Study On A Novel Drive Train And The Optimized Strategy For Variable-speed Pitch Controlled

When environment and energy is treated as the critical issues of human survivaland development, the wind energy has been widely recognized by all countries becauseof its non-polluting and renewable characteristics. The wind turbine has the tendency ofhigh power, high efficiency and high reliability, so the drive train system and controlsystem has been widely concerned. In this paper, a novel drive train realizes the purposeof variable speed input and constant speed output. And the control system plays a keyrole in wind energy capture maximization, system fatigue load reduction, service lifeextension and etc. The following aspects are studied.①The drive train consists of a planetary gear train and a hydrodynamic torqueconverter with adjustable guide blades. The purpose of variable speed input andconstant speed output as well as step-less speed regulation of the system can be realized.To further research the speed regulation principle and its stability, with the planetarytransmission theory, the nonlinear dynamic mathematical model of the novel drive trainwith wind turbine established on the basis of hydrodynamics energy head theory isresearched. And a new power distribution calculation method is proposed, consideringthe problem in the actual operation.②Based on aerodynamics and an analysis of basic control strategy forvariable-speed pitch controlled wind turbine, an optimized control strategy of enlargingthe transition region is proposed to mitigate the harmful effects. A three-controllersmooth transition scheme is designed to fulfill the optimal tracking to the optimizedcontrol strategy．③A fuzzy PID controller applied to the drive train system is designed based onfuzzy theory and PID control theory. And in the transition region, the variable-speedpitch controlled system is based on the fuzzy neural network theory.④Simulations of the controllers are carried out by applying MATLAB/Simulink.Compared with the effect of the traditional PID controller to the system, the fuzzy PIDcontroller has advantages in higher precision and smaller overshoot. The result alsoindicates that variable-speed pitch control system has a good effect.