Design of supervisory fault tolerant control for wind turbine generator system operated in region II

This paper discusses the design of supervisory control on the wind turbine generator system operated in Region II. There are two objective controls here, namely maximizing the power extraction and accommodating the minor fault on control components (sensor and actuator). This control system then is called as Supervisory Fault Tolerant Control (SFTC) which is consisted of supervisory level and regulatory control. For the first objective, the supervisory level applies an extremum seeking (ES) algorithm to adjust the reference generator speed to be an optimum value correlated with the maximum generator output power. Here the proportional - integral (PI) controller as the regulatory controller is applied to make the wind turbine generator system tracking the reference speed. For the second objective, the supervisory level uses an extended observer in order to provide fault estimation used in the compensation mechanism. The compensation mechanism is conducted in the measurement signal (as an input of the controller) and in the output of the controller in order to accommodate sensor fault and actuator fault respectively. The simulation results prove that ES-based SFTC yields the power output much larger and more steady than reference formula-based SFTC, and SFTC can tolerate the minor faults in sensor and actuator well.