A variable-speed drive including: a DC power supply bus including a positive line and a negative line; a bus capacitor connected between the positive line and the negative line of the DC power supply bus; an inverter module supplied with power by the DC power supply bus and controlled to provide a variable voltage to an electrical load; a first switching branch connected between the positive line and the negative line of the bus and including at least one first electronic switch; and a first module including a braking resistor, or a second module including a mechanism for storing and regenerating electrical energy generated during braking of the electrical load, wherein the first module and the second module are removable and interchangeable.