Battery array and process for controlling the state of charge of a battery array

• US 20050052155A1
• Filed: 09/02/2004
• Published: 03/10/2005
• Est. Priority Date: 09/06/2003
• Status: Abandoned Application

• Current Assignee: Draeger Safety Incorporated (FPS Vermögensverwaltung GmbH)
• Original Assignee: Draeger Safety Incorporated (FPS Vermögensverwaltung GmbH)
• Inventors: Surig, Andreas
• Application Number:
  US10/932,424
• Publication Number:
  US 20050052155A1
• Time in Patent Office: Days
• US Class Current: 320/116
• CPC Class Codes: H02J 7/0025 Sequential battery discharge in systems with a plurality of batteries
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/007182 in response to battery voltage

Abstract

A battery array is provided for connection to an electric load as well as to a battery charger. A process for controlling the state of charge of a battery array is also provided. The energy needed to supply an electric device not connected to the electric network is taken from a battery, which is composed of a plurality of galvanic cells connected in series. The energy that can be supplied by such a series-connected array, a so-called battery line, is limited for safety reasons. Moreover, it is difficult to determine the state of charge, because the calibration points necessary for the determination of the state of charge, namely, the two states of charge “full” and “empty,” are reached by such a series-connected array only rarely if ever. A battery array that has a plurality of series-connected arrays connected in parallel, whose states of charge are estimated separately is provided. The corresponding process controls the state of charge of the battery array, in which the individual series-connected arrays are charged and discharged in a preset sequence.

Claims

1. A battery array for connection to an electric load as well as to a battery charger, the battery array comprising:

a plurality of said battery lines connected in parallel, each battery line including a plurality of galvanic cells connected in series and a measuring unit associated with each of said battery lines for one or more of estimating the state of charge and measuring values for determining the state of charge of said battery line;

an evaluating and control unit connected with said measuring units for estimating the state of charge and receiving and evaluating said measured values;

a plurality of switches, one of said switches being arranged between each one of said battery lines and said electric load and one of said switches being arranged between each one of said battery lines and said battery charger said switches being actuated by said evaluating and control unit for opening and closing.

2. A battery array in accordance with claim 1, wherein the energy that can be supplied by one of said individual battery lines is selected in adaptation to said electric load that can be connected such that it will be consumed for a typical use of said electric load within a period of time for which the state of charge of said battery line can be reliably determined by said corresponding measuring unit for estimating the state of charge of said battery line.

3. A battery array in accordance with claim 1, wherein said electric load is part of or is connected to a gas-measuring device.

4. A process for controlling the state of charge of a battery array the process comprising the steps:

providing a plurality of the battery lines connected in parallel, each battery line including a plurality of galvanic cells connected in series and a measuring unit associated with each the battery line for one or more of estimating the state of charge and measuring values for determining the state of charge of the battery line;

providing an evaluating and control unit connected with the measuring units for estimating the state of charge and receiving and evaluating the measured values;

providing a plurality of switches, one of the switches being arranged between each one of the battery lines and the electric load and one of the switches being arranged between each one of the battery lines and the battery charger the switches being actuated by the evaluating and control unit for opening and closing;

measuring values with each measuring unit for estimating the state of charge of the respective battery line for determining the state of charge of the corresponding battery line and sending the values to the evaluating and control unit;

calculating a value for the state of charge with the evaluating and control unit from the measured values;

when the battery array is connected to the electric load, selecting with the evaluating and control unit the one of the battery lines with the highest state of charge for releasing charge to the electric load on the basis of the values calculated in said step of calculating by actuating the corresponding switch for closing and actuating the rest of the switches for opening;

when the battery array is connected to a the battery charger, selecting with the evaluating and control unit the battery line with the lowest state of charge for taking up charge from the battery charger on the basis of the values calculated in said step of calculating by actuating the corresponding switch for closing and actuating the rest of the switches for opening;

as soon as the battery line with the highest charge has been completely discharged in the step including releasing charge to the electric load, and the battery line with the lowest charge has been completely charged in the step including taking up charge from the battery charger, a corresponding signal is recognized by the evaluating and control unit and the sequence is started again from the step of measuring values.

5. A process in accordance with claim 4, wherein if more than one of the battery lines has the highest state of charge, the battery line that had been selected to release its charge to the electric load the longest time ago is selected in said step including releasing charge to the electric load.

6. A process in accordance with claim 4, wherein if more than one of the battery lines has the lowest state of charge, the battery line that had been selected to take up charge from the battery charger the longest time ago is selected in the step including taking up charge from the battery charger.

7. A process in accordance with claim 4, wherein said electric load is connected to or is part of a gas-measuring device.

8. A battery array for connection to an electric load as well as to a battery charger, the battery array comprising:

a plurality of battery lines connected in parallel;

a plurality of galvanic cells, each of said galvanic cells being associated and connected with one of said battery lines;

a measuring unit associated with each of said battery lines for measuring values to be used for one or more of estimating the state of charge and for determining the state of charge of the associated battery line;

an evaluating and control unit connected with said measuring units for estimating the state of charge and receiving and evaluating said measured values;

a switching means for switching between an open and closed electrical connection between each one of said battery lines and said electric load and for switching between an open and closed electrical connection between each one of said battery lines and said battery charger said switching means being actuated by said evaluating and control unit for opening and closing.

9. A battery array in accordance with claim 8, wherein said measuring unit measures values for estimating the state of charge of the respective battery line and for determining the state of charge of the corresponding battery line and sends the values to the evaluating and control unit and said evaluating and control unit calculates a value for the state of charge with the from the measured values.

10. A battery array in accordance with claim 9, wherein said evaluating and control unit selects the one of the battery lines with the highest state of charge, when the battery array is connected to a the electric load, for releasing charge to the electric load on the basis of the values calculated by actuating the corresponding switch by closing to provide electrical connection and actuating the rest of the switches by opening to end electrical connection.

11. A battery array in accordance with claim 9, wherein said evaluating and control unit selects the battery line with the lowest state of charge, when the battery array is connected to a the battery charger, for taking up charge from the battery charger on the basis of the valves calculated by actuating the corresponding switch for closing to provide electrical connection and actuating the rest of the switches by opening to end electrical connection.

12. A battery array in accordance with claim 8, wherein the energy that can be supplied by one of said individual battery lines is selected in adaptation to said electric load that can be connected such that it will be consumed for a typical use of said electric load within a period of time for which the state of charge of said battery line can be reliably determined by said corresponding measuring unit for estimating the state of charge of said battery line.

13. A battery array in accordance with claim 8, wherein said electric load can be connected is a gas-measuring device.