Patent ID: 7714530
Filing Date: 2010-05-11
Classification: H02P

Abstract:
1. Control system (ECS) for a synchronous electric motor (M) comprising a stator (S) with at least one winding (W) and a rotor (R) with permanent magnets; the system (ECS) comprising: a rectifier circuit (RC) with an input ( a driver circuit (DC), which is connected to the output of the rectifier circuit (RC) and to the stator winding (W), and includes a plurality of controlled switches (SW position sensor means (PS) for supplying an alternating position signal (H) which is indicative of the angular position of the rotor (R); and a control circuit (CC) with a first input which is designed to receive a signal (RS) indicative of the speed of rotation required (ω control the driver circuit (DC) when the motor (M) is started up, on the basis of the position signal (H) of the rotor, and so as to apply to the stator winding (W) a voltage with an absolute value which is reduced by a predetermined amount (dcmin) compared with the output voltage (V then, starting with the transition of the rotor (R) to a predetermined angular position, generate a counting signal (N) which varies according to a linear time function (t) and to reset this counting signal (N) when it reaches a predetermined reference value (N then control the driver circuit (DC) selectively on the basis of the position signal (H) of the rotor or on the basis of the said counting signal (N), when the speed of rotation (ω) of the motor (M) is respectively lower and higher than the speed required (ω control the driver circuit (DC) so as to apply to the stator winding (W) a voltage, the absolute value of which thus increases according to a predetermined function when the speed of rotation (ω) of the rotor (R) increases up to a predetermined value.