Reliability Evaluation With Wind Power And Electric Vehicle And Coordinated Optimization Research

With the double pressures of environmental pollution and energy shortage, WTG(wind turbine generation) and EV(electric vehicle), that have the characteristics of clean and pollution-free, have been rapid development. The randomness of EV charging and the uncertainty of wind power output will bring big challenge to power grid operation for reliability and economy. In this background, related research about the wind power and EVs is presented in this context.First, a reliability model of WTGs is established based on the combination of the Weibull distribution and the Markov chain. We use the switch-section partitioning method and make out its search recurrence relation. After defining the first-level load zone node, we propose the dynamic division strategy of island operation. By adopting the fault analysis method with the attributes defined in the switch-section, we evaluate the reliability of the distribution network with WTGs using a sequential Monte Carlo simulation method.Additionally, on the basis of the above, By considering the space-time characteristics of EVs, we establish the schedulable EVs time distribution model, spatial distribution model, initial state of charge(SOC) model and battery efficiency coefficient model. With the controlled charging/discharging of EVs, the coordinated dispatching strategies of WTGs and EVs in normal state and fault state are proposed. It adopts the sequential Monte Carlo simulation method for studying the reliability evaluation of distribution network with WTGs and EVs.Then, in order to improve the economic operation of power system with WTGs and EVs, the strategies containing wind loss punishment and load loss punishment are lead up on the power grid side and the economic optimization model for WTG, EVs and thermal power, in which the total system operation cost is taken as the objective, is built. Considering various constraints, the particle swarm optimization algorithm is used to solve the model.Finally, in order to the smooth the fluctuations of wind power it proposes two-level optimal coordination control method according to the different time scales in the paper. In long time scale, filter time constant is adjusted based on fuzzy algorithm then it takes the SOC of battery as the optimization goal to complete the first level control of HESS. The second level control is aimed at realizing power distribution and keeping the SOC of supercapacitor in the active state based on power transfer control in short time scale.