Power controller for a vehicle

• US 6,806,588 B2
• Filed: 02/27/2001
• Issued: 10/19/2004
• Est. Priority Date: 03/01/2000
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Masaki, Ryoso, Morooka, Yasuo, Amano, Masahiko
• Primary Examiner(s): Toatley, Jr., Gregory J.
• Application Number:
  US09/793,560
• Publication Number:
  US 20010019224A1
• Time in Patent Office: 1,330 Days
• Field of Search: 307/10.1, 307/10.7, 307/48, 307/66, 320/136, 320/134, 320/104, 320/132, 320/103
• US Class Current: 307/10.7
• CPC Class Codes: B60L 2210/12 Buck converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/545 Temperature
• 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 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: F02N 11/0866 comprising several power sources, e.g. battery and capacitor or two batteries
• CPC Class Codes: F02N 2011/0888 DC/DC converters
• CPC Class Codes: F02N 2011/0896 Inverters for electric machines, e.g. starter-generators
• CPC Class Codes: H02J 7/1423 with multiple batteries
• CPC Class Codes: H02J 9/002 in which a reserve is maintained in an energy source by disconnecting non-critical loads, e.g. maintaining a reserve of charge in a vehicle battery for starting an engine
• 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 power controller for a vehicle can operate electrical load upon stopping of engine or turning OFF of a key switch, without lowering of remaining capacity of a main battery. The control system has a control portion controlling operation of a power generator and an electrical load mounted on an automotive vehicle. The control system also includes remaining capacity measuring means for measuring a remaining capacity of a battery. The control portion energizes a predetermined power load when an engine is stopped or a key switch is held OFF, and operation of the power load is stopped when a remaining capacity of the battery measured by the remaining capacity measuring means becomes smaller than a predetermined value.

Claims

1. A control system for a power supply for an automotive vehicle, said control system comprising:

a control portion which controls operation of a power generator and an electrical load connected to the power supply; and

remaining capacity measuring means for measuring a remaining capacity of a battery;

wherein

said control portion operates a predetermined power load when an engine of said vehicle is stopped or a key switch is OFF; and

said control portion causes operation of said power load to be stopped when a remaining capacity of the battery measured by said remaining capacity measuring means falls below a predetermined value.

2. The control system for an automotive power supply as set forth in claim 1, wherein:

said control portion sets a plurality of threshold values for the remaining capacity of the battery, said threshold values corresponding to priorities of respective elements of said power load;

said control portion sequentially stops elements of the power load having a low priority in sequential order in response to a lowering of remaining capacity of the battery.

3. The control system for an automotive power supply as set forth in claim 1, wherein said control portion operates a predetermined power load when the engine is stopped or the key switch is OFF, and starts the engine when remaining capacity of the battery is lowered below a predetermined value.

4. The control system for an automotive power supply as set forth in claim 3, further comprising a setting switch for controlling whether starting of the engine is permitted when the key switch is OFF, wherein

when said key switch is OFF, said control portion starts the engine only when said setting switch is ON.

5. The control system for an automotive power supply as set forth in claim 1, wherein said control portion'"'"'s stopping operation of said power load when the remaining capacity of the battery becomes smaller than a predetermined value includes stopping operation of the control system itself.

6. The control system for an automotive power supply as set forth in claim 6, wherein said control portion resumes operation when the key switch is turned ON after once stopping the operation of the control portion itself.

7. A control system for an automotive vehicle power supply having a control portion which controls a power generator or power load connected to the power supply, said control system comprising:

remaining capacity measuring means for measuring a remaining capacity of a main battery and an auxiliary battery; and

a voltage converter for charging from the main battery to the auxiliary battery;

wherein

said control portion causes operation of said voltage converter when a vehicle engine is stopped or a key switch is OFF, and stops operation of said voltage converter when remaining capacity of the main battery falls below a predetermined value.

8. A power supply control system for an automotive vehicle having an engine that drives an electric generator for charging a vehicle battery, and a control unit which controls operation of the generator and of elements of an electrical load that are coupled to the generator and to the battery;

said control system comprising;

means for determining whether a key switch of said vehicle is in an on state;

means for determining whether said engine is operating; and

means responsive to a determination that said key switch is off, or that said key switch is on and the engine is not operating, for measuring a remaining charge of said battery;

wherein

said control unit disables operation of said elements of said load when the remaining charge is below a predetermined value at a time when either said key switch is off, or said key switch is on and said engine is not running.

9. The power supply control system for an automotive vehicle according to claim 8, wherein

said control unit includes a sequence of successively decreasing threshold values for said remaining charge, which threshold values correspond to a sequence of priorities assigned to said elements of said load; and

said control unit disables said elements of said load in sequence according to said assigned priorities, in response to decreasing of said remaining charge.