Research On Frequency Conversion And Speed Governing Of Water Pumping Driven By Wind Turbine

The application of water pumping driven by wind turbine in the remote areas can not only solve the problem of drinking water for local residents and livesto ck,but also effectively use abundant wind energy resources.In order to improve the efficiency and reliability for system of water pumping driven by wind turbine when the wind speed fluctuates,the quasi Z source inverter is used to replac e the c ircuit structure of boost and inverter c ircuit,the speed of motor is adjusted in real time using the method of variable frequency vector speed regulation in this paper.The main research contents of the paper are as follows :The research significance and background of water pumping driven by wind turbine are introduced,and the research status in different countries is described in this paper.The structure of water pumping driven by wind turbine is designed,and the characteristics of the components are analyzed in detail.The working princ iple of the quas i Z source inverter is analyzed in detail and a mathematical model is established in this paper.The DC voltage utilization rate of the quasi Z source inverter is improved by the modulation method of the three harmonic injections into SPWM.The principle of variable frequency vector speed control for three-phase asynchronous motor is analyzed,and the speed of motor is adjusted in real time by using the method of variable frequency vector speed control when the output power of the wind turbine is changed in this paper.According to the actual s ituation of the local residents,the motor,the water pump and the wind turbine are matched and the parameters of the capacitor,inductor and diode of impedance network were designed.The analys is of wind turbine,quasi Z source inverter,variable frequency vector speed regulation method of water pumping driven by wind turbine are carried out by building the simulation models in this paper.The simulation results show that the quasi Z source inverter replaces the circuit structure of boost and inverter circuit,which can ensure the stable operation of the water pumping driven by wind turbine,and improve the system operation effic iency and reliability;According to the change of wind speed,frequency conversion vector speed control method is used to adjust the speed of the water pump motor in real time,which not only can reduce the starting current of the three-phase asynchronous motor,but also can make the system of water pumping driven by wind turbine pump more water when the wind speed is large,and pump less water when the wind speed is small.