Abstract: A control device for a multi-phase inverter is connected to a power supply source through a DC circuit and controlled in pulse width modulation by a control circuit (20), including several pairs of static switches installed in parallel with free wheel diodes, the mid-point of each pair being connected to a load; switching is done by comparison in said control circuit between an input signal defined by control voltages that are a function of simple voltage set values and a triangular carrier wave output by a triangular wave generator. The device uses a constant switching frequency and a parameter other than the frequency of the carrier wave, the value of which varies in a random manner in order to obtain after switching the simple voltage set values between the phases and the neutral of the load.