Research Of The Adjustable-Pitch System Control Technology For MW Wind Turbine

With the rapid development of global economy and increasingly improving of people's living standard, the shortage of the routine energy will be more and more serious, and the limited fossil fuel of the earth will be exhausted gradually, so it has already been an urgent subject for social sustainable development that we should develop new renewable sources. Wind energy is exactly a kind of inexhaustible renewable sources, development and utilization of wind energy is an effective measure to protect the ecological environment of the earth and slow down the consumption of the earth resource. Wind turbine is the best tool to develop and utilize wind energy, therefore, China and even the whole world all greatly develop and popularize wind power. Wind power becomes the fastest increasing new clean electric power in the world. So further research of wind turbine variable-pitch control technology has very important meaning for persistent wind turbine development and home production. The thesis focus on the variable-pitch structure and control system of MW wind turbine group. The background of the thesis is "MW variable-speed constant- frequency wind turbine group (No. 2001AA512022)", which is supported by National 863 Plan. The thesis expands its investigation on relevant variable-pitch control problems of wind turbine, the main contents can be concluded as follows:Hydraulic driving system is designed under the condition that the operation requirments and enviroment of wind turbine has been fully considered. Because of the great nolinearity of wind turbine, traditional PID control effect is not satisfied and adaptive control technology is adopted for variable-pitch control. Through the experiments on the 1MW wind turbine, the control performances all meet the demands under the operation state.For the design of parallel redundancy variable-pitch servo system, an adaptive decoupling control technology is presented to restrain the machine coupling influenced by dual hydraulic cylinders system. Firstly through feedforward decoupling, then the dual hydraulic cylinders controller's parameters will be modified by the feedback. The synchronous control caused by the feedback resulting from the adaptive control law will keep synchronism with dual hydraulic cylinders in position to realize synchrodrive. The simulations results indicate that the proposed schemes have the advantages of rapid response, strong robustness, and low synchronous error.In addition, due to the independent variable-pitch control based on PMSM is anther significant development trend, the independent variable-pitch actuator is designed . According to PMSM, the IP position servo system is built, and then a method of optimal preview feedforward compensation for this system is also presented to improve the tracking performance based on IP position control system. To adapt the parameters variability of the system, adopts Adaline to implement preview feedforward compensation. The simulation results of this application demonstrate the significance of the proposed method. The results demonstrate that the control effect is good.