Research On Adaptive Control Of Electric Pitch Control System

Wind energy is clean, renewable and large reserves energy. Power-generating capacity can be scale and commercial development in a short time. It is the most growth potential new energy in the world. So the research and development of efficient and reliable wind power generation system has become hot spots in the field of world energy technology research. Pitch control technology is one of the key technologies of wind power generation system. Especially for large-scale wind turbine, the research of pitch control technology is greatly practical. Based on domestic MW wind power generation system, electric pitch control system is researched in this paper.In this paper, the aerodynamics basic theory and the basic law of pitch control is researched. The basic control structure of pitch system is discussed. According to the subject requirements, AC asynchronous motor is selected as the electric pitch implementation motor. In the field orientation control conditions, AC asynchronous motor mathematical model is simplified, by the research of asynchronous motor multivariable, nonlinear and strong coupling mathematical model and vector control principle. Appling indirect field orientation vector control technology, the electric pitch control scheme is designed based on the three closed-loop control of position, speed and current.For wind power generation pitch control system is difficult to establish the mathematical models, adaptive control is applied based on the scheme of pitch servo system three closed-loop control. For the load torque of pitch servo system is not constant, the anti-interference ability of pitch system must be strong. So Pitch servo system speed loop applies model reference adaptive control. In practice, the pitch system position output is required to be fast, accurate tracking and no overshoot, so pitch servo system position loop applies fuzzy adaptive control. Simulation results show that the speed loop appling model reference adaptive controller not only can suppress external interference and environmental changing, but also eliminate the impact of system parameters changing. Position loop appling fuzzy PD adaptive controller can be online real-time tuning PD parameters according to the system need, so the control effect achieves electric servo system required performance.The wind turbine power control is studied in the paper, based on the research and design of electric pitch servo control system. Putting electric pitch adaptive control servo system into the wind turbine machine system, the generator power regulator is designed. For wind turbine system is non-linear and multi-variable, the power regulator applies neural network adaptive controller. Applying the Matlab software, the simulation model of unified power wind turbine adaptive control is set up. And the wind generator circulating situation is simulated in wind speed above rating speed. Simulation results show that the actual output power maintains the vicinity of the rating power by the neural network adaptive controller.