Patent ID: 8390165

Claim:
A synchronous motor drive system including a synchronous motor and a motor driver, the synchronous motor comprising: a rotor having magnetic poles distributed circumferentially along a rotation direction of the rotor at equal intervals; and a stator having stator coils arranged circumferentially along the rotation direction of the rotor, each coil wound by concentrated winding, wherein every M consecutive stator coils belong to a different one of stator coil groups arranged at equal intervals, M being an integer three or greater, every N consecutive stator coil groups belong to a different one of stator coil group sets, N being an integer two or greater, any one stator coil group in each set being in a same position in terms of electrical angle as one stator coil group in any other set, so that the sets of consecutive stator coil groups have rotational symmetry about a rotation axis of the rotor, each of the M consecutive stator coils in each stator coil group is connected at one end to a separate terminal of the motor driver and to a neutral point at another end, any two consecutive stator coils in each stator coil group have properties to generate magnetic fields having opposite polarities in response to currents of a same phase supplied via the respective terminals, the M consecutive stator coils are arranged at an interval of π+(π/(3M)) radians, and the motor driver supplies currents having a phase difference of n/(3M) radians to the any two consecutive stator coils via the respective terminal.