Stochasticity Control Strategy Based on Discrete Model for the Power System with Wind Farm Incorporating Stochastic Sources

With the large-scale development of renewable energy leading to the increase of stochastic sources in the power system, the stochasticity of the system is more obvious and the control strategy should match these stochastic variations. Firstly, the stochastic source probability distribution (SSPD) model is proposed based on the Weibull distribution in this paper. According to the operation characteristics of the doubly-fed-induction generator (DFIG) at different rotor speeds and the SSPD model, the active power discrete model is then derived, which is defined at the point of common coupling (PCC) of the wind farm. And from the perspective of the overall energy of the power system, the reactive power discrete model of the wind farm PCC is proposed based on the Lyapunov stability theory. Sequentially, a reactive power support controller (RPSC) is designed on the grid side converter (GSC) of DFIG to provide more stable voltage support for the PCC under the influence of the stochastic source and the fault of the power system. Case study based on the New England 9-Bus System with DFIG is given to illustrate the effectiveness of the RPSC and the results show its potential applications for power gird with stochastic sources.