The Design And Research On Small Wind Power Grid Inverter System

The development and utilization of wind energy as a renewable energy havebecome a focus of attention. The large and medium-scale wind power grid-connectedoperation, which requires higher gird stability, is the common form of wind energyutilization. Therefore, the research of small wind power systems is meaningful. Thesystems use direct-drive permanent magnet synchronous generator so that thegenerator can run in a larger range of wind speeds with high efficiency. Without usingthe transmission, the power generation efficiency has been greatly improved while thecosts of the operation and maintenance decreasing. This method points out a new wayfor the development of small-scale wind power generation system.The core of this paper is to take full advantage of the wind energy in low speed.The system circuit topology, which uses two isolated main circuit, and the parametersof the main circuit is designed based on this thinking. Foreline BOOST circuit is usedto boost the power variation of the generator output and stabilizing the bus voltage,while the subsequent using a single-phase bridge inverter circuit to invert the stablefront stage DC current.Then the paper describes the grid-connected control strategy. To ensure the gridstability, the strategy uses voltage source input, current source output control method,while using the direct current control in current output link. The bipolar modulationtriangle wave comparison control and digital lock control mode are used to completethe instruction of current control. Then the key link of the triangle wave control modeare analyzed-PI controller design. And describe digital implementation of the PIcontroller.This paper designs a1kW inverter device and analyzes its performance. Thetopology for the small-scale wind power generation system makes a critical effort toimprove performance in low wind speed. Besides, rational control strategy improvesoverall performance of the system. After experimental verification, the performanceof the grid-connected inverter device used in low wind speed is superior, in line withthe design requirements of system.