Reactive Power Compensation Of Wind Farm Based On STATCOM

Nowadays wind power is the clean energy which is widely used by industrial life,industry push wind power technology to the new height. With a large number of wind turbines paralleled into the grid, when short-circuits occurred to the grid, the wind farm could not take off the grid, and provide reactive power to the grid to help system restore from faults, so this can improve LVRT of wind turbines. The main research content of this paper is:Firstly, the paper analyze and set up the fan and mathematical model of DFIG, and in view of the frequency converter of DFIG related design work, and through the simulation results verify the rationality of the design of the generator. The six sets of the same type of doubly-fed wind turbines equivalent to a doubly-fed wind turbine, and the capacity of the wind farm is 9MW.Secondly, according to the features of small capacity of STATCOM and the related design work of this device,the mathematical model of the wind power system reactive power compensation device of STATCOM was derived. The design scheme of using LCL filter by BODE figures can verify it effectively reduced the reactance value, simultaneously reducing the cost.Again, based on the mathematical model of STATCOM, this paper explores its control strategy and designs double closed-loop control strategy. Meanwhile this passage based on the method of engineering design in order that parameters can be settled. And in view of the STATCOM is merged into 9MW equivalent wind farm, and based on the conditions of adding and unloading perceptual loads in order that this paper can build the simulation model,through the simulation results verify the reactive compensation effects of the design of STATCOM.Finally this paper carries on the research of LVRT on the wind power system in the software of MATLAB, analyzing the dynamic response of the related parameters of this system under the condition of three-phase symmetrical short-circuits fault. Under this condition adopting the two different control strategies, one is the crowbar circuit of rotor side,another is the combination of crowbar circuit and STATCOM that optimized by particle swarm optimization algorithm. Verified by the simulation results of crowbar circuit and STATCOM which can be real-time settled, this scheme can cooperate better in order to achieve LVRT, improve the stability of the system.