Network-based analysis of long-term voltage stability considering loads with recovery dynamics

This study investigates the influence of network structures on long-term voltage stability of power systems considering loads with recovery dynamics. A power system model with load dynamics is established in terms of a network graph and the aggregate nonlinear recovery load model. Stability conditions are proposed for static and small-disturbance voltage stability of power systems, which reveal the interactions between network graph, load demand and load characteristics and sheds new light on the static and small-disturbance voltage stability mechanisms. The impact of the penetration of renewable energy sources is discussed as one illustration. The Monte Carlo method is used for case studies of several widely established IEEE power network test cases. Small-world, scale-free and random networks are considered for the generation of a broad range of network topologies. The simulation results are consistent with the stability conditions. The study in this paper may provide guidance in network planning and operation of power systems.