Patent ID: 8519663

Claim:
A power supply system for an element, among a rotor and a stator, of an electric machine, comprising: a converter for converting a direct input current into a polyphase alternating output current including a plurality M of phases, the converter comprising two input terminals, the converter being arranged at an input of said element and being adapted to deliver the polyphase alternating current to said element, a controller for controlling the converter, a storage bank including at least one storage capacitor arranged between the input terminals of the converter, and a protection device for protecting the element from over-voltages and/or over-currents of said polyphase alternating current, arranged between the converter and said element, and including a plurality of switching arms arranged between the respective phases of the polyphase alternating current, each switching arm including two thyristors connected head-to-tail and in parallel, the controller capable of applying a negative voltage to terminals of at least one of the two thyristors during a period greater than a predetermined turn-off time of the at least one thyristor.