Battery charging apparatus

• US 6,522,105 B2
• Filed: 10/22/2001
• Issued: 02/18/2003
• Est. Priority Date: 10/23/2000
• Status: Expired due to Fees

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company), Shindengen Electric Manufacturing Company Limited
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company), Shindengen Electric Manufacturing Company Limited
• Inventors: Fujiwara, Tadashi, Kodama, Koji, Kaneko, Masaharu, Kubo, Kazuyuki
• Primary Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US09/982,795
• Publication Number:
  US 20020047686A1
• Time in Patent Office: 484 Days
• Field of Search: 320/137, 320/139, 320/133, 320/125, 320/119, 320/155, 307/87
• US Class Current: 320/155
• CPC Class Codes: H02J 7/1423 with multiple batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

When charging a battery of a low-voltage system, a battery charging apparatus of the present invention switches on a field-effect transistor and distributes the output of a generator via a diode to the battery. Further, when charging a battery of a high-voltage system, the battery charging apparatus switches off the field-effect transistor and distributes the output of the generator via the diode to the battery. At this time, the field-effect transistor is switched, and chops the output of the generator. Then, by selecting the duty of a clock signal for controlling this switching, the output powers of the generator when charging the high-voltage system and when charging the low-voltage system are made substantially equal, reducing fluctuation in the input torque of the generator.

Claims

1. A battery charging apparatus comprising:

a generator which generates ac power;

a first charging system which distributes the output of said generator at a timing in synchronism with the output of said generator to a first battery of a low-voltage system, thereby charging the first battery;

a second charging system which distributes the output of said generator at a timing in synchronism with the output of said generator and different to the timing of charging said first battery to a second battery of a high-voltage system, thereby charging the second battery; and

a switch system which chops the output of said generator which is to be distributed to said second battery so as to reduce change in the output power of said generator.

2. The battery charging apparatus according to claim 1, said first charging system comprising

a first diode, an anode thereof being connected to an output terminal side of said generator and a cathode thereof being connected to an electrode side of said first battery; and

a first field-effect transistor, provided between the cathode of said first diode and the electrode of said first battery, the first field-effect transistor becoming conductive when said first battery is to be charged and becoming nonconductive when said said battery is to be charged;

said second charging system comprising a second diode, an anode thereof being connected to an output terminal side of said generator and a cathode thereof being connected to an electrode side of said second battery; and

said switch system comprising a second field-effect transistor, provided between the output terminal of said generator and ground, the second field-effect transistor switching and chopping the output of said generator based on a clock signal having a duty which is set so as to reduce change in the output power of said generator.

3. The battery charging apparatus according to claim 2, the conduction of said second field-effect transistor being controlled in compliance with change in the output phase of said generator when charging said first battery, and based on said clock signal when charging said second battery.

4. The battery charging apparatus according to claims 2 and 3, wherein said generator generates current in multiple phases, and said first and second diodes and said first and second field-effect transistors are provided for each of the multiple phases.

5. A battery charging apparatus comprising:

a generator which generates ac power;

a first charging system which distributes the output of said generator at a timing in synchronism with the output of said generator to a first battery of a low-voltage system, thereby charging the first battery;

a second charging system which distributes the output of said generator at a timing in synchronism with the output of said generator, and in the same cycle as the cycle which said first battery is charged in, to a second battery of a high-voltage system, thereby charging the second battery; and

a switch system which chops the output of said generator which is to be distributed to said second battery so that the output power wave form of said generator resembles a sine wave.

6. The battery charging apparatus according to claim 5, said first charging system comprising

a first diode, an anode thereof being connected to an output terminal side of said generator and a cathode thereof being connected to an electrode side of said first battery; and

a first field-effect transistor, provided between the cathode of said first diode and the electrode of said first battery, the first field-effect transistor becoming conductive when said first battery is to be charged and becoming nonconductive when said said battery is to be charged;

said second charging system comprising a second diode, an anode thereof being connected to an output terminal side of said generator and a cathode thereof being connected to an electrode side of said second battery; and

said switch system comprising a second field-effect transistor, provided between the output terminal of said generator and ground, the second field-effect transistor switching and chopping the output of said generator based on a clock signal having a duty which is set so that the output power wave form of said generator resembles a sine wave.

7. The battery charging apparatus according to claim 6, the conduction of said second field-effect transistor being controlled in compliance with change in the output phase of said generator when charging said first battery, and based on said clock signal when charging said second battery.

8. The battery charging apparatus according to claim 6, wherein said generator generates current in multiple phases, and said first and second diodes and said first and second field-effect transistors are provided for each of the multiple phases.

9. A battery charging apparatus comprising:

a generator which generates ac power;

a first charging system which distributes the output of said generator at a timing in synchronism with the output of said generator to a first battery of a low-voltage system, thereby charging the first battery;

a second charging system which distributes the output of said generator at a timing in synchronism with the output of said generator and different to the timing of charging said first battery to a second battery of a high-voltage system, thereby charging the second battery; and

a switch system which, when the number of rotations of the input axis of said generator is below a number of rotations providing a boundary between boosting and not-boosting the output voltage of said generator, chops and boosts the output of said generator so as to reduce change in the output power of said generator when charging the first battery and when charging the second battery, and, when the number of rotations of the input axis of said generator exceeds the number of rotations providing said boundary, switches the duty of the output of said generator so as to reduce change in said duty.

10. The battery charging apparatus according to claim 9, said first charging system comprising

a first diode, an anode thereof being connected to an output terminal side of said generator and a cathode thereof being connected to an electrode side of said first battery; and

a first field-effect transistor, provided between the cathode of said first diode and the electrode of said first battery, the first field-effect transistor becoming conductive when said first battery is to be charged and becoming nonconductive when said said battery is to be charged;

said second charging system comprising a second diode, an anode thereof being connected to an output terminal side of said generator and a cathode thereof being connected to an electrode side of said second battery; and

said switch system comprising a second field-effect transistor, provided between the output terminal of said generator and ground, the second field-effect transistor switching based on a clock signal having said duty and chopping the output of said generator.

11. The battery charging apparatus according to claim 10, the conduction of said second field-effect transistor being controlled in compliance with change in the output phase of said generator when charging said first battery, and based on said clock signal when charging said second battery.

12. The battery charging apparatus according to claim 10, wherein said generator generates current in multiple phases, and said first and second diodes and said first and second field-effect transistors are provided for each of the multiple phases.