Project 1 Mechanical design of battery pack
AIM:
> To prepare a detailed battery pack drawing along with its enclosure & state the assumptions taken.
Cell: ANR26650M1-B
>This is a nanophosphate high power lithium ion cell.
>A123's high performance Nanophosphate lithium ion phosphate (LiFeO4) battery technology delivers high power and energy density combined with excellent safety performance and extensive life cycling in a lighter weight, more compact package.
>Our cells have low capacityloss and impedence growth over time as well as high usable energy over a wide state of charge range, allowing our systems to meet end of life power and energy requiremnets with minimal pack oversizing.
Commercial Solutions:
Advanced Lead Acid batteries for,
>Datacenter UPS.
>Telecom BAckup.
>IT Backup.
>Autonomously Guided Vehicle (AGV's).
>Industrial Robotics & Material Handling Equipments.
>Medical Devices.
Goverment SOlutions:
>Military Vehicles.
>military Power Grids.
>Soldier Power.
>Directed Energy.
Grid Solutions:
>Frequency Regulation.
>Renewables Integration.
>Reverse Capacity.
>Transmission & Distribution.
Transportation Solutions:
>Commercial Vehicles.
>Off-Highway Vehicles.
>Passenger Vehicles.
ANR26650M1-B Technical Data:
Constant Power Discharge Charcteristics at 23 Degree C:
2.5C Constant Current Discharge At Various Tempratures:
Cycle Life Performance, 100% DOD, Various Tempratures & Discharge Rates:
About Cell:
>The LithiumWerks ANR26650M1-B is the next generation of A123 systems pioneering 26650 cylindrical cell, now with greater power and energy density and lower impedance.
>This versatile lithium ion cell is suitable for a wide variety of applications and system designs.
About Module:
>A battery management system (BMS) is any electronic system but manages a rechargable battery (cell or battery pack), such as by protecting the battery from operating outside it's safe operating area, monitoring it's state, calculating secondary data, reporting that data, controlling it's envirnoment.
About Battery PAck:
>A battery pack is a set of any number of (preferably) identical battries or indiviual battery cells.
>They may be configured in a series, parellel or a mixture of both to deliver the desired voltage, capacity or power density.
Mechanical Design Of Battery Pack:
>The high voltage battery is one of the most important component of a battery electric vehicle (BEV).
>The battery parameters have a significant influence on other componenets and attributes of the vehicle like,
Maximum Traction Motor Torque.
Maximum Regenration Brake Torque.
Vehicle Range.
Vehicle Total Weight.
Vehicle Price.
>Pretty much all major aspects ofa pure electric vehicle (EV) depend on the parameters of the high voltage battery.
>For our electric vehicle battery design we are going to start from 4 core input parameters:
Chemistry.
Voltage .
Average energy Consumption Of The Vehicle On A Driving Cycle.
Vehicle Range.
>A battery consists of one or mpre electrochemical cells(battery cells) whic are converting chemical energy into electrical energy (during discharging) and electrical energy into chemical energy (during charging).
>The type of elements contained witha battery and the chemical reactions during discharging-charging events define the chemistry of a battery.
>A battry cell consists of five major components:
Electrodes (Cathode & ANode).
Seperators.
Terminals.
Electrolyte.
Connector( a case or enclosure).
>For automotive applications there are different types of cells used:
>Indiviual battery cells are grouped together into a single mechanical and electrical unit called a battery module.
>The modules are electrically connected to form a battery pack.
>There are several types of abttries (chemistry) used in hybrid and electric vehicle propulsion systems but we are going to consider only lithium-ion cells.
>The main reason is that L-ion battries have a higher specific energy [Wh/kg] and specific power [w/Kg] compared with other types.
Electric Vehicle Design Battry Calculations:
Assumptions:
>Battery Energy = 18kwh.
>Voltage (to run the vehicle) = 400V.
Energy:
18 kWh.
Number Of Cells:
N=energy/(nominal voltage*capacity)
N=1800/(3.3*2.5)
N=2182.
>We need a minimum of 2182 cells to get 18kWh energy, now based on that we need to deicide configuration - series & parellel.
>Inseries configuration capacity remians the same and voltage will be the sum of indiviual cell voltage.
>In a parellel configuration, thevoltage remains the same and capacity accumaltes.
>We assumed 400V are required to run the vehicel, the nominal voltage of each one cell is 3.3V.
>number of series cells required to produce 400V (Ns) = voltage required / nominal voltage of one cell.
Ns = 400 / 3.3.
Ns = 121.21 =122.
