Method for determining a maximum charge current and a maximum discharge current of a battery

• US 6,724,172 B2
• Filed: 12/30/2002
• Issued: 04/20/2004
• Est. Priority Date: 06/26/2002
• Status: Expired due to Fees

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Inventors: Koo, Jae-Seung
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US10/331,228
• Publication Number:
  US 20040000892A1
• Time in Patent Office: 477 Days
• Field of Search: 320/127, 320/128, 320/135, 320/158, 320/163
• US Class Current: 320/128
• CPC Class Codes: H02J 7/0063 with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A method for determining a maximum charge current of a battery is provided which comprises: determining a steady-state charge resistance based on a current state of charge of the battery; determining a no-load charge voltage based on the current state of charge of the battery; calculating a maximum temporary charge current; and calculating a maximum charge current based on the maximum temporary charge current.

Claims

1. A method for determining a maximum charge current of a battery, comprising:

determining a steady-state charge resistance based on a current state of charge of the battery;

determining a no-load charge voltage based on the current state of charge of the battery;

calculating a maximum temporary charge current; and

calculating a maximum charge current based on the maximum temporary charge current.

2. The method of claim 1, wherein the battery has a maximum charge voltage, and further wherein the maximum temporary charge current is calculated by:

[(the maximum charge voltage−

the no-load charge voltage)/(the steady-state charge resistance)].

3. The method of claim 1, wherein the maximum charge current is calculated by:

[(the maximum temporary charge current)*(a predetermined charge time period gain)].

4. A method for determining a maximum discharge current of a battery, comprising:

determining a steady-state discharge resistance based on a current state of charge of the battery;

determining a no-load discharge voltage based on the current state of charge of the battery;

calculating a maximum temporary discharge current; and

calculating a maximum discharge current based on the maximum temporary discharge current.

5. The method of claim 4, wherein the battery has a minimum discharge voltage, and further wherein the maximum temporary discharge current is calculated by:

[(the no-load discharge voltage−

the minimum discharge voltage)/(the steady-state discharge resistance)].

6. The method of claim 4, wherein the maximum discharge current is calculated by:

[(the maximum temporary discharge current)*(a predetermined discharge time period gain)].

7. A battery management system for managing a battery of a hybrid electric vehicle, the battery management system determining a maximum charge current of the battery, the battery management system comprising:

a processor for controlling charging of the battery;

memory for storing instructions for execution by the processor;

a first module stored in the memory, the first module comprising;

logic for determining a steady-state charge resistance based on a current state of charge of the battery;

logic for determining a no-load charge voltage based on the current state of charge of the battery;

logic for calculating a maximum temporary charge current; and

logic for calculating a maximum charge current based on the maximum temporary charge current.

8. A battery management system for managing a battery of a hybrid electric vehicle, the battery management system determining a maximum discharge current of the battery, the battery management system comprising:

a processor for controlling discharging of the battery;

memory for storing instructions for execution by the processor;

a first module stored in the memory, the first module comprising;

logic for determining a steady-state discharge resistance based on a current state of charge of the battery;

logic for determining a no-load discharge voltage based on the current state of charge of the battery;

logic for calculating a maximum temporary discharge current; and

logic for calculating a maximum discharge current based on the maximum temporary discharge current.

9. A method of more accurately determining maximum charging and discharging currents for a battery of a hybrid electric vehicle, the method comprising:

determining a plurality of maximum voltage differentials corresponding to a plurality of possible state of charges for the battery, each maximum voltage differential based on a difference between a predetermined voltage limit for the battery and a no-load voltage value for each of the plurality of possible state of charges;

determining a plurality of steady-state resistances corresponding to the plurality of possible state of charges;

measuring a first state of charge of the battery;

determining one of a maximum charge current and a maximum discharge current by dividing the maximum voltage differential corresponding to the first state of charge by the steady-state resistance corresponding to the first state of charge.