An adaptive nonlinear control strategy for a stand-alone permanent magnet synchronous generator driven by a variable speed wind turbine

Abstract

This paper presents a simple control structure using rotor flux oriented vector technique for a stand-alone permanent magnet synchronous generator (PMSG) associated to PWM rectifier, PWM DC–DC converter and PWM inverter. The DC–DC converter feeding an electronic load is controlled to maintain the dc-bus voltage at a desired constant value. The isolated PMSG is assumed to be driven by a variable speed wind turbine. A sliding mode control strategy has been developed to regulate the direct axis current, ensure maximum power tracking issue as well dc-bus voltage regulation. The online estimation of the rotor flux using sliding mode concept is provided. The control and estimator stability analysis is based on Lyapunov theory. Simulation results, carried out in Matlab/Simulink software, are presented to demonstrate the effectiveness of the proposed control method when the control system operates under load variations and parameters uncertainties. The proposed adaptive control can be used in remote area where wind speed is low.