An electric machine includes a phase lead and a winding set with first and second windings. The first and second windings are connected to the phase lead and are connected electrically in parallel with one another. A current sensor is coupled to the first winding and is arranged to measure a portion of current flowing through the phase lead which flows through the first winding.

A rotary electric machine for a vehicle is provided. The rotary electric machine includes a power system circuit which has a power element and is grounded via a first ground terminal and a first connecting line and a control system circuit which controls the power system circuit and is grounded via a second ground terminal and a second connecting line.

A motor control device controls a drive of a motor having a motor winding includes an angle calculation unit, a drive control unit, and an abnormality diagnosis unit. The angle calculation unit acquires a detected value from a rotation angle sensor that detects a rotation angle of the motor and calculate the rotation angle of the motor. The drive control unit controls the drive of the motor based on the rotation angle of the motor. When an abnormality in the rotation angle of the motor is detected while the motor is being driven, the abnormality diagnosis unit performs an abnormality diagnosis of an energized system while maintaining an energized state.

An electric motor controller for controlling an electric motor and methods of determining a loss of phase condition for at least one phase of three-phase input power provided to an electric motor controller are provided. The controller is configured to obtain phase sample data representing an input power electrical characteristic for at least one phase of three-phase power received by the controller and receive direct current (DC) bus data representing a measured DC bus electrical characteristic. The controller is also configured to calculate a ratio between the phase sample data and the DC bus data, and determine that a loss of phase condition exists for a phase of the three-phase power when the ratio exceeds a predetermined threshold.

An inverter control device for controlling a rotating electric machine drive device that drives an alternating current rotating electric machine and includes an inverter and a DC link capacitor, the inverter being connected to a DC power supply via a contactor, being connected to the rotating electric machine, and performing power conversion between direct current and three-phase alternating current, the DC link capacitor smoothing a DC link voltage, which is a DC-side voltage of the inverter, and the inverter control device performing switching control on switching elements that form the inverter.

A method and system of determining an electro-mechanical fault condition in a synchronous machine having a stator, a rotor, and exciter. The method includes: a) obtaining an exciter current signal which is a measurement of an exciter current through stationary windings of the exciter, b) transforming the exciter current signal to obtain an exciter current frequency spectrum, and c) determining whether an electro-mechanical fault condition is present, and a type of the electro-mechanical fault condition, based on harmonic content related to the frequency of the stator, of the exciter current frequency spectrum.

A motor control device includes a current command calculation unit configured to calculate a current command value for driving a motor, a current detection unit configured to detect a value of a current that flows through a power line of the motor, a current deviation calculation unit configured to calculate a current deviation, which is a difference between the current command value and the detected current value, a voltage command calculation unit configured to calculate a voltage command value applied to the motor based on the current deviation, a filter processing unit configured to calculate data by filtering the current deviation, the absolute value of the current deviation, or the power of the current deviation and to output the data as index data, and a power line breakage detection unit configured to detect a breakage of the power line based on the index data.

The control device for a rotary electrical machine which is connected between a DC power source and a rotary electrical machine and which controls driving of the rotary electrical machine by converting DC power from the DC power source into AC power, includes a power conversion circuit which is configured from a plurality of switching elements, a phase current detection unit which detects phase currents in the rotary electrical machine, a phase current ratio derivation unit which derives a ratio in which the phase currents detected by the phase current detection unit are equal to or greater than a reference value, or equal to or lower than the reference value, and an element fault determination unit which determines a fault status of each of the switching elements when the ratio derived by the phase current ratio derivation unit is equal to or greater than a previously established ratio threshold value.

A motor control circuit for an electric motor of an electric power assisted steering system comprises a switching circuit comprising a plurality of electrical switches, a current demand signal generator which converts the torque demand signal into a current demands signal; and a fault mode motor current controller that is responsive to an error signal that represents the difference between the current demand signal and the actual current flowing in the motor and is operable in the event of a fault where one phase is open-circuit to drive the remaining two phases as a single combined phase by generating a single voltage demand signal that is representative of the voltage to be applied across the combined phases, the voltage signal being in turn fed into a drive circuit for the switches that generates pulse width modulated switching signals for the switching circuit required to apply the voltage across the combined phases.

A phase loss detection device, a compressor including the same, and a phase loss detection method are disclosed. The phase loss detection device may include a signal converting circuit and a processor. The signal converting circuit is configured to convert voltage signals corresponding to respective phases of multiphase alternating current (AC) power monitored from a motor. The processor is configured to receive the converted voltage signals from the signal converting circuit, and configured to calculate, based on the converted voltage signals, one or more phase angles between the respective voltage signals. The processor is configured to determine that phase loss occurs if any one or more of the calculated phase angles deviate from a nominal value of a corresponding phase angle of the multiphase AC power by a value higher than a predetermined threshold. The phase loss detection can be performed in a convenient, effective and reliable way.