Project 2
project 2
Answer :-
AIM:- Using MATLAB/simulink and the drive cycle from the attached excel sheet, find-
a) .The max heat generation of the battery
b). The SOC of the battery at 2 *104second of the battery operation
| 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 | -o.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 |
Consider the battery resistance is 0.5 mOhm, delta time is 0.1 and entropic factor is 2
Theory:-
ans:-
formula:-
heat generated = joules heat + entropy heat
Heat Generation:
Batteries generate heat during charge and discharge due to enthalpy changes, electrochemical polarization, and resistive heating inside the cell. Temperature variation inside the batteries can lead to the uneven temperature distribution which creates uneven charge/discharge behaviour within the battery pack. So, thermal runaway may occur in a cell when heat is not properly controlled and possibly cause fire and explosion.
entropy heat:
the heat generation due to entropy change inside a battery occurs when electro chemical reaction are performed. the entropy heat is reversible heat resulting from change in open circuit voltage with respect to temperature at two electrodes.
power :-
P=V*I=I^2*R
heat:-
H=∫P.dt with the limits of time 0 to t
H=I^2*R*t
where,
P=power
V=voltage
I=current
R=resistance
H=heat
T=time
a).The max heat generation of the battery ?
answer:-
Maximum heat generated = maximum joule heat + 2(maximum joule heat).
Imax = -0.896 A
tmax = 1.7 sec
Rint = 0.0005 ohm
maximum joule heat = (Imax)^2 * R * tmax
maximum joule heat = (-0.896)^2 * 0.0005 * 1.7
= 0.000682393J
Maximum heat generated = maximum joule heat + 2(maximum joule heat)
Maximum heat generated = 0.000682393J+2=2.000682393J
b) The SOC of the battery at 2 *104second of the battery operation
Aim : The SOC of the battery at 2 *104second of the battery operation
SOC = State of Charge is defines the how energy is usable for application
SOC = Q / Qmax
where,
Q = Available capacity
Qmax = Overall capacity
for the simulation model following blocks are used:
- Generic Battery - Implements a generic battery model for most popular battery types. Temperature and aging (due to cycling) effects can be specified for Lithium-Ion battery type.
2.Controlled current source - Converts the Simulink input signal into an equivalent current source. The generated current is driven by the input signal of the block. You can initialize your circuit with a specific AC or DC current. If you want to start the simulation in steady-state, the block input must be connected to a signal starting as a sinusoidal or DC waveform corresponding to the initial values.
- Signal Builder Block -To use any type of signal till 208 stop time.
- Scope- to Display the output graph
- Powergui -Set simulation type, simulation parameters, and preferences
Result and Conclusion:
- The max heat generation of the battery
The Max heat generated in which the current flowing in and out i.e., charge and discharge due to internal resistance and chemical reaction during charging and discharging of the battery the heat is generates of 2.0006823936 Jouls.