Project 2
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
Your Answers
a.Answer:
Given
joules heat:
From ohm’s Law, V = IR
When a current is flowing through a resistance, there is heat dissipated in the resistor. This heat dissipation is called joule heating. Joule heating is also known as ohmic heating.
Power,
P=VI=IR*I=I^2R
Joule heat,
H=I^2Rt
Where, P = Power
V = Voltage
I = Current
R = Resistance
H = Heat
t = Time
Maximum heat generated:
Maximum heat generated = maximum joule heat + 2(maximum joule heat)
From the given sheet the maximum joule heat is 0.896 joules
Maximum heat generated = maximum joule heat + 2(maximum joule heat)
= 0.896+2(0.896)
=2.688 joules
b.Answer:
Aim: The project aims to use MATLAB/Simulink to analyze the provided drive cycle data from an Excel sheet,To determine two key aspects of battery performance they are Max Heat Generation and SOC at 2*104 Seconds
The project provide insights into the thermal behavior and energy usage of the battery under the given operational conditions, which can be valuable for battery management and optimization in various applications.
1. Max Heat Generation: You will calculate the maximum heat generated by the battery during its operation. This involves simulating the battery's behavior and monitoring its power dissipation to find the point in the drive cycle where it generates the most heat due to electrical and thermal processes.
2. SOC at 2*104 Seconds: You will also calculate the State of Charge (SOC) of the battery at a specific time, which is 2 * 10^4 seconds into its operation. This helps you understand how much energy is remaining in the battery at that point.
Model Explanation:
The figure shows the SOC of the battery at 2*104 second of the operation simulink model. The voltage measurement block is connected across the battery pack to measure the battery pack voltage. The scope output used for the battery pack consists of SOC (State of Charge). The controlled current signal is given as the load to the battery pack. The constant block is determined with battery capacity and it is given to the controlled current block.
Figure1 Battery pack with soc operation simulink model
Signals with respect to time that are taken from given data and the signal in signal builder is as follows
The parameter given inside the battery is given below,
|
S.No |
Battery parameters |
Value |
|
1 |
Nominal voltage of a cell |
7.2V |
|
2 |
Rated capacity of a cell |
5.4Ah |
|
3 |
Maximum voltage of a cell |
8.38V |
Nominal voltage of the battery pack = 7.2V
Rated capacity of the battery pack = 5.4Ah
The model is for an 7.2V 5.4Ah battery.
The figure 3 shows the single battery output for SOC,current and voltage.
The SOC (state of charge) is started to reduce from 100% to 50% corresponding to the load given.
Figure : Single battery output for SOC, voltage and current
The figure shows the overall output voltage of the battery pack. The calculation for the overall output voltage of the battery pack is given below.
Overall voltage of the battery pack = 8.38V
Figure : Overall output voltage of the battery pack
Conclusion: Through MATLAB/Simulink analysis of the provided drive cycle data,Determined the battery's maximum heat generation and calculated its State of Charge (SOC) at 2 * 10^4 seconds, providing valuable insights for battery performance assessment.