ELECTRICAL SYSTEMS

Electrical systems 201 for connecting rotary electric machines with gas turbine spools are provided. One such electrical system 201 comprises: a first dual-wound rotary electric machine 111 mechanically coupled with a first gas turbine spool and comprising a first three-phase sub-machine 111-1 and a second three-phase submachine 111-2; a second dual-wound rotary electric machine 113 mechanically coupled with a second gas turbine spool and comprising a third three-phase sub-machine 113-1 and a fourth three-phase submachine 113-2; and a set of N = 4 bidirectional converter circuits 401-404 for conversion of alternating current (ac) to and from direct current (dc), each of which has an associated index n = (1,...,N), and for all n, the ac side of the nth bidirectional converter circuit is connected with the nth three-phase sub-machine. The dc side of the first converter circuit 401 is connected with the dc side of the third converter circuit 403, and the dc side of the second converter circuit 402 is connected with the dc side of the fourth converter circuit 404.