A DC/AC electrical power converter device having inlet terminals for electrically connecting to a DC electricity power supply network, outlet terminals for electrically connecting to an electric motor, a chopper electrical converter coupled to the inlet terminals, and an electrical inverter coupled between the chopper electrical converter and the outlet terminals. The converter device further includes a control unit for controlling the electrical inverter and that is configured to operate using pre-calculated pulse width modulation with pre-calculated unchanging switching instants for the controlled switches of the electrical inverter regardless of the frequency of rotation of the motor and of the voltage of the electricity network for connection to the device.