Synergetic control for stand-alone permanent magnet synchronous generator driven by variable wind turbine

This paper presents the synergetic control of a permanent magnet synchronous generator (PMSG) associated with a rectifier, a bidirectional DC–DC converter and an inverter all controlled by pulse width modulation (PWM). The bidirectional DC–DC converter feeding a battery is controlled to maintain the DC bus voltage at a desired constant value. The permanent magnet synchronous generator is driven by a variable speed wind turbine. The synergetic control developed aims at regulating the current on the d-axis, at ensuring the monitoring of the maximum power point, at regulating the DC bus voltage by controlling the charge/discharge of a battery mounted in parallel as well as the regulation of the voltage at the load. The studied wind chain can be used in remote areas not connected to the national grid where the wind speed is low. The analysis of the controller convergence is based on the Lyapunov theory. Simulations performed in the MATLAB/Simulink numerical environment have demonstrated the effectiveness of the proposed control method when the wind power system operates under load variations and parameter uncertainties.