A motor drive apparatus includes a motor, a power converter, and a controller that controls the voltage supplied to the motor by the power converter. The power converter converts a voltage of a 400 V-class AC power supply to a voltage with an effective value lower than an effective value of the 400 V-class AC power supply. The power converter converts the voltage by a switching operation of a plurality of switching elements. The motor is configured so that a value of φ×Vx/Ld is greater than Pmax when an effective value voltage Vx=200 V. A d-axis inductance of the motor is Ld. A flux linkage of the motor is φ. A maximum output of the motor in a device where the motor is mounted is Pmax. The controller has a control mode in which an effective value voltage higher than Vx is applied to the motor.

A motor drive apparatus includes a motor, a power converter, and a controller that controls the voltage supplied to the motor by the power converter. The power converter converts a voltage of a 400 V-class AC power supply to a voltage with an effective value lower than an effective value of the 400 V-class AC power supply. The power converter converts the voltage by a switching operation of a plurality of switching elements. The motor is configured so that a value of φ×Vx/Ld is greater than Pmax when an effective value voltage Vx=200 V. A d-axis inductance of the motor is Ld. A flux linkage of the motor is φ. A maximum output of the motor in a device where the motor is mounted is Pmax. The controller has a control mode in which an effective value voltage higher than Vx is applied to the motor.

An electric motor system is described. The electric motor system includes a drive circuit configured to supply variable frequency current and a contactor configured to supply line frequency current, wherein the drive circuit includes a three-phase inverter and an H-bridge including two phases of the inverter. The electric motor system also includes an electric motor and a controller. The controller is configured to control the inverter to supply variable frequency current to the electric motor over a first duration and determine to control the drive circuit to transition from supplying variable frequency current to supplying line frequency current. The controller is also configured to determine a polarity of a sensed alternating current (AC) voltage, disable at least two switches of the H-bridge, and control the contactor to close, thereby preventing the contactor and the inverter from energizing the electric motor at the same time once the contactor is closed.

An electric motor system is described. The electric motor system includes a drive circuit configured to supply variable frequency current and a contactor configured to supply line frequency current, wherein the drive circuit includes a three-phase inverter and an H-bridge including two phases of the inverter. The electric motor system also includes an electric motor and a controller. The controller is configured to control the inverter to supply variable frequency current to the electric motor over a first duration and determine to control the drive circuit to transition from supplying variable frequency current to supplying line frequency current. The controller is also configured to determine a polarity of a sensed alternating current (AC) voltage, disable at least two switches of the H-bridge, and control the contactor to close, thereby preventing the contactor and the inverter from energizing the electric motor at the same time once the contactor is closed.

A current command module is configured to, based on a direct current (DC) bus voltage for an electric motor of the vehicle, generate a d-axis current command for the electric motor and a q-axis current command for the electric motor. A voltage command module configured to generate voltage commands based on the d-axis current command and the q-axis current command. A battery switching control module is configured to: determine a voltage operating state of a battery based on the voltage commands; compare a battery parameter to at least one of a predetermined voltage parameter and a predetermined current parameter during a dwell time when a plurality of switches of the battery are open; and generate a switch control signal to transition at least one switch of the plurality of switches to cause the battery to operate in the voltage operating state based on the comparison.

A current command module is configured to, based on a direct current (DC) bus voltage for an electric motor of the vehicle, generate a d-axis current command for the electric motor and a q-axis current command for the electric motor. A voltage command module configured to generate voltage commands based on the d-axis current command and the q-axis current command. A battery switching control module is configured to: determine a voltage operating state of a battery based on the voltage commands; compare a battery parameter to at least one of a predetermined voltage parameter and a predetermined current parameter during a dwell time when a plurality of switches of the battery are open; and generate a switch control signal to transition at least one switch of the plurality of switches to cause the battery to operate in the voltage operating state based on the comparison.

An electric motor system is described. The electric motor system includes a drive circuit configured to supply variable frequency current and a contactor configured to supply line frequency current, wherein the drive circuit includes a three-phase inverter and an H-bridge including two phases of the inverter. The electric motor system also includes an electric motor and a controller. The controller is configured to control the inverter to supply variable frequency current to the electric motor over a first duration and determine to control the drive circuit to transition from supplying variable frequency current to supplying line frequency current. The controller is also configured to determine a polarity of a sensed alternating current (AC) voltage, disable at least two switches of the H-bridge, and control the contactor to close, thereby preventing the contactor and the inverter from energizing the electric motor at the same time once the contactor is closed.

An electric motor system is described. The electric motor system includes a drive circuit configured to supply variable frequency current and a contactor configured to supply line frequency current, wherein the drive circuit includes a three-phase inverter and an H-bridge including two phases of the inverter. The electric motor system also includes an electric motor and a controller. The controller is configured to control the inverter to supply variable frequency current to the electric motor over a first duration and determine to control the drive circuit to transition from supplying variable frequency current to supplying line frequency current. The controller is also configured to determine a polarity of a sensed alternating current (AC) voltage, disable at least two switches of the H-bridge, and control the contactor to close, thereby preventing the contactor and the inverter from energizing the electric motor at the same time once the contactor is closed.

A converter device includes: a power conversion circuit including a reactor and a switching element, rectifying a voltage of alternating-current power supplied from an alternating-current power supply to a direct-current voltage, and boosting and outputting the direct-current voltage; a current detector detecting a current flowing in the reactor; a filter circuit filtering a first signal detected by the current detector; and a control unit generating a control signal on the basis of a carrier and a second signal generated by the filter circuit and controlling, on the basis of the control signal and with a first period, the switching element, the first period being a period of the carrier. The filter circuit cuts off a repetition frequency component in the first period and passes a repetition frequency component in a second period, the second period being longer than the first period.

A converter device includes: a power conversion circuit including a reactor and a switching element, rectifying a voltage of alternating-current power supplied from an alternating-current power supply to a direct-current voltage, and boosting and outputting the direct-current voltage; a current detector detecting a current flowing in the reactor; a filter circuit filtering a first signal detected by the current detector; and a control unit generating a control signal on the basis of a carrier and a second signal generated by the filter circuit and controlling, on the basis of the control signal and with a first period, the switching element, the first period being a period of the carrier. The filter circuit cuts off a repetition frequency component in the first period and passes a repetition frequency component in a second period, the second period being longer than the first period.