BATTERY MODULE SHORT CIRCUIT PROTECTION

• US 20160094056A1
• Filed: 09/30/2014
• Published: 03/31/2016
• Est. Priority Date: 09/30/2014
• Status: Active Grant

• Current Assignee: CPS Technology Holdings, LLC
• Original Assignee: Johnson Controls Technology Company (Johnson Controls International plc)
• Inventors: Dulle, Ronald J.
• Granted Patent: US 10,033,213 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H
• CPC Class Codes: B60L 50/64 Constructional details of batteries specially adapted for electric vehicles
• CPC Class Codes: B60L 50/66 Arrangements of batteries
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: G01R 31/006 on road vehicles, e.g. automobiles or trucks testing of ignition installations peculiar to internal combustion engines F02P17/00
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: G01R 31/50 Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections testing of sparking plugs H01T13/58
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults
• CPC Class Codes: H01M 10/4257 Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries
• CPC Class Codes: H01M 10/4264 with capacitors
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H02H 7/18 for batteries; for accumulators
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

The present disclosure includes an automotive battery system including a first battery that couples to an electrical system. Additionally, the first battery includes a first battery chemistry. Further, the automotive battery system includes a second battery coupled in parallel with the first battery and couples to the electrical system. Furthermore, the automotive battery system includes a first switch coupled to a positive terminal of the second battery, which electrically couples or decouples the second battery to or from the electrical system. Moreover, the automotive battery system includes a battery control unit that detects a short circuit condition of the first battery, the second battery, or both and decouples the second battery from the electrical system by opening the first switch upon detecting the short circuit condition.

Claims

1. An automotive battery system, comprising:

a first battery configured to couple to an electrical system, wherein the first battery comprises a first battery chemistry;

a second battery coupled in parallel with the first battery and configured to couple to the electrical system;

a first switch coupled to a positive terminal of the second battery and configured to electrically couple or decouple the second battery to or from the electrical system; and

a battery control unit configured to detect a short circuit condition of the first battery, the second battery, or both and to decouple the second battery from the electrical system by opening the first switch upon detecting the short circuit condition.

2. The battery system of claim 1, wherein the battery control unit comprises a wake-up control unit configured to wake-up the battery control unit upon detection of a potential short circuit condition while the battery control unit is in a hibernation mode.

3. The battery system of claim 2, wherein the wake-up control unit receives a voltage signal from an output of the first battery and the second battery, determines a an instantaneous rate of change of the voltage signal, and provides a wake-up signal to short circuit detection electronics of the battery control unit when the instantaneous rate of change of the voltage signal is greater than a predetermined threshold value.

4. The battery system of claim 3, wherein the wake-up control unit comprises an op-amp differentiator configured to manipulate a voltage signal from an output of the first battery and the second battery to a voltage representation of the instantaneous rate of change of the voltage signal.

5. The battery system of claim 4, wherein the wake-up control unit further comprises a comparator to compare the voltage representation to the predetermined threshold value and output the wake-up signal to the short circuit detection electronics.

6. The battery system of claim 1, comprising a capacitor bank configured to provide sufficient power to operate the battery control unit and the first switch during the short circuit condition.

7. The battery system of claim 6, wherein the capacitor bank comprises a total capacitance of around 500 μ

F.

8. The battery system of claim 6, wherein the capacitor bank draws less than around 300 μ

A of quiescent current.

9. The battery system of claim 6, wherein the battery control unit is configured to detect the short circuit condition down to a 0Ω

short circuit.

10. The battery system of claim 1, comprising a second switch coupled to a positive terminal of the first battery and configured to electrically couple or decouple the first battery to the electrical system, and wherein the battery control unit is configured to decouple the first battery from the electrical system by opening the second switch upon detecting the short circuit condition.

11. The battery system of claim 1, wherein the second battery comprises a second battery chemistry with a higher coulombic efficiency than the first battery chemistry.

12. The battery system of claim 11, wherein the first battery chemistry is lead-acid and the second battery chemistry is a lithium ion chemistry.

13. The battery system of claim 1, wherein the first switch is a bi-stable relay.

14. A method for operating a short circuit detection and protection system of an automotive battery system, comprising:

powering down vehicle system electronics except for a wake-up control unit;

comparing an instantaneous rate of change of a voltage output by a battery module to a predetermined threshold voltage;

providing a wake-up signal to short circuit detection electronics when the instantaneous rate of change of the voltage output is greater than the predetermined threshold voltage;

determining via the short circuit detection electronics whether a short circuit condition exists; and

opening a switch coupled between an individual battery within the battery module and a terminal of the battery module when the short circuit condition exists.

15. The method of claim 14, comprising providing power to the short circuit detection electronics and to the switch via a capacitor bank.

16. The method of claim 14, wherein determining whether the short circuit condition exists comprises acquiring an accurate current measurement indicative of the short circuit condition via the short circuit detection electronics.

17. The method of claim 14, wherein comparing the instantaneous rate of change of the voltage output to the predetermined threshold voltage comprises:

manipulating the voltage output with an op-amp differentiator to output a voltage representation of the instantaneous rate of change of the voltage output; and

comparing the voltage representation to the predetermined threshold voltage via a comparator that outputs the wake-up signal.

18. The method of claim 14, wherein providing the wake-up signal to the short circuit detection electronics comprises providing a high signal to a clock input of a processor of the short circuit detection electronics.

19. A battery module for use in a vehicle, comprising:

a housing;

a first terminal and a second terminal;

a first battery disposed in the housing and configured to couple to across the first terminal and the second terminal;

a second battery disposed in the housing, coupled in parallel with the first battery, and configured to couple to the first terminal and the second terminal;

a switch disposed between a positive terminal of the first battery and the first terminal;

a battery control unit configured to control operation of the first battery, the second battery, and the switch;

a wake-up control unit electrically coupled to the first terminal and configured to detect a potential short circuit condition and to provide a wake-up signal to the battery control unit upon detection of the potential short circuit condition to wake-up the battery control unit when the vehicle is in a vehicle hibernation mode; and

a capacitor bank disposed within the housing and configured to provide power to the battery control unit and the switch after the wake-up control unit awakens the battery control unit.

20. The battery module of claim 19, wherein the wake-up control unit comprises an op-amp differentiator to detect an instantaneous rate of change of voltage at the first terminal.

21. The battery module of claim 20, wherein the wake-up control unit provides the wake-up signal to the battery control unit when an output of the op-amp differentiator is greater than a predetermined threshold.

22. The battery module of claim 19, wherein the first battery comprises a different battery chemistry from a battery chemistry of the second battery.