I am looking forward to design 1 kWh battery pack along with Battery management system using 3.7V, 2.2 Ah Li-ion cells

Balakrishna Nallamothu

Other Parts Discussed in Thread: BQ76940

Hi,

I am new to power electronics and design. I am looking forward to design Li-ion battery pack with following specifications. In this regard, I need your help in choosing my Ti parts in various stages.

Input specifications:

Individual Li-ion cell specifications: 3.0V - 4.2V (3.7V is nominal), 2 Ah is capacity.

Battery pack: 14 cells in series , 10 cells in parallel. (48V, 20 Ah).

Design requirements for battery pack with battery charger, battery protection / management:

Maximum charging current is 10A.

Maximum discharge current is 4A.

Charger input: 230V AC.

Charger output: 60V DC, 10-15A current.

(Transformerless AC to DC type Charger design may be considered inview of less weight and size constraints)

For utilizing power from battery pack to utilities, DC to AC conversion is also required if possible in the same design circuit.

Basically, a low weight (probably transformerless inverter type design) DC to AC inverter circuit may be integrated along with battery charger and battery management system.

Expecting support from Ti team.

Regards

Balakrishna.

CSIR, India.

over 8 years ago

0 Vish Nadarajah over 8 years ago

TI__Expert 6085 points

For product information and selection, and battery power management portfolio,for chargers, gauging and monitors & protection please refer to the WWW. TI.com.

Each of these have references and technical details for ground-up designs.

For the battery monitors and protection portion for the 14 cells. suggest you look at the

bq76940 device.

hope this helps

vish

0 Ed Walker over 8 years ago in reply to Vish Nadarajah

Prodigy 5 points

Hello Balakrishna,

Thank you for posting this question.

While we don’t have a complete reference design for you, we can suggest many areas to explore for solutions.

In the Applications and Designs section there are many examples.

http://www.ti.com/lsds/ti/applications/industrial/power-delivery/overview.page

http://www.ti.com/lsds/ti/applications/industrial/grid-infrastructure/overview.page

On an Offline UPS the design will consist of:

Bias Supply, 12V, low wattage, to power the various stages of the system.
Power Factor Control, PFC, on the AC input
This is a boost circuit, single phase or multiphase, that is needed to meet Agency Certification.
Buck charger for the battery stack
Boost from battery stack to high voltage for DC-AC inverter
DC-AC inverter to create the AC at the output.
This will take the boosted DC high voltage and force it to be sinusoid.
It is not a trivial task to make a clean AC waveform.
4 Quadrant operation is required to force the output high and pull it back low again, all in a clean low distortion manner.
Micro Controller for various housekeeping chores:
Communications to outside world.
Metrology for stages, reporting currents, voltages, battery condition.
User interface, display, sounds, beeps.
Other operating IP of the design.

From TI’s Applications and Designs section:

TI Home > Applications > Single Phase UPS

http://www.ti.com/solution/single_phase_ups

This provides insight into the stages required for UPS.

One area missing is the DC-AC inverter.
We do not have analog IC's to do this function.

For this look in our Smart Grid Infrastructure area.
http://www.ti.com/lsds/ti/applications/industrial/grid-infrastructure/overview.page

Under SOLAR ENERGY there are examples of digital control.
C2000 Piccolo is the MCU used for these designs.
TMS320C2000™ DSP Controllers: A Perfect Fit for Solar Power Inverters

Let me know if this helps.

Power management

Power management forum

I am looking forward to design 1 kWh battery pack along with Battery management system using 3.7V, 2.2 Ah Li-ion cells