Week-6 Challenge: EV Drivetrain

1. Which types of power converter circuits are employed in electric and hybrid electric vehicle?

Ans - Following are the types of Power Converters are used in Electric Vehicle

1) AC to DC Converter (Rectifier : For charging purpose of Battery)

Explaination = This AC to DC Converter is comprises of 4 different blocks that is transformer block which reduced the given supply voltage to required voltage, second one is rectifier block which convert the pulsating DC, third one is filter circuit which neglect the ripples present in the voltage, last one is voltage regulator which provide the required supply i.e. 5V, 12V, 48V.

2) DC to AC Converter (Inverter : For running the Induction Motor)

Explaination = This DC to AC converter is included with MOSFET ior IGBT which convert DC supply coming from battery into AC supply and run the Induction motor in Electric ir Hybrid Electric Vehicle.

3) DC to Variable DC (Chopper : For providing the supply to car infotainment system like, sound system, Auto adjustable mirror, Display, etc).

4) AC to AC (Cycloconverter :It is also known as a cycloinverter which converts a constant voltage, constant frequency AC waveform to another AC waveform of a different frequency. A cycloconverter achieves this through synthesizing the output waveform from segments of the AC supply (without an intermediate DC link).

2. An Electric Vehicle's powertrain with 72V battery pack in shown in the diagram below. The duty ratio for acceleration operation is 'd1' and for the braking operation the duty ratio is 'd2'.

Ans -

3. Develop a mathematical model of a DC Motor for the below equation using Simulink.

Ans :

Graph of Speed

4. Refer to the blog on below topic:

Induction Versus DC brushless motors by Wally Rippel, Tesla

Explain in brief about author’s perspective.

Ans : 1) In this article Wally Rippel is trying to explain the difference between the Induction Motor and Brushless DC Motor as well as give the summary of old scenario of electrical revolution.Where lead acid batteries are used in old days which is now replaced by lithium ion batteries.

2) In DC brushless motor rotor is introduced with 2 or more permanent magnet on it which generates the DC magnetic field.This DC magnetic field is enters in the stator core and interacts with windings, eventually torque interaction is produced between rotor and stator.

3) In 3 phase Induction Motor like a brushless DC motor permanent magnet is not exist on rotor.Rotor has has burried peripheral conductors which are shorted by their end.When current is flowing in the stator windings produces a magnetic field that enters into rotor windings and torque is produced.

4) AC induction motor has less starting torque than DC motors and this motors are constant speed motors.Efficiency of BLDC motor is high and cost is also high due to permanent magnets. Size of BLDC motor is big as compared to Induction motor of same ratings.