Abstract: The method and the corresponding device allow to start a synchronous motor with the chosen rotation direction, with a very high static torque, without requiring any modification of the structure of the synchronous motors currently in use, by means of an adapted electronic circuit managed by a microprocessor.

Abstract: A method for the starting and steady-state supply of a permanent-magnet synchronous motor, particularly for driving a centrifugal hydraulic pump. The method comprises three successive steps: a first learning step, a second starting step, and a third steady-state step. During the first step, the rotor is turned through two angles of 180 mechanical degrees in the same direction, storing the parameters of the rotor and particularly determining the initial current and the mechanical zero point of the rotor. During the second step, by generating with a power supply (inverter) a practically sinusoidal current waveform, the rotor is started with a higher current than the stating current and with a low frequency which gradually increases, waiting for the rotor at its transit through 80, 100, 260 and 280 mechanical degrees. Once the intended steady-state speed has been reached, a practically sinusoidal current is applied and the rotor is waited for at transit through the zero points.