The Maximum Power Point Tracking Controller Of The 600W Wind Power System

Wind energy is a kind of renewable green energy resource. Some problems such as high start-up wind speed, short life of storage battery and low utilization coefficient of wind energy that exist in small wind power system need to be further discussed. This paper discusses the Maximum Power Point Tracking (MPPT) control, the charging and discharging of battery of 600W small wind power system, etc.By designing windward speed bumps of small wind turbine with the speed acceleration device, the structure of system is simplified; the cost of system is lowered and the stability of wind turbine’s windward system has improved; This paper describes the working principle of all constituent parts of wind power system, and establishes mathematical model of wind speed, wind turbine and permanent magnet synchronous generator, and simulation is performed on wind speed and wind turbine; variable step size searching algorithm has been improved; as the two constraints, power difference and flag are introduced, which can increase the search speed of maximum power point of the system, eliminate the phenomenon of oscillation near the maximum power point,enhance the stability of wind power system; the mathematical model of Boost converter and BUCK converter is established, the working principle and control method of DC/DC converter are analyzed, and model simulation have been performed; the Boost-BUCK bi-directional converter circuit which can control the charging and discharging of battery has been optimized, this circuit can change the voltage and current of battery charging and discharging according to the condition of battery, which can extend the service life of battery.The structure of Maximum Power Point Tracking (MPPT) controller and the way to select the main components are provided, the simulation of MPPT control of the system and the tests of Boost converter and Boost-BUCK converter are carried out based on mathematical model, the result shows that the variable step control strategy to step representation long wind speed signal respond time is 0.6 s and wind energy utilization coefficient keep in 0.48, the simulation and test results preliminarily demonstrate the feasibility of the research.