Reseach Of Direct-Drive Permanent Magnet Synchronous Wind Turbine Generation Control System

People widely pay more attention on wind energy because it is a regenerated energy. The variable-speed constant-frequency wind generation is very important in modern wind power system. It's very suitable for wind generation because it can capture as much energy as possible. At present, direct-drive technology is the development trend of wind power generation system, but the electricity generated by direct-drive wind power generator has many problems, Such as voltage amplitude and frequency are changing with wind speed, the power is also unstable and so on.In order to solve these problems,The paper has done full-scale study on the direct-dirve variable-speed constant-frequency wind power generation from theory to simulation. The author has done thoroughly description on the characteristic of the direct-drive wind power generation and based on the existent Maximum Power Point Tracking Algorithm, established the topology configuration of Trapezoidal Permanent Synchronous Generator, three-phase uncontrolled Rectifier, DC-DC boost circuit, full-bridge Inverter circuit. A new Maximum Power Point Tracking Algorithm and speed-estimated control was put forward to increase the response of the system.The phase current of the generator is trapezoidal just for the inductance exit in the DC-DC boost circuit, in order to make the output power more stabilization, and reduce torque ripple, then EMF should be trapezoidal. The three-phase voltage is trapezoidal by the Trapezoidal Permanent Synchronous Generator, being commuted by the bridge of rectifier; Pulse is a series of smaller wave flattened. After was filter by large inductor, obtaining more flattered DC voltage.The generator and wind turbine can be coupled directly that has gained renewed attention on Large-Scale low speed wind power system; Three-phase uncontrolled Rectifier has high realiability, simple hardware circuitry; DC-DC boost circuit can step up the DC link voltage to meet the Invert circuit, then connecting to the gird; Wind power generation vary with the change of the wind speed using Maximum Power Point Tracking algorithm, Maintain optimal tip-speed ratio, maximum power is captured from wind by the wind turbine.MATLAB/Simulink tool box is employed to construct the dynamic simulation modules for whole stall regulation wind turbine generator system so that the dynamic operation of the system may be simulated,Maximum Power Point Tracking algorithm is tested. The result of the simulation and experiment all validated the validity and feasibility of theoretical model and control strategy.