Project 2 Thermal modeling of battery pack
Introduction:-
Lithium-ion batteries are widely used as energy sources in different hybrid systems, however, the operation characteristics of the battery in such systems are strongly dependent on the operation temperature, and therefore, with the purpose to improve these characteristics a good thermal control system should be utilized. The modeling thermal management system for the battery pack in Hybrid Electric Vehicles (HEVs), allows controlling the operating temperature of the pack for different load cycles and ambient temperatures.
Simulink model for battery pack thermal effect:-
In this project, the requirement that we need to simulate the thermal effect and life cycle performance of the lithium-ion battery pack at various temperatures, charges, and discharge rates. Following are the model of the lithium-ion battery packs with fault:-
In these models, the 3 battery packs are connected in series. The first pack of batteries contains cells 01 to cell 09 which means the pack has 9 cells connected in series and the third pack contains cells 11 to cell 20 which means it has 10 cells connected in series. The second pack contains cell 10 which is at fault condition because of the thermal effect of the system. the electrical parameter of the first and third battery packs are set such as their capacity, open ckt voltage, cell resistance, and capacitance shown below:-
The second pack having at fault so it has reduced electrical parameters such as capacity, open ckt voltage, and capacitance and increases the terminal resistance and cell resistance which are shown in the following:- 
In these models, the different blocks are used such as ( temperature source, convection heat transfer, conduction heat transfer, temperature sensor, thermal reference, scope, bus selector, and heat sensing subsystem ):-
Temperature source:- These temperature source blocks are used to set the ambient temperature and they also allow to change in the temperature. it provides the source of temperature to the battery through the convection and conduction process.
Convection heat transfer:- This is a convection heat transfer plate that works on the convection process and transfers the ambient temperature to the battery pack.
Conduction heat transfer:- It is also the heat transfer plate by the conducting process. it conducts heat from the temperature source to the battery packs.
Temperature sensor:- In this simulation, the second and third packs provide their subsystem to measure temperature. These subsystems include the temperature sensor block and thermal reference. The temperature sensor senses the temperature of the pack concerning the thermal reference
Scope:- scope is used to display the graph of temperature across the battery pack.
Temperature sensing subsystem:-
The cyclic charge and discharge current applies to the battery pack at a peak amplitude of 50 and has a frequency of 1/100 to act as a load to all battery pack systems.
Modification in Simulink model as per requirement:-
1) The Simulink model modify as per requirement. In the above model, the first battery pack has 9 cells connected in series and the second phasing 1 cell thirdired phasing 10 cells but now we require the thecellscell in series so we need to modify that first pack havincellscell in series from 1 to 5 and the second pack having 6 cell and third pack havincellscell in series from 6 t 10. The naming the of premainsmain same becuseaffectsfect the temperature and SOC graph
2) The second modification is to build the temperature sensing model for the first battery pack. the second and third ptemperaturesture canmeasuredsure Iujustmust want to check the cell temperature for the first pack of batteries. The more builtuild by the component such as temperature sesothermalemal reference, scope, Simulink ps converter Thishese model is sense ing temperature of the first battery pack.
Cycle configuration:-
The battery pack with fault model but now with some modification. Now in thmodelsodel having a load is in the form of an alternating current which is provided by the current source block. Thloadsload connects the positive terminal to the battery pack and the negative terminal to the electrical reference. this load is a cyclic charge and discharges the battery pack with a particular frequency and charging-discharging current.
This cyclic charge-discharge current block parameter is set such as the frequency value is 1/600 Hz and the peak current is taken as 50 A and simulation time is taken as 7200 s.
Result:- The result of the cyclic charge and discharge load on the battery pack is shown below:-
The temperature at 300K:-
From the above temperature vs time graph, We can see that there is a gradual increase in the temperature of the three packs. Initially, the three packs start with the same temperature at 300K. As we see from the graph the second pack temperature after some seconds increases as compared to the first and third pack.The temperature of the three pack increase in a fluctuating manner because of the charging and discharging load.
At 300 seconds:- The Third pack temperature is at 340 K and the second pack is at 392.5K. It means the temperature increase while the working battery pack.
In the 2000s:- The temperature of the third pack was about 365K and the second pack is 435K. At 5000s:- the temperature of the third pack is 365Kand the temperature of the second pack is 435K. In general increase in temperature of all three packs can be attributed to the continuous charging and discharging load. The second peak contains a fault cell, its temperature shoots up and remains at a much higher level compared to another pack.
The temperature of the first battery pack cell at 300 K:-
The temperature of the first pack started at 300 K. In the 2000s:- the temperature of the first pack is 369K this temperature is higher than that of the third pack because the first pack has more cells than this pack. 
The temperature at 310 K:-
From the above temperature vs time graph, We can see that same in the above case there is a gradual increase in the temperature of the three packs. Initially, the three packs start with the same temperature at 310K. As we see from the graph the second pack temperature after some seconds increases as compared to the first and third pack.The temperature of the three pack increase in a fluctuating manner because of the charging and discharging load.
At 300 seconds:- The Third pack temperature is at 350 K and the second pack at 401.5K. It means the temperature increase while the working battery pack.
In the 2000s:- The temperature of the third pack was about 376.5K and the second pack is 441K.
At 5000s:- the temperature of the third pack is 378Kand the temperature of the second pack is 443.6K. In general increase in temperature of all three packs can be attributed to the continuous charging and discharging load. The second peak contains a fault cell, its temperature shoots up and remains at a much higher level compared to the other pack. As compared to the above 300K, there is a slight increase in temperature of each battery pack because while increase in ambient temperature more heat is transferred to the cell in the battery pack through conduction and convection plate. 
The temperature of the first battery pack cell at 310K:-
The temperature of the first pack starts at 310 K.
In the 2000s:- the temperature of the first pack is 377.8K this temperature is higher than that of the third pack because the first pack had more cells than the third pack.
At 5000s:- the temperature is 382K.
The temperature at 315K:-
From the above temperature vs time graph, We can see that same in the above case there is a gradual increase in the temperature of the three packs. Initially, the three packs start with the same temperature at 315K. As we see from the graph the second pack temperature after some seconds increases as compared to the first and third pack.The temperature of the three pack increase in a fluctuating manner because of the charging and discharging load.
At 300 seconds:- The Third pack temperature is at 357 K and the second pack is at 410.5K. It means the temperature increase while the working battery pack.
In the 2000s:- The temperature of the third pack was about 380K and the second pack is 441K. At 5000s:- the temperature of the third pack is 378Kand the temperature of the second pack is 445.6K. In general increase in temperature of all three packs can be attributed to the continuous charging and discharging load. The second peak contains a fault cell, its temperature shoots up and remains at a much higher level compared to the other pack. As compared to the above 310K, there is a slight increase in temperature of each battery pack because while increase in ambient temperature than more heat is transferred to the cell in the battery pack through conduction and convection plate.
The temperature of the first battery pack at 315K:-
The temperature of the first pack starts at 315 K.
In the 2000s:- the temperature of the first pack is 382K this temperature is higher than that of the third pack because the first pack had more cells than the third pack.
At 5000s:- the temperature is 388K.
State of charge:-
From the SOC result graph, we can see that the SOC can accelerate from 40% to 65% throughout the whole simulation period. The continuous decrease and increase in the SOC correspond to the charge and discharge load provided by the AC source block. From SOC graph observation cell 10 is designed as a fault cell due to its reduced capacity, capacitance, and open circuit voltage and increase in the terminal and cell resistance. This causes the SOC of the second pack to fall slightly greater than the other two packs.
Drive cycle configuration:-
In this configuration, I remove the AC block which provides cyclic charge /discharge load to the battery pack. Now instead of these, I place the set of blocks for drie cycle load to the applied battery pack. these blocks are as follows:-
1) Signal builder block
2) Controlled current source block
3) Simulink Ps converter block
4) Electrical reference block
In signal, the builder block contains the drive cycle with the current profile. These signal builder blocks are connected to the controlled current source through the Simulink ps converter. The current signal is provided to the controlled current source and this source is connected to the battery pack terminal and another terminal of the battery connect to the electrical reference. In this manner apply the load to the battery pack.
The drive cycle plot image is shown below:-
The drive cycle configuration is shown in the image below:-
Result:-
The temperature at 300K:-From the temperature result, we can see that the three battery packs all start with the same initial temperature at 300.
At 1125 s:- the temperature of the second pack rises noticeably as compared to the third pack. The temperature of the third pack is below the range of temperature of 300.02K and then rises to 300.08K the second pack's temperature is between 300.25K and then shoots up to 300.40K.
At 1215s:- The temperature of the battery pack decrease. the second pack temperature is 300.043K and then decreases up to 300.033K. Similarly, the third pack temperature decreased from 300.02 and decrease to 300.0018K. In general, the vehicle accelerates rapidly and the current has a high value reflecting the temperature of the second pack increases sharply, and the other two battery packs' temperature increases but not more than the second pack. 
The temperature at 315K:-
The temperature at 315K:-From the temperature result, we can see that the three battery packs all start with the same initial temperature at 315K.
At 601 s:- the temperature of the second pack rises noticeably as compared to the third pack. The temperature of the third pack is 315.030K and then rises to 315.035K and the second pack's temperature is 315.05K and then shoots up to 315.055K. After that, the temperature starts to decrease. the second pack temperature decreased from 315.055 to 315.0455K.and third pack temperature decreased from 315.035 to 315.0325.
At 802s:- The temperature of the battery pack decrease. the second pack temperature is at 315.0520K and then decreases up to 315.045K. Similarly, the third pack temperature was at 315.03K and decreased to 315.025K. In general, the vehicle accelerates rapidly and the current has a high value reflecting the temperature of the second pack increases sharply, and the other two battery pack temperatures increase but not more than the second pack. compare to an ambient temperature of 300K, the overall temperature of the pack is higher at an ambient temperature of 315K causing more heat transfer through the conduction and convection plate to the battery pack.
The temperature of the first battery pack at 315 K:- The first battery pack temperature is higher because it contains more cells that's why it generates more heat.
State of charge:-
From the SOC graph, We can see that there is an increase in the SOC. Initially, the second pack SOC starts with 40.2% which is a very low value as compared to the other two packs. The first and third packs start with 43.5%.
At 20 min:-The SOC is started to increase up to 20 min and after 20 min the SOC has a constant level. The reduced capacitance and capacity and increased resistance cause the second pack to get charged more quickly than the other two packages.
Conclusion:-
In conclusion, the thermal modeling of a 110-cell series arrangement has been performed at different temperature levels such as 300K, 310K, and 315K for three charging and discharging conditions. For each configuration, the load can be changed AC source and drive cycle load applied to the battery pack. the temperature and state of charge of each pack at each ambient temperature level for each load application were plotted, analyzed, and explained.
MODEL LINK-https://www.mathworks.com/help/physmod/simscape/ug/lithium-ion-battery-pack-with-fault.html