Patented control for long PFC system lifespan

The Prophi® power factor controller has an optimised control mode. The implemented control standard algorithms reduce the number of switching cycles as well as the operating time per capacitor stage.

The aim is to have the same number of switching cycles and, if possible, the same operating time per capacitor stage.

The lifespan of the entire system can be significantly increased through even loading of all stages with an automatically regulated PFC system. This means that invested capital earns money for longer and that new investments can be avoided.

The hybrid switching (i.e. the combination of capacitor contactors and dynamic thyristor modules for contact-free rapid switching of capacitors) combines the advantages of rapid switching without network perturbation with the cost advantages of common PFC systems.

Functional principle

The single-phase electronic measuring system collects the reactive and effective current ratios of the network through the current and voltage measurement. Using the current from one phase and the voltage from the other two phases, the reactive power controller calculates the necessary reactive power to achieve the set target power factor.

The capacitor steps are switched on or off if any differences occur and the reactive power controller differentiates between the switching of capacitors through contactors or thyristors.

The control through capacitor contactors is optimised; this means that the reactive power controller achieves the cos-phi target with a minimum of switch actions. The transistor outputs for the almost immediate control of semiconductors compensate any difference.