These units are a.c./a.c. converters that use a minimum active energy from the grid to generate reactive energy with a continuously variable amplitude, from 0 up to a maximum value of Q ( KVAr ) . They manage sinusoidal currents, with no distortion, and permit reactive energy compensation with any grid.

Since the regulation does not present steps as the traditional energy compensation devices, as contactors or thyristors, it is possible to obtain a cos FI = 1, permanently, as long as the reactive demand does not exceed the power of the Reactive Compensation Unit.

This units are an ideal complement to conventional compensation devices, more economic, or for those applications where the small short-circuit power of the grid in the connection point does not permit compensation with a.c. capacitors.

In wind power plants with asynchronous generators, they increase the power factor from fixed compensation value to unity.