A motor controller for an electric motor is provided. The motor controller includes an inverter configured to supply current to stator windings of the electric motor. The motor controller further includes a plurality of sensors configured to generate a sensor signal in response to detecting a parameter. The sensor signal represents a measured parameter. The motor controller further includes a processor coupled in communication with the inverter and with the plurality of sensors. The processor is configured to, in a first mode, transmit a control signal to the inverter to operate the electric motor at a first frequency. The processor is further configured to receive the sensor signal from the plurality of sensors. The processor is further configured to determine a first fault condition is present at the electric motor based on the measured parameter represented by the sensor signal.

The present invention relates to an inverter which is capable of adjusting an output frequency of a three-phase voltage output to a motor based on a result of comparison in magnitude between the minimum operating voltage of the motor and a DC link voltage applied to a DC link. The inverter includes: a measurement part configured to measure a DC link voltage applied to a DC link; a conversion part configured to convert the DC link voltage into a three-phase voltage and output the three-phase voltage to the motor; and a control part configured to make comparison in magnitude between the DC link voltage and the minimum operating voltage of the motor and adjust an output frequency of the three-phase voltage based on a result of the comparison.

The invention relates to a motor control method for a vehicle. The method includes: determining that a motor control unit (MCU) malfunctions; monitoring an output alternating current frequency of an electric motor; and controlling, based on the output alternating current frequency, the electric motor to switch between an active short circuit state and a safety pulse off state. The invention further relates to a motor control circuit for a vehicle, a motor drive system, and a vehicle.

This power conversion device comprises: a power converter including a switching element; and a control unit which controls the power converter. The control unit calculates a torque electric current detection value and an excitation electric current detection value from an electric current flowing to an external device, and when an absolute value of the torque electric current detection value is greater than or equal to the excitation electric current detection value, performs control such that the excitation electric current detection value follows the torque electric current detection value.

An apparatus, such as an adjustable frequency drive (AFD), includes an inverter configured to be selectively coupled to a motor in a first mode and an AC line in a second mode and a control circuit configured to operate the inverter as a motor drive in the first mode and as a power compensator in the second mode. The power compensator may provide power factor correction. The control circuit may include a scalar controller configured to control the inverter according to a voltage vs. frequency characteristic determined by a field weakening point reference and the control circuit may vary the field weakening point reference in the second mode. The inverter may have an input coupled to a DC bus and the control circuit may be configured to adjust a frequency of the inverter in the second mode to increase a voltage on the DC bus.

Examples include a method for controlling a synchronous motor using a variable speed drive. The motor includes a permanent magnet rotor generating a magnetic flux. The method includes applying a predefined electrical command signal to the motor and estimating a motor speed in response to the applying of the predefined electrical command signal. The method also includes reaching a desired estimated motor speed and, in response to reaching the desired estimated motor speed, estimating a parameter related to the magnetic flux of the permanent magnet rotor. The method further includes recording the estimated parameter.

The present disclosure is constructed on the prior art inverter architecture, a pulse code width modulation (PCWM). This is an open loop motor control system without sensing its rotor position. The present disclosure employs a closed loop method to track the optimum efficiency motor operating point directly. A bench load test is conducted to gather information for an AI type control, which includes both load angle vs. voltage command charts and power factor vs. voltage command charts, with load levels as parameters for certain frequency command ranges. This way, the optimum efficiency motor operating points are generated a priori. The AI type control is mechanized to track the optimum efficiency motor operating points.

A system for controlling a motor may include an alternating current (AC) bus configured to transmit an AC power signal to a set of stator windings, where the AC power signal produces a first rotating magnetic flux at the set of stator windings. The system may also include a high frequency contactless transformer configured to transmit an excitation signal to a set of rotor windings, where the excitation signal produces a second rotating magnetic flux at the rotor. The system may also include electrical circuitry configured to determine a rotor voltage and a rotor current associated with the excitation signal, determine a rotor flux magnitude estimate and a rotor flux angle estimate based on the rotor voltage and the rotor current, and determine an inverter control signal operable to generate the excitation signal based at least partially on the rotor flux magnitude estimate and the rotor flux angle estimate.

The systems and methods disclosed relate to arc resistant medium voltage motor control centers for bypass and synch transfer. A drive control system comprising: a variable frequency drive cabinet comprising a variable frequency drive; a power supply line; at least one motor control cabinet having a top portion and a bottom portion, wherein the at least one motor control cabinet is arc resistant, wherein the at least one motor control cabinet comprises: a medium voltage fused bypass controller in the top portion; a medium voltage non-fused transfer controller in the bottom portion; a reactor compartment, wherein the reactor compartment is arc resistant; wherein the variable frequency drive is coupled to the power supply line and the non-fused transfer controller, and the fused bypass controller is coupled to the power supply line.

A method and system to prevent unexpected operation of a motor when the voltage level on a DC bus drops is disclosed. The voltage level on the DC bus is monitored during a run command. When a run is commanded, the processor executes a control routine to determine a desired amplitude and frequency for the output voltage required to control the motor connected to the motor drive. If the desired frequency of the output voltage exceeds a maximum frequency for the measured voltage on the DC bus, as established by parameters stored in the motor drive, the motor drive limits the output frequency to the maximum frequency for the corresponding measured voltage. The motor drive continually monitors the measured voltage present on the DC bus and further reduces the maximum output frequency allowed during the run if the present value of the measured voltage drops below a previously measured value.