Project 2 Thermal modeling of battery pack

AIM:

To simulate the model for thermal modelling of battery pack and the effects of thermal and compare life cycles performance at various temperatures ,charge and discharge rates using MATLAB .for 10 cell series lithium ion battery model

OBJECTIVES:-

   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 and state of charges and discharges rates.following are the model of the li-ion battery pack with fault.

SIMULINK MODEL FOR 10CELLS SERIES LI-ION BATTERY:-

Signal buider subsytem:

cell _1_to_4 subsystem:-

cell_5:-

cell_6_to_10:

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:-

battery(table based):-

convective heat transfer:-

this block models heat transfer in a thermal network by convection due to fluid motion.the rate of heat transfer is proportinal to the temperature differance,heat transfer coefficient,and surface area in contact with the fluid.

conductive heat tranfer:-

 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.

thermal mass:-

temperature sensor:-

this block measures temperature in a thermal network.there is no heat flow through the sensor.the pfysical signal port T reports the temperature differance across the sensor.

subsystem outputs:-

output scopes:-

 various state of charge result:-

cell 1_to_4

cell_5

cell_6_to_10

various temperature results:-

temp_1_to_4

temp_5

temp_6_to_10

life cycle performance:-

Each round of full discharge and then full recharge is called battery cycle life. A battery's cycle life can range from 500 to 1200. That means a life cycle of 18 months to 3 years for a typical battery.

CONCLUSION:-

Hence ,the simulation for 10 cells series lithium ion battery model and its outputs has been verified.