Predictive current control strategies of grid connected-self excited induction generator

Abstract

This paper deals with a grid-connected wind energy system. The main objective of this work is to apply direct current predictive control to a wind energy system in order to optimize its production. Optimizing production means not only improving the quality of the energy produced but also better trajectory tracking of the variables to be controlled. We have applied predictive current control to the PWM rectifier to get the maximum power at the wind turbine and predictive current control to the PWM inverter in order to obtain a unit power coefficient and to reduce the total harmonic distortion rate of the current injected to the grid. In order to show the robustness of the proposed control law related to variations in the internal parameters of the squirrel cage induction generator, we have compared the results obtained with the classical direct torque control and PI (at the PWM rectifier level) and the direct active and reactive power control and PI regulator control (applied to PWM inverter). The results obtained in the MATLAB/SIMULINK numerical environment show a better trajectory tracking, a fast convergence as well as the effectiveness of the proposed control approach towards the variation of the internal parameters of the generator.

Keywords

• Squirrel cage induction generator
• Maximum power point tracking
• Predictive current control