An object of the present invention is to provide a motor control device that can suppress electromagnetic noises including a switching noise and to an electric vehicle system using the motor control device. A motor control device includes: a power converter that is controlled by a pulse width modulation signal; a motor that is driven by the power converter; and a controller that generates the pulse width modulation signal, based on a carrier signal. When switching between a first carrier frequency (fc1) of the carrier signal and a second carrier frequency (fc2) of the carrier signal, the controller varies proportions of the first carrier frequency and the second carrier frequency in accordance with a number of rotations of the motor, the second carrier frequency being higher than the first carrier frequency.

An object of the present invention is to provide a motor control device that can suppress electromagnetic noises including a switching noise and to an electric vehicle system using the motor control device. A motor control device includes: a power converter that is controlled by a pulse width modulation signal; a motor that is driven by the power converter; and a controller that generates the pulse width modulation signal, based on a carrier signal. When switching between a first carrier frequency (fc1) of the carrier signal and a second carrier frequency (fc2) of the carrier signal, the controller varies proportions of the first carrier frequency and the second carrier frequency in accordance with a number of rotations of the motor, the second carrier frequency being higher than the first carrier frequency.

Disclosed is a series mode modulation configuration and a parallel voltage equivalent modulation configuration. In the series mode modulation configuration a unipolar modulation is utilized. Unipolar modulation utilizes a zero vector and produces a voltage across the load with a frequency factor of 2×. In the parallel voltage equivalent mode modulation configuration there are two H bridges driving two coils with identical current. The H bridges can advantageously be operated out of phase with one another (e.g., 180 out of phase with one another to interleave the currents to further reduce ripple current stress.

Disclosed is a series mode modulation configuration and a parallel voltage equivalent modulation configuration. In the series mode modulation configuration a unipolar modulation is utilized. Unipolar modulation utilizes a zero vector and produces a voltage across the load with a frequency factor of 2×. In the parallel voltage equivalent mode modulation configuration there are two H bridges driving two coils with identical current. The H bridges can advantageously be operated out of phase with one another (e.g., 180 out of phase with one another to interleave the currents to further reduce ripple current stress.

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 power conversion device includes a switching control unit that controls respective switching elements constituting a plurality of chopper circuits, a rectified-voltage detection unit, a bus-bar voltage detection unit, and a bus-bar current detection unit. The switching control unit includes an on-duty calculation unit that calculates a reference on-duty of respective drive pulses with respect to the switching elements based on a bus-bar voltage and a bus-bar current, an on-duty correction unit that corrects the reference on-duty to output on-duties of the respective drive pulses based on the bus-bar current, so that change amounts of respective reactor currents become substantially the same, and a drive-pulse generation unit that generates the respective drive pulses, based on the respective on-duties.

A power conversion device includes a switching control unit that controls respective switching elements constituting a plurality of chopper circuits, a rectified-voltage detection unit, a bus-bar voltage detection unit, and a bus-bar current detection unit. The switching control unit includes an on-duty calculation unit that calculates a reference on-duty of respective drive pulses with respect to the switching elements based on a bus-bar voltage and a bus-bar current, an on-duty correction unit that corrects the reference on-duty to output on-duties of the respective drive pulses based on the bus-bar current, so that change amounts of respective reactor currents become substantially the same, and a drive-pulse generation unit that generates the respective drive pulses, based on the respective on-duties.

To provide a high-voltage apparatus control device capable of judging the connection state of a connector and discharging residual charge in a short time. A control device 1 controls an electric compressor and is provided with an interlock loop 4 annexed to a connector 9 for connecting the electric compressor to an HV battery 17. The control device 1 detects connection/disconnection of the connector 9 on the basis of the state of the interlock loop 4 and forcibly discharges residual charge in an internal smoothing capacitor 14 when disconnection of the connector 9 is detected.

To provide a high-voltage apparatus control device capable of judging the connection state of a connector and discharging residual charge in a short time. A control device 1 controls an electric compressor and is provided with an interlock loop 4 annexed to a connector 9 for connecting the electric compressor to an HV battery 17. The control device 1 detects connection/disconnection of the connector 9 on the basis of the state of the interlock loop 4 and forcibly discharges residual charge in an internal smoothing capacitor 14 when disconnection of the connector 9 is detected.