Project 1
1.Design a battery pack for a car roughly 150 Kw with 120 V. Use 3500 mAh 3.6V nominal NMC chemistry cell.
a. Design the battery pack configuration.
Ans:
No.of cells in series=120/3.6=33.33
case1 round to 33
outputvoltage=33*3.6=118.8V
case2 round to 34
output voltage=34*3.6=122.4
so we can select 34 cells in series
Power=V*I
I=P/V=150K/120=1250A
no.of cell in parallel= total power/rated voltage=1250/120=10.41 cell
So we need 34 cells in series and 10 cells in parallel connection here
here no.of cell in series is greater than 18 so we can go for Master and slave topology
b. Draw the BMS topology for this battery pack.
Ans:
2. Build a 3S2P battery pack configuration with generic battery block using Matlab/Simulink.
Ans:
Objective:To conect batteries in 3S2P configuaration in matlab/simulink That is 3 cells in series connection and 2 cell in parallel connecction
Total number of cell in battery pack=3*2=6 cells
Block used:Battery ,voltage measurement,scope,constant,bus selector,display,controlled current source and power gui
Design:
Nominal voltage of the battery pack=no.of cells in series*nominal voltage of cell=3*7.2=21.6V
Rated capacity of battery pack=no.of cells in parallel*rated capacity of the cell=2*5.4=10.8Ah
Overall voltage of the battery pack=maximum voltage of the battery*no.of cell in series=3*8.4=25.2V
The model is for a 21.6V 10.8Ah battery pack
3S2P battery pack simulation model is shown above
Model explanation:
The above fig shows the s2p battery pack simulink model.The voltage measurement block is connected across the battery pack to measure the battery pack voltage .The scope output is used for the battery pack consists of SOC current and voltage The controlled current signal is given as the load to the battery .The constant block is determined with battery capacity and its output is given to controlled current source.
Run the simulation for 10 sec and we got the following result.
Result:
The soc current,voltage output of a single battery is shown above here after 10sec soc reduced 0.08% current reduced to 1.5A voltage output reduced to 8.355V
The overall output of battery pack is shown above here we got final voltage 25.06 so we got the desired output from battery pack
Conclusion: Created 3S2P battery pack configuration with generic battery block using Matlab/Simulink and results are obtained.