Power control of an AFE rectifier during unbalanced grid voltage using predictive current control

This paper presents a predictive current control strategy for Active Front End (AFE) rectifier supplying active and reactive power to the electric system during unsymmetrical voltage fault conditions without the use of a Phase Locked Loop (PLL) or Frequency Locked Loop (FLL). For a given active and reactive power and supply voltage, the strategy generates the required reference currents. A predictive current control strategy is used to impose those currents by the AFE rectifier. It is shown that the amount of active and reactive power that can be injected into the grid will depend on voltage unbalanced level. Simulations and experimental results showing the performance of the strategy are presented during unbalanced voltage sag and swells.