BATTERY PACK DISTRIBUTED ISOLATION DETECTION CIRCUITRY

• US 20130154656A1
• Filed: 12/19/2011
• Published: 06/20/2013
• Est. Priority Date: 12/19/2011
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Tabatowski-Bush, Benjamin A.
• Granted Patent: US 9,404,956 B2
• Time in Patent Office: Days
• US Class Current: 324/434
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/52 characterised by DC-motors
• CPC Class Codes: B60L 58/18 of two or more battery modules
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: G01R 31/36 Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults
• 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

Abstract

A power system for a vehicle includes at least two battery packs spaced away from each other. A first battery pack includes a plurality of battery cells and a switching element electrically connected with the battery cells. A second battery pack includes a resistor electrically connected in series with the switching element, and sense circuitry configured to detect voltage across the resistor indicative of leakage current associated with the first battery pack.

Claims

1. A vehicle comprising:

first and second battery packs spaced away from each other within the vehicle; and

a leakage detection circuit (i) including a first precision resistor disposed within the first battery pack and electrically connected with chassis ground, and a switching element and first series limiting resistor disposed within the second battery pack and electrically connected in series with the first precision resistor, and (ii) configured to respond to leakage currents within the second battery pack.

2. The vehicle of claim 1 further comprising a second series limiting resistor electrically connected in series with the first precision resistor and disposed within the first battery pack.

3. The vehicle of claim 1 further comprising sense circuitry disposed within the first battery pack and configured to measure voltage across the first precision resistor.

4. The vehicle of claim 3 further comprising at least one controller configured to determine presence of leakage current associated with the second battery pack based on the voltage across the first precision resistor.

5. The vehicle of claim 4 further comprising another isolation detection circuit disposed within the first battery pack and including a second precision resistor electrically connected with chassis ground.

6. The vehicle of claim 5 wherein the sense circuitry is further configured to measure voltage across the second precision resistor.

7. The vehicle of claim 6 wherein the at least one controller is further configured to determine presence of leakage current associated with the first battery pack based on the voltage across the second precision resistor.

8. The vehicle of claim 1 further comprising an electric machine configured to transform electrical power from the battery packs into motive power to move the vehicle.

9. A vehicle comprising:

a plurality of battery packs positioned at different locations within the vehicle, one of the packs including (i) a plurality of resistors each being electrically connected with chassis ground and a different one of the packs and (ii) sense circuitry configured to detect voltage across each of the resistors; and

at least one controller configured to determine presence of leakage currents associated with other of the packs based on the detected voltages.

10. The vehicle of claim 9 wherein the resistors are precision resistors.

11. The vehicle of claim 10 further comprising a switching element and series limiting resistor disposed within each of the battery packs and electrically connected in series with one of the precision resistors.

12. The vehicle of claim 11 wherein the at least one controller is further configured to selectively close the switching elements to cause current to flow through the switching elements and the precision resistors electrically connected to the switching elements.

13. A power system for a vehicle comprising:

a first battery pack including a plurality of battery cells and a switching element electrically connected with the battery cells; and

a second battery pack spaced away from the first battery pack and including (i) a resistor electrically connected in series with the switching element and (ii) sense circuitry configured to detect voltage across the resistor indicative of leakage current associated with the first battery pack.

14. The system of claim 13 wherein the resistor is a precision resistor.

15. The system of claim 14 wherein the first battery pack further includes a series limiting resistor electrically connected between the switching element and the precision resistor.

16. The system of claim 14 wherein the second battery pack further includes a series limiting resistor electrically connected between the switching element and the precision resistor.

17. The system of claim 14 wherein the second battery pack further includes another precision resistor and wherein the sense circuitry is further configured to detect voltage across the another precision resistor indicative of leakage current associated with the second battery pack.