Project 2 Thermal modeling of battery pack

Aim: For a 10 cell series lithium ion battery model, simulate the thermal effects and compare life cycle performance at various temperatures, charge & discharge rates using MATLAB.

• Simulation model shows how a fault can be introduced into one of the cells to see the impact on battery performance and cell temperatures.
• 10 identical Table based battery is connected in series.
• The fault is represented by changing the parameters for the Cell 6 Fault, reducing both capacity and open-circuit voltage, and increasing the resistance values.

Model:

Subsystem:

Block used in Model are:

Cyclic charge/discharge profile:

The ideal AC current source maintains the sinusoidal current through it, independent of the voltage across its terminals. The output current is defined by

I = I0 * sin(2*pi*f*t + PHI),

where, I0 is the peak amplitude, f is the frequency in Hz, and PHI is the phase shift in radians.

Battery(Table based):

This block models a battery based on tabulated characteristics as functions of SOC, and optional temperature.

Other batteries is modeled identical parameters as shows fig. below except, Battery 6, in which both capacity and open-circuit voltage are reduced by 0.7 factor, and resistance values are increased by 5 times.

Temperature source Model:

Convective heat transfer:

This block models heat transfer in a thermal network by convection due to fluid motion. The rate of heat transfer is proportional to the temperature difference, heat transfer coefficient, and surface area in contact with the fluid.

As see in the below fig. convective heat transfer area, for faulty battery (battery 6) is 1/10 time to other battery.So that more heat will transfer to faulty battery.

Conductive heat transfer:

This block models heat transfer in a thermal network by conduction through a layer of material.

Below scope result shaws the temperature of healty and faulty battery. As see faulty battery has greater temperature

SOC Plots:

The plot shows the all cells SOC above.

All cells soc are oscillating between 30% to 39%

But the cell 6 SOC oscillating between to 30% from 44% due to its high temperature.

Conclusion:

• For a 10 cell series lithium ion battery model we simulate the thermal effects and compare life cycle performance at various temperatures, charge & discharge rates using MATLAB.
• If anyone battery with a different temperature, then the whole pack’s capacity, SOC and life cycle should be affected.

Reference: https://in.mathworks.com/help/simscape/ug/lithium-ion-battery-pack-with-fault.html