What about regeneration of energy from brakes... This was our Semester project at University of Engineering and Technology Lahore Punjab Pakistan

1. Demonstration of
Regenerative Braking
System
2014-ME-360
2014-ME-362
2014-ME-371
2014-ME-373

2. Contents: -
 Introduction
 Definition
 How does it work
 KERS
 Benefits
 Limitations
 Conclusions
 References

3. Introduction:-
 Stop... start... stop... start. If you make a habit of driving in city
traffic, you'll know it can be a huge waste of time. What's less
obvious is that it's also a waste of energy.
 Getting a car moving needs a big input of power, and every
time you hit the brakes all the energy you've built up disappears
again, wasted in the brake pads as heat energy.
 Wouldn't it be good if you could store this energy somehow and
reuse it next time you start to accelerate?
 That's the basic concept of regenerative brakes, which are
widely used in electric trains and the latest electric cars. What
are they? How do they work? Let's take a closer look!

4. What is Regenerative Braking
System?
 Regenerative braking technology funnels the energy
created by the braking process back into the system in the
form of charging the battery for further use.
 Many modern electric drive vehicles and HEVs use
regenerative braking systems.

5. How does it work?
 The system that drives the vehicle does the majority of the
braking. When the driver steps on the brake pedal of an
electric or hybrid vehicle, these types of brakes put the
vehicle's electric motor into reverse mode, causing it to run
backwards, thus slowing the car's wheels. While running
backwards, the motor also acts as an electric generator,
producing electricity that's then fed into the vehicle's
batteries.

6. Layout of a Regenerative Braking
System: -
Description of Regenerative Braking System (RBS)

7. Kinetic Energy Recovery System
(KERS): -
 The device recovers the kinetic energy that is present in the
waste heat created by the car’s braking process which is
used in storing energy in the battery..
 The concept of transferring the vehicle’s kinetic energy
using Flywheel energy storage was postulated by physicist
Richard Feynman in the 1950s.
 It is basic system used in regenerative braking system.

8. Cars with Regenerative Braking: -
 Toyota Prius
 Honda Insight
 Ford Escape Hybrid
 Tesla Roadster
 Chevy Volt
Tesla RoadsterToyota Prius

9. Benefits of Regenerative Braking
System: -
 Reduction of pollution
 Increase in engine life
 Breaking is not total loss
 Wear Reduction
 Increases the lifespan of friction braking systems.

10. Limitations: -
 The friction brake is a necessary back-up in the event of
failure of the regenerative brake.
 Most road vehicles with regenerative braking only have
power on some wheels (as in a 2WD car) and regenerative
braking power only applies to such wheels, so in order to
provide controlled braking under difficult conditions (such
as in wet roads) friction based braking is necessary on the
other wheels.
 The regenerative braking effect drops off at lower speeds, it
doesn’t work at high speed.

11. Conclusion:-
 The energy efficiency of a conventional brake is only about
20 percent, with the remaining 80 percent of its energy being
converted to heat through friction. The good thing about
regenerative braking is that it may be able to capture as
much as half of that wasted energy and put it back to work.
 This reduces fuel consumption by 10 to 25 percent.

12. References: -
 http://auto.howstuffworks.com/auto-parts/brakes/brake-
types/regenerative-braking.htm
 http://www.hybridcars.com/components/regenerative-
braking.html
 http://www.hybridcars.com/related-
technologies/hydraulic-hybrids.html
 http://www.railway-technical.com/brake1.shtml

13. Thank you