Week-6 Challenge: EV Drivetrain

1)

the converters used in power electronics are

*AC-DC converters(controlled rectifier)

*AC-AC converters(AC voltgae controller)

*DC-DC converters(DC choppers)

*DC-AC converters(inverters)

in plug in hybrid vehicle AC to DC converters are used to convert the AC supply at the charging station to DC current because battery can be only charged with DC current.

DC DC converters are used in both EV and HVEC to boost the voltage levels as needed by the electronics systems

in EV, AC motors are used to convert the DC current from the battery to AC current,DC to AC converters are used.

2)

given parameters are

rated armature voltage=72V

rated armature current=400A

Ra=0.5,kfi=0.7

to find vehicle voltage=battery voltage*duty cycle

72*0.7

vehicle voltage=50.4v

the speed torque equation is

w=(V/Kfi)-(RaT/(kfi)^2)

sub the values

w=(50.4/0.7)-(0.5T/0.7)^2)

w=72-1.020T

T=70.58-0.980w

given torque equation

T=24.7+0.0051(W^2)

substituting calculated torque

70.58-0.98w=24.7+0.0051(w)^2

we get two values,taking the positive value

the steady state of vehicle is 38.60rad/secs for duty cycle 70%

3)

simulink model is constructed using the given equation

4)

In the blog the author starts explaining the motors by giving an example of ICEs that not all engines are the same and are required as per users needs also depending upon the performance and price which is true for electric vehicles too. In earlier times DC brushed motors and contactor controllers were used, which are now replaced by lithium-ion batteries and DC brushless motors and modulating inverters. Also stating that the technology is developing day by day in every field

In the end of the blog the author concludes that the DC brushless motors will mostly dominate the EV and HEV markets and the induction motors will dominate in high performance pure electric vehicles. He also questions about electric intensiveness and increase in the performance of hybrid electric vehicles and the fact that much of the hardware is almost common in both the drives which means we will see both the technologies working side by side during the golden era of EV and HEVs.