Week-11 Challenge: Braking
1.For a defined driving cycle, calculate the energy required for braking.
SOLUCTION:
DURING BRAKING ALSO REQUIRED THE SAME AMOUNT OF POWER REQUIRED FOR ACCELERATION SO APPLYING THOSE STANDARD EQUACTIONS WERE ENERGY FOR BRAKING BY THE FORMULA:
E#rgy=1/2.M.v^2
M=MOSS OF THE VEHICLE.
V=VELOCITY
WE CAN CALCULATE THE ENERGY IN WATT/H
ASSUMPTIONS:
M=1000KG
Vi=100Kn/H(INTIOAL SPEED)
Vf=0(FINAL SPEED)
ACCELERATION:2.5M/S^2
FROM THAT,
ACCELERATION POWER:58
CONVERTED INTO SEC SO 58/3600^10=0.1611KW
NOW FROME 100 TO 0 HOW MUCH IS BREAKING POWER IS REQURIED THAT WE HAVE TO CALCULATED:
E#rgy=1/2.M.V^2
=0.S*1000*(Vi-vF)^2
=0.5*1000*(101.12)^2
=13.88KJ
2.Why electric motor can’t develop braking torque at high speed similar to starting? How electric and mechanical brakes are coordinated?
soluction:
now speed torque charterstics of the motor is:
the first graph that till the motor reaches the critical speed it has constant torque and once it reaches the critical speed,the curve is having a downslope which is a constant power region.and this graph denotes the accelerating operation of the motor.for the deceleration or braking operation of the motor,this graph is morrored down which will be having the speed(+v)and (-v).
example: we can say that an ev can achive 0-100kmph in 10sec.accelerationoperation goes this way low speed and high torque constant torque region is achived which has accelerating power and by reaching the critical speed it shifts to constantpower region and thus it easy for an ev to reach 0-100kmph.
electric and mechanical brakes are coordinated:
SERIES:
BRAKES WILL BE APPLIED ONE AFTER ANOTHER SO WHICH THEY ARE CONNECTED IN SERIES.EITHER ONE BREAK STRAGETY AT A TIME EITHER REGENERATING BRAKING OR MECHANICAL BRAKING AT A TIME.
PARALLEL:
IN THIS CASE OF PARALLEL BOTHTHE BRAKES ARE APPLIED SIMULTANEOUSLY,BOTH AT TIME.
ELECTRICDRLVEN INTELLIGENT BRAKE:
THE NISSAN HAS DEVELOPED APRATICAL BRAKE STRATEGY CALLED ELECTRIC DRIVEN INTELLIGENT BRAKE DEVELOPED BY NISSONLEADS.
TECHNOLOGY FUNCTIONALLITY:
AFTER STEPPING ON THE BRAK PEDAL.THE SYASTEM PRODUCED A NATURAL AND ADEQUATE BRAKING FORCE THAT CORRESPONDS TO THE OPERATION.THE AMOUNT OF ENERGY REGENERATIONALSO NEEDS TO BE INCREASEDAS MUCH AS POSSIBLE.EDIB (ELECTRIC DRIVEN INTELLIGENT BREAKE.CONTROL THE REGENERATIVE BRAKE AND FRICTION BRAKE TO SUPPORT BOTH OF THESE REQUIREMENTS.DOWN THE PEDAL AND SENSE OF DECELERATION.
3.Make a MATLAB program which plots contour of given motor speed, torque and efficiency values. Attach the code as a .m file attach a screenshot of all the plots.
SOLUCTION:
MATLAB PROGRAM:
OUTPUT:
AS WE SEE IN OUTPUT WE GOING INSIDE TO CIRCLE OUR EFFICIENCY GET INCREASES AND OUTSIDE IT WILL DECREASES.
THE-END