Project 2 Thermal modeling of battery pack

li-ion battery

Li-ion batteries one of the comman types of battery type used on automotive industries due to oits relaiblity and power produce compare to other battery types 

In this project we are going to construct a 10 no of cells in a series model and simulating its thermal effect and compare the charge and discharge rates of the battery

10 cell series type model

In this type we are going to design the battery type on series connection of li-ion batteries

Blocks need for the model 

Electrical Blocks

Battery(Table based)

Resistor

Controlled current source

refernce

Thermal blocks

Convective current source

Temperature source

Temperature sensor

reference

Simulink blocks

PS-simulink converter

scope

Gain and add blocks

Model

for a 10 no of series connection 

Battery (table based)

in the table based battery we asre going to give the inputs for SOC,Charge and Discharge cycles

SOC estimation

soc can be estimate by the The corrected current is the function of discharging current. There is a quadratic relationship between the corrected current and discharging current of battery. by the formula of

Ic(t)=K2I(t)^2+K1I(t)+k0

SOC values

while the state of charge of a cell were selected as (0, 0.1 , 0.25, 0.5, 0.75, 1) were the temperature has been depend

On fade dimenssions the 

in this block the no of load voltage and terminal voltages are default were the No of volt can be derived with the equation of 

V_0,fade = V₀ ( 1+ (dV₀ * n / 100*N))

no of no load voltage are set as -5 because of discharge rate after certain period of use

Change in load

the battery capacity change

were the battery capacity of the model has given at decrease state beacuse after certain Number of cycle the battery capacity will reduce and the discharge cycle are set to 100 for this model

Battery capacity can be derived by 

Q_nom,fade = Q_nom (1+ d_AH* sqrt(n/N)/100)

Resistance change

were the resistance of the battery has set to -2 because of resistance change after certain period of time after N no of cycles

resistance of vehicle can be calculated by R_i,fade = R_i (1+ (d_Ri * sqrt (n/N)/100))

 Initial targets

while the initial target the SOC has set to 1 due to we have to find the state of charge rate of the battery and

the discharge rate also set to be 1 to find the discharge rate for the battery for the set temprature

Temperature source block

to find the plot of the given temperature to the battery while charge and discharge cycle the temperature has given as input to the model

temperature sensor 

The temperature sensor has set the area parameter in m^2 to find the rate of the battery

Results

At 400k 100m^2

Soc at 400k

At 350k

SOC at 350k