An apparatus for controlling a rotary electric machine includes: first and second inverters corresponding to first and second winding groups; first and second voltage detectors; and first and second control units. Each of the first and second inverters includes plurality of switching elements. The first and second voltage detectors each detects input voltage of corresponding inverter. The first control unit limits a first current command value of the first winding group, when both of the first and second inverter input voltages are in normal, and a first differential value is larger than a determination threshold, and the second control unit limits a second current command value of the second winding group, when both of the first and second inverter input voltages are normal, and a second differential value is larger than the determination threshold.

An apparatus for controlling a rotary electric machine includes: first and second inverters corresponding to first and second winding groups; first and second voltage detectors; and first and second control units. Each of the first and second inverters includes plurality of switching elements. The first and second voltage detectors each detects input voltage of corresponding inverter. The first control unit limits a first current command value of the first winding group, when both of the first and second inverter input voltages are in normal, and a first differential value is larger than a determination threshold, and the second control unit limits a second current command value of the second winding group, when both of the first and second inverter input voltages are normal, and a second differential value is larger than the determination threshold.

A method and system for operating an electric machine are described. In one example, the system includes a motor stator having a first group of windings and a second group of windings. Each group of the windings is electrically coupled to a different inverter so that the system may have a layer of operational redundancy.

A method and system for operating an electric machine are described. In one example, the system includes a motor stator having a first group of windings and a second group of windings. Each group of the windings is electrically coupled to a different inverter so that the system may have a layer of operational redundancy.

A control device of an electric motor, including an electric motor, a drive portion that supplies power to the electric motor, a voltage commanding portion that controls the drive portion on the basis of a torque command, and control a drive torque of the electric motor, a current limiting portion that outputs a limiting signal for limiting power outputted by the drive portion in a case in which a current value between the drive portion and the electric motor exceeds a predetermined value, and a limiting permission determining portion that determines whether the current limiting portion permits or prohibits an output of the limiting signal to the drive portion, when the drive torque of the electric motor cannot satisfy the torque command in a case in which the current limiting portion outputs the limiting signal, the limiting permission determining portion prohibits the current limiting portion from outputting the limiting signal to the drive portion.

In a control device for an AC rotary machine that includes a first three-phase winding and a second three-phase winding having a phase difference, a voltage is applied to each phase of the first three-phase winding at an ON interval or an OFF interval equaling or exceeding a first predetermined value. When a first three-phase current is determined to be undetectable, a first voltage command is generated such that ON timings or OFF timings relating respectively to at least two phases of the voltage applied to the first three-phase winding are within a second predetermined value that is smaller than the first predetermined value, and when a second three-phase current is determined to be undetectable, a second voltage command is generated such that ON timings or OFF timings relating respectively to at least two phases of a voltage applied to the second three-phase winding are within the second predetermined value.

The disclosure relates generally to the field of electric motors, and in particular to fault detection in an electric motor controller. In an example embodiment, an electric motor controller comprises: a driver circuit configured to drive an electric motor in response to a received speed demand signal (wreq); a measurement circuit configured to measure current through windings of the electric motor, the measurement circuit comprising a back emf, BEMF, observer configured to determine an estimated BEMF value (ê.sub.δ), a BEMF error threshold and an estimated rotor angular speed value (ω̂) from the measured currents; a detector circuit configured to receive the rotor speed demand signal (wreq), the estimated BEMF value (ê.sub.δ), the BEMF error threshold, the estimated rotor angular speed value (ω̂) and a measured rotor speed (wmeas) from a rotor speed sensor on the electric motor and to detect a fault in the electric motor controller if the estimated BEMF value (ê.sub.δ) lies outside the BEMF error threshold and the measured rotor speed (wmeas) is within a defined rotor speed error threshold.

The disclosure relates generally to the field of electric motors, and in particular to fault detection in an electric motor controller. In an example embodiment, an electric motor controller comprises: a driver circuit configured to drive an electric motor in response to a received speed demand signal (wreq); a measurement circuit configured to measure current through windings of the electric motor, the measurement circuit comprising a back emf, BEMF, observer configured to determine an estimated BEMF value (ê.sub.δ), a BEMF error threshold and an estimated rotor angular speed value (ω̂) from the measured currents; a detector circuit configured to receive the rotor speed demand signal (wreq), the estimated BEMF value (ê.sub.δ), the BEMF error threshold, the estimated rotor angular speed value (ω̂) and a measured rotor speed (wmeas) from a rotor speed sensor on the electric motor and to detect a fault in the electric motor controller if the estimated BEMF value (ê.sub.δ) lies outside the BEMF error threshold and the measured rotor speed (wmeas) is within a defined rotor speed error threshold.

A control device for a motor including a first coil and a second coil which are insulated from each other is provided. The control device includes a first circuit and a second circuit that switches a first process to a second process when the first circuit fails. The external circuit generates an instruction for performing a process of increasing an amount of operation which is calculated by one of the first circuit and the second circuit according to the number of control systems when the other of the first circuit and the second circuit fails.

A control device for a motor including a first coil and a second coil which are insulated from each other is provided. The control device includes a first circuit and a second circuit that switches a first process to a second process when the first circuit fails. The external circuit generates an instruction for performing a process of increasing an amount of operation which is calculated by one of the first circuit and the second circuit according to the number of control systems when the other of the first circuit and the second circuit fails.