Grid reactors are used to ensure better protection against overvoltages and to lower harmonic distortions of current, generated by non-linear loads.

Among others, the use of grid reactors is recommended in the following cases:
  several drives, connected in parallel close to each other,
  supplying power to equipment using the grid with high level of distortions,
  supplying power to devices when the voltage is unbalanced,
  low impedance lines.