Grid synchronization of power converters to weak unbalanced networks with disturbances

Abstract

In the context of the multiplication of micro-grids or delocalized energy sources, one must face more and more disturbances coming especially from weaker isolated grids. The control of the active rectifier unit connecting the grid must be designed not only for surviving a voltage dip with some ride-through methods, but for actually controlling the currents during a network unbalance. This purpose is served with the accurate synchronization to the grid considering all its perturbations and allowing advanced dynamics for any type of disturbances. This paper presents the use of a performant PLL coming from renewable sources power converters oriented for drive applications.