Week-6 Challenge: EV Drivetrain
1. there are 3types of converter used in EV & HEV
AC-DC converter: this is the most commonly used converter in HEV and EV and were in this thevehicle is charged from a outside source that is using alternating current which it gets the propulsion power, and the battery needs need to charged from trhe charging station
2.D-DC converter: in this the type of converter the voltages are boosted up and the chopping off the voltage levels is done and also were asthe charctwersyics of the dc-dc converter depend on the vehicle speed , torque and etc..
3/DC-AC converter: in this type of converter the input to battery is ac and then from there using the power electronic device the dc is convertered to AC by using inverter so that the motor cntorlled will be the ac
2. as the parameters are given below
battery pack(V)=72v
rated armeture current=400A
armeture resistance=0.5ohm
motor constant(k`phi`)=0.7
chopper switching frequency=400hz
duty cycle=70%w
so,
vehicle output voltage = vbat*dutycycle
=72*0.70
vehicle output voltage=50.4v
the euation for the vehicle torque is given by
Tv=(Vv-wk'phi')/Ra*k'phi'
Tv=(50.04-.7w)*0.7/0.5
Tv=70.56-0.98w
Tv=24.7+0.0051W^2
so we get an quadratic equation ; hence forth solving thgis we will get two value
w=38.85rad/s and w=-235.95rad/s
so we take possitive value
so the steady speed state of the vehicle is 38.85rad/sec
3.the devloped mathematical equation for dc motor for speed and tourque ahs been m,ade and attached in the answe file the graph genrate has been shown below
3. as per the study by wally about BLDCmotor and induction motor
in brushless DCmotor the torque is less compares to induction motor ,
the dc brushless motor have two premanent magnetic coil in it and the rotor which the torque is provided and it rotaes when the current is given to the coil and duer to the magnetic feild induced in it , where as to control the torue and speed of the motor the inverter is used in the brushless motor
the induction motor is one where it is a 3pahase motor its magnitude is different there will be 3seperate input wire in the coils in the induction motor there no megnet in it , it has high torque compared to dc brushless motor , and in the utility based apliances the induction motor is best one
the efficiency is more in dc brshless motor and the heating of the motor is less compared to induction motor
in future coming days dc brushsless motor is used in phev and ev also , in the previous the ev1 car the induction motor is used