A method for phase-voltage based motor period measurement includes generating a commanded phase voltage and applying the commanded phase voltage to a first phase voltage input of an electric motor, a second phase voltage input of the electric motor, and a third phase voltage input of the electric motor, measuring a first period of a phase voltage associated with the first phase voltage input and the second phase voltage input and comparing the measured first period to a frequency of the commanded phase voltage, and, in response to a determination that the measured first period of the phase voltage associated with the first phase voltage input and the second phase voltage input is outside of a range of the frequency associated with the commanded phase voltage, identifying a fault associated with the first integrated circuit or signal path.

A method for phase-voltage based motor period measurement includes generating a commanded phase voltage and applying the commanded phase voltage to a first phase voltage input of an electric motor, a second phase voltage input of the electric motor, and a third phase voltage input of the electric motor, measuring a first period of a phase voltage associated with the first phase voltage input and the second phase voltage input and comparing the measured first period to a frequency of the commanded phase voltage, and, in response to a determination that the measured first period of the phase voltage associated with the first phase voltage input and the second phase voltage input is outside of a range of the frequency associated with the commanded phase voltage, identifying a fault associated with the first integrated circuit or signal path.

A motor driving device for driving a motor is provided. The motor driving device includes: a driver outputting a drive signal for driving the motor to the motor; and a controller controlling a duty ratio of the drive signal based on three control parameters which are an initial duty ratio, a duty ratio increasing speed, and a target duty ratio. The controller has a normal control mode in which each of the three control parameters is a predetermined value, and a cryogenic control mode in which at least one of the three control parameters is a smaller value than in the normal control mode.

A method for phase-voltage based motor period measurement includes generating a commanded phase voltage and applying the commanded phase voltage to a first phase voltage input of an electric motor, a second phase voltage input of the electric motor, and a third phase voltage input of the electric motor, measuring a first period of a phase voltage associated with the first phase voltage input and the second phase voltage input and comparing the measured first period to a frequency of the commanded phase voltage, and, in response to a determination that the measured first period of the phase voltage associated with the first phase voltage input and the second phase voltage input is outside of a range of the frequency associated with the commanded phase voltage, identifying a fault associated with the first integrated circuit or signal path.

A method for phase-voltage based motor period measurement includes generating a commanded phase voltage and applying the commanded phase voltage to a first phase voltage input of an electric motor, a second phase voltage input of the electric motor, and a third phase voltage input of the electric motor, measuring a first period of a phase voltage associated with the first phase voltage input and the second phase voltage input and comparing the measured first period to a frequency of the commanded phase voltage, and, in response to a determination that the measured first period of the phase voltage associated with the first phase voltage input and the second phase voltage input is outside of a range of the frequency associated with the commanded phase voltage, identifying a fault associated with the first integrated circuit or signal path.

In one aspect, a system for determining an initial angular position of a rotor of a synchronous machine includes a motor driver module configured to provide a motor driver voltage signal to the synchronous machine, the motor driver voltage signal being sufficient to induce an electrical current in the synchronous machine; and a rotor position determination module configured to receive an indication of the current generated in the machine and to determine the initial position of the rotor based on the indication of the current generated in the machine. The motor driver voltage signal includes at least a first portion, a second portion, and a third portion, the first portion has a first non-zero voltage during a first temporal duration, the second portion has a second non-zero voltage during a second temporal duration, and the third portion has a substantially zero voltage during a third temporal duration, the first portion has a first polarity and the second portion has a second polarity that is opposite to the first polarity, and the first temporal duration and the second temporal duration are different.

In one aspect, a system for determining an initial angular position of a rotor of a synchronous machine includes a motor driver module configured to provide a motor driver voltage signal to the synchronous machine, the motor driver voltage signal being sufficient to induce an electrical current in the synchronous machine; and a rotor position determination module configured to receive an indication of the current generated in the machine and to determine the initial position of the rotor based on the indication of the current generated in the machine. The motor driver voltage signal includes at least a first portion, a second portion, and a third portion, the first portion has a first non-zero voltage during a first temporal duration, the second portion has a second non-zero voltage during a second temporal duration, and the third portion has a substantially zero voltage during a third temporal duration, the first portion has a first polarity and the second portion has a second polarity that is opposite to the first polarity, and the first temporal duration and the second temporal duration are different.

A method and apparatus are provided for controlling a sensorless multi-phase permanent magnet (PM) motor by sensing induced motor terminal voltages from the PM motor while the rotor is spinning, generating an input voltage vector signal from the plurality of induced motor terminal voltages, projecting the input voltage vector signal to a transformed voltage vector signal which does not include DC-offset components by using a Clarke transformation without a zero component that is applied to the input voltage vector signal, and estimating an initial rotor position of the rotor from the transformed voltage vector signal, wherein said sensing, projecting, and estimating are performed while a power converter for the sensorless multi-phase PM motor is disabled.

A method and apparatus are provided for controlling a sensorless multi-phase permanent magnet (PM) motor by sensing induced motor terminal voltages from the PM motor while the rotor is spinning, generating an input voltage vector signal from the plurality of induced motor terminal voltages, projecting the input voltage vector signal to a transformed voltage vector signal which does not include DC-offset components by using a Clarke transformation without a zero component that is applied to the input voltage vector signal, and estimating an initial rotor position of the rotor from the transformed voltage vector signal, wherein said sensing, projecting, and estimating are performed while a power converter for the sensorless multi-phase PM motor is disabled.

A circuit for controlling a motor that includes control circuitry configured to determine whether a commutation event has occurred for a first sector of a plurality of sectors of a cycle for the motor based on a first selected phase current signal and a second selected phase current signal. In response to a determination that the commutation event has occurred for the first sector, the control circuitry is configured to determine that the motor is operating in a second sector of the plurality of sectors of the cycle for the motor. The control circuitry is further configured to determine a second angle of stator voltage vector for the motor based on the determination that the motor is operating in the second sector and generate the control signal based on the second angle of stator voltage vector for the motor.