SOLID-STATE ACTIVE SWITCH MATRIX FOR HIGH ENERGY, MODERATE POWER BATTERY SYSTEMS

• US 20140184161A1
• Filed: 09/10/2013
• Published: 07/03/2014
• Est. Priority Date: 12/31/2012
• Status: Active Grant

• Current Assignee: Seeo, Inc. (Robert Bosch GmbH)
• Original Assignee: Seeo, Inc. (Robert Bosch GmbH)
• Inventors: Ye, Changqing, Deal, Larry, Paris, Peter
• Granted Patent: US 9,362,757 B2
• Time in Patent Office: Days
• US Class Current: 320/121
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/0019 using switched or multiplexed charge circuits
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A battery management system employs electronic switches and capacitors. No traditional cell-balancing resistors are used. The BMS electronically switches individual cells into and out of a module of cells in order to use the maximum amount of energy available in each cell and to completely charge and discharge each cell without overcharging or under-discharging.

Claims

1. A battery module comprising:

a plurality of cells connected to one another electrically;

a plurality of sensors configured to measure properties of the cells and of the battery module; and

an electronic switch assembly associated with each cell;

wherein the switch assembly is configured to remove its associated cell from service when directed to by a computer system; and

wherein the electronic switch assembly is configured to establish direct electrical connection between cells adjacent to the removed cell.

2. The module of claim 1 wherein the electronic switch assembly comprises transistors and a capacitor.

3. The module of claim 1 wherein the electronic switch assembly comprises four MOSFETs and a capacitor.

4. The module of claim 1 wherein the four MOSFETs are arranged in two sets of two MOSFETS connected in series and the two sets are connected in parallel.

5. The module of claim 1 wherein the electronic switch assembly further comprises a capacitor configured to maintain battery module operation while a cell is removed from service and the direct electrical connection between adjacent cells is established.

6. A battery pack comprising:

a computer system;

a plurality of modules, each of which comprises a plurality of battery cells connected to one another electrically; and

an electronic switch assembly associated with each battery cell;

wherein the electronic switch assembly is configured to remove its associated cell from service when instructed by the computer system; and

wherein the electronic switch assembly is configured to establish direct electrical connection between cells adjacent to the associated cell.

7. A method of managing a battery pack comprising:

providing one or more modules wherein each comprises a plurality of cells;

providing an electronic switch assembly associated with each cell, wherein the electronic switch assembly is configured to remove its associated cell from service while establishing direct electrical connections between cells adjacent to the removed cell;

providing sensors associated with each module, wherein the sensors are configured to measure and store data in a memory location for at least individual cell voltages, module voltage, and module temperature;

applying an algorithm to the stored data using a computer processor in order to make decisions about whether to remove any cells from service;

using a communication interface to communicate the decisions to the electronic switch assemblies.

8. The method of claim 7 wherein applying the algorithm comprises:

determining values for an overall cell voltage, a resistance of each cell, a SOC of each cell and a SOC of each module and storing the values in a memory location;

comparing one or more of the values to predetermined threshold values to determine which of the values is unacceptable;

deciding whether to remove cells from service or to remove modules from service or to shut down the battery pack based on the unacceptable values.

9. A battery pack comprising:

one or more modules wherein each comprises a plurality of cells;

an electronic switch assembly associated with each cell, the electronic switch assembly configured to remove its associated cell from service while establishing direct electrical connections between cells adjacent to the removed cell;

a memory location;

sensors associated with each module, wherein the sensors are configured to gather data on at least individual cell voltage, module voltage, and module temperature and to store the data in the memory location;

a computer processor to apply an algorithm to the sensor data in order to make decisions as to removing any cells from service;

a communication interface to send the decisions to the electronic switch assemblies.

10. A computer-readable medium comprising code which, upon execution by a computer processor implements a method, the method comprising:

measuring at least individual cell voltage, module voltage, and module temperature while a battery pack is operating;

recording in a memory location the individual cell voltage, module voltage, and module temperature;

comparing, using a computer processor, one or more of the values of individual cell voltage, module voltage, and module temperature values to predetermined threshold values to determine which of the values is unacceptable; and

determining whether to remove cells from service or to remove modules from service or to shut down the battery pack based on the unacceptable values.