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 rotary current machine system and method for controlling an electric rotary current machine, in particular an induction machine, having a rotor, a stator and at least two phase windings is disclosed. At least one electrical signal, in particular a voltage signal, is applied to at least one phase winding, preferably all phase windings, of the rotary current machine, and the current waveform in the at least one phase winding is measured. An intermodulation signal component, induced in the rotary current machine by slotting effects and magnetic saturation effects, which is determined from the current waveform measured in the at least one phase winding, is used for controlling the rotary current machine.

The semiconductor device includes: a current detection circuit configured to detect a current flowing through a three-phase motor by driving of a drive circuit; and a controller configured to control the drive circuit, based on the detected current. The controller is configured to control, when the three-phase motor is stationary, an energization pattern in such a way that a wave detection current sequentially flows from the drive circuit to each phase of the three-phase motor, to obtain, from the wave detection current detected by the current detection circuit, a first, a second and a third interphase current differences, each of which is a difference among wave detection currents flowing in directions opposite to one another, to determine the energization pattern based on a magnitude relationship among the first, the second and the third interphase current differences.

An electric machine includes a rotor, a stator, at least one measurement circuit, and a controller. The rotor includes a plurality of salient poles arranged radially around a rotation axis of the electric machine and spaced apart from the rotation axis of the electric machine. The stator includes a plurality of coils configured to selectively align with the plurality of salient poles of the rotor. The at least one measurement circuit is configured to measure at least one current through at least one of the plurality of coils. The measured current includes a current ripple. The controller configured to compute a position of the rotor based on a characteristic of the current ripple.

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 controlling switched reluctance machine (SRM) utilizing a SRM control system. The method allows for adaptive pulse positioning over a wide range of speeds and loads. An initial rotor position is provided for the SRM utilizing an initialization mechanism. A pinned point on a phase current waveform is defined during an initial current rise phase of the current waveform. A slope of the current rise is determined as the current waveform reaches the pinned point. The slope is then fed to the commutation module of the SRM control system. An error signal from calculated inductance or current slope is used as an input to a control loop in the SRM control system. The time determining module determines an optimum time signal to fire a next pulse. The optimum time signal is fed to the SRM for turning the plurality of SRM switches to on and off states.

A method and an apparatus for sensorless profiling of a current waveform in a switched-reluctance motor (SRM) is disclosed. The apparatus comprises a switched-reluctance motor having at least one stator pole and at least one rotor pole, a phase inverter controlled by a processor, a load, a converter and a software control module at the processor. The current waveform sets a target magnitude for a programmable dwell angle that scales a programmable waveform shape. Slope of the current is continuously monitored which allows the shaft speed to be updated multiple times and to track any change in speed and fix the dwell angle based on the shaft speed. The method reduces the overall radial force magnitude by compensating nonlinear torque production thereby reducing the acoustic noise reduction and torque ripple which results in computational efficiency of the SRM.

A method for determining an initial rotor position of a permanent magnet synchronous motor (PMSM) includes: generating a plurality of transient currents by applying a plurality of voltages to each phase stator winding of a three phase stator winding of the PMSM; generating three phase current differences according to the plurality of transient currents; determining a first zone in which the initial rotor position of the PMSM is located according to the three phase current differences, wherein angles between 0-360 degrees are divided into a plurality of zones, and the first zone is selected from the plurality of zones; calculating three line current differences according to the three phase current differences; and determining the initial rotor position of the PMSM according to the first zone and the three line current differences.

Implementations of a system for sensing rotor position of a PMSM may include: a controller which may be coupled with the PMSM. The controller may be configured to apply a plurality of voltage vectors to the PMSM to generate a plurality of sensing signals from a stator of the PMSM in response. A comparator may be coupled to the PMSM configured to receive and to compare each one of the plurality of sensing signals with a threshold voltage. A rise time measurement circuit may calculate a plurality of rise times using the plurality of sensing signals in response to receiving a signal from the comparator. The rotor-angle estimation circuit may be configured to identify from the plurality of rise times a shortest rise time and a voltage vector corresponding with the shortest rise time and thereby identify the position of the rotor of the PMSM.

In the position sensorless control method in low-speed region of the fault-tolerant permanent magnet motor system based on the envelope detection and the non-orthogonal phase-locked loop of the present disclosure, the position sensorless control of the motor is implemented by injecting the high-frequency voltage signals into any two non-faulty phase windings of the motor, extracting the high-frequency response currents of the high-frequency injected phases by the digital bandpass filter, calculating the differential mode inductances of the two phase windings through the envelope detecting and signal processing, and extracting the rotor position and rotational speed signals from the estimated two phase inductances through the non-orthogonal phase-locked loop. In addition, the controller of the present disclosure is small in size, high in accuracy, and high in reliability, which can effectively meet the performance requirements of the onboard electric actuators.