Large-scale power system controlled islanding based on Backward Elimination Method and Primary Maximum Expansion Areas considering static voltage stability

Abstract

This paper proposes a novel approach for separation of bulk power system into several stable subsystems following a severe disturbance. An interconnected power system may become unstable due to wide area contingency when it is operated close to the stability boundaries as a result of increased demand, power industry restructuring and competition in the deregulated electricity markets. Meanwhile, large-scale power system controlled splitting is the last resort to prevent catastrophic cascading outages and wide area blackout. The proposed method of this paper reduces the huge initial search space of the islanding strategy to only interface boundary network by clustering the coherent generators and simplifying the network graph. Then, Backward Elimination Method (BEM) based on Primary Maximum Expansion Areas (PMEAs) has been proposed to generate all proper islanding scenarios in the simplified graph. The Newton–Raphson power flow method and Q–V modal analysis have been used to evaluate the steady state stability of the islands in each generated scenario. Binary Imperialistic Competitive Algorithm (BICA) has then been applied to minimize total load-generation mismatch considering no-isolated bus, voltage permitted range and static voltage stability constraints. Comprehensive discussions have been provided using the simulations on NPCC 68-bus test system. The results demonstrate the speed, effectiveness and capability of the proposed strategy to generate fast feasible splitting solutions considering static and dynamic stability.