Rotating electrical machine for vehicle

• US 20050156543A1
• Filed: 01/18/2005
• Published: 07/21/2005
• Est. Priority Date: 01/19/2004
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Asao, Yoshihito, Kitamura, Yutaka
• Granted Patent: US 6,975,080 B2
• Time in Patent Office: Days
• US Class Current: 318/109
• CPC Class Codes: H02J 7/16 Regulation of the charging current or voltage by variation of field
• CPC Class Codes: H02P 9/02 Details
• CPC Class Codes: H02P 9/107 for limiting effects of overloads
• CPC Class Codes: H02P 9/48 Arrangements for obtaining a constant output value at varying speed of the generator, e.g. on vehicle H02P9/04 - H02P9/46 take precedence
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A rotating electrical machine for a vehicle is capable of improving the acceleration performance and the fuel mileage of the vehicle while achieving the prevention of occurrence of overvoltage and the improvement of its power generation characteristic at the same time. The machine includes an armature having an armature core and an armature winding wound around the armature core for generating an output voltage to charge a battery; a rotor having a rotor core with a field winding wound therearound, and permanent magnets for supplying magnetic flux to the armature core; and a voltage control section that adjust the output voltage of the armature by controlling the field current based on the value of an output voltage of the armature winding and the value and the direction of flow of the field current flowing through the field winding.

Claims

1. A rotating electrical machine for a vehicle comprising:

an armature having an armature core and an armature winding wound around said armature core for generating an output voltage to charge a battery;

a rotor having a rotor core with a field winding wound therearound, and permanent magnets for supplying magnetic flux to said armature core; and

a voltage control section that adjust said output voltage of said armature by controlling said field current based on the value of an output voltage of said armature winding and the value and the direction of flow of said field current flowing through said field winding;

wherein when said rotor rotates, said voltage control section inhibits an output current from being output from said armature winding to said battery by controlling said output voltage of said armature winding to one of a plurality of control voltages that are set equal to or lower than an overvoltage of said battery.

2. The rotating electrical machine for a vehicle as set forth in claim 1, wherein said voltage control section includes:

a voltage detection section that detects an output voltage of said armature winding;

a field current detection section that detects the value and direction of said field current flowing through said field winding;

a field current instruction calculation section that calculates the value and direction of a field current to be supplied to said field winding based on the output voltage of said armature winding detected by said voltage detection section and the value and direction of said field current detected by said field current detection section; and

a field current control section that controls said current flowing through said field winding based on the result of calculation of said field current instruction calculation section.

3. The rotating electrical machine for a vehicle as set forth in claim 1, wherein

said plurality of control voltages include, at least, a load-interruption control voltage Vlow to inhibit an output current from being output from said armature winding to said battery and a normal control voltage Vn to perform normal power generation, said load-interruption control voltage Vlow and the normal control voltage Vn being set as follows:

Vn≧

Vb>

Vlow

where Vb represents the voltage of said battery; and

said output voltage of said armature winding is controlled to switch into said load-interruption control voltage Vlow when a load on an engine with which said rotor is connected is reduced.

4. The rotating electrical machine for a vehicle as set forth in claim 3, wherein said load on said engine is reduced when said vehicle with said engine installed thereon starts accelerating.

5. The rotating electrical machine for a vehicle as set forth in claim 4, wherein the start of acceleration of said vehicle is detected based on at least either one of an amount, speed and acceleration of depression of an accelerator pedal.

6. The rotating electrical machine for a vehicle as set forth in claim 3, wherein said plurality of control voltages further includes a regeneration control voltage Vhigh to regenerate said battery, said regeneration control voltage Vhigh being set as follows:

Vhigh>

Vn≧

Vb>

Vlow.

7. The rotating electrical machine for a vehicle as set forth in claim 6, wherein said voltage control section controls to switch said output voltage of said armature winding into said regeneration control voltage Vhigh when said vehicle starts decelerating with the charged state of said battery being below a predetermined level.

8. The rotating electrical machine for a vehicle as set forth in claim 7, wherein the start point of deceleration of said vehicle is detected based on at least either one of the speed and acceleration of release of an accelerator pedal and an amount of depression of a brake pedal.

9. The rotating electrical machine for a vehicle as set forth in claim 6, wherein said control voltages are corrected based on the temperature of said battery.

10. The rotating electrical machine for a vehicle as set forth in claim 1, wherein said rotor rotates at a rotational speed that is equal to or lower than a rotational speed of said rotor corresponding to a maximum rotational speed of an engine with which said rotor is connected.

11. The rotating electrical machine for a vehicle as set forth in claim 1, wherein said voltage control section decreases said field current to zero from a normal supply direction, and when said output voltage of said armature winding exceeds said control voltage, said voltage control section controls said output voltage of said armature winding to said control voltage by reversely exciting said field winding to supply a reverse-excitation current thereto.

12. The rotating electrical machine for a vehicle as set forth in claim 11, wherein said reverse-excitation current is set based on said output voltage of said armature winding and the rotational speed of said rotor immediately after a field magnetomotive force due to said field current has been returned from a maximum field magnetomotive force to zero, in accordance with a combination of magnetizing forces of said armature winding, said field winding and said permanent magnets.

13. The rotating electrical machine for a vehicle as set forth in claim 3, wherein said output voltage of said armature winding is controlled to make a gradual shift when returned from said load-interruption control voltage Vlow to said normal control voltage Vn.

14. The rotating electrical machine for a vehicle as set forth in claim 13, wherein a set time for the gradual shift is set based on at least either one of the speed of said vehicle, the rotational speed of said engine, the shift position of a transmission, and the magnitude of an electric load.

15. The rotating electrical machine for a vehicle as set forth in claim 1, wherein said rotor core has magnetic pole portions of a claw pole type.

16. The rotating electrical machine for a vehicle as set forth in claim 15, wherein said permanent magnets are disposed at opposite sides of said magnetic pole portions.

17. The rotating electrical machine for a vehicle as set forth in claim 1, wherein said rotating electrical machine has functions of both a charging generator and an electric motor.