A rotary-machine control device includes: a connection switching device switching a connection state of stator windings of a rotary machine; a current detection unit detecting a rotary machine current flowing in the rotary machine; a voltage application unit applying voltage to the rotary machine; a control unit generating a voltage command provided to the voltage application unit and outputting a switching command to switch the connection state to the connection switching device; and an open-phase determination unit determining presence or absence of disconnection in the rotary machine or presence or absence of disconnection of a power distribution line to the rotary machine. During rotation of the rotary machine, the control unit outputs the switching command and the open-phase determination unit determines presence or absence of disconnection.

The control circuit for a system provided with a power converter of multi-phase rotating electric machine, and is provided with a switch driving unit that drives the upper and lower arm switches based on the switching command to drive the rotating electric machine, an emergency power source that generates power with a power supplied from the power storage unit, an abnormality determination unit that determines whether a failure occurs in the control circuit, and an emergency control unit that performs, when the emergency determination unit determines that a failure occurs in the control circuit, a short circuit control in which either the upper arm switches or the lower arm switches are turned ON and the other arm switches are turned OFF by using the emergency power generated by the emergency power source.

An electric power conversion device has a function of detecting, at low cost and at an early stage, a sign of insulation failure of a transformer or a rotational machine. This electric power conversion device is provided with an inverter circuit and a PWM signal generation unit that makes a comparison between a carrier signal and a voltage command value and generates a PWM signal for driving the inverter circuit. The electric power conversion device feeds and receives electric power through connection to a transformer or a rotational machine provided with a winding wire. The electric power conversion device is provided with: a current sensor that detects a current to be fed to or received from the transformer or the rotational machine; and a diagnostic unit that diagnoses insulation degradation of the transformer or the rotational machine.

A method and system of operating a multi-phase electric machine include operating an inverter to control the multi-phase machine. The inverter has a plurality of inverter legs including an auxiliary inverter leg. Each of the plurality of inverter legs has at least one switch device. The multi-phase machine has a plurality of phases in which each phase is controlled by a respective inverter leg of the inverter. The method and system also include determining whether a phase of the multi-phase machine is experiencing a partial phase loss, for example, by injecting a signal into the phases and analyzing the frequency response. In response to determining that a phase of the multi-phase machine is experiencing a partial phase loss, the method and system include utilizing the auxiliary inverter leg to supplement energy to the phase experiencing the partial phase loss to continue operating the multi-phase machine.

A steering assist device may comprise an Ath power path controller positioned on an Ath power path connecting an Ath leg of an inverter with an Ath phase of a steering motor, a Bth power path controller positioned on a Bth power path connecting a Bth leg of the inverter with a Bth phase of the steering motor, a Cth power path controller positioned on a Cth power path connecting a Cth leg of the inverter with a Cth phase of the steering motor, and a controller unit determining a state of at least one of the Ath power path controller to the Cth power path controller based on at least one of an Ath phase voltage to a Cth phase voltage respectively formed at the Ath leg to the Cth leg of the inverter and controlling the steering motor according to a result of the determination.

In a method for detecting a motor phase fault of a motor arrangement, the motor phases of which are connected to a drive circuit having a DC voltage intermediate circuit and an inverter. A motor phase voltage at at least one of the motor phases with respect to a reference potential is captured while the inverter is switched off; and a voltage profile of the captured motor phase voltage is used to determine whether there is a motor phase fault on one of the motor phases of the motor arrangement.

A motor protector and a method for operating the same. The motor protector includes: a power supply unit adapted to receive electric power from power supply lines of a motor to power the motor protector; a measuring unit adapted to measure electric parameters of the motor; and a controller configured to at least perform steps of: receiving from the measuring unit the electric parameters; determining, based on the electric parameters, whether the motor experiences a first failure related to overheating of the motor; enabling, in accordance with determination of the first failure of the motor, the power supply unit to power a closing mechanism of the motor protector after a predetermined time, thereby closing the closing mechanism to power the motor by the power supply lines; determining, based on the electric parameters, whether the motor experiences a second failure different from the first failure; and enabling, in accordance with determination of the second failure of the motor, the power supply unit to stop powering the closing mechanism. Hence, the motor protector can discriminate types of the motor failures and adopt corresponding measures for different failures.

An apparatus is disclosed that in one embodiment includes a circuit configured to selectively activate a transistor. The circuit is further configured to assert a signal when the circuit detects an electrical short between terminals of the transistor or when the circuit detects the transistor does not conduct current while the transistor is activated by the circuit. The circuit is further configured to output another signal, which is set to a first state or a second state. The other signal is set to the first state when the circuit detects the electrical short. The other signal is set to the second state when the circuit detects the transistor does not conduct current while activated.

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.

A current sensor state determination device determines that an abnormality is caused in a current sensor when a sum of phase currents based on current detection values from each of the current sensors in three phases is greater than a first determination value, and determines that no abnormality is caused in the current sensor when the sum of phase currents is equal to or less than the first determination value. The state determination device determines that the current sensor is normal when it is determined that (i) no abnormality is caused in a preset electric angle range equal to or less than one electric-angle cycle of the rotating electric machine and (ii) a value of an electric current flowing in the rotating electric machine in a rotating coordinates system calculated based on the current detection value is equal to or greater than a second determination value.