A dual-voltage brushless motor (30) includes a casing, a motor shaft (20) rotatably coupled to the casing, a rotor fixedly connected to the motor shaft (20), and a stator (28) configured to face the motor. The rotor contains a plurality of permanent magnets, and the stator (28) includes a first set of winding and a second set of winding. The first winding is electrically isolated from the second winding. The dual-voltage brushless motor (30) is adapted to be driven when the first set of winding receives a first control signal or when the second set of winding receives a second control signal. By configuring two separate motor controllers of the motor, the motor (30) can be operated under different power supplies such as AC power supply and DC power supply. As a result the application of the motor is greatly extended.

A motor control system includes an estimator responsive to measured motor winding voltage and measured motor winding current to generate an estimated position signal indicative of an estimate of a position of the motor and/or an estimated speed signal indicative of an estimate of a speed of the motor. A diagnostic checker circuit compares the estimated position signal and/or the estimated speed signal to a respective one of an actual position of the motor or an actual speed of the motor.

A microcomputer of a drive control device for controlling the driving of a brushless motor has a positioning part and a torque acceleration control unit. The positioning unit controls the power to be supplied to the windings, to thereby position the rotor at a drive start position which is a position of the rotor relative to the stator at which the drive control of the brushless motor can start, before starting the drive control of the brushless motor. The torque acceleration control unit controls the power to be supplied to the windings so that a torque acceleration falls within a predetermined range that the collision stress generated when the outer wall of the end of the shaft collides with the inner wall of the hole of an impeller (rotating member) is equal to or smaller than a predetermined value, when the rotor is positioned.

A rotation angle detecting method includes measuring a current flowing through a motor, and obtaining a rotation angle of the motor based on a value of the measured current. The obtaining of the rotation angle of the motor includes obtaining the rotation angle in an inertial rotation of the motor based on a rotational angular velocity of the motor immediately before a first time point, a time period from the first time point to a second time point, and a time period from the second time point to a third time point. The first time point is a time point at which driving of the motor is stopped, the second time point is a time point at which a polarity of the value of the measured current is inverted, and the third time point is a time point at which the value of the measured current becomes zero.

The present disclosure provides a system and method for detecting a resolver signal of a motor allowing accurate detection of a peak magnitude, a peak time, a peak point, etc. of a resolver output signal. A bandpass filter and a moving average processor are configured to remove noise introduced into the resolver output signal and maintain a magnitude of the resolver output signal at original magnitude without change. A phase compensation process performed by a lead phase compensator can compensate a phase delay time for the resolver output signal.

The present invention allows a driving device, which drives a three-phase brushless motor in a sensorless manner, to detect an initial position of the brushless motor and start drive of the motor without performing positioning processing. In a device for driving a brushless motor by sequentially switching six energizing modes, in which two phases to be energized are selected out of three phases, energization is performed sequentially in six energizing modes before start of drive so that the motor does not rotate, and each induced voltage of an opened phase is acquired, induced voltage difference is obtained in each predetermined combination of energizing modes, and it is estimated to which one of six divided regions an initial position of the brushless motor corresponds based on a maximum value of induced voltage differences obtained.