Evaluation on Power Supply Capability of Power Grid with Intermittent Sources

In this paper, on the basis of the traditional power supply capability evaluation model, probability analysis model of power supply capacity is proposed based on the full probability theory, and the impacts of volatility and permeability of intermittent power on power supply capacity is analyzed by taking wind power as example. Firstly, probability power flow algorithm and system probability model of each component are introduced, and semi-invariant method and Gram-Charlier series expansions are used to calculate the probability distribution of current in each branch. By comprehensive considering the uncertainty of the system structure, full probability evaluation method is put forward based on static power supply ability. Secondly, through taking IEEE14 buses system as example, considering the N-1 fault constraint conditions, it shows that volatility and permeability of the intermittent energy has a significant influence on the power supply ability by comparing the deterministic power flow with the probability power flow for system with different wind power penetration. Finally, the quickness and accuracy of evaluation method are verified in comparison with monte-carlo simulation.