The Study Of Grid Inverter Control System Based On Distributed System Of Wind In DC Microgrid

With the problem of the energy crisis and the environmental pollution becomingmore and more serious, the development of distributed generation derived from renewableenergy has become an inevitable trend of the future power grid. It has become a hot spotof academic research how to get the electricity system of distributed generation into powergrid high-efficiency. The distributed generation of Micro grid need to be incorporated intopower grid through the power electronic interface.Using direct form will reduce the degreeof coupling between the mico-grid and AC system，and improve the utilization efficiencyof equipment. It reduces the impact of AC fault on micro-grid. At the same time, with thedevelopment of the power electronic technology, microelectronics technology and controltheory,the power transformation equipment based on the technology of PWM (PulseWidth Modulation)has been widely applied in the permanent magnet direct-drive windpower system. PWM inverter has advantages of constant dc voltage, high power factorand bidirectional energy flow. According to the requirements of Interconnection, the studyof using grid phase locking technology control PWM inverter gradually become a researchhotspot at home and abroad. And it has very important and practical significance.In this paper, we used the stable operation of the DC micro-grid as a starting point,simulated and researched the grid inverter which using three-phase synchronous PLLcontrol technology. We analyzed the basic structure of the dc micro-grid, established themodel of distributed wind power generation and analyses operation characteristics andcontrol methods of the energy storage element(battery and super capacitor) in islandoperation mode.At the same time, we introduced energy management method of the dcmicro-grid. We tell it Multi-agent system and draw the block diagram of the controlmodule of each component in Dc micro-grid. At last, we simulated and tuned the systemof the wind power inverter control, provide a result of three-phase locked loop whenpower grid volatility. The simulation results show that the study of three-phase PLLcontrol technology can make distributed wind power into ac power grid smoothly.