Project 2 Thermal modeling of battery pack

1.

A Lithium ion battery pack model has been constructed using 10 no of cells in series and enclosed in the file TherMod attached herewith.The basic building blocks of the model are as under.

A. Lithium ion cells: 10

B.Current Measurement:1

C.Piecewise Linear Voltage Source:1

D.Convective Heat Transfer:10

E.Temperature Sensor: 10

F.Thermal Mass:10

G.Thermal Reference: 10

H.Solver Configuration : 2

I.Scope:10

J.P-S Converter:11

K.Controlled Temperature Source:1

L.Constant Block:1

M.Electrical Reference:1

It is clear that the model consists of three parts,namely an Electrical part,a Thermal part for assessment of temperature and a Mechanical part for calculation of SoC.

The default setting in the Constant Temperature Source Block was 293.15.This was changed to 303.15 and thereafter to 283.15 in order to assess the impact of temperature.In both cases the pattern of plot as obtained in Scope was found to be different.In the first case instead of dropping temperature was found to shoot up.In tHe second case though temperature was dropping yet the slope or gradient was changed slightly.

In the circuit for calculation of SoC the default setting in the constant block was changed from 100 to 90 and thereafter to 80.Scope reading was found to change accordingly.This clearly show that temperature has a profound impact on charging-discharging cycle as well as the lifespan of a Lithium ion battery.