Project 1

AIM:

To design a battery pack for a car.

Given

cell parameters

capacity = 3500mAh=3.5Ah

nominal voltage = 3.6V

Given power =150kW

so required current I = P/V

I = 150000/120=1250A

No of cells in series = Motor voltage /nominal voltage

=120/3.6=33.3

Rounding off

Case 1:

No of cells = 33

Nominal voltage = nominal voltage of cell * 33

=33*3.6=118.8V

Case 2:

No of cells = 34

Nominal voltage = nominal voltage of cell * 34

=34*3.6=122.4V

No of cells in parallel = continous current/cell nominal capacity

=1250/3.5

=357.14

Case 1:

Number of cells = 357

so 357*3.5=1249.5A

Case 2:

number of cells = 358

358*3.5=1253A

So case 2 is selected since it gives current greater than rated.

So no of parallel cells = 358

So no of series parallel cells = 358*34=12172 cells

34S358P cells

Master slave topology is used and 34 cells in series are divided into two groups having 17 cells in series.

Result

The battery pack for proposed system is designed.