Project 2
AIM:
Using MATLAB/simulink and the drive cycle from the attached excel sheet, find-
- The max heat generation of the battery
- 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 |
-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 |
Consider the battery resistance is 0.5 mOhm, delta time is 0.1 and entropic factor is 2
Ans-
heat generated = joules heat + entropy heat
joules heat
from ohms law we know that
V=IR
when the current flowing through a resistance, there is a heat dissipated inn the resistor this heat dissipation is called joules heating.
joules heating is also known as ohmic heating
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
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.
batterry resistance = 0.5m ohm = 0.0005ohm.
- a) 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
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.
- 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.
- Bus Selector -This block accepts a bus as input which can be created from a Bus Creator, Bus Selector or a block that defines its output using a bus object. The left listbox shows the elements in the input bus. Use the Select button to select the output elements. The right listbox shows the selections. Use the Up, Down, or Remove button to reorder the selections. Check 'Output as virtual bus' to output a single bus.
- 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