Design And Implementation Of Current Source Grid-Connected Inverter For Small-scale Wind Turbine

Wind power is a kind of non-pollution renewable energy source. With the requirements of the ecological environment and energy, the development of wind energy is being taken more and more attention. In a large number of wind generators, a small-scale PM wind generator with large-inductance is one of the most promising variable speed generators applied to small wind power system due to its large range of speed changing, constant current output and simple grid connected, etc. The inverter is the key of grid-connected operation, which affects the utilization efficiency of wind energy and control system stability. This paper mainly focuses on the grid-connected inverter for large-inductance small-scale PM wind generator in which the circuit topology, control method and other aspects are analyzed and studied.This paper first introduces the developing status and the technological development trend of wind power. Second the mathematical model of current source grid-connected inverter system is established, and the digital PI control combined with input current feed-forward control is used to eliminate the influence of input current disturbance on grid current and improve the control effect. According to the whole control block diagram and mathematical models, the simulation model is established in PSIM. The simulation results have verified the validity of the control strategy. Based on the clear control scheme, the hardware circuits of grid-connected inverter for small-scale PM wind generator with large-inductance were designed in which the dsPIC30F4011chip was selected as the main controller. The control program was designed in the MPLAB IDE v7.62environment. Finally, the test results have shown that the frequency and phase of the gird-connection inverter can flow the grid voltage quickly, which further demonstrates the validity of the proposed control strategy.