Battery system monitoring apparatus

• US 10,393,823 B2
• Filed: 02/03/2016
• Issued: 08/27/2019
• Est. Priority Date: 02/18/2015
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Inventors: Kudo, Akihiko, Kanai, Tomonori, Arima, Tomoyuki, Tsukamoto, Akiko
• Primary Examiner(s): Phan, Huy Q
• Assistant Examiner(s): Dickinson, Dustin R
• Application Number:
  US15/548,565
• Publication Number:
  US 20180017631A1
• Time in Patent Office: 1,301 Days
• CPC Class Codes: G01R 19/00 Arrangements for measuring currents or voltages or for indicating presence or sign thereof G01R5/00 takes precedence; for measuring bioelectric currents or voltages A61B5/24
• 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 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: H01M 10/48 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 Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

An object is to achieve management control of an assembled battery using an accurate measured value of a cell voltage. A battery system monitoring apparatus 10 that monitors and controls a battery system includes battery monitoring circuits 100 provided for respective cell groups 120. Each of the battery monitoring circuits 100 includes a cell voltage measurement module 6 that is connected with two electrodes of respective single battery cells 110 of a corresponding cell group 120 via voltage detection lines 2 and that measures a cell voltage of each of the single battery cells 110 at each of predetermined timings. An RC filter 4 is connected with the voltage detection lines 2. The RC filter 4 includes resistors and capacitors. The cell voltage measurement module 6 extends intervals at which the cell voltage is to be measured when a stored charge amount in the capacitor in the RC filter 4 changes.

Claims

1. A battery system monitoring apparatus for monitoring and controlling a battery system, the battery system including a plurality of cell groups, each cell group including a plurality of single battery cells connected in series with each other, the battery system monitoring apparatus comprising:

a plurality of battery monitoring circuits provided for the respective cell groups, each battery monitoring circuit including a cell voltage measurement module that is connected with two electrodes of respective single battery cells of a corresponding cell group via voltage detection lines and that measures a cell voltage of each of the single battery cells at each of predetermined timings; and

a filter circuit connected with the voltage detection lines, the filter circuit including resistors and capacitors, wherein

the cell voltage measurement module extends intervals at which the cell voltage is to be measured by the cell voltage measurement module when a stored charge amount in a capacitor in the filter circuit changes.

2. The battery system monitoring apparatus according to claim 1, further comprising:

balancing resistors connected electrically with the voltage detection lines and the filter circuit, the balancing resistors discharging each of the single battery cells in the cell group associated with the corresponding battery monitoring circuit, wherein

the battery monitoring circuit includes;

a discharge switch that changes a state of a discharge current flowing from each of single battery cells in the cell group associated with the battery monitoring circuit via a corresponding balancing resistor; and

a balancing control module that controls the discharge switch, and

when the stored charge amount in the capacitor in the filter circuit changes by the switching of the state of the discharge current by the discharge switch, the cell voltage measurement module extends the intervals at which the cell voltage is to be measured.

3. The battery system monitoring apparatus according to claim 2, wherein the balancing control module controls the discharge switch such that the state of the discharge current can be changed after the cell voltage measurement module has measured the cell voltage.

4. The battery system monitoring apparatus according to claim 1, wherein

the battery monitoring circuit includes, for diagnosing the cell voltage measurement module, a diagnosis switch that changes a connection state across the voltage detection lines connected with the two electrodes of each of the single battery cells in the cell group associated with the battery monitoring circuit and a diagnosis control module that controls the diagnosis switches, and

when the stored charge amount in the capacitor in the filter circuit changes by the switching of the connection state across the voltage detection lines by the diagnosis switch, the cell voltage measurement module extends the intervals at which the cell voltage is to be measured.

5. The battery system monitoring apparatus according to claim 4, wherein the cell voltage measurement module extends the intervals at which the cell voltage is to be measured by changing to delay measurement timings of the cell voltage when the stored charge amount in the capacitor in the filter circuit changes.

6. The battery system monitoring apparatus according to claim 5, wherein the cell voltage measurement module advances the measurement timings of the cell voltage in a stepwise fashion until original intervals at which the cell voltage is to be measured are reached after the measurement timings of the cell voltage have been delayed.

7. The battery system monitoring apparatus according to claim 4, wherein the cell voltage measurement module extends the intervals at which the cell voltage is to be measured by nullifying measurements of the cell voltage when the stored charge amount in the capacitor in the filter circuit changes.