Week-6 Challenge: EV Drivetrain

Question 1:

Explanation:

• There are 3 converters used in electric vehicle and hybrid electric vehicle
• They are – AC to DC converter, DC to AC converter, DC to DC converter

AC to DC converter:

• AC to DC is called as rectifier
• Examples such as mobile charger, laptop charger
• It gives low voltage as output
• It is used in transformer for step down the voltage/current
• It has both positive and negative cycles for each phase shifting
• It is mainly used in charging of electric vehicle
• It is unidirectional
• Unidirectional means current can flow in one direction to charge the device
• It has a huge application in the field of power circuits
• The AC current cannot be stored
• It produces alternating waveforms thus having equal positive and negative cycles
• Types are
• Full wave rectifier
• Half wave rectifier
• Bridge rectifier

DC to AC converter:

• DC to AC is called inverter.
• The commonly used device is the UPS (Uninterrupted Power Supply) in home
• DC can be stored in the form of battery
• It is positive cycle and generates sin wave during the waveform generation
• It stores DC and gives AC as variable AC or required AC in it
• Widely used in inverters
• Can store 1 phase as well as 3 phase

DC to DC converter:

• DC to DC converter is called as chopper or buck converter
• Chopper has 3 phase works in 440V in nature
• It has an application in automobiles
• Used in car infotainment system, wiper, headlight, sensors etc
• Used in dc motor drives and dc related application
• It is either bidirectional or unidirectional
• Regeneration of braking this converter is used

Question 2:

Explanation

Motor and controlled parameters:

Rated armature voltage (V) = 72 V

Rated armature current (I) = 400 A

Ra=0.5 Ω

KΦ=0.7 Vs

Chopper switching frequency=400 Hz

Duty cycle =70%

EV speed state =?

Output voltage = voltage * duty cycle

= 72*0.7

= 50.4 V

T_v = V_v* (Kϕ /R_a) – ((Kϕ)² /R_a) * ω ---------------(1)

T_v = Vehicle Torque (Nm)

V_v = Vehicle Voltage (V)

ω = Steady State speed of Vehicle

Kϕ = Motor Constant

R_a = Armature Resistance

Sub the values in (1)

T_v = ((50.4 * 0.7) / 0.5)) – ((0.7)² / 0.5)) * ω

T_v = 70.56 – 0.98 ω -------------(2)

vehicle speed torque character.

T_v = 24.7 – 0.0051 ω² ------------(3)

Steady State,

(2) = (3)

70.56 – 0.98 ω = 24.7 – 0.0051 ω²

0.0051 ω² +0.98 ω -45.85 = 0 ----------(4)

It is solved by using quadratic equ.

= (−b ± ) / 2a

= -0.98 ± / 2* 0.0051

= 38.92 rad/sec

Question 3:

Explanation:

Question 4:

Explanation:

• Walley rippel is a man ho works in tesla
• He gaves the theory of induction vs brushless dc motor in which he says the major points about his opinion
• Now a days demand for electric vehicle demands is increasing all over the world due to carbon emission
• To overcome in this in future we are upgrading from to electric vehicle
• Tesla is the leading electric manufacturing in the world
• He talks about the induction motor which operates on AC voltage
• This is widely used motor when compared to other motor
• In the same way brushless dc motor is a widely used application
• The working of a 3 stage engine and a DC brushless motor
• Back when I had hair on my head and carried a , there were lead acid batteries, DC brush motors, and contactor controllers.
• Today, none of these remain (including my hair). Lead has been replaced by lithium and DC by either DC brushless, Contactors, meanwhile, have given way to modulating inverters
• With brushless machines, the rotor includes two or more permanent magnets that generate a DC magnetic field (as seen from the vantage point of the rotor). In turn, this magnetic field enters the stator core
• DC brushless rotor, the induction rotor has no magnets – just stacked steel laminations with buried peripheral conductors that form currents flowing in the stator windings produce a rotating magnetic field that enters the rotor.
• When a 3-phase induction motor is connected to utility type 3-phase power, torque is produced
• DC brushless drives will likely continue to dominate in the hybrid and coming plug-in hybrid markets, and that induction drives will likely maintain dominance for the high-performance

Conclusion:

All the models were created with necessary files