Research On Small Vertical Axis Wind Power Grid Connected Inverter

With the fossil energy crisis and environmental pollution problems become prominent,and green renewable energy has been development.As a representative of renewable energy,wind power technology has received attention at home and abroad in recent years.Grid connected inverter is the key electrical equipment in wind power generation system,and its control strategy is closely related to the safety,stability and efficiency,thus affecting the entire distributed generation system and power grid operation.Therefore,the construction of precise wind power generation system and the control strategy suitable for wind power system need further research and development.For small wind power grid-connected inverters,PI control has the disadvantages of steady-state error,poor disturbance rejection ability and high harmonic content.The mathematical model of grid-connected inverter topology was established.The superiority of quasi-proportional resonance(QPR)control based on SPWM was discussed from two angles of mathematical and physical model.The influence of three parameters was discussed.The specific parameter design method was set.The integration of improved repetitive control and QPR control was introduced.The simulation experiment show that the composite control strategy can resist periodic and aperiodic disturbances,improve the steady-state accuracy and reduce the harmonic content.Aiming at the power quality problem,a control strategy with harmonic and reactive power real-time compensation function was proposed.Firstly,the LCL type multifunction grid connected inverter was built.A control method of real-time tracking the harmonic and reactive power was designed based on the instantaneous reactive power theory.The design method of LCL filter was discussed.The simulation experiment proved the correctness of real-time compensation harmonic,reactive power control strategy and the design of LCL parameters.