Cell balancing with local sensing and switching

Patent metadata

Field	Value
Publication number	US-2019148952-A1
Application number	US-201816188551-A
Country	US
Kind code	A1
Filing date	Nov 13, 2018
Priority date	Nov 14, 2017
Publication date	May 16, 2019
Grant date	—

Abstract

A system and method for cell balancing within a battery module includes local sensing and switching at each of the battery cells. A switching circuit is associated with each one of the battery cells to connect or functionally disconnected the battery cell from the battery module. A module controller generates one or more parameter threshold values as maximum operating values for each of the battery cells. Each cell has a cell controller associated therewith to monitor one or more cell parameters, which are communicated to a summing module via a shared monitoring line, averaged, and communicated to the module controller. The cell controllers each receive a parameter threshold value via a shared control line and command the associated switching circuit to functionally disconnect and to bypass the battery cell if the cell parameter exceeds the corresponding parameter threshold value. Methods of checking the battery module are also provided.

First claim

What is claimed is:

1 . A system for cell balancing comprising:
a battery module including a plurality of battery cells in a series configuration; each battery cell of said plurality of battery cells having a switched cell terminal and a non-switched cell terminal associated therewith; one or more switching circuits each configured to switch an associated battery cell of said plurality of battery cells between a first mode with the associated battery cell being in-service with said battery module, and a second mode with the associated battery cell being functionally disconnected from said battery module; each of said one or more switching circuits including a first switch configured as a closed circuit in the first mode to allow a flow of electrical current between said switched cell terminal of said associated battery cell and a module node, and as an open circuit in the second mode to block the flow of electrical current between said switched cell terminal of said associated battery cell and the module node; each of said one or more switching circuits including a cell bypass conductor in electrical contact with said non-switched cell terminal of said associated battery cell; each of said one or more switching circuits including a second switch configured as an open circuit in the first mode to block a flow of electrical current between said cell bypass conductor and the module node, and as an open circuit in the second mode to allow the flow of electrical current between said cell bypass conductor and the module node; a cell controller associated with each of said one or more switching circuits and configured to monitor a cell parameter of said associated battery cell associated therewith and to cause said switching circuit to change from the first mode to the second mode in response to said cell parameter exceeding a parameter threshold value.

2 . The system as set forth in claim 1 , wherein each battery cell of said plurality of battery cells is an associated battery cell having one of said one or more switching circuits associated therewith.

3 . The system as set forth in claim 1 , further including:
a threshold input terminal on each of said cell controllers for receiving an input signal corresponding to said parameter threshold value; and a shared control line in electrical communication with a module controller and with said threshold input terminal of each of said cell controllers to communicate said parameter threshold value therebetween.

4 . The system as set forth in claim 3 , wherein said parameter threshold value is one of two or more parameter threshold values;
wherein said threshold input terminal of each of said cell controllers is one of two or more threshold input terminals of each of said cell controllers; and wherein said shared control line is one of two or more shared control lines each in electrical communication with said module controller and with a corresponding one of said two or more threshold input terminals of each of said cell controllers to communicate a corresponding one of said two or more parameter threshold values.

5 . The system as set forth in claim 1 , further including:
a parameter output terminal on each of said cell controllers for providing an output signal corresponding to at least one of said cell parameters; and a shared monitoring line in electrical communication with each of said cell controllers to communicate said at least one of said cell parameters from each of said cell controllers to a common destination.

6 . The system as set forth in claim 5 , wherein said shared monitoring line is one of two or more shared monitoring lines, with each of said two or more shared monitoring lines in electrical communication with each of said cell controllers and said common destination.

7 . The system as set forth in claim 5 , wherein said shared monitoring line is configured to communicate a plurality of said cell parameters.

8 . The system as set forth in claim 7 , wherein said plurality of said cell parameters are communicated at different times over said shared monitoring line.

9 . The system as set forth in claim 7 , wherein said plurality of said cell parameters are communicated concurrently over said shared monitoring line.

10 . The system as set forth in claim 7 , wherein each of said plurality of said cell parameters is associated with a different carrier frequency.

11 . The system as set forth in claim 1 , wherein said cell parameter is selected from a group comprising: a cell heat flux, a cell current, a cell state of charge, a cell temperature, and a cell voltage.

12 . A system for cell balancing comprising:
a battery module including a plurality of battery cells in a series configuration; one or more switching circuits each configured to switch an associated battery cell of said plurality of battery cells between a first mode with the associated battery cell being in-service with said battery module, and a second mode with the associated battery cell being functionally disconnected from said battery module; a cell controller associated with each of said one or more switching circuits and configured to monitor a cell parameter of said associated battery cell associated therewith and to cause said switching circuit to change from the first mode to the second mode in response to said cell parameter exceeding a corresponding parameter threshold value; a threshold input terminal on each of said cell controllers for receiving an input signal corresponding to at least one of said parameter threshold values; and a shared control line in electrical communication with a module controller and with said threshold input terminal of each of said cell controllers to communicate said parameter threshold values therebetween.

13 . The system as set forth in claim 12 , further including:
a parameter output terminal on each of said cell controllers for providing an output signal corresponding to at least one of said cell parameters; and a shared monitoring line in electrical communication with each of said cell controllers to communicate the one of the cell parameters from each of said cell controllers to a common destination.

14 . A method for cell balancing comprising:
measuring values of one or more cell parameters of each of a plurality of battery cells connected in series by a cell controller functionally associated with each of the battery cells; comparing by each of the cell controllers the measured values of each of the one or more cell parameters to a parameter threshold value associated with each of the one or more cell parameters; signaling by one of the cell controllers a command signal to a corresponding switching circuit to remove an associated one of the battery cells from service within the battery module in response to the measured value of any of the one or more cell parameters exceeding the parameter threshold value associated with a corresponding one of the one or more cell parameters; inhibiting an electrical current path between the associated one of the battery cells and a module node by a first switch in response to the command signal from the associated cell controller to cause the associated one of the battery cells to be functionally disconnected from service in the battery module; establishing an electrical current path through a bypass conductor around the associated one of the battery cells by a second switch in response to the command signal from the associated cell controller to allow the battery module to function with the associated one of the battery cells being functionally disconnected from service in the battery module.

Assignees

• Neapco Intellectual Property Holdings Llc
• Aware Mobility LLC

Inventors

• Remboski Donald
• Dedo Jacqueline

Classifications

• H02J7/825

  Detection of fully charged condition · CPC title

• H02J7/84

  Control of state of health [SOH] · CPC title

• H02J7/65

  against overtemperature · CPC title

• H02J7/63

  against overdischarge · CPC title

• H02J7/62

  against overcurrent · CPC title