Project 2 Thermal modeling of battery pack

AIM:

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

EXPLANATION:

In this project, the requirement that we need to simulate the thermal effect and life cycle performance of lithium-ion battery packs at various temperatures, charges, discharge rates. Following are the model of the lithium-ion battery pack with fault.

SIMULINK MODEL:

MODEL EXPLANATION:

The Above model shows the representation of the 10 cell series connection. A lithium-ion battery pack of 10 cells is used. In order to check for the thermal effects, one of the cells is considered faulty. Fault in the sense that the temperature of this cell is higher than the other nine. The battery is assumed to be air-cooled and provided with ventilators with ambient air and temperature. For modeling this case, all the cells are connected with ambient temperature. The convective heat transfer from the surrounding to the cells and conductive between the cells is also modeled using the respective blocks. There are temperature sensor blocks used to detect the temperature from the cells. The current drawn from the cells is controlled by the 'Controlled CUrrent Source' block. The data of a drive cycle in the form of a current is fed to this current controller. A signal builder block is used to feed this drive cycle data and it is stored in the form of current vs time. After running the model SOC vs time and temperature vs time graphs are plotted.

BLOCK PARAMETERS:

HERE WE CAN MAKE THE 10 SERIES CELL AND SEPARATE THEM WITHIN THEIR CHARACTERISTICS,

CELL 1 TO 4

CELL 05

CELL 06 TO 10

CREATE A SUBSYSTEM INSIDE THE BATTERY CELLS:

Each of the subsystems consists of the cell variables which are taken the source from the values

TEMPERATURE SENSORS:

This block measures temperature in a thermal network. There is no heat flow through the sensor. The physical signal port T reports the temperature difference across the sensor.

TEMPERATURE SOURCE:

This block represents an ideal energy source in a thermal network that can maintain a constant absolute temperature at the port regardless of the heat flow rate.

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.

CONDUCTIVE HEAT TRANSFER:

This block models heat transfer in a thermal network by conduction through a layer of material. The rate of heat transfer is governed by Fourier's law and is proportional to the temperature difference, material thermal conductivity, area normal to the heat flow direction, and inversely proportional to the layer thickness.

CURRENT SENSOR:

The block represents an ideal current sensor, that is, a device that converts current measured in any electrical branch into a physical signal proportional to the current.

Connections + and - are conserving electrical ports through which the sensor is inserted into the circuit. The connection I is a physical signal port that outputs the current value.

AC CURRENT SOURCE:

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

DISPLAY

The display shows the Ambient Temperature of the Block Model which are having a 10 series connection.

RESULT OUTPUTS:

TEMPERATURE OF THE CELL;

SOC OF THE CELL;

RESULT:

HERE WE CAN SIMULATE THE THERMAL EFFECTS AND COMPARE LIFE CYCLES PERFORMANCE AT VARIOUS TEMPERATURES, CHARGE AND DISCHARGE RATES USING MATLAB, FOR A 10 CELL SERIES LITHIUM-ION BATTERY MODEL.