Battery current measurement with real time pre-gain adjust and programmable excitation source

• US 7,521,934 B1
• Filed: 10/16/2006
• Issued: 04/21/2009
• Est. Priority Date: 10/16/2006
• Status: Expired due to Fees

• Current Assignee: Yazaki North America Incorporated (Yazaki Corporation)
• Original Assignee: Yazaki North America Incorporated (Yazaki Corporation)
• Inventors: Jones, James Leroy III, Wu, Yuanyuan, Guo, Sam Yonghong
• Primary Examiner(s): Nguyen; Vincent Q
• Assistant Examiner(s): NATALINI, JEFF WILLIAM
• Application Number:
  US11/581,709
• Time in Patent Office: 918 Days
• Field of Search: 324/425
• US Class Current: 324/425
• CPC Class Codes: G01R 15/005 Circuits for altering the indicating characteristic, e.g. making it non-linear
• CPC Class Codes: G01R 19/0092 measuring current only all subgroups of G01R19/00 take precedence
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36

Abstract

A current measurement control system for a power supply system is provided. The current measurement control system includes a load module that estimates a total load of the power supply system. An amplification module selectively determines an amplification factor based on the total load and amplifies a current signal based on the amplification factor. A current measurement module measures current based on the amplified current signal.

Claims

1. A method of measuring current for a power supply system, comprising:

determining a load combination;

determining a first coefficient and associating the first coefficient with the load combination and an amplification factor;

determining a second coefficient based on the first coefficient and associating the second coefficient with the load combination and the amplification factor;

measuring a voltage of the power supply system; and

estimating a current based on the voltage, the first coefficient, and the second coefficient.

2. The method of claim 1 further comprising:

setting a first current level for the load combination;

measuring a first voltage after setting the first current level;

setting a second current level for the load combination;

measuring a second voltage after setting the second current level;

and wherein the first coefficient is determined based on the first current level, the first voltage, the second voltage, and the second current level.

3. The method of claim 2 wherein the determining the second coefficient is based on the first coefficient, the first voltage, and the first current.

4. The method of claim 1 further comprising setting a gain as the amplification factor based on the load combination.

5. The method of claim 1 further comprising setting an excitation level as the amplification factor based on the load combination.

6. A current measurement control system for power supply systems, comprising:

a load module that determines a load combination;

a control module that;

determines a first coefficient associated with the load combination and an amplification factor;

determines a second coefficient based on the first coefficient, the load combination and the amplification factor; and

measures a voltage of the power supply system; and

a current measurement module that estimates a current based on the voltage, the first coefficient, and the second coefficient.

7. The system of claim 6, wherein the control module:

sets a first current level for the load combination;

measures a first voltage after setting the first current level;

sets a second current level for the load combination; and

measures a second voltage after setting the second current level, wherein the first coefficient is determined based on the first current level, the first voltage, the second voltage, and the second current level.

8. The system of claim 7, wherein the second coefficient is based on the first coefficient, the first voltage, and the first current.

9. The system of claim 6, wherein the control module sets a gain as the amplification factor based on the load combination.

10. The system of claim 6, wherein the control module sets an excitation level as the amplification factor based on the load combination.