Project 2
Using MATLAB/simulink and the drive cycle from the attached excel sheet, find-
1)The max heat generation of the battery
| Time | Time Step | Battery Current |
| 00:00.4 | 0.1 | -0.9632 |
| 00:00.5 | 0.2 | -0.952 |
| 00:00.6 | 0.3 | -0.9072 |
| 00:00.7 | 0.4 | -0.9632 |
| 00:00.8 | 0.5 | -1.0304 |
| 00:00.9 | 0.6 | -0.9632 |
| 00:01.0 | 0.7 | -1.0304 |
| 00:01.1 | 0.8 | -1.008 |
| 00:01.2 | 0.9 | -0.9856 |
| 00:01.3 | 1 | -0.9632 |
| 00:01.4 | 1.1 | -0.9184 |
| 00:01.5 | 1.2 | -0.9296 |
| 00:01.6 | 1.3 | -0.9296 |
| 00:01.7 | 1.4 | -0.9296 |
| 00:01.8 | 1.5 | -0.9184 |
| 00:01.9 | 1.6 | -0.9408 |
| 00:02.0 | 1.7 | -0.896 |
| 00:02.1 | 1.8 | -0.9072 |
| 00:02.2 | 1.9 | -0.9072 |
| 00:02.3 | 2 | -0.9408 |
| 00:02.4 | 2.1 | -0.9296 |
| 00:02.5 | 2.2 | -0.9296 |
| 00:02.6 | 2.3 | -0.9968 |
| 00:02.7 | 2.4 | -0.9968 |
| 00:02.8 | 2.5 | -0.9408 |
| 00:02.9 | 2.6 | -0.9408 |
| Battery resistance | 2 milli ohm |
Solution: 1) The max heat generation of the body: Joules heat
R=0.5 milliohms
To calculate the Joules heat=(Imax)^2*R*(tmax)
We have I max=-0.896 at tmax=2 mins=120sec
=(-0.896)^2*0.5*(120)
Max joules heat=48.16896 milli Joules
Entropic heat data given is 2
So total heat generated is =48.16896+2=50.16896milli joules
2) The SOC of the battery at 2 *104second of the battery operation,Consider the battery resistance is 0.5 mOhm, delta time is 0.1 and entropic factor is 2.
Solution:
SOC: State of charge is the level of charge of the cell/ battery related to its capacity.
SOC is measured in terms of % and it ia also defined as SOC=1-DOD where DOD is Deapth of discharge
A fully charged battery has 100% SOC.
Here we are measuring SOC of battery/cell by providing current as input , And a Resistor load of (0.5milli ohm) is connected in series with current source.
The block used here are Signal builder where we have loaded max heat generation data having discharging current wrt time.
The stop time set is 208 sec as mentioned in question.
A Bus selector is used. 3 outputs are taken from that , they are SOC , current and voltage.
And a powergui block.
The simulink block for SOC is shown below.
The graphs of SOC, Current and voltage are shown below:
The input data loaded to Signal builder characteristics are shown below.
The discharge current characteristics plot is shown below
When 6.5A of load is connected to the battery , the complete discharge of battery takes place in 48 mins
With 13A of load , discharge happens in 24 mins
With 32.5A of load , complate discharging of battery happens in 8 mins.