Research On The Control Technology Of Nine-phase Stator Permanent Magnet Wind Power Generator

Due to the limited reserves fossil fuels and causing environmental pollution,clean energy has received more and more attention.The Chinese Government put renewable energy as an important part of national energy sustainable development strategy.Among many kinds of energy,wind energy has broad developing prospect because of the merit of clean and rich reserves.Among the conventional wind power systems,direct-driven permanent magnet synchronous wind energy conversion system is very suitable for offshore wind power systems which operation and maintenance cost is cheap because of getting rid of the gear box.However,conventional permanent magnet synchronous generators have the disadvantage of heat-dissipation problem,which can cause permanent magnet heating even damage.In this thesis a new nine-phase stator permanent magnet wind power generator is proposed and analyzed,which permanent magnets and windings on the stator,decreasing the risk of demagnetization greatly.The study included direct torque control strategy,direct torque control strategy based on space vector pulse width modulation,maximum power point tracking control based on wind speed estimation and considering loss torque.The experimental platform and driving system are built.Both simulation and experimental results demonstrate the effectiveness of the proposed strategies.Besides,sliding mode pitch angle control and sliding mode pitch angle control optimal control based on fuzzy control boundary layer are proposed for modern large wind turbines.The effectiveness of control strategies is validated through the simulation results.The main points of this thesis are as follows:1?On the analysis of the structure of nine-phase stator permanent magnet generators wind power generation system,the mathematical model is established and the simulation model based on Matlab/Simulink is built.2?Nine-phase stator permanent magnet generator direct torque control strategy has been analyzed,including conventional strategy based on switching table and the DTC-SVM control strategy.3?Maximum power point tracking control strategy based on DTC is proposed,and because of kinds of loss lead to the low efficiency,a maximum power point tracking control strategy based on wind speed estimation and considering loss torque is designed.4?On the basis of sliding mode pitch angle control,the width of boundary layer is analyzed.Sliding mode pitch angle control optimal control based on fuzzy control boundary layer is proposed which can reduce the chattering of pitch actuator effectively.5?Based on the real-time dSPACE DS1005,a digital driving experimental platform of wind power generation system is built.Experimental results verify the validity of proposed control algorithms.