The invention relates to a variable speed drive comprising a direct-current power bus having a positive line (16) and a negative line (17), and an inverter module (14) supplied by the direct-current bus in order to supply a variable voltage to an electric load (M). The drive comprises an energy-recovery device (10) comprising a first direct-current/direct-current converter (20), the output stage of the first converter (20) being connected in series to the positive line of the direct-current bus, a second direct-current/direct-current converter (30), the input stage of the second converter (30) being connected between the positive line and the negative line of the direct-current bus, and an electric energy storage module (Cs) connected in parallel with the input stage of the first converter (20) and with the output stage of the second converter (30).