EMB1499Q: Active Cell balancing by EMB1499Q

Hi Prashant,

Unfortunately, moving to 23S will start to violate absmax voltages of the part. If you need to do 23S, I recommend using 12S/11S "sub-modules"

In terms of theory of operation, the EMB1499 is a forward converter that has been modified to be bi-directional, and have an interface to the EMB1428. The EMB1499 regulates current (not voltage like most DC-DC converters!) into and out of the cells. The EMB1428 is essentially a large gate driver with some convenient interfacing that drives a FET switch matrix to connect certain cells to the regulated side of the converter.

Does that help?

Regards,
David

7183.bms.pdfDear Mr. David.

Thank you so much for your explanation. We got the concept.

As we are trying to balance 23 cells we have designed the basic architecture as shown in the attached file.

Kindly let us know whether it is okay or not.

Thank you for your kind support.

Regards,

Prashant

Hi Prashant,

I would recommend using 1 TMS570, and  utilizing the daisy chain functionality of the pl455. I would also recommend splitting it between 2 different EMB1499's. This way you can have two very clean "submodules" on one PCB. I think going this route will be much better practically and reduce your chances of running into issues like strange GND loops, EMI, etc. Additionally, it will let you balance two cells out of the 23s module simultaneously.

If you would like a diagram, I could  draw  one up. I hesitate to recommend going with this  set up.

Dear Mr. David,

We really appreciate for your kind support.

Based on your suggestion we have modified our diagram. Kindly once have a look at it.

We are  planning to charge and discharge the individual cell across the stack voltage. Hence, we have divided battery stack voltages in two parts: Vstack-1(1 to 16) and Vstack-2(17 to 23).

Kindly see the attached file and let us know whether it is okay or not.

Thank you,

Regards,

Prashantbms_1.pdf

Hi Prashant,

This is certainly one option.I think one challenge  you will run into is that the TMS570 only has one UART peripheral. You would also want to isolate  the SPI i think. For your reference, I have attached two  block diagrams that  you may  want to consider