System and method for monitoring a nickel cadmium battery in a passenger aircraft

• US 10,132,874 B2
• Filed: 06/03/2015
• Issued: 11/20/2018
• Est. Priority Date: 06/19/2014
• Status: Active Grant

• Current Assignee: Lufthansa Technik AG (Deutsche Lufthansa AG)
• Original Assignee: Lufthansa Technik AG (Deutsche Lufthansa AG)
• Inventors: Sperling, Florian, Guettler, Andrej
• Primary Examiner(s): TANG, MINH NHUT
• Application Number:
  US15/320,081
• Publication Number:
  US 20170139015A1
• Time in Patent Office: 1,266 Days
• CPC Class Codes: G01R 31/008 on air- or spacecraft, railway rolling stock or sea-going vessels
• CPC Class Codes: G01R 31/371 with remote indication, e.g. on external chargers
• CPC Class Codes: G01R 31/374 with means for correcting the measurement for temperature or ageing
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• 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

Abstract

A system for monitoring a nickel-cadmium battery incorporating twenty nickel-cadmium battery cells connected in series in a passenger aircraft includes a plurality of cell sensors for measuring the cell voltage and the cell temperature of individual battery cells and a data processing unit, and is set up to measure the battery current. The data processing unit is set up to determine a state of health value which is indicative of the state of health of the battery from the measurement data of the cell sensors and the measured battery current.

Claims

1. A system for monitoring a battery having multiple battery cells connected in series, comprising:

a plurality of cell sensors;

a current measuring device; and

a data processing unit,

wherein the system is configured to interconnect with a battery having multiple battery cells connected in series, such that when the system is interconnected with the battery;

the plurality of cell sensors are configured to continuously measure a corresponding cell voltage of each battery cell of the battery and continuously measure a corresponding cell temperature of each battery cell of the battery;

the current measuring device is configured to continuously measure a battery current of the battery, where the battery current of the battery is a total current flowing through the battery; and

the data processing unit is configured to receive the cell voltage of each battery cell of the battery, receive the cell temperature of each battery cell of the battery, receive the battery current, and determine a state of health value that is indicative of a state of health of the battery from the cell voltage of each battery cell of the battery, the cell temperature of each battery cell of the battery, and the battery current,

wherein a filling level of the each battery cell of the battery is determined from;

the cell voltage of the each battery cell of the battery;

the cell temperature of the each battery cell of the battery; and

the battery current of the battery,

wherein a reduction of a proportion of distilled water in an electrolyte of the each battery cell of the batten, results in a lowering of the filling level of the each battery cell of the battery, and correlates with a duration of overcharging of the each battery cell of the battery.

2. The system according to claim 1,

wherein when the system is interconnected with the battery, each battery cell of the battery is associated with a corresponding cell sensor of the plurality of cell sensors, such that each cell sensor of the plurality of cell sensors measures the cell voltage of a corresponding battery cell of the battery and measures the cell temperature of the corresponding battery cell of the battery.

3. The system according to claim 2,

wherein the system is configured such that, during loading of the battery:

each cell sensor of the plurality of cell sensors measures a loading cell voltage of the corresponding battery cell of the battery; and

the current measuring device measures a loading battery current of the battery, and

wherein the data processing unit is configured to;

receive the loading cell voltage of each battery cell of the battery;

receive the loading battery current of the battery; and

determine a corresponding internal resistance of each battery cell of the battery,

where the internal resistance of the each battery cell of the battery is a ratio of the loading cell voltage of the each battery cell of the battery to the loading battery current of the battery.

4. The system according to claim 2,

wherein the battery is a nickel-cadmium battery.

5. The system according to claim 4,

wherein the nickel-cadmium battery has twenty nickel-cadmium battery cells connected in series.

6. The system according to claim 4,

wherein the data processing unit is configured to take into consideration one or more of the following parameters when determining the state of health value:

an instantaneous load of the battery;

a corresponding current state of charge of each battery cell of the battery;

the cell temperature of each battery cell of the battery;

a number of charging and discharging cycles of the battery;

a number of operational hours of the battery;

a corresponding filling level of each battery cell of the battery;

a corresponding insulation of each battery cell of the battery; and

an insulation of the battery.

7. The system according to claim 6,

wherein the insulation of the each battery cell of the battery is determined from the filling level of the each battery cell of the battery.

8. The system according to claim 6,

wherein the insulation of the battery is determined from leakage currents measured between battery terminals of the battery and a battery housing of the battery.

9. The system according to claim 6,

wherein the number of operational hours of the battery and/or the number of charging and discharging cycles of the battery is determined from the battery current of the battery.

10. The system according to claim 6, further comprising:

a display,

wherein the state of health value is displayed on the display.

11. The system according to claim 10,

wherein the display has a plurality of lamps or luminous states that are differently coded depending on the state of health value.

12. The system according to claim 2,

wherein the plurality of cell sensors and the data processing unit are configured to communicate with each other wirelessly.

13. The system according to claim 2, further comprising:

a test device,

wherein the system is configured to utilize the test device to test whether the system is functioning properly.

14. A battery system, comprising:

the system according to claim 2; and

the battery,

wherein the system is configured to interconnect to the battery such that the plurality of cell sensors, the current measuring device, and/or the data processing unit are arranged inside a battery housing of the battery.

15. A method for monitoring a battery having multiple battery cells connected in series, comprising:

providing the system for monitoring a battery having multiple battery cells connected in series according to claim 1;

interconnecting the system with a battery having multiple battery cells connected in series;

continuously measuring a corresponding cell voltage of each battery cell of the battery and a corresponding cell temperature of each battery cell of the battery via the plurality of cell sensors;

continuously measuring a battery current of the battery via the current measuring device; and

determining a state of health value that is indicative of the state of health of the battery from the cell voltage of each battery cell of the battery, the cell temperature of each battery cell of the battery, and the battery current, via the data processing unit,

determining a filling level of the each battery cell of the battery from;

the cell voltage of the each battery cell of the battery;

the cell temperature of the each battery cell of the battery; and

the battery current of the battery,

wherein a reduction of a proportion of distilled water in an electrolyte of the each battery cell of the battery results in a lowering of the filling level of the each battery cell of the battery, and correlates with a duration of overcharging of the each battery cell of the battery.

16. The method according to claim 15,

wherein the battery is a nickel-cadmium battery.

17. The method according to claim 16,

wherein when the system is interconnected with the battery, each battery cell of the battery is associated with a corresponding cell sensor of the plurality of cell sensors, such that each cell sensor of the plurality of cell sensors measures the cell voltage of a corresponding battery cell of the battery and measures the cell temperature of the corresponding battery cell of the battery,

wherein the battery has twenty nickel-cadmium battery cells, and

wherein the battery is located in an aircraft.

18. An aircraft, comprising:

the system according to claim 1.

19. The aircraft according to claim 18,

wherein the data processing unit is configured to connect to a data bus of the aircraft.

20. The aircraft according to claim 18,

wherein the battery is a nickel-cadmium battery.