Battery-pack fault detecting device and method for detecting fault of battery-pack

Patent metadata

Field	Value
Publication number	US-9835688-B2
Application number	US-201314653576-A
Country	US
Kind code	B2
Filing date	Dec 17, 2013
Priority date	Dec 21, 2012
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

A battery-pack fault detecting device and a method for detecting a fault of a battery pack are provided. The battery-pack fault detecting device includes: N diodes, in which each battery is connected with one of the N diodes in anti-parallel via a detecting line; N+1 switches; a switch control circuit for switching on or switching off each switch; a voltage collecting circuit connected with the switch control circuit for collecting a voltage of the battery; an analog-to-digital conversion circuit for performing an analog-digital conversion on the voltage of the battery to obtain a digital voltage; a detection control circuit connected with the switch control circuit and the analog-to-digital conversion circuit, for controlling the switch control circuit to switch on or off each switch and for comparing the digital voltage with a preset value to judge a fault of the battery pack.

First claim

What is claimed is:

1. A battery-pack fault detecting device for detecting a battery pack comprising a plurality of N batteries connected in series and N being an integer greater than two, comprising:
N diodes, wherein each battery is connected with one of the N diodes in anti-parallel via a detecting line, and two adjacent batteries share one detecting line;
N+1 switches;
a switch control circuit, for switching on or switching off each switch of the N+1 switches in sequence, wherein each switch is connected between one diode and the switch control circuit, and one end of each diode of the N diodes is connected with the switch control circuit via one switch of the N+1 switches;
a voltage collecting circuit, connected with the switch control circuit for collecting a voltage of the battery connected to the switch of the N+1 switches being switched on;
an analog-to-digital conversion circuit, connected with the voltage collecting circuit for performing an analog-digital conversion on the voltage of the battery to obtain a digital voltage; and
a detection control circuit, connected with the switch control circuit and the analog-to-digital conversion circuit, for controlling the switch control circuit to switch on or switch off each switch and for comparing the digital voltage with a preset value to judge a fault of the battery pack.

2. The battery pack fault detecting device according to claim 1 , further comprising a filtering circuit connected between the voltage collecting circuit and the analog-to-digital conversion circuit.

3. The battery pack fault detecting device according to claim 1 , further comprising an alarm circuit connected with the detection control circuit for alarming the fault of the battery pack.

4. The battery pack fault detecting device according to claim 1 , further comprising an (N+1) th diode for absorbing a surge, wherein a cathode of the (N+1) th diode is connected with a negative electrode of a first battery of the N batteries, and an anode of the (N+1) th diode is grounded.

5. A method for detecting a fault of a battery pack comprising a plurality of (N+1) batteries connected in series, a plurality of switches and a switch control circuit, and N being an integer greater than two, wherein the plurality of (N+1) batteries is connected with the switch control circuit via the plurality of switches, comprising:
step 1, detecting a voltage of each battery in a preset sequence, comprising: only switching on two switches at both ends of an N th battery each time, collecting a voltage of the N th battery, and performing an analog-digital conversion on the voltage of the N th battery to obtain a digital voltage;
step 2, judging whether the digital voltage reaches a preset value A and, if yes, following step 3; if no, following step 5;
step 3, only switching on two switches at both ends of the N th and an (N−1) th batteries, collecting a voltage V′ n of the N th and the (N−1) th batteries, and performing the analog-to-digital conversion on the voltage V′ n to obtain a digital voltage V″ n ; only switching on two switches at both ends of the N th and the (N+1) th batteries, collecting a voltage V′ n+1 of the N th and the (N+1) th batteries, and performing the analog-to-digital conversion on the voltage V′ n+1 to obtain a digital voltage V″ n+1 ;
step 4, judging whether an average value of V″ n and V″ n+1 reaches a preset value B and, if yes, judging that the N th battery has a fault; if no, judging that detecting lines at both ends of the N th battery have a fault; and
step 5, judging whether voltages of all batteries have been collected, if yes, terminating fault detecting; if no, returning to step 1.

6. The method according to claim 5 , wherein the step 1 further comprises: filtering the voltage of the N th battery before performing the analog-to-digital conversion on the voltage of the N th battery to obtain a digital voltage.

7. The method according to claim 5 , wherein the step 3 further comprises:
filtering the voltage V′ n of the N th and the (N−1) th batteries before performing the analog-to-digital conversion on the voltage V′ n to obtain a digital voltage V″ n ; and
filtering the voltage V′ n+1 of the N th and the (N+1) th batteries before performing the analog-to-digital conversion on the voltage V′ n+1 to obtain a digital voltage V″ n+1 .

8. The method according to claim 5 , wherein the step 4 further comprises alarming that the N th battery has the fault or the detecting lines at both ends of the N th battery have the fault.

9. The method according to claim 5 , wherein each battery is connected with a diode in anti-parallel via a detecting line, and two adjacent batteries share one detecting line.

10. The method according to claim 9 , wherein the preset value A is a forward voltage drop of the diode connected with the N th battery in anti-parallel.

11. The method according to claim 9 , wherein the preset value B is a sum of a rated voltage of the N th battery and a forward voltage drop of the diode connected with the N th battery in anti-parallel.

Assignees

• Byd Co Ltd

Inventors

• Zhu Xiang
• He Zhiqiang
• Yang Yun

Classifications

• H01M10/482

  for several batteries or cells simultaneously or sequentially · CPC title

• G01R31/3658 Primary

  Physics · mapped topic

• G01R31/362

  Physics · mapped topic

• G01R35/00

  Testing or calibrating of apparatus covered by the other groups of this subclass · CPC title

• G01R19/16542

  for batteries (charge condition monitoring in G01R31/36) · CPC title