Project 2 Thermal modeling of battery pack

Introduction:

                 The performance and life-cycle costs of electric vehicles (EV) and hybrid electric vehicles (HEV) depend inherently on energy storage systems such as batteries. Battery pack performance directly affects the all electric range, power for acceleration, fuel economy, and charge acceptance during energy recovery from regenerative braking. Because the battery pack cost, durability, and life also affect the cost and reliability of the vehicle, any parameter that affects the battery pack must be optimized.

                 Temperature and temperature uniformity have a strong influence on battery pack performance and consequently, that of HEVs and EVs. All the modules in the pack should be operated within the optimum temperature range suitable for the particular electrochemical couple used. In addition, uneven temperature distribution in a pack leads to different charge/discharge behaviour that results in unbalanced modules and reduced pack performance . Because HEV batteries have high specific power and undergo aggressive HEV charging/discharging profiles, thermal issues in an HEV pack are of more concern than in EV packs.

in this project we are using NCR 18650 LI cell.

in this circuit we connected in series.

here one cell is using in series connection  this are faulty cell. and heare we add the resistor to the circuit.

the bellow we using sevaral types of dash boardes for we know the soc and temprature of the cell and ambiant temprature.

in this we are using UDDS drive cycle for checking the different conditiones.

vehicle Current Model:

• In vehicle current requirement subsystem block,the signal builder block used to apply UDDS current profile and simulink-ps converter block used to convert the simulink signal to physical signal.connectin port block used to output the signal.

               

What is Fauly Cell ?

               A faulty cell demonstates performance that is different than the other cell usually most cell will be displaying the same SOC ,temperature voltage level etc.but a faulty cell will show sign of overheating,faster discharge(due to reduced capacity or reduced OCV) oe will be unbalanced cell.this will be impact the performace of the entire pack as the faulty cell will limit the pack from utilizing its maximum potential.

in this project the faulty cell is repesenting by adding an extra external resistor.this will make the cell react diffirently then the other cells.