Toward the Optimization of a PMSG Wind Energy Conversion System On-Grid by a Robust Mixed Controller

Abstract

The grid interconnected Wind Energy Conversion System (WECS) remains a major challenge. To deal with the effect of the intermittent nature of wind speed. This paper presents the design of a combined nonlinear controller based on a sliding mode controller (MSMC) for a wind system. This control technique includes a smooth switching sliding mode observer (SS-SMO) and a non-singular terminal sliding mode controller (NT-SMC). The SS-SMO is used to observe the torque/speed disturbances, while the NT-SMC is used as a regulator. A voltage control technique is adopted to maintain the voltage at the common DC-link. To control the electrical power injected into the grid a Backstepping controller is proposed. The WECS is built around a wind turbine coupled to a Permanent Magnet Synchronous Generator (PMSG). The proposed technique is robust against model uncertainties and external disturbances. In addition, the complexity of the system is reduced by replacing the mechanical speed and position sensors with the estimated parameter. The simulations results show the performances in terms of monitoring of set point, stability, and robustness with respect to the variation of wind speed.