Wind Power Grid Inverter LVRT Research

With the development of economic and our society, the need for energy sources has been increasing, the energy problem has been become a public concern in our society. Wind energy as a clean and green source of renewable energy gets the rapid development and wide application. It has been one of the most important research area in the field of new energy.With the development of the exploitation and utilization of wind energy, wind energy technology also have marked progress, and become a commercially-viable embranchment of energy technology. Wind power grid will become the main trends of wind energy. The global installed wind capacity has grown rapidly. The proportion of Wind power generation capacity of power grid capacity can not be ignored, when the grid fails, if all the wind turbine are off the grid, the wind power system can not provide the support of the voltage and frequency, it will cause harm to the whole electric system. Therefore, the research on the security of wind power grid has become one of the hotspots, The low voltage ride-through (LVRT) capability of wind farms is very important.This thesis is based on the development of2KW direct drive wind power grid-connected inverter project. When the grid fails, how do we detect and track the voltage, so that the capability of grid-connected inverter low voltage ride through can be enhanced.(1) This paper analyzes the structure and working principle of the wind power generation system, analyzes the domestic and international standards of wind power system low voltage ride through grid, and then get the low voltage ride through standard.(2) In this paper i analyze the structure and working principle of the direct drive wind power generation system, focus on the rectifier circuit, the unloading circuit and the inverter circuit topology, and then set up the experimental system, including unloading circuit IBGT+resistors, grid inverter circuit.(3) In this paper i analyzed the main circuit topology of the system, design hardware PWM inverter control part, and then build the inverter experimental platform. I write the software of the inverter control part, come to the experimental waveforms, and then analyze the experimental results.Finally, this wind grid-connected inverter low voltage ride through experimental system which i designed achieve the desired effect. It’s very important to the development of wind power in large scale grid-connected and new green energy.