Hybrid filter with an optimized switching method of the compensation capacitors and predictive active filter control

Inhalt:
A hybrid filter, consisting of a parallel-connected reactive power compensator (RPC) and a shunt active power filter (APF), is presented. The RPC is used to compensate inductive reactive power by need-based switching capacitors to the grid. At this, a charging circuit and a switching method, which is causing no inrush currents and no transient currents, are introduced. The APF is based on a voltage source inverter and is used for the compensation of distortion power. A simple, but very efficient predictive control scheme is presented. Both filters are built up as three-phase four-wire systems, so that the presented methods are also suitable for single-phase systems.