Optimal load shedding strategy in power systems with distributed generation

An optimal load shedding strategy for power systems with multiple distributed generation is presented. According to distributed generation's role in emergency state, they are classified as the central generation type, nondispatchable type and storage type. The dynamic and static models of each type following a major disturbance are developed. Based on the analysis of a major disturbance in a grid system, interconnection or distributed generation system, the load shedding is formulated as an optimization problem subject to system, operation and security constraints. To handle the differential equations that represent the dynamics of different types of generators, a discretization technique is used to transfer differential equations into algebraic equations. The final nonlinear optimization problem is then solved by mathematical programming. The method is first tested on a small system. Then a 30-bus distribution system with multiple distributed generation is adopted to test the proposed method for a more practical application.