Device for uninterruptible power supply and for active filtering

The device has loads connected to an a.c. sub-network connected to a supply via a switch and a primary winding of a coupling transformer. The a.c. side of a first current converter is connected between the switch and primary winding. The a.c. side of a second converter is connected to the secondary winding. The converters' d.c. sides are connected to an intermediate d.c. circuit and at least one energy storage device and/or energy generator. The device has loads (L) connected to an a.c. sub- supply (N2) connected to a supply (N1) via a switch (S) and a series primary winding (PW) of a coupling transformer (T). The a.c. side of a first current converter (SRPAR) is connected between the switch and primary winding. The a.c. side of a second current converter (SRSER) is connected to the secondary winding (SW). The converters' d.c. sides are connected to an intermediate d.c. circuit (G) and at least one energy storage device (ES) and/or energy generator (EE).