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.
Aim:
To design the battery pack with the capacity 150Kw 120V by using 3500mAh 3.6V. And BMS topology for the battry pack
Calculation:
To design the battery pack we need to calculate cells which are connected in series and parallel to meet the requirment.
Given:
The required condition - 120v and 150 Kw.
Nominal voltage = 3.6v
Capacity = 3500mAh = 3.5Ah
To meet the requirment of 120v and 150KW, we need to find the number of cells connected in series and parallel.
Current (I) = Power(P)/Voltage(V)
= 150000/120
= 1250 amps
Required voltage 120
Series
Number of cells in series = required voltage /Nominal voltage of the cell
= 120/3.6= 33.33
Number of cells in series = 34 cell
Total voltage = nominal voltage of cell * number of cells in series
Total voltage = 34*3.6 = 122.4
The output voltage can be adjusted to 120v by a Buck boost converter to meet the requirment of 120v.
Parallel
Number of cells in parallel = Required capacity/Cell capacity
= 1250/3.5
Number of cells in parallel = 358 cells
Combination of 34S358P.
b)Draw the BMS topology for this battery pack.
Battery Management Sytem (BMS):
BMS Topologi used in this battery pack is Master and Slave BMS Topologies. Because the total battery pack is made of sub battery packs so controlling and manufacturing will be easy.
Master and Slave BMS which has number of slave controllers are 2 and a Master controller which can handel 2 slaves.
2. Build a 3S2P battery pack configuration with generic battery block using Matlab/Simulink.
Matlab model of the battery cells:
The parameter given inside the battery is given below,
S.NO Battery parameters Value
1 Nominal voltage of a cell 7.2V
2 Rated capacities of a cell 5.4Ah
3 Maximum voltage of a cell 8.3V
Scope output
