Abstract: A power supply system is provided. The power supply system includes a converter converting a direct input current into a polyphase alternating output current including a plurality M of phases. The converter includes two input terminals, is arranged at the input of the element and delivers the polyphase alternating current to element. The power supply system also includes a controller controlling the converter, a storage bank including at least one storage capacitor between the input terminals, a device protecting the element from over-voltages or over-currents of the polyphase alternating current, between the converter and element, including a plurality of switching arms between the respective phases of the polyphase alternating current. Each switching arm includes two thyristors connected head-to-tail and in parallel. The controller applies a negative voltage to the terminals of at least one thyristor during a period greater than a predetermined turn-off time of the thyristor.

Abstract: This power supply system for powering an element (18), among a rotor (18) and a stator, of an electric machine, includes: a converter (30) for converting a direct input current into a polyphase alternating output current including a plurality M of phases, the converter (30) including two input terminals (42A, 42B), the converter (30) being arranged at the input of the element (18) and being adapted to delivering the polyphase alternating current to the element (18), a controller (32) for controlling the converter (30), a storage bank (34) including at least one storage capacitor (66, 68) arranged between the input terminals (42A, 42B) of the converter, and a device (36) for protecting the element (18) from over-voltages and/or over-currents of said polyphase alternating current, arranged between the converter (30) and the element (18), and including a plurality of switching arms (76) arranged between the respective phases of the polyphase alternating current, each switching arm (76) including two thyristors (