A heuristic approach to local load shedding scheme for reliability assessment of composite generation and transmission system

To improve the calculation efficiency of reliability assessment of composite generation and transmission system, the authors propose a heuristic approach to local load shedding scheme. The basic ideas of the proposed method is that according to the principle of local load shedding, the load shedding node sets, which can effectively alleviate the impact of the fault, are searched by power flow tracing in certain region near the faulty component. Using the proposed scheme the global optimization within the whole system to obtain optimal load shedding amount can be avoided, so the algorithm of the proposed scheme possesses high calculation efficiency. The calculation and analysis results from such reliability test systems as RBTS and IEEE-RTS79 show that heuristic local load shedding scheme can considerably quicken the calculation speed under the presupposition of maintaining higher calculation accuracy, and by means of the proposed scheme the calculation bottleneck of power system reliability assessment can be effectively overcome.