1. A waste-heat recovery system for a waste-heat source, comprising:
an ORC (Organic-Rankine Cycle) postconnected with respect to the waste-heat source, the ORC including:
a heating device connected to the waste-heat source,
a down-running generator, and
an expansion machine coupled to the down-running generator and for performing a steam expansion, the expansion machine including
magnetic bearings, with an associated control device and a power supply via a direct current intermediate circuit of a generator
frequency converter, wherein in the event of a power supply failure, an electric energy that the down-running generator continues
to generate is used to supply the magnetic bearings with the associated control device.