Predictive direct torque control of a rotor-side matrix converter driven grid connected DFIG with torque and flux ripples minimisation criterion

Abstract

The doubly fed induction generator (DFIG) is the most commonly used machine for variable speed wind power generation, and the single stage matrix converter (MC) can potentially replace the conventional back-to-back voltage source converters (VSCs) for rotor to grid inter connection. In this research work, the performance of grid connected DFIG with rotor side MC is analysed with predictive direct torque control (P-DTC) technique incorporating a criterion for minimising the torque and rotor flux ripples at a fixed switching frequency. Space vector modulation (SVM) is utilised for MC side control. The system exhibits better transient and steady-state behaviour over conventional configurations, for both sub and super-synchronous operating modes, as evaluated by simulation based on a 2 MW DFIG model in MATLAB-Simulink environment.