Robust Fault Diagnosis and Fault Tolerant MPPT Control of PMSG-WECS using Certainty Equivalence Principle

In this paper certainty equivalence principle along with sliding mode control strategy is utilized for Fault Diagnosis (FD) and Fault Tolerant (FT) Maximum Power Point Tracking (MPPT) control of Permanent Magnet Synchronous Generator based Wind Energy Conversion System (PMSG-WECS). At first stage, the dynamic model of the PMSG is developed and then the model is converted to Bronwsky form. Consequently, the overall system is subdivided into two subsystems i.e., second order visible dynamics system and a first order internal dynamic system. Diagnosis and estimation of fault is accomplished by using certainty equivalence principle while fault is tolerated by using sliding mode controllers. This strategy helps not only in reduction of controllers gains that will reduced chattering effect but also estimate structured faults. The proposed controllers effectively tolerate actuator faults and improve MPPT efficiency. Simulations under varying load and varying inertia and matched faults confirms the robustness of the proposed controllers. All the simulations are carried out in MATLAB/SIMULINK environment.