Project 2 Thermal modeling of battery pack

Project Title: Thermal modelling 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.

Software Used: Simulink, MS Word.

Solution:

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.

Simulink Model:

The following Simulink model contains 2 subsystems (with and without thermal effects) of 10 cell series lithium iron phosphate battery pack (LiFePO₄) chemistry (3.3V, 2.3 Ah).

Battery pack configuration with Thermal Effects:

Battery pack without Thermal Effects:

The Battery Pack is supplied with constant temperature of 30⁰ C.

The model is simulated for 1 hr.

Results:

Controlled Current Source Plot:

Voltage Plot:

At Temperature 30⁰ C:

At Temperature 10⁰ C:

Current Plot:

At Temperature 30⁰ C:

At Temperature 10⁰ C:

SOC Plot:

At Temperature 30⁰ C:

At Temperature 10⁰ C:

Cell Temperature Plot:

At Temperature 30⁰ C:

At Temperature 10⁰ C:

Conclusion:

As the battery pack is a 10-cell series connection, we can see that the voltage of the battery pack with thermal effects is less than the voltage of the battery pack at all temperatures. The voltage decreased as the temperature changed from 30⁰ C to 10⁰ C.

Due to series connection, there is a negligible difference in current plot between both the battery packs.

The SOC has a negligible difference when the ambient temperature was at 30⁰ C, but as the temperature was changed to 10⁰ C, the SOC of the battery with thermal effects decreased compared to the battery without thermal effects.