Use of a control system of a polyphase rotary electric machine comprising phase short-circuit means, and use of the corresponding rotary electric machine

Polyphase rotary electrical machine (1) comprising a control system (10) comprising phase short-circuiting means (15, 18), said machine (1) of the excitation type being coupled mechanically to a thermal engine (6) of a motor vehicle, and operating as a generator connected to an on-board electrical network (2) of said vehicle, said phase short-circuiting means (15, 18) short-circuiting at least one phase winding (9) when a measurement of a direct voltage (B+) of said network (2), regulated by a regulation device (11), exceeds a predetermined threshold value, and when a phase current (IΦ1, IΦ2, IΦ3, IΦn) in said phase winding (9) is cancelled and changes direction, wherein said machine (1) protects, by means of said phase short-circuiting means (15, 18), electrical equipment connected to said network (2) in the event of an excess voltage on said network (2) caused by at least one event from amongst the following:

• a fault of an excitation circuit (7), a fault of said regulation device (11), assisted starting of the jump start type, overspeed, or racing of said thermal engine (6).