Battery system with cell voltage detecting units

Patent metadata

Field	Value
Publication number	US-9921270-B2
Application number	US-201113822807-A
Country	US
Kind code	B2
Filing date	Aug 12, 2011
Priority date	Sep 14, 2010
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

A battery system with at least one module includes a plurality of battery cells. A cell voltage detecting circuit is associated with each battery cell of the plurality of battery cells. The cell voltage detecting circuits of the at least one module are connected to a multiplexer. An output of the multiplexer is connected to a communication bus via an analog-digital converter. The communication bus is connected to an evaluating unit. The multiplexer is additionally connected to at least one auxiliary voltage source that is known to the evaluating unit. In a method for monitoring a battery system with at least one module including a plurality of battery cells, a voltage of each of the battery cells is detected and fed to an evaluating unit via a cell voltage detecting unit. An output signal of the cell voltage detecting unit is tested for plausibility.

First claim

The invention claimed is:

1. A battery system, comprising:
an evaluation unit;
an analog-to-digital converter;
a communication bus connected to the evaluation unit;
an auxiliary voltage source configured to provide a predetermined voltage having a predefined magnitude and frequency, the predetermined voltage being known to the evaluation unit;
a multiplexer having an output and a plurality of selectable inputs, the output being connected via the analog-to-digital converter to the communication bus, at least one of the plurality of selectable inputs being connected to the auxiliary voltage source, the multiplexer being configured to provide the predetermined voltage to the communication bus via the analog-to-digital converter; and
at least one battery module including a plurality of battery cells, each battery cell of the plurality of battery cells having an associated cell voltage sensing circuit configured to a sense cell voltage of the respective battery cell, each the cell voltage sensing circuit being connected to at least one of the plurality of selectable inputs of the multiplexer,
wherein the evaluation unit is configured to:
receive, on the communication bus, digitized values of the sensed cell voltages of the plurality of battery cells;
detect, on the communication bus, digitized values of the predetermined voltage provided by the auxiliary voltage source;
determine that the analog-to-digital converter is not properly functioning in response to the digitized values of the predetermined voltage no longer being detected on the communication bus; and
determine that the analog-to-digital converter is not properly functioning in response to the digitized values of the predetermined voltage detected on the communication not having the predefined magnitude and frequency.

2. The battery system as claimed in claim 1 , wherein the auxiliary voltage source is configured to provide the predetermined voltage as a low frequency oscillating voltage.

3. The battery system as claimed in claim 2 , wherein the auxiliary voltage source is configured to provide the predetermined voltage as a square wave.

4. A method for monitoring a battery system having at least one battery module having a plurality of battery cells, each battery cell of the plurality of battery cells having an associated cell voltage sensing circuit, comprising:
sensing a cell voltage for each battery cell of the plurality of battery cells with the associated cell voltage sensing circuits;
routing the sensed cell voltages for each battery cell to an evaluation unit via a plurality of selectable inputs of a multiplexer, the multiplexer having an output connected a communication bus via an analog-to-digital converter, the evaluation unit being connected to the communication bus;
providing a predetermined voltage having a predefined magnitude and frequency with an auxiliary voltage source, the predetermined voltage being known to the evaluation unit;
routing the predetermined voltage from the auxiliary voltage source to the evaluation via at least one of the plurality of selectable inputs of the multiplexer;
receiving, with the evaluation unit, on the communication bus, digitized values of the sensed cell voltages of the plurality of battery cells;
detecting, with the evaluation unit, on the communication bus, digitized values of the predetermined voltage provided by the auxiliary voltage source; and
determining that the analog-to-digital converter is not properly functioning in response to the digitized values of the predetermined voltage no longer being detected on the communication bus; and
determining that the analog-to-digital converter is not properly functioning in response to the digitized values of the predetermined voltage detected on the communication not having the predefined magnitude and frequency.

5. A motor vehicle comprising:
a drive system; and
a battery system connected to the drive system, the battery system including:
an evaluation unit;
an analog-to-digital converter;
a communication bus connected to the evaluation unit;
at least one auxiliary voltage source configured to provide a predetermined voltage having a predefined magnitude and frequency, the predetermined voltage being known to the evaluation unit;
a multiplexer having an output and a plurality of selectable inputs, the output being connected via the analog-to-digital converter to the communication bus, one of the plurality of selectable inputs being connected to the at least one auxiliary voltage source, the multiplexer being configured to provide the predetermined voltage to the communication bus via the analog-to-digital converter; and
at least one battery module including a plurality of battery cells, each battery cell of the plurality of battery cells having an associated cell voltage sensing circuit configured to a sense cell voltage of the respective battery cell, each the cell voltage sensing circuit being connected to at least one of the plurality of selectable inputs of the multiplexer,
wherein the evaluation unit is configured to:
receive, on the communication bus, digitized values of the sensed cell voltages of the plurality of battery cells;
detect, on the communication bus, digitized values of the predetermined voltage provided by the at least one auxiliary voltage source; and
determine that the analog-to-digital converter is not properly functioning in response to the digitized values of the predetermined voltage no longer being detected on the communication bus; and
determine that the analog-to-digital converter is not properly functioning in response to the digitized values of the predetermined voltage detected on the communication not having the predefined magnitude and frequency.

Assignees

• Butzmann Stefan
• Bosch Gmbh Robert
• Samsung Sdi Co Ltd

Inventors

• Butzmann Stefan

Classifications

• H02J7/54

  Passive balancing, e.g. using resistors or parallel MOSFETs · CPC title

• H02J7/52

  for charge balancing, e.g. equalisation of charge between batteries · CPC title

• H01M10/48

  Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte (constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569) · CPC title

• H01M10/482

  for several batteries or cells simultaneously or sequentially · CPC title

• G01R31/362 Primary

  Physics · mapped topic