Week-6 Challenge: EV Drivetrain
Q.1 TYPES OF POWER CONVERTERS
EV CHARGER- Which are majorly used for charching the ev vevhicles where the ac is converted to the dc and are given to the batteries(RECTIFIERS)
MOTOR DRIVE-The same dc is converted agiain as ac which is given to the equipments of the vehicles (INVERTERS)
CHOPPERS- Where DC from the batteries are reduced and are given to the parts of vehicles such as light speakers
Where one level of AC is converted to another level of AC such as fan regulators ac regulators
step up and step down choppers
Q.2 GIVEN DATA
Rated armature voltage=72volts
Arnmature resistance =0.5ohms
Armature current=400A
K pi =0.7volt sec
suty cycle(d)=70%(0.7)
voltage applied = rated voltage *duty cycle
=72*0.7
=50.4
we know T=((V*Kpi)-w*(k pi^2))/Ra
=((50.4*0.7)-w*(0.49))/0.5
=70.56-0.98*w
already we given in question T=24.7+0.0051*w^2
compare both the equations
24.7+0.0051*w^2=70.56-0.98*w
0.0051w^2+0.98w-45.86
on solving this quadratic eq we get
w=38.91,-231.07
speed will be in positive range so steady state speed value will be=38.91
Q3.mathematical model for the DC MOTOR
By using the values which are given above we have modalled an DC MOTOR IN SIMULINK
STEP 1 : Take the constant block and enter the voltage value as 50.4
STEP 2 : Take an another constant block as kpi (torque constant) block and enter the value of 0.7
STEP 3 : divide the above two blocks and the output is given to tha summation block
STEP 4 : Take constant block and name it a armatur eresistance and enter 0.5ohms and the value is divided by an another constant KPI^2 block
STEP 5: Take constant block named it as torque and enter the value as 32.42 and multiply with the above step m4 result and given to the summation block
STEP 6 : Output of the summation block has been displayerd using the display block and scope block
THE ABOSOLUTE ANS WE GET IN THE ABOVE ABOVE Q2 IS CLEARLY OBSERVED IN THIS MODAL w=38.91
SCREENSHOTS ARE PLACED BELOW
Q4.IM VERSUS BLDC
WALLEY REPPEL is an proponent in the electrical vehicles and an engineer at Aerovironment and he is famous for the question WHO KILLED THE EV? here we are going to compare the INDUCTION MOTOR AND BRUSHLESS DC MOTORS in the view of author
The stator part of the both IM and BLDC motors are on same constructiuon where the stator is supplied with the sme three phase and are used to produce the magnetic field arond the windngs where in the BLDC the ROTOR is made up of the PERMANENNT MAGNET which produce the fields and aree interact with the current carrying conductors to produce the TORQUE but in the case of IM the rotor is made up of the stacked steel lamination with burried pheripheral conductors that form a shorted structure where current in the stator produce RMF which leads to the production of the EMF and this curent interact with the magnetic fiels to produce the FORCE
In the IM thre will be no inverters and it has the ability to start under the load conditions and the BLDC produce no starting torque they need inverters aid whose phase is maintained in the step with the anglular position of the rotor
Energy efficienc of the BLDC is higher than the IM and also the eddy and hysterisis loses are reduced
Even these has mojor advantages and benifs on comparing one another there is NO WINNER
BLDC is dominant in the HYBRID and PLUG IN HYBRID and the IM is with an HIGH PERFOMANCE in the ELECTRIC VEHICLE
Both are going to rule the vehicle industry in the comming dacades