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.
b. Draw the BMS topology for this battery pack.
Here Given is,
Rated voltage = 120V
Nominal Voltage = 3.6V
Cell capacity = 3500 mAh = 3.5Ah
Battery capacity = 150Kw
Now, the battery capacity in ampere-hour is,
Battery capacity = 150 Kw/120 = 1250Ah.
Now,
No. of cells in series is,
Cells in series = Rated voltage/ Cell nominal Voltage = 120/3.6 = 33.33 cells in series.
Now here in this condition, we should round off the cells to higher and lower values i.e 33 and 34.
Total voltage = Cells in series * cell nominal voltage
Now if we take 33 cells,
So the Total voltage = 33 * 3.6 = 118.8 V
Now we take 34 cells,
So the total voltage = 34*3.6 = 122.4V
So here we have to consider 33 cells as the nominal voltage does not excide the load battery voltage.
So there are 33 cells in the series.
Now for cells in parallel,
Cells in parallel = Total current or total battery capacity / cell capacity = 1250/3.5 = 357.14
So now we round of the cells in parallel to high and low i.e. to 357 and 358 cells in parallel.
Output capacity = number of cells in parallel * cell capacity
So if we consider 357 cells,
Output capacity = 357 * 3.5 = 1249.5Ah
If we consider the number of cells is 358,
Total battery capacity = 358 * 3.5 = 1253Ah
Output current capacity shouldn't be less,
The current requirement is 1250 Ah, the output shouldn't be less, so we choose 358 cells.
The battery pack configuration is,
33S358P.
BMS topology for battery pack,
Battery configuration is 33S358P so total number of cells = 11814.
As here there are more than 7000 cells, we need to use Modular topology.
So there will be 8 parallel and 2 series connections, 18S44P and 15S44P,
2. Build a 3S2P battery pack configuration with generic battery block using Matlab/Simulink.
This is a 3S2P battery pack configuration.