Research On Fault Tolerant Control Of Wind Turbine Control System

Wind power as an important clean energy, has attracted the attention of the countries all over the world. Wind turbine is a mechanical-electrical--hydraulic integrated complex nonlinear dynamic system, which consists of rotor blade system, gear box, drive train, generator and its control system. Under the random intermittent wind, wind turbine shows the characters of stochastic and switching. Modeling and control for such a system is a more difficult problem. At the same time, the wind turbine control system contains some common failures such as sensor and actuator faults. Control system faults have serious impact on the performance and security of wind turbine. Therefore, research on fault tolerant control technology of wind turbine has very important significance to the safety and efficient operation for wind turbine.In this thesis, the first part discusses the optimal control problem of wind turbine, the maximum power point tracking (MPPT) strategy with Active Disturbances Rejection Controller (ADRC) technology is used to control the Doubly-Fed Induction Generator (DFIG) wind turbine and Permanent-Magnet Synchronous Generator (PMSG) wind turbine respectively. The objective of this strategy is to achieve the optimal control of maximum power captured. For the multi-parameters and parameters tuning problems of ADRC, a hybrid optimization method is used. Simulation results show that MPPT with ADRC can well obtain the optimal power captured of wind turbine. The second part discusses the fault-tolerant control problem for the sensor and actuator faults of the wind turbine. The normal and fault stochastic piecewise affine (PWA) models for wind turbine are established. Then, according to the method of nonlinear dissipative system stability theory and Hoo robust control method, the H∞fault tolerant controller existence theorems and the solving methods for the sensor and actuator faults of wind turbine are got. Simulation results show that stochastic PWA modeling method of wind turbine with H∞fault-tolerant control method can better solve the random nonlinear dynamics modeling and fault-tolerant control problems of the wind turbine.