Inverter control device and vehicle control device

Patent metadata

Field	Value
Publication number	US-10351002-B2
Application number	US-201515517753-A
Country	US
Kind code	B2
Filing date	Nov 13, 2015
Priority date	Nov 14, 2014
Publication date	Jul 16, 2019
Grant date	Jul 16, 2019

Abstract

An inverter control device that controls a rotary electric machine drive device that includes an inverter with a plurality of switching elements, where the active short circuit control is executed in a high rotational speed region, and the shut-down control is executed in a low rotational speed region, which is on a low rotational speed side with respect to the high rotational speed region, in accordance with at least a rotational speed of the rotary electric machine.

First claim

The invention claimed is:

1. An inverter control device that controls a electric machine drive device that includes an inverter with a plurality of switching elements, the inverter control device comprising:
an electronic control unit that is programmed to perform switching control on the switching elements and to execute fail-safe control when a failure has occurred in the rotary electric machine drive device, wherein:
the inverter is connected to a DC power source and connected to an AC rotary electric machine drivably coupled to wheels of a vehicle to perform electric power conversion between DC power and multi-phase AC power, the inverter including a series circuit including an upper switching element and a lower switching element that form an arm for one phase of the AC power, and the inverter including a freewheeling diode connected in parallel with each of the switching elements with a direction from a lower side toward an upper side defined as a forward direction;
active short circuit control and shut-down control, in which all the switching elements are brought into an off state, are selectively executed in the fail-safe control, the active short circuit control being either upper-side active short circuit control, in which the upper switching elements of the arms for all the multiple phases are brought into an on state, or lower-side active short circuit control, in which the lower switching elements of the arms for all the multiple phases are brought into an on state; and
the active short circuit control is executed in a high rotational speed region, and the shut-down control is executed in a low rotational speed region, which is on a low rotational speed side with respect to the high rotational speed region, in accordance with at least a rotational speed of the rotary electric machine.

2. The inverter control device according to claim 1 , wherein
when the rotational speed of the rotary electric machine is raised to the high rotational speed region during execution of the shut-down control, a control scheme is caused to transition to the active short circuit control.

3. The inverter control device according to claim 1 , wherein
when the rotational speed of the rotary electric machine is lowered to the low rotational speed region during execution of the active short circuit control, a control scheme is caused to transition to the shut-down control.

4. The inverter control device according to claim 1 , wherein:
the inverter is connected to the DC power source via a power source switch that blocks supply of electric power in an off state; and
a maximum rotational speed at which execution of the shut-down control is allowed is:
set to a rotational speed at which a DC power source current and regenerative power that match the rotational speed of the rotary electric machine are less than allowable maximum rated values in accordance with a DC power source voltage when the power source switch is in an on state, and
set to a rotational speed at which a peak value of a counter electromotive force among lines for three phases is less than a maximum rated voltage allowed in the rotary electric machine drive device when the power source switch is in an off state.

5. The inverter control device according to claim 4 , wherein
when the power source switch is in an off state, the maximum rotational speed is further set such that a voltage of a smoothing capacitor that is raised by a charge supplied from the rotary electric machine during execution of the shut-down control is less than an allowable maximum value in accordance with a capacity of the smoothing capacitor, the smoothing capacitor being configured to smooth a DC link voltage which is a voltage on a DC side of the inverter.

6. The inverter control device according to claim 1 , wherein
a minimum rotational speed at which execution of the active short circuit control is allowed is set to a rotational speed at which an absolute value of negative torque transferred to the wheels during execution of the active short circuit control is less than an absolute value of maximum allowable negative torque prescribed in advance.

7. The inverter control device according to claim 1 , wherein
a minimum rotational speed at which execution of the active short circuit control is allowed is set to a rotational speed at which a phase current that flows during execution of the active short circuit control is less than a maximum value in a range of a current in which a magnetic force of a permanent magnet of the rotary electric machine can be held at a maximum temperature at which the rotary electric machine is operable.

8. An inverter control device that controls a rotary electric machine drive device that includes an inverter with a plurality of switching elements, the inverter control device comprising:
an electronic control unit that is programmed to perform switching control on the switching elements and to execute fail-safe control when a failure has occurred in the rotary electric machine drive device, wherein:
the inverter is connected to a DC power source and connected to an AC rotary electric machine drivably coupled to wheels of a vehicle to perform electric power conversion between DC power and multi-phase AC power, the inverter including a series circuit including an upper switching element and a lower switching element that form an arm for one phase of the AC power, and the inverter including a freewheeling diode connected in parallel with each of the switching elements with a direction from a lower side toward an upper side defined as a forward direction;
at least two modulation control schemes including pulse width modulation control and rectangular-wave control are selectively executed, the pulse width modulation control being a control scheme in which a plurality of pulses with different duties are output in one cycle of electrical angle, and the rectangular-wave control being a control scheme which is performed along with field weakening control, in which regulation is performed in a direction of weakening a field of the rotary electric machine, and in which one pulse is output in one cycle of electrical angle;
active short circuit control and shut-down control, in which all the switching elements are brought into an off state, are selectively executed in the fail-safe control, the active short circuit control being either upper-side active short circuit control, in which the upper switching elements of the arms for all the multiple phases are brought into an on state, or lower-side active short circuit control, in which the lower switching elements of the arms for all the multiple phases are brought into an on state; and
the active short circuit control is executed when a failure has occurred in the rotary electric machine drive device during execution of the rectangular-wave control, and the shut-down control is executed when a failure has occurred in the rotary electric machine drive device during execution of the pulse width modulation control.

9. The inverter control device according to claim 8 , wherein
during execution of one of the active short circuit control and the shut-down control which has been selected in accordance with the modulation control scheme, the control scheme of the fail-safe control is caused to transition to the other of the active short circuit control and the shut-down control on the basis of a rotational speed of the rotary electric machine.

10. The inverter control device according to claim 9 , wherein:
the inverter is connected to the DC power source via a power source switch that blocks supply of electric power in an off state;
when the rotational speed of the rotary electric machine is raised to be equal to or mor

Assignees

• Aisin Aw Co

Inventors

• Saha Subrata
• Yoshida Takashi
• Sugiyama Yuki
• Tajima Yoichi
• Kokubo Masaya

Classifications

• B60L50/51

  characterised by AC-motors · CPC title

• H02P27/06 Primary

  using DC to AC converters or inverters (H02P27/05 takes precedence) · CPC title

• H02P27/08

  with pulse width modulation · CPC title

• H02H7/1227

  responsive to abnormalities in the output circuit, e.g. short circuit · CPC title

• B60L3/04

  Cutting off the power supply under fault conditions (protective devices and circuit arrangements in general H01H; H02H) · CPC title