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.

a) Given, we have to design a battery of 150 KWh with 120 V.

Cell configuration is 3.5 Ah and 3.6 V.

To achieve 120 V, 3.6 * 34 = 122.4 V. If we take 33 cells in series, then the pack voltage will be 118.8 V, which is less than the required pack Voltage.

So, we need to connect 34 Cells in series to get 122.4 V.

1,50,000 Wh / 122.4 V = 1225.49 Ah

1225.49 Ah / 3.5 Ah = 350.14 cells.

350 * 3.5 Ah = 1225 Ah.

1225 Ah * 122.4 V = 149.94 KWh.

If we take 350 cells we’ll get 149.94 KWh battery, which is not the rated Energy.

So, 351 * 3.5 Ah = 1228.5 Ah

1228.5 Ah * 122.4 V = 150.368 KWh. Meeting the required ratings.

Hence, the Battery configuration for 150 KWh with 120 V is 34P 351S.

In the above challenge, the voltage given as 120V, in the market we have only two Topologies to handle over 76V.

They are Master & Slave topology and Modular topology. But, considering the Cons of both topologies, I’ll go with Master & Slave topology. Because, implementation is easy and maintenance cost is less when compared to Modular topology.

For this we require two AFEs and one Master.

3.6 V & 1228.5 Ah

2. Build a 3S2P battery pack configuration with generic battery block using Matlab/Simulink.