ROTARY ELECTRIC MACHINE CONTROL SYSTEM

• US 20100201293A1
• Filed: 12/01/2008
• Published: 08/12/2010
• Est. Priority Date: 12/28/2007
• Status: Active Grant

• Current Assignee: Aisin AW Company Limited (Aisin Corp.)
• Original Assignee: Aisin AW Company Limited (Aisin Corp.)
• Inventors: Yoshida, Takashi, Saha, Subrata, Izawa, Jin, Ogino, Daisuke
• Granted Patent: US 8,405,335 B2
• Time in Patent Office: Days
• US Class Current: 318/139
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 2260/167 of motors or generators
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 58/14 Preventing excessive discharging
• CPC Class Codes: B60L 58/26 by cooling
• 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 20/50 Control strategies for responding to system failures, e.g. for fault diagnosis, failsafe operation or limp mode
• CPC Class Codes: B60W 2710/083 Torque
• 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
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

A rotary electric machine control system includes a battery electric power calculation unit for calculating battery electric power that is supplied from the battery; a torque limitation unit for limiting an output torque of the rotary electric machine; and a battery electric power abrupt variation estimation unit for estimating that the battery electric power is in an abrupt variation state in which the battery electric power is varying abruptly on the basis of at least one of a variation rate of the battery electric power and a variation rate of a rotational speed of the rotary electric machine.

Claims

1. A rotary electric machine control system including a rotary electric machine and an inverter interposed between a battery and the rotary electric machine to control a current that flows through the rotary electric machine, comprising:

a battery electric power calculation unit for calculating battery electric power that is supplied from the battery;

a torque limitation unit for limiting an output torque of the rotary electric machine; and

a battery electric power abrupt variation estimation unit for estimating that the battery electric power is in an abrupt variation state in which the battery electric power is varying abruptly on the basis of at least one of a variation rate of the battery electric power and a variation rate of a rotational speed of the rotary electric machine, wherein

the torque limitation unit changes, in the case where the battery electric power abrupt variation estimation unit estimates that the battery electric power is in the abrupt variation state, a mode of limitation of the output torque from a mode of limitation of the output torque used in a non-abrupt variation state in which the battery electric power is not varying abruptly.

2. The rotary electric machine control system according to claim 1, wherein

the torque limitation unit executes torque limitation in the non-abrupt variation state in which the battery electric power is not varying abruptly and during an excess time when the battery electric power calculated by the battery electric power calculation unit is higher than an excess-time threshold for determining whether or not the battery electric power is excessive, and

the torque limitation unit executes torque limitation in the abrupt variation state in which the battery electric power is varying abruptly and during an abrupt variation time when the battery electric power is higher than an abrupt-variation-time threshold that is smaller than the excess-time threshold.

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

the battery electric power abrupt variation estimation unit estimates that the battery electric power is varying abruptly in the case where the battery electric power is higher than a battery electric power abrupt-variation-time threshold on the basis of which it is determined whether or not the variation rate of the battery electric power is high, or in the case where the variation rate of the rotational speed of the rotary electric machine is higher than a rotational speed abrupt-variation-time threshold on the basis of which it is determined whether or not the variation rate of the rotational speed of the rotary electric machine is high.

4. The rotary electric machine control system according to claim 3, wherein

the battery electric power calculation unit derives the battery electric power on the basis of an actual rotational speed of the rotary electric machine and a required torque required of the rotary electric machine.

5. The rotary electric machine control system according to claim 2, further comprising:

an excess-time torque limit value calculation unit for calculating, in the case where the torque limitation unit executes torque limitation during the excess time, a torque limit value on the basis of excess-time limit electric power which is a maximum value of the battery electric power that is allowed during the excess time.

6. The rotary electric machine control system according to claim 5, further comprising:

an abrupt-variation-time torque limit value calculation unit for calculating, in the case where the torque limitation unit executes torque limitation during the abrupt variation time, a torque limit value on the basis of abrupt-variation-time limit electric power which is a maximum value of the battery electric power that is allowed during the abrupt variation time.

7. The rotary electric machine control system according to claim 2, further comprising:

an excess-time torque limit value calculation unit for calculating, in the case where the torque limitation unit executes torque limitation during the excess time, a torque limit value on the basis of excess-time limit electric power which is a maximum value of the battery electric power that is allowed during the excess time; and

an abrupt-variation-time torque limit value calculation unit for calculating, in the case where the torque limitation unit executes torque limitation during the abrupt variation time, a torque limit value on the basis of abrupt-variation-time limit electric power which is a maximum value of the battery electric power that is allowed during the abrupt variation time, wherein

the excess-time limit electric power is higher than the abrupt-variation-time limit electric power.

8. The rotary electric machine control system according to claim 7, wherein

only the rotary electric machine serving as a motor is to be controlled, and

the torque limit value is calculated on the basis of limit electric power which is a maximum value of the battery electric power that is allowed and a motor loss required by the rotary electric machine to serve as a motor.

9. The rotary electric machine control system according to claim 7, wherein

a first rotary electric machine serving as a generator and a second rotary electric machine serving as a motor are to be controlled, and

the torque limit value is calculated on the basis of limit electric power which is a maximum value of the battery electric power that is allowed, electric power required by the second rotary electric machine to serve as a motor, and electric power required by the first rotary electric machine to serve as a generator.

10. The rotary electric machine control system according to claim 7, wherein

the torque limit value is calculated on the basis of a motor speed predicted value obtained as a sum of a product of a variation rate of a motor speed and a coefficient based on a control delay and a current motor speed.

11. The rotary electric machine control system according to claim 10, wherein the torque limit value is calculated on the basis of a generator estimated electric power predicted value obtained as a sum of a product of a variation rate of generator electric power and a coefficient based on a control delay and current generator electric power.