Electric rotating machine control system and vehicle driving system including the electric rotating machine control system

• US 20090243523A1
• Filed: 03/06/2009
• Published: 10/01/2009
• Est. Priority Date: 03/25/2008
• Status: Active Grant

• Current Assignee: Aisin AW Company Limited (Aisin Corp.)
• Original Assignee: Aisin AW Company Limited (Aisin Corp.)
• Inventors: Tanaka, Kazuhiro, Saha, Subrata, Izawa, Jin, Ogino, Daisuke
• Granted Patent: US 8,253,359 B2
• Time in Patent Office: Days
• US Class Current: 318/376
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 7/10 Dynamic electric regenerative braking B60L7/22 takes precedence
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: F16H 2037/0866 Power split variators with distributing differentials, with the output of the CVT connected or connectable to the output shaft
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A control system includes an electric rotating machine; a driving circuit that is connected to a DC power supply, the driving circuit includes a frequency conversion unit configured such that, when the electric rotating machine is to be driven in a power running mode, the frequency conversion unit converts an output of the DC power supply into AC electric power, and when the electric rotating machine is to be driven in a regenerative operation mode, the frequency conversion unit converts an output of the electric rotating machine into DC electric power; and a control unit that controls the driving circuit, wherein the control unit judges whether a connection between the DC power supply and the driving circuit is being maintained, and is configured such that, when the connection is not being maintained, regenerative electric power generated by the electric rotating machine is reduced by controlling the driving circuit.

Claims

1. An electric rotating machine control system comprising:

an electric rotating machine;

a driving circuit that is connected to a DC power supply, the driving circuit includes a frequency conversion unit configured such that;

when the electric rotating machine is to be driven in a power running mode, the frequency conversion unit converts an output of the DC power supply into AC electric power, and

when the electric rotating machine is to be driven in a regenerative operation mode, the frequency conversion unit converts an output of the electric rotating machine into DC electric power; and

a control unit that controls the driving circuit,

wherein the control unit judges whether a connection between the DC power supply and the driving circuit is being maintained, and is configured such that, when the connection is not being maintained, regenerative electric power generated by the electric rotating machine is reduced by controlling the driving circuit.

2. The electric rotating machine control system according to claim 1, wherein, when the connection between the DC power supply and the driving circuit is not being maintained, the control unit controls the driving circuit such that regenerative torque obtained by the electric rotating machine becomes zero.

3. The electric rotating machine control system according to claim 1, wherein:

the driving circuit includes a voltage conversion unit between the DC power supply and the frequency conversion unit, the voltage conversion unit boosts the output of the DC power supply, and

when the connection between the DC power supply and the driving circuit is not being maintained, the control unit stops an operation of the voltage conversion unit.

4. The electric rotating machine control system according to claim 1, wherein the control unit judges, based upon an input/output voltage at the connection that connects the driving circuit and the DC power supply, whether the connection between the DC power supply and the driving circuit is being maintained.

5. The electric rotating machine control system according to claim 4, wherein, when the input/output voltage is greater than a predetermined overvoltage threshold, the control unit judges that the connection between the DC power supply and the driving circuit is not being maintained.

6. The electric rotating machine control system according to claim 5, wherein, when a voltage change rate, at which the input/output voltage rises per unit of time, is greater than a predetermined change rate threshold, the control unit judges, based upon a rapid-change-state overvoltage threshold set to a smaller value than the predetermined overvoltage threshold, whether the connection between the DC power supply and the driving circuit is being maintained.

7. The electric rotating machine control system according to claim 4, wherein the predetermined overvoltage threshold is set to a sum of a maximum voltage of the DC power supply and a maximum value of an error of a voltage measurement unit that detects the input/output voltage.

8. A vehicle driving system comprising:

the electric rotating machine control system according to claim 1;

a first electric rotating machine and a second electric rotating machine as the electric rotating machine; and

a power distribution mechanism that distributes a driving force generated by another driving source that differs from the first electric rotating machine and the second electric rotating machine, wherein;

a part of the driving force thus distributed by the power distribution mechanism is transmitted to a wheel, and a remaining part of the driving force is transmitted to the first electric rotating machine, and

the driving force generated by the second electric rotating machine is transmitted to the wheel.

9. The vehicle driving system according to claim 8, wherein:

the power distribution mechanism has a configuration including a planetary gear mechanism having a first rotating element, a second rotating element, and a third rotating element, and

the first electric rotating machine is connected to the first rotating element, the driving source that differs from the first electric rotating machine and the second electric rotating machine is connected to the second rotating element, and the second electric rotating machine and the third rotating element are connected to the wheel.