A Two-Degree-of-Freedom Internal Model-Based Active Disturbance Rejection Controller for a Wind Energy Conversion System

Abstract

Active disturbance rejection control (ADRC) is a widely employed control strategy due to its ability to deal with the disturbance and parametric uncertainties. Extended state observer (ESO) serves as the core block in an ADRC. ESO estimates the lumped disturbance in the wind energy conversion system (WECS) which is then canceled by designing a suitable control law. However, for a complex system such as WECS, the exact estimation of disturbance by using ESO is difficult. To overcome this difficulty, an ADRC is designed in this paper by adopting a two-degree-of-freedom (TDF) internal model controller framework for a permanent magnet synchronous generator (PMSG)-based WECS. The setpoint and disturbance rejection filters of TDFIMC are considered as two tuning parameters instead of using the controller and observer bandwidths as tuning parameters in ADRC. The efficiency of the proposed controller to regulate the active and reactive power in the presence of parametric uncertainties and disturbance is examined by pursuing first simulation studies followed by experimentation on a 1-kW PMSG-based WECS developed in our laboratory. Both simulation and experimental results clearly show that, by employing the proposed control scheme, the steady-state and transient responses of active and reactive power transfer to the grid are enhanced. Furthermore, on comparing its performances with that of a multiloop active disturbance rejection controller (MADRC), it is also confirmed that the former exhibits superior performance.