Research On Wind Power Grid-Connected System

With the increasing concern on new energy sources, the wind power generation has become the hot research topic in the area of renewable resources utilization, and it has become the study focus on how to convert the variable wind energy into power which can be connected to grid. Based on direct-drive wind power generation system, this paper uses magneto alternator and takes inverter as the electric energy transducer, using DSP to control the converter to make the wind power of the generator following grid in real time.In this paper, a feasible and effective grid-connected system is proposed based on a detailed analysis of all kinds of proposals. Firstly it uses three phase uncontrolled rectifier to change the unsteady alternating voltage of the wind power generator into a direct voltage, then through a DC-DC ZVT-Boost converter, it boosts the direct boost to a high voltage, at last by controlling the bridge converter, it obtains the steady alternating current that can follow grid in real time.The main circuit parameters of 2KW wind power system are selected through theoretical derivation and calculation. The developed control theory is applied to the design. In order to get the ideal electric energy, it takes voltage source as the input and the current source as the output control. By SPLL( soft phase locked loop) technology it gets the grid voltage waveforms; By PI control and grid voltage feed forward control,it gets the singals which is used to compare with the triangle wave to get the SPWM wave controlling the on and off of the power switches. The PI control can increase system performance greatly,and the grid voltage feed forward control can reduce the grid interfering signal in favor of the system stability. Moreover, for the purpose of increasing the control efficiency, this paper uses high performance digital signal processor TMS320LF2407A as the main controller, and the AT89C52 as the assistant controller, to accomplish the control masks such as data collection, analysis, implementation of algorithm, producing SPWM waves in real time, and so on.