CONTROL APPARATUS FOR POWER CONVERSION SYSTEM INCLUDING DC/AC CONVERTER CONNECTED BETWEEN ELECTRIC ROTATING MACHINE AND DC POWER SOURCE

• US 20120091933A1
• Filed: 10/13/2011
• Published: 04/19/2012
• Est. Priority Date: 10/15/2010
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: INAMURA, Hiroshi, Tsuji, Hiroya
• Granted Patent: US 8,760,096 B2
• Time in Patent Office: Days
• US Class Current: 318/400.3
• CPC Class Codes: B60L 7/06 for vehicles propelled by ac motors
• CPC Class Codes: H02M 1/322 Means for rapidly discharging a capacitor of the converter for protecting electrical components or for preventing electrical shock
• CPC Class Codes: H02P 27/06 using dc to ac converters or inverters H02P27/05 takes precedence
• CPC Class Codes: H02P 3/22 by short-circuit or resistive braking
• CPC Class Codes: H02P 6/34 Modelling or simulation for control purposes
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility

Abstract

A control apparatus is for use in a power conversion system including a DC/AC converter circuit connected to an electric rotating machine at output terminals thereof and to a DC power source at input terminals thereof through a switching means, a capacitor being connected across the input terminals of the DC/AC converter circuit. The control apparatus includes a current supply means configured to perform current supply control to supply a current to the electric rotating machine in order to discharge the capacitor by manipulating the DC/AC converter circuit in a state where the switching means is set open, and a speed lowering means configured to apply a brake force to a rotating shaft of the electric rotating machine to reduce a rotational speed of the electric rotating machine prior to the current supply control being performed by the current supply means if the rotational speed exceeds a specified speed.

Claims

1. A control apparatus for a power conversion system including a DC/AC converter circuit connected to an electric rotating machine at output terminals thereof and to a DC power source at input terminals thereof through a switching means, a capacitor being connected across the input terminals of the DC/AC converter circuit, the control apparatus comprising:

a current supply means configured to perform current supply control to supply a current to the electric rotating machine in order to discharge the capacitor by manipulating the DC/AC converter circuit in a state where the switching means is set open; and

a speed lowering means configured to apply a brake force to a rotating shaft of the electric rotating machine to reduce a rotational speed of the electric rotating machine prior to the current supply control being performed by the current supply means if the rotational speed exceeds a specified speed.

2. The control apparatus according to claim 1, wherein the current supply means is configured to be capable of variably changing a phase of the current flowing through the electric rotating machine during the current supply control.

3. The control apparatus according to claim 1, wherein the current supply means includes a robust control means configured to suppress variation of a direction of a vector of the current flowing through the electric rotating machine in a stationary coordinate system due to variation of a rotational angle of the electric rotating machine during the current supply control.

4. The control apparatus according to claim 3, wherein the current supply means includes a voltage setting means configured to set a command voltage to be applied to a stator winding of the electric rotating machine to openloop-control the direction of the vector of the current flowing through the electric rotating machine in accordance with the rotational angle of the electric rotating machine, and is configured to manipulate the DC/AC converter circuit based on the command voltage,

the robust control means including a command voltage fixing means configured to fix the rotational angle of the electric rotating machine inputted to the voltage setting means as an input parameter at a value acquired prior to the current supply control being performed by the current supply means.

5. The control apparatus according to claim 2, wherein the power conversion system requires the electric rotating machine not to rotate reversely.

6. The control apparatus according to claim 1, wherein the speed lowering means is configured to apply a brake force to the rotating shaft of the electric rotating machine by manipulating the DC/AC converter circuit.

7. The control apparatus according to claim 1, wherein the speed lowering means includes a brake means configured to apply a brake force to the electric rotating machine by mechanically contacting the rotating shaft of the electric rotating machine.

8. The control apparatus according to claim 1, wherein the electric rotating machine is mounted on a vehicle as a main engine of the vehicle, the power conversion system including a means to release a mechanical coupling between the electric rotating machine and drive wheels of the vehicle.