A rotating electrical machine control device where the changeover control circuit switches the source of electric power for the electronic control unit when the electric power that is supplied from the second DC power supply to the electronic control unit becomes equal to or lower than a predetermined first reference value and electric power that is output from the backup power supply is equal to or higher than a predetermined second reference value, and the electronic control unit uses the electric power supplied from the backup power supply to cause the inverter o perform the switching operation to perform fail-safe control.

A rotating electrical machine control device where the changeover control circuit switches the source of electric power for the electronic control unit when the electric power that is supplied from the second DC power supply to the electronic control unit becomes equal to or lower than a predetermined first reference value and electric power that is output from the backup power supply is equal to or higher than a predetermined second reference value, and the electronic control unit uses the electric power supplied from the backup power supply to cause the inverter o perform the switching operation to perform fail-safe control.

An inverter control device that controls an inverter unit that converts a DC voltage from a converter unit to an AC voltage and supplies the AC voltage to the DC motor includes a storage unit that stores therein information regarding a synchronization-loss limit; a synchronization-loss limit-current calculation unit that calculates the limitation value on the synchronization-loss limit current on the basis of the magnet temperature of the DC motor, the bus voltage to be applied to the inverter unit, and the information regarding a synchronization-loss limit; and a control unit that compares the primary current to be input to the converter unit with the limitation value and that, when the primary current exceeds the limitation value, outputs an adjustment command to adjust the operating frequency of the DC motor such that the primary current becomes equal to or less than the limitation value.

A motor control device includes: an inverter circuit including a semiconductor switching element for drive which drives a motor; a cut-off circuit including a semiconductor switching element for cut-off which cuts off an electric connection between the motor and the inverter circuit; a failure detection unit; a rotation number detection unit; and a control unit. In a case where the failure detection unit detects a failure of the semiconductor switching element for drive, the control unit turns off the semiconductor switching element for drive, and in a case where the number of rotations of the motor which is detected by the rotation number detection unit is less than a predetermined first threshold, the control unit further turns off the semiconductor switching element for cut-off.

A motor control device includes: an inverter circuit including a semiconductor switching element for drive which drives a motor; a cut-off circuit including a semiconductor switching element for cut-off which cuts off an electric connection between the motor and the inverter circuit; a failure detection unit; a rotation number detection unit; and a control unit. In a case where the failure detection unit detects a failure of the semiconductor switching element for drive, the control unit turns off the semiconductor switching element for drive, and in a case where the number of rotations of the motor which is detected by the rotation number detection unit is less than a predetermined first threshold, the control unit further turns off the semiconductor switching element for cut-off.

A gate driver circuit includes a comparator and a gate driver. The comparator is configured to detect a short circuit in a first power field effect transistor (FET). The gate driver is configured to drive a gate of the first power FET by generating a first signal at a first drive current. In response to the comparator detecting a short circuit in the first power FET, the gate driver is further configured to pulse the first signal at a first pulldown current. After the pulse has ended, the gate driver is further configured to drive the gate of the first power FET at a first hold current. The first hold current is less than the first pulldown current.

In a motor control device that can perform more appropriate motor control, a switching arm has a first upper FET, a second upper FET, and a lower FET connected in series to one another. A source electrode of the second upper FET and a drain electrode of the lower FET are connected to each other via an intermediate line. The intermediate line is connected to a U-phase motor coil of a motor via a power line. The first upper FET, the second upper FET, and the lower FET are each provided with a parasitic diode that prevents current from flowing from a battery side to a ground side. A phase opening relay FET is provided on the U-phase power line. A parasitic diode of the phase opening relay FET is provided such that a current is not applied from the U-phase motor coil to the U-phase switching arm.

In a motor control device that can perform more appropriate motor control, a switching arm has a first upper FET, a second upper FET, and a lower FET connected in series to one another. A source electrode of the second upper FET and a drain electrode of the lower FET are connected to each other via an intermediate line. The intermediate line is connected to a U-phase motor coil of a motor via a power line. The first upper FET, the second upper FET, and the lower FET are each provided with a parasitic diode that prevents current from flowing from a battery side to a ground side. A phase opening relay FET is provided on the U-phase power line. A parasitic diode of the phase opening relay FET is provided such that a current is not applied from the U-phase motor coil to the U-phase switching arm.

A control system for an electric motor comprising a stator having a plurality of stator coils and a rotor movable along the stator comprises a position detection device and a coil monitoring device. In this case, the position detection device is designed to generate position data representing a position of the rotor along the stator, and the coil monitoring device is designed to generate coil data representing a status of one or a plurality of the stator coils. The control system furthermore comprises a safety device designed to carry out a coordination between the coil data and the position data. Moreover, the safety device is designed to cause the electric motor to be transferred to a safe state if an error has been discovered during the coordination.

A control system for an electric motor comprising a stator having a plurality of stator coils and a rotor movable along the stator comprises a position detection device and a coil monitoring device. In this case, the position detection device is designed to generate position data representing a position of the rotor along the stator, and the coil monitoring device is designed to generate coil data representing a status of one or a plurality of the stator coils. The control system furthermore comprises a safety device designed to carry out a coordination between the coil data and the position data. Moreover, the safety device is designed to cause the electric motor to be transferred to a safe state if an error has been discovered during the coordination.