Project 4
TO find out the capacity of battery pack and no. of series parallel connectioon we have to first calculate the power, than travel factor , power required in series parallel connection.
steps
power = v*i
1200 =65*i
i= 1200/65travel factor
= 18.46 amp.
Current withdrawn By Motor 18.46 Amp
Assure Current Loss 1-10%
After loss new motor current 18.46*1.05=19.38 amp
Now Calculate the Power requried at max speed
At 60KMPH power = voltage*current
65*19.38
=1260w
travel factor
Travel Factor = 225/60
= 3.75
Power requried = Power*Travel Factor
power rquried=1260*3.75= 4725 = 4.7 kw
Now calculate Battery pack capacity based of efficiency
Battery pack efficiency 85%
47/0.85
=5.52kw
Total Battery Pack capacity
= 5.52/0.85
= 6.49 kwh
Series Connection
Motor Voltage 65 V
Cell Volatge 3.7v
No of series cells. 65/3.7
= 18
18 cells in series
Parallel Connection
Motor Current 19.38 A
Cell current 2.8 A
No of parallel cells 19.35/2.8
= 7
7 Cells in parallel
steps for simulink the battery
As per above calculation we have to use 18cells in series and 7 cells are in parallel, do the parallel connection first and then connect all parallel connected cells in series this is ease the process to find a faulty cell while maintenance time
but before connecting them we have to check all are in balanced condition or not
after placing a cells in cell holder do the series parallel connection ,
for connection use a nickle strip and connect the nickle strip to the cells or battery pack use spot welding (if you do not have spot welding then use soldering method but it is not recommended because it produces more heat).
Now connect the Battery management system (BMS) to a battery pack.
By connecting voltmeter measure the voltage across BMS and check required voltage is getting or not.
after that enclose the battery pack by using epoxy sheet for safety purpose.