Malfunction detecting apparatus

• US 20080103707A1
• Filed: 10/25/2007
• Published: 05/01/2008
• Est. Priority Date: 10/26/2006
• Status: Active Grant

• Current Assignee: Yazaki Corporation
• Original Assignee: Yazaki Corporation
• Inventors: Iwasaki, Katsuyuki, Sekizaki, Masashi
• Granted Patent: US 8,428,896 B2
• Time in Patent Office: Days
• US Class Current: 702/58
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/005 Detection of state of health [SOH]

Abstract

For providing a malfunction detecting apparatus for detecting a malfunction of a voltage detecting device accurately, a low-voltage-system CPU controls voltage detecting circuits to detect voltage between both terminals of one unit cell from among unit cells included in blocks corresponding to voltage detecting circuits. When variation of the voltage between both terminals detected by the low-voltage-system CPU is at least allowable error determined by a detection accuracy of the voltage detecting circuits, an abnormal condition of the voltage detecting circuits is detected.

Claims

1. A malfunction detecting apparatus comprising:

a plurality of voltage detecting devices for detecting a voltage between both terminals of each unit cell, which is secondary battery type, included in respective blocks, the voltage detecting device being provided for each block of the respective blocks divided from a battery pack formed with a plurality of unit cells connected in series to each other; and

a malfunction detecting device detecting an abnormal condition of the voltage detecting devices based on the voltage between both terminals of each cell, which is detected by each voltage detecting device,

wherein the malfunction detecting device controls the each voltage detecting device to detect the voltage between both terminals of one unit cell from among the unit cells included in each block, which is provided correspondingly to each of the voltage detecting devices,

and detects the abnormal condition of the voltage detecting device when a dispersion of each detected voltage between both terminals is at least a threshold value determined by detection accuracy of the voltage detecting devices.

2. The malfunction detecting apparatus as claimed in claim 1, further comprising an equalization device equalizing each voltage between both terminals of the unit cells, based on the voltages between both terminals of the unit cells which are detected by the plurality of voltage detecting devices when a vehicle ignition is switched off,

wherein the malfunction detecting device controls the each voltage detecting device to detect the voltage between both terminals of the one unit cell from among the unit cells included in the each block, which is provided correspondingly to each of the voltage detecting devices when the vehicle ignition is switched on.

3. The malfunction detecting apparatus as claimed in claim 1, wherein the malfunction detecting device controls the each voltage detecting device to simultaneously detect the each voltage between both terminals of the one unit cell from among the unit cells included in the each block, which is provided correspondingly to each of the voltage detecting devices.

4. The malfunction detecting apparatus as claimed in claim 3, further comprising:

a first communication line connecting between one of the plurality of voltage detecting devices and the malfunction detecting device;

an isolation interface arranged on the first communication line for communicating between the one of the plurality of voltage detecting devices and the malfunction detecting device in an isolation condition; and

a second communication line connecting between the one of the plurality of voltage detecting devices and a remainder of the plurality of voltage detecting devices other than the one,

wherein the malfunction detecting device transmits a detection instruction, which makes the one of the plurality of voltage detecting devices detect the voltage between both terminals of the one unit cell from among the unit cells included in the corresponding block, through the first communication line and the isolation interface, to the one of the plurality of voltage detecting devices,

Wherein the one of the plurality of voltage detecting devices transmits a synchronization signal to the remainder of the voltage detecting devices through the second communication line according to the detection instruction,

and the remainder of voltage detecting devices detects the voltage between both terminals of the one unit cell from among the unit cells included in the corresponding block, according to transmitting the synchronization signal.

5. The malfunction detecting apparatus as claimed in claim 2, wherein the malfunction detecting device controls the each voltage detecting device to simultaneously detect the each voltage between both terminals of the one unit cell from among the unit cells included in the each block, which is provided correspondingly to each of the voltage detecting devices.

6. The malfunction detecting apparatus as claimed in claim 5, further comprising:

a first communication line connecting between one of the plurality of voltage detecting devices and the malfunction detecting device;

an isolation interface arranged on the first communication line for communicating between the one of the plurality of voltage detecting devices and the malfunction detecting device in an isolation condition; and

a second communication line connecting between the one of the plurality of voltage detecting devices and a remainder of the plurality of voltage detecting devices other than the one,

wherein the malfunction detecting device transmits a detection instruction, which makes the one of the plurality of voltage detecting devices detect the voltage between both terminals of the one unit cell from among the unit cells included in the corresponding block, through the first communication line and the isolation interface, to the one of the plurality of voltage detecting devices,

Wherein the one of the plurality of voltage detecting devices transmits a synchronization signal to the remainder of the voltage detecting devices through the second communication line according to the detection instruction,

and the remainder of voltage detecting devices detects the voltage between both terminals of the one unit cell from among the unit cells included in the corresponding block, according to transmitting the synchronization signal.