A method includes driving a selected motor winding to be in a tri-state during a time interval having a finite time length value of a time window, sensing a zero-crossing (ZC) of an oscillating back electromotive force induced in the motor winding during the time window in which the motor winding is in the tri-state, and producing a ZC sensing signal, which has a first edge at a first time instant at the sensed ZC and a second edge at a second time instant separated from the first time instant by a half oscillation of the oscillating back electromotive force, detecting a phase of a current flowing in the motor winding at a time instant time-shifted with respect to the second time instant of the second edge of the ZC sensing signal, and adjusting the finite time length value based on the detected phase of the current.

A motor speed monitoring system can include a monitor channel having an input configured to connect to an inverter output of an inverter to receive motor command signals from the inverter, and an intelligence module configured to determine a motor speed based on the motor power signals from the inverter.

A closed-loop method of starting a permanent magnet synchronous motor comprises driving the rotor by energizing stator windings using motor control signals based on an initial standstill rotor angle. Periodically estimating values of rotor flux linkage magnitude and/or angle based on back-electromotive force (emf) induced in the stator windings by the rotating rotor. The estimated values of rotor flux linkage magnitude are used to estimate respective new rotor angles which are used to generate updated motor control signals to drive the rotor. Control of the motor is switched-over to a closed-loop synchronous operation motor control algorithm in response to any one or any combination of the following conditions: at a predetermined period of time from initiation of the closed-loop start-up method; or upon determination that the rotor has reached a minimum operating speed; or upon determination that the estimated value of rotor flux linkage magnitude reaches or exceeds a threshold value.

A controller is adapted to be coupled to a brushless direct current (DC) motor and includes an analog-to-digital converter (ADC), a computing device, and a driver. The ADC is configured to receive an analog back electromotive force (BEMF) waveform from the brushless DC motor and sample the analog BEMF waveform to produce a digital BEMF waveform. The computing device is coupled to the ADC and is configured to receive the digital BEMF waveform and determine a position and a speed of the rotor based on the digital BEMF waveform. The driver is coupled to the ADC and the computing device and is configured to receive the position and the speed of the rotor and provide a drive signal based on the position and the speed of the rotor of the brushless DC motor.

A controller is adapted to be coupled to a brushless direct current (DC) motor and includes an analog-to-digital converter (ADC), a computing device, and a driver. The ADC is configured to receive an analog back electromotive force (BEMF) waveform from the brushless DC motor and sample the analog BEMF waveform to produce a digital BEMF waveform. The computing device is coupled to the ADC and is configured to receive the digital BEMF waveform and determine a position and a speed of the rotor based on the digital BEMF waveform. The driver is coupled to the ADC and the computing device and is configured to receive the position and the speed of the rotor and provide a drive signal based on the position and the speed of the rotor of the brushless DC motor.

A motor controller comprises a switch circuit and a driving circuit. The switch circuit is coupled to a three-phase motor for driving the three-phase motor. The driving circuit generates a plurality of control signals to control the switch circuit. The motor controller utilizes a first pulse width modulation waveform and a second pulse width modulation waveform for driving the three-phase motor, where the first pulse width modulation waveform and the second pulse width modulation waveform have different frequencies from each other. The motor controller utilizes the second pulse width modulation waveform to detect a phase switching time point, where the frequency of the first pulse width modulation waveform is greater than the frequency of the second pulse width modulation waveform.

A motor controller comprises a switch circuit and a driving circuit. The switch circuit is coupled to a three-phase motor for driving the three-phase motor. The driving circuit generates a plurality of control signals to control the switch circuit. The motor controller utilizes a first pulse width modulation waveform and a second pulse width modulation waveform for driving the three-phase motor, where the first pulse width modulation waveform and the second pulse width modulation waveform have different frequencies from each other. The motor controller utilizes the second pulse width modulation waveform to detect a phase switching time point, where the frequency of the first pulse width modulation waveform is greater than the frequency of the second pulse width modulation waveform.

The present disclosure relates to a motor driver and a method of driving a motor capable of driving a motor with optimum efficiency. The method of driving the brushless direct current (BLDC) motor may include an initial driving operation, a test operation of adjusting a turn-on time and a transition time in the test mode step by step, driving the BLDC motor by applying the adjusted turn-on time and the adjusted transition time, and detecting a driving error of the BLDC motor, an operation of repeating the test operation when the driving error is not detected in the test operation, and an operation of setting the turn-on time and the transition time, which are adjusted in an operation just before the driving error is detected, as a turn-on time and a transition time in an optimum driving mode.

The present disclosure relates to a motor driver and a method of driving a motor capable of driving a motor with optimum efficiency. The method of driving the brushless direct current (BLDC) motor may include an initial driving operation, a test operation of adjusting a turn-on time and a transition time in the test mode step by step, driving the BLDC motor by applying the adjusted turn-on time and the adjusted transition time, and detecting a driving error of the BLDC motor, an operation of repeating the test operation when the driving error is not detected in the test operation, and an operation of setting the turn-on time and the transition time, which are adjusted in an operation just before the driving error is detected, as a turn-on time and a transition time in an optimum driving mode.

An object of the present invention is to sufficiently suppress a vibration and noise generated in a motor.

A motor control device includes a first inverter circuit and a second inverter circuit of a redundant system, the first inverter circuit and the second inverter circuit controlling a motor, and a control unit that controls the first inverter circuit and the second inverter circuit. The first inverter circuit converts the DC power into the AC power based on a PWM signal generated by using a first carrier signal. The second inverter circuit converts the DC power into the AC power based on a PWM signal generated by using a second carrier signal. The control unit shifts phases of the first carrier signal and the second carrier signal by using, as a reference, pulsation of an electromagnetic force caused by a magnetic circuit of the motor.