Credible Capacity Evaluation Method of Distributed Generation Based on Islanding Algorithm

Abstract

More and more distributed generation (DG) is integrated into the distribution network, which can improve the power supply capacity of the power system. However, due to the strong uncertainty of the wind and solar photovoltaic (PV) power, only their electricity value is considered but capacity value is usually ignored in the distribution network planning. An evaluation method for the credible capacity of DG is proposed in the paper, which could consider the flexible change of distribution network topology. Based on islanding algorithm, the load increment caused by the integration of DG are evaluated under the equal power supply reliability criterion. And the load increment is regarded as the credible capacity of DG. Firstly, the definition of DG credible capacity under equal power supply reliability criterion is introduced, and a credible capacity evaluation method is proposed. Then, in order to accurately consider the impact of DG on power supply reliability, an optimal islanding model of active distribution network is established and the model is solved by sequential Monte Carlo simulation. It can make full use of the interconnection switch to supply important loads during fault firstly. Finally, the dichotomy is used to achieve the credible capacity of DG under equal power supply reliability criterion. The effectiveness of the method is verified by case study on IEEE 33-bus system.