Reactive power compensation plants are used to decrease the load of cables and power distributions caused by inductive currents and to save reactive power costs. The power factor controller is a main part of such a plant and connects or disconnects capacitor stages automatically. The power factor controller Prophi is suitable for the use in conventional or dynamic reactive power compensation systems, and a mixed
operation is possible as well.

The one phase electronic measuring system detects the reactive and real vectors of current through current and voltage path. By means of these values the controller computes the phase divergence between the fundamentals of current and voltage, and compares it to the set phase divergence. In case of a difference, capacitor contactors will be switched on or off. Here the reactive power controller distinguishes the switching of capacitors via contactors or semiconductor switches. The controlling via capacitor contactors is carried out optimized, which means, that the target cos-phi is reached by as less switching operations as possible. Transistor outputs for the controlling of semiconductor switches compensate any difference.

With the overtemperature disconnection, connected stages can be disconnected to lower the inner temperature and to protect the capacitors. An upper and lower limit can be set with a switch off time.

One relay output can be used for ventilator control, where an upper and lower limit is programmable