Week-11 Challenge: Braking
I am online student batch EV -16
1) For a defined driving cycle, calculate the energy required for braking.
Ans
2) Why electric motor can’t develop braking torque at high speed similar to starting? How electric and mechanical brakes are coordinated?
In regenerative braking, the motor will act as a generator because the direction of the current will be reversed. The armature is spun through the field by the deceleration of the vehicle. whatever amount of voltage is produced it recharges the battery. motor reverse increase it creates back electromotive force or BACK EMF. more emf diminishes the instantaneous torque.
when speed is already high and no extra load is applied it is no a chance to increase the torque. we can reduce by, increasing dc bus voltage limitless acceleration.
The regeneration brake system converts heat energy into useful energy. An electric motor is unable to provide all the brake torque for large decelerations if braking torque is applied to only one axle then it has a chance of instability. to ignore the situation regenerative breaking is operating with a mechanical brake system.
There are two types of brake control series
1- series brake control
2- parallel brake control
series - we apply the mechanical brake or regenerative braking one after another.
parallel - in this system we apply both mechanical brakes and regenerative brakes simultaneously.
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.
