Rotating electrical machine control device

1. A rotating electrical machine control device that controls drive of a rotating electrical machine having multiphase open-end windings through a first inverter and a second inverter, the multiphase open-end windings being independent of each other, wherein

the first inverter is connected to a one-end side of the multiphase open-end windings to convert electric power between direct current and multiphase alternating current,

the second inverter is connected to an other-end side of the multiphase open-end windings to convert electric power between direct current and multiphase alternating current,

the first inverter and the second inverter can be controlled by a plurality of control schemes, respectively, the control schemes differing from each other in at least one of a switching pattern and a switching frequency and being independent of each other,

a first speed region in which rotational speed of the rotating electrical machine is relatively low at same torque and a second speed region in which rotational speed of the rotating electrical machine is higher than in the first speed region are set as control regions of the rotating electrical machine, and

the rotating electrical machine control device has a control mode in which the first inverter and the second inverter are controlled by a same control scheme in the first speed region, and the first inverter and the second inverter are controlled by different control schemes in the second speed region,

wherein the first inverter is configured to receive a direct current from a first battery when the rotating electrical machine is driven, and the second inverter is configured to receive a direct current from a second battery when the electrical machine is driven.

2. The rotating electrical machine control device according to claim 1 , wherein in the second speed region, a control scheme for each of the first inverter and the second inverter is set according to rotational speed of the rotating electrical machine.

3. The rotating electrical machine control device according to claim 1 , wherein in the second speed region, a control scheme for each of the first inverter and the second inverter is set according to a ratio of a root-mean-square value of multiphase alternating-current electric power to a root-mean-square value of direct-current electric power.

4. The rotating electrical machine control device according to claim 1 , wherein the control schemes whose switching patterns are different from each other include pulse width modulation control in which a plurality of pulses having different patterns are outputted in one electrical angle cycle, and rectangular-wave control in which one pulse is outputted in one electrical angle cycle.

5. The rotating electrical machine control device according to claim 4 , wherein

the pulse width modulation control includes continuous pulse width modulation and discontinuous pulse width modulation as the plurality of different control schemes,

the continuous pulse width modulation includes sinusoidal pulse width modulation and space vector pulse width modulation as the plurality of different control schemes,

the discontinuous pulse width modulation includes asynchronous modulation in which a pulse is outputted without synchronization with rotation of the rotating electrical machine and synchronous modulation in which a pulse synchronized with rotation of the rotating electrical machine is outputted, as the plurality of different control schemes, and

the synchronous modulation includes multi-pulse modulation in which a plurality of pulses are outputted per electrical angle cycle of the rotating electrical machine.

6. The rotating electrical machine control device according to claim 4 , wherein

in the first inverter and the second inverter, an arm for one alternating-current phase includes a series circuit of an upper-stage-side switching element and a lower-stage-side switching element, and

the control schemes whose switching patterns are different from each other include active short-circuit control that brings the upper-stage-side switching elements of the arms for all of a plurality of phases into an on state or brings the lower-stage-side switching elements of the arms for all of the plurality of phases into an on state.

7. The rotating electrical machine control device according to claim 4 , wherein of the first inverter and the second inverter, one inverter that is controlled by a pulse with a relatively low switching frequency when the pulse width modulation control is performed is configured using first switching elements whose switching loss upon a transition between an off state and an on state is relatively large, and an other inverter that is controlled by a pulse with a relatively high switching frequency when the pulse width modulation control is performed is configured using second switching elements whose switching loss is relatively small.

8. The rotating electrical machine control device according to claim 7 , wherein the first switching elements are Si-IGBTs or Si-MOSFETs, and the second switching elements are SiC-MOSFETs, GaN-MOSFETs, or SiC-IGBTs.

9. The rotating electrical machine control device according to claim 5 , wherein

in the first inverter and the second inverter, an arm for one alternating-current phase includes a series circuit of an upper-stage-side switching element and a lower-stage-side switching element, and

the control schemes whose switching patterns are different from each other include active short-circuit control that brings the upper-stage-side switching elements of the arms for all of a plurality of phases into an on state or brings the lower-stage-side switching elements of the arms for all of the plurality of phases into an on state.

10. The rotating electrical machine control device according to claim 9 , wherein of the first inverter and the second inverter, one inverter that is controlled by a pulse with a relatively low switching frequency when the pulse width modulation control is performed is configured using first switching elements whose switching loss upon a transition between an off state and an on state is relatively large, and an other inverter that is controlled by a pulse with a relatively high switching frequency when the pulse width modulation control is performed is configured using second switching elements whose switching loss is relatively small.

11. The rotating electrical machine control device according to claim 10 , wherein the first switching elements are Si-IGBTs or Si-MOSFETs, and the second switching elements are SiC-MOSFETs, GaN-MOSFETs, or SiC-IGBTs.

12. A rotating electrical machine control device that controls drive of a rotating electrical machine having multiphase open-end windings through a first inverter and a second inverter, the multiphase open-end windings being independent of each other, wherein

the first inverter is connected to a one-end side of the multiphase open-end windings to convert electric power between direct current and multiphase alternating current,

the second inverter is connected to an other-end side of the multiphase open-end windings to convert electric power between direct current and multiphase alternating current,

the first inverter and the second inverter can be controlled by a plurality of control schemes, respectively, the control schemes differing from each other in at least one of a switching pattern and a switching frequency and being independent of each other,

a first speed region in which rotational speed of the rotating electrical machine is relatively low at same torque and a second speed region in which rotational speed of the rotating electrical machine is higher than in the first speed region are set as control regions of the rotating electrical machine, and

the rotating electrical machine control device has a control mode in which the first inverter and the second inverter are controlled by a same control scheme in the first speed region, and the first inverter and the second inverter are controlled by different control schemes in the second speed region,

wherein the first inverter is configured to receive a direct current power supply from a first direct current source and includes a first capacitor in parallel between the first inverter and the first direct current source, and the second inverter is configured to receive a direct current power supply from a second direct current source and includes a second capacitor in parallel between the second inverter and the second direct current source.

13. The rotating machine according to claim 1 , wherein when the first inverter and the second inverter are controlled by the same control scheme, phases of currents including ripple components differ by substantially 180 degrees from each other in the respective converters.

14. The rotating machine according to claim 12 , wherein when the first inverter and the second inverter are controlled by the same control scheme, phases of currents including ripple components differ by substantially 180 degrees from each other in the respective converters.