A power supply system comprises an AC input, an AC output, and a DC input; a DC intermediate circuit; a first converter connected, via a first bistable switching circuit, between the AC input and the DC intermediate circuit; a second converter connected, via a second bistable switching circuit, between the DC intermediate circuit and the AC output; a third converter connected, via a third bistable switching circuit, between the DC input and the DC intermediate circuit; a bypass circuit connected, via a bypass bistable switching circuit, between the AC input and the AC output and configured to provide a bypassing path from the AC input to the AC output; and a control unit.