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.

A motor controller comprises a switch circuit and a control unit. The switch circuit is coupled to a motor for driving the motor. The control unit is configured to generate a control signal to control the switch circuit. The motor controller is configured to generate a current signal and a voltage signal. When a current phase of the current signal is at a predetermined crossing phase, the motor controller calculates a difference value between the current phase of the current signal and a voltage phase of the voltage signal, where the motor controller is configured to control the difference value. The motor controller may stabilize the motor and avoid noise by modulating the difference value. The motor controller may modulate the difference value, such that the difference value is equal to a predetermined phase difference.

A method for initial position detection of an electric motor includes determining a delta voltage for each of three pairs of stator windings by sequentially energizing and deenergizing each pair. The delta voltage is measured through a non-energized stator winding connected to a center tap of each respective pair. A minimum delta voltage is determined from an absolute value of a minimum of the three delta voltages. The minimum delta voltage is associated with a remaining stator winding not included in the respective pair. The two delta voltages not associated with the minimum delta voltage are compared to determine the proximity of the remaining stator winding to one of a D-axis of a rotor of the electric motor and a Q-axis of the rotor.

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 method for initial position detection of an electric motor includes determining a delta voltage for each of three pairs of stator windings by sequentially energizing and deenergizing each pair. The delta voltage is measured through a non-energized stator winding connected to a center tap of each respective pair. A minimum delta voltage is determined from an absolute value of a minimum of the three delta voltages. The minimum delta voltage is associated with a remaining stator winding not included in the respective pair. The two delta voltages not associated with the minimum delta voltage are compared to determine the proximity of the remaining stator winding to one of a D-axis of a rotor of the electric motor and a Q-axis of the rotor.

A control system (1) comprising a multi-motor converter (PWR) for the closed-loop control of a number of n EC motors (M1, . . . , Mn) operated in parallel, the rotor position of each motor being detected without a sensor and being controlled by the converter they share.

A motor unit comprises a switch circuit and a control unit. The switch circuit comprises a first terminal and a second terminal, where the switch circuit is coupled to a motor for driving the motor. The first terminal has a first voltage signal. The control unit generates a plurality of control signals to control the switch circuit. When the first terminal is in a floating state, the motor unit utilizes left-right asymmetry of the first voltage signal to judge whether the motor is in a forward rotation state or not. The motor unit further comprises the motor, where the motor comprises a rotor, a silicon steel plate, and a coil. The silicon steel plate has an asymmetrical structure.

Provided are a motor rotation angle measurement device and method. The device may comprise: a signal conditioning circuit, configured to receive a three-phase output voltage of a motor and separately generate three square-wave signals; and a processor, configured to generate a six-multiplying frequency pulse whenever jumping of any one of the three square-wave signals, is detected in a rotation period of a motor, generate compensation pulses between the current six-multiplying frequency pulse and a next six-multiplying frequency pulse based on a time interval between the current six-multiplying frequency pulse and a previous six-multiplying frequency pulse and a preset compensation subdivision coefficient k, and accumulate the number of the compensation pulses, wherein the number of the compensation pulses is related to the rotation angle of the motor.

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.

Provided are a motor rotation angle measurement device and method. The device may comprise: a signal conditioning circuit, configured to receive a three-phase output voltage of a motor and separately generate three square-wave signals; and a processor, configured to generate a six-multiplying frequency pulse whenever jumping of any one of the three square-wave signals, is detected in a rotation period of a motor, generate compensation pulses between the current six-multiplying frequency pulse and a next six-multiplying frequency pulse based on a time interval between the current six-multiplying frequency pulse and a previous six-multiplying frequency pulse and a preset compensation subdivision coefficient k, and accumulate the number of the compensation pulses, wherein the number of the compensation pulses is related to the rotation angle of the motor.