Research On Maximum Power Point Tracking Control For10kw Variable-speed Fixed-pitch Wind Generators

In recent years, as people focus on environmental issues, wind power has been developed rapidly. Direct-drive permanent magnet synchronous generator, a new type of wind turbines, attracts more and more attention, because of its gearless, low operating costs and high power generation efficiency. Power generation efficiency of the wind turbine become low if there is no control system in wind power system. If wind turbines runs at the optimal tip speed ratio, the efficiency of the power generation efficiency is up to about0.5.At the beginning of this paper, some kinds of topology for a direct-drive permanent magnet synchronous wind power system is introduced, including a topology of non-controlled rectifier followed by a full controlled device, a topology with DC/DC links, and a topology of dual-PWM converter. Then control method of wind turbines in different wind speed region is introduced. Above the rated wind speed, wind turbines can change the pitch angle to limit the rotor speed to keep the whole system in a state of constant power. Under the rated speed, rotor speed of the wind turbine must be change according to the wind speed to ensure the wind turbine extract maximum power from wind.Several common maximum power point tracking control methods are introduced, and their advantages and disadvantages are pointed out. In Matlab R2008a/Simulink, mathematical models of wind power system, such as wind model, PMSG model, machine-side converter, are built up. The Maximum power point tracking method is simulated and verified.On the experimental platform of direct-drive wind power system, variable speed motor control is realized by the method of vector control of permanent magnet synchronous machine, after coding DSP program in CCS3.3.