Week-11 Challenge: Braking
Ans.1 Here i used "New York Drive Cycle". Getting the Data from the EPA website and prepare a Excel data sheet.
To calculate the energy required for braking, here we have 33 decelerations points were made during this driving cycle, So 33 braking energy is to be calculated and sum it up to get the Total braking energy.
Braking Energy= (1/2)*M*V^2
Let us take the mass(M) of the vehicle is 800kg
Vf(Final velocity): The minimum velocity obtained after braking is considered as final velocity.
Vi(Initial velocity) : The maximum velocity obtained before braking is considered as initial velocity.
so, V=(Final Velocity(Vf) - Initial Velocity(Vi))
Calculation Excel sheet:
Mass Taken=800kg
So the braking energy is 318.1KJ
Ans.2- When the motor is at rest and it has to operate from standstill position to the reach the moderate speed the higher torque is required to bring the motor in operation. Whereas when the vehicle is already at high speed the capping or the limit is reached by the motor operation and thus any further higher torque could not be obtained while braking which means Accelerating torque is always high as compare to Braking torque of the MOtor. The braking operation happens in the motion which is been distributed as per proportion in the Brake energy and the Regenerative Braking.
In Mechanical braking which we usually see and experience in all vehicles the brake pedal in the vehicle cabin helps us to engage or disengage the brakes. Currently the braking technology have done wonders by inventing life saving braking technologies such as ABS, EBD, BA and others. All these technologies play vital role in stopping the vehicle and coming back to rest from a high speed. In all these vehicles when the driver applies the brakes the brake pads come closer to the disc connected with the driving disc. The brake pads usually help in efficient braking.
There are two generic methods by which the vehicle could be braked in the ELECTRIC BRAKES.
Series - The Regenerative Braking or the Mechanical Braking both are applied one after another.
Parallel - The Regenerative Braking or the Mechnical Braking both are applied Parallely.
When the brake pedal is pressed the hydraulic fluid reaches the brake piston and created the braking pressure on the wheels and the same kinetic energy is been used by the Regenerative Braking for generating more power using the Bi-directional converters.
An example of the proposition of Regenerative Braking and the Mechanical Braking
EDIB (Electric Driven Intelligent Brake) controls In "NISSAN LEAF" the regenerative brake and friction brake to support both of these requirements. Further, it also controls the reactive force from the pedal in order to unify the feeling when stepping down on the pedal and the sense of deceleration.
Ans.3- MATLAB program which plots contour of given motor speed, torque and efficiency values.
Contour PLOT:
