MONITORING SYSTEM AND METHOD

• US 20100283473A1
• Filed: 05/11/2009
• Published: 11/11/2010
• Est. Priority Date: 05/11/2009
• Status: Active Grant

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Inventors: Vandensande, Geert
• Granted Patent: US 8,258,792 B2
• Time in Patent Office: Days
• US Class Current: 324/434
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]

Abstract

A method and system for monitoring a voltage of a battery cell or a battery stack. A first monitoring unit has a first plurality of battery monitoring nodes, first and second data ports, a first supply port switchably coupled to the first plurality of battery monitoring nodes, a second supply port switchably coupled to the first plurality of battery monitoring nodes, and a third supply port. A controller is connected to the first monitoring unit. Alternatively, a reference voltage may be connected to the controller or it may be connected to the first monitoring unit.

Claims

1. A method for monitoring one or more batteries, comprising:

measuring a voltage of a first cell of a first battery using a first monitoring unit to generate a first measurement result, wherein measuring the voltage of the first cell of the first battery includes using a first reference voltage;

measuring the first reference voltage using a second monitoring unit to generate a second measurement result; and

using the first measurement result and the second measurement result to calculate a first correction factor suitable for use in correcting a set of measurements from at least one of the first and second monitoring units.

2. The method of claim 1, further including:

measuring a voltage of a second cell of the first battery using the first monitoring unit, wherein measuring the voltage of the second cell includes using the first reference voltage; and

using the first correction factor to correct the measurement of the voltage of the second cell.

3. The method of claim 1, further including measuring voltages of a plurality of additional cells of the first battery using the first monitoring unit, wherein measuring the voltages of the plurality of additional cells includes using the first reference voltage;

and

using the first correction factor to correct the measurements of the voltages of the plurality of cells.

4. The method of claim 1, further including:

measuring a voltage of a first cell of a second battery using the second monitoring unit to generate a third measurement result, wherein measuring the voltage of the first cell of the second battery includes using a second reference voltage;

measuring the second reference voltage using a third monitoring unit to generate a fourth measurement result; and

using the third measurement result and the fourth measurement result to calculate a second correction factor suitable for use in correcting a set of measurements from at least one of the first and second monitoring units.

5. The method of claim 1, further including using the first and second correction factors to correct the set of measurements from at least one of the first, second, and third monitoring units.

6. The method of claim 1, further including configuring at least one of the first and second monitoring units to measure a voltage across the first cell or a group of cells.

7. The method of claim 6, further including providing a selectable input port to at least one of the first and second monitoring units, the selectable input port for coupling to a third monitoring unit, the third monitoring unit adjacent to at least one of the first and second monitoring units.

8. The method of claim 6, further including providing a first additional selectable input port for coupling to an adjacent monitoring unit and that is capable of measuring a voltage that is related to the reference voltage of the adjacent monitoring unit and providing a second additional selectable input port for measuring a voltage of an external reference voltage.

9. The method of claim 1, further including using a controller to calculate the first and second correction factors.

10. The method of claim 1, further including:

coupling a controller to at least one of the first and second monitoring units; and

coupling the first reference voltage to the controller.

11. The method of claim 1, further including:

coupling a controller to at least one of the first and second monitoring units; and

coupling the first reference voltage to an additional selectable port to measure a voltage of the first external reference voltage of at least one of the first and second monitoring units.

12. The method of claim 1, further including:

coupling a controller to at least one of the first and second monitoring units;

coupling the first reference voltage to the first monitoring unit; and

coupling the second reference voltage to the second monitoring unit.

13. The method of claim 1, further including:

measuring first voltage at a first node in the first monitoring unit;

measuring a second voltage at a second node in a second monitoring unit;

using the first voltage at the first node and the second voltage at the second node to calculate a second correction factor suitable for use in correcting a set of measurements from at least one of the first and second monitoring units.

14. A monitoring system, comprising:

a first monitoring unit having a first plurality of battery monitoring nodes, first and second data ports, a first supply port switchably coupled to the first plurality of battery monitoring nodes, a second supply port switchably coupled to the first plurality of battery monitoring nodes, and a third supply port; and

a controller having at least first, second, and third nodes, the first node coupled to the first data port, the second node coupled to the second supply port, and the third node coupled for receiving a reference voltage.

15. The monitoring system of claim 14, further including a second monitoring unit having a second plurality of battery monitoring nodes, first and second data ports, a first supply port switchably coupled to the second plurality of battery monitoring nodes, a second supply port switchably coupled to the second plurality of battery monitoring nodes, and a third supply port, the first data port of the second monitoring unit coupled to the second data port of the first monitoring unit, and the third supply port of the second monitoring unit coupled to first supply port of the first monitoring unit.

16. The monitoring system of claim 15, wherein the first monitoring unit further includes:

a gain stage having first and second inputs and an output, the first input switchably coupled to a first portion of the first plurality of battery monitoring nodes and the second input switchably coupled to the second plurality of battery monitoring nodes;

a converter circuit having first input coupled to the output of the gain stage, a second input coupled to the third supply port of the first monitoring unit, and an output; and

a logic circuit having an input node coupled to the output of the converter circuit, a first input/output node coupled to the first data port, and a second input/output node coupled to the second data port.

17. A monitoring system, comprising:

a first monitoring unit having a first plurality of battery monitoring nodes, first and second data ports, a first supply port switchably coupled to the first plurality of battery monitoring nodes, a second supply port switchably coupled to the first plurality of battery monitoring nodes, a third supply port, and a first reference port switchably coupled to the first plurality of battery monitoring nodes and second reference port switchably coupled to the first plurality of battery monitoring nodes; and

a controller having at least one port, the at least one port coupled to the first data port.

18. The monitoring system of claim 17, further including a first reference voltage source having first and second terminals, the first terminal coupled to the first reference port and the second terminal coupled to the second reference port.

19. The monitoring system of claim 18, further including:

a gain stage having first and second inputs and an output, the first input switchably coupled to a first portion of the first plurality of battery monitoring nodes and the second input switchably coupled to the second plurality of battery monitoring nodes;

a converter circuit having first input coupled to the output of the gain stage, a second input coupled to the third supply port of the first monitoring unit, and an output;

a logic circuit having an input node coupled to the output of the converter circuit, a first input/output node coupled to the first data port, and a second input/output node coupled to the second data port;

a first switch having first and second terminals, the first terminal coupled to the first plurality of battery monitor nodes and the second terminal coupled to the first reference port; and

a second switch having first and second terminals, the first terminal coupled to the first plurality of battery monitor nodes and the second terminal coupled to the second reference port.

20. The monitoring system of claim 18, further including:

a second monitoring unit having a second plurality of battery monitoring nodes, third and fourth data ports, a fourth supply port switchably coupled to the second plurality of battery monitoring nodes, a fifth supply port switchably coupled to the second plurality of battery monitoring nodes, a sixth supply port, and a third reference port switchably coupled to the second plurality of battery monitoring nodes and a fourth reference port switchably coupled to the second plurality of battery monitoring nodes; and

a second reference voltage source having first and second terminals, the first terminal coupled to the third reference port of the second monitoring unit and the second terminal coupled to the fourth reference port of the second monitoring unit.