Research And Implementation Of Electric Pitch Control System On MW Wind Turbine

In the energy era, the public draw much attention on development andutilization of green resources, in which wind energy performs as arepresentative as well as a major focus in research. Wind power is greenand environmentally harmless thus develops rapidly all over the world. Ascapacity of Grid-tied Wind Generator keeps increasing, control strategy ofwind turbine gains more and more attentions. As a result, pitch system,especially electric pitch system, which plays an important role in the wholecontrol system, is becoming of prime importance for MW wind turbines.Major work in the dissertation is demonstrated below.The dissertation starts from basic theory of wind turbines inAerodynamics and analyze factors that affects output power, thus discussesoperating modes of wind turbines using active pitch control. Then,demands of pitch system from the wind turbines control strategy as well asbasic structure of electric pitch system is analyzed.In order to achieve better performance in case output power fluctuateswith high frequency, the dissertation proposes an improved variable-speedpitch control strategy in electric pitch systems with fuzzy theory. Then amodule for electric variable-speed pitch control utilizing simulationsoftware is established. And based on the simulation module, controlstrategy of variable-speed pitch system is proved to be effective.According to demands from modern wind power system, specificdesign and optimization is accomplished from the aspects of: pitch motor,cabinet structure, system power distribution and data communication.Considering the prime importance of emergency power supply,corresponding design and optimization based on supercapacitor models isalso achieved in order to ensure safety and stabilization of the whole system.Finally a hardware experimental platform is established according tospecific design above, and software involving main states machine andhuman-machine interface is accomplished. Test result verifies the designand optimization.