EFFICIENT BATTERY MANAGEMENT SYSTEM

• US 20140320065A1
• Filed: 04/30/2013
• Published: 10/30/2014
• Est. Priority Date: 05/01/2012
• Status: Active Grant

• Current Assignee: XNRGI, Inc.
• Original Assignee: Saroj Kumar Sahu
• Inventors: SAHU, SAROJ KUMAR, PATNAIK, MADHUSHREE
• Granted Patent: US 9,172,260 B2
• Time in Patent Office: Days
• US Class Current: 320/107
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0019 using switched or multiplexed charge circuits
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits

Abstract

A battery management system that monitors and controls the charging and discharging of a battery pack in the most versatile way at the block level with little dissipative loss but fast balancing is disclosed. The system has capability of using blocks of cells using different chemistry in the same battery pack. Such versatility makes it very useful for usage with erratic grid conditions, solar, wind and other natural energy sources for charging the battery.

Claims

1. A battery management system (BMS) comprising of at least two blocks of electrochemical cells, with the voltage of each block being monitored with a high impedance circuit in response to a command from a central processor, with each block being connected to one or more independent isolated power supplies through a set of switches in a way that

(a) When the said set of switches is not activated, the said corresponding block is not connected to any of the isolated power supplies,

(b) When the said set of switches is activated, the said corresponding block is connected to one of the isolated power supplies,

(c) The sets of switches are controlled in such a way that there would be no activation that would connect any two blocks to the same isolated power supply.

2. The BMS of claim 1, wherein periodically the Block voltages are monitored, and in response to that, one or more Blocks deemed to have lower capacity than the rest are connected to isolated power supplies by activating the switches of claim 1, so as to add extra charge to the activated blocks, thus providing the balancing function.

3. The BMS of claim 2, wherein the period of switching during which the Block voltages are measured and the switch activation is in effect, is less than 10 times the total average charge time of the battery required by the application.

4. The BMS of claim 2, wherein the balancing takes place during both, charging and discharging.

5. The BMS of claim 2, wherein during charging the stack is electrically disconnected from the outside world when either

(a) the voltage of any Block is greater than the prescribed maximum limit, or,

(b) the total number of Coulombs counted into the entire stack of blocks exceeds a prescribed maximum limit, or,

(c) Current through the stack exceeds a prescribed maximum limit.

6. The BMS of claim 2, wherein during discharging the stack is electrically disconnected from the outside world when either

(a) the voltage of any Block is smaller than the prescribed minimum limit, or,

(b) the total number of Coulombs counted out of the entire stack of blocks exceeds a prescribed maximum limit, or,

(c) Current through the stack exceeds a prescribed maximum limit.

7. The BMS of claim 2, wherein the switch is an electro-mechanical relay with one throw position and two poles.

8. The BMS of claim 2, wherein the switch is a solid state electrical switch with no moving parts with one throw position and two poles.

9. The BMS of claim 1, wherein the Battery has at least one Block that is of different chemistry than the rest of the Blocks.

10. The BMS of claim 1, wherein a central signal processing and decision unit reads the Block voltages and actuates the switches according to a predetermined algorithm.