Battery charging system for hybrid electric vehicles

• US 20060232238A1
• Filed: 03/29/2006
• Published: 10/19/2006
• Est. Priority Date: 03/29/2005
• Status: Abandoned Application

• Current Assignee: Mitsubishi FUSO Truck & Bus Corporation (Daimler Truck Holding AG)
• Original Assignee: Mitsubishi FUSO Truck & Bus Corporation (Daimler Truck Holding AG)
• Inventors: Horii, Yusuke
• Application Number:
  US11/391,702
• Publication Number:
  US 20060232238A1
• Time in Patent Office: Days
• US Class Current: 320/104
• CPC Class Codes: B60K 6/28 characterised by the electric energy storing means, e.g. batteries or capacitors
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 58/20 having different nominal voltages
• 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: B60Y 2400/112 Batteries
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• 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 battery charging system for hybrid electric vehicles that is capable of charging a low voltage battery with good energy efficiency. The battery charging system includes a high voltage battery for supplying electric power to a vehicle drive motor; and a voltage converter for converting a voltage, input from the high voltage battery, to a first voltage and outputting the first voltage. The battery charging system further includes a low voltage battery that is charged with the first voltage from the voltage converter; and an alternator, which is driven by an engine, connected with the low voltage battery in parallel with the voltage converter. The output voltage of the alternator is lower than the first voltage and higher than the rated voltage of the low voltage battery.

Claims

1. A battery charging system for hybrid electric vehicles comprising:

a high voltage battery for supplying electric power to a vehicle drive motor;

a voltage converter for converting a voltage, input from said high voltage battery, to a first voltage and outputting said first voltage;

a low voltage battery that is charged with said first voltage from said voltage converter; and

an alternator, which is driven by an engine, connected with said low voltage battery in parallel with said voltage converter;

wherein an output voltage of said alternator is lower than said first voltage and higher than a rated voltage of said low voltage battery.

2. The battery charging system as set forth in claim 1, wherein a voltage difference between said first voltage and the output voltage of said alternator is set to a predetermined voltage difference or greater.

3. The battery charging system as set forth in claim 2, wherein said predetermined voltage difference is 2 V, said first voltage is 28.5 V, said rated voltage of said low voltage battery is 24 V, and the output voltage of said alternator is 26.5 V.