to the differential-algebraic equation (DAE) structure for power system, this paper presents the algorithm for the DSR of power system with DAE structure, after the presentation of DSR algorithm for power system with ordinary differential equation (ODE) structure. It also presents the models for the composite dynamic load, i.e., ZM load, IM load and PM load. And then, based on the simulation results, the DSRs of composite dynamic load are described. Finally, the impact of composite dynamic load on the DSR is summarized.