Mechanical Engineering Project

KERS-Kinetic Energy Restoration System

Sai Krishna Bandi - 1021210406 S. Shivasubramanian - 1021210414Prashant A - 1021210421Arvindh S - 1021210422 Haynes Job - 1021210426 Sudeep Raj - 1021210436

I validate that this project is approved by me and the group is under my guidance and supervision.

V. MATHANRAJ2Contents:IntroductionConventional Breaking SystemRegenerative Breaking & Its WorkingHow it worksComponentsExpenditureBenefits of Regenerative Breaking SystemLimitations of Regenerative Breaking SystemConclusion

What are brakes?A brake is a device that decelerates a moving object / prevents an object from accelerating.Brakes use friction to convert kinetic energy into heatGuiding principle- kinetic energy increases quadratic ally with velocity -K = mv2 / 2When the brake is pushed the caliper containing piston pushes the pad towards the brake disc which slows the wheel down.

Convectional braking system

Conventional braking systems use friction to counteract the forward momentum of a moving car. As the brake pads rub against the wheels, excessive heat energy is created. This heat energy dissipates into the air, wasting up to 30% of the car's generated powerRegenerative brakingRegenerative braking technology funnels the energy created by the braking process back into the system in the form of charging the battery for further useIn a regenerative braking system the energy normally lost in the braking process is transferred to the generator from the rotating axel and then transferred to the battery, thus saving energy

6Vehicles driven by electric motors use the motor as a generator when using regenerative braking: it is operated as a generator during braking and its output is supplied to an electrical load; the transfer of energy to the load provides the braking effect.Many modern hybrid and electric vehicles use this technique to extend the range of the battery pack.

vvMotorIC EngineGeneratorBatteryWheelWheelMotorTransmissionIC EngineGeneratorBatteryWheelWheelMotorTransmissionIC EngineGeneratorBatteryWheelWheelScenario 1: Low speed - Power is provided by electric motor using energy supplied by the DC batteryScenario 2: Braking Kinetic energy is converted to electric energy during regenerative braking by electric motor and supplied to battery.Scenario 3: High speed Power is provided by IC engine and electric motor via generator. Generator also charge battery during high speed.Over viewHOW IT WORKSRegenerative braking does more than simply stop the car. Electric motors and electric generators (such as a car's alternator) are essentially two sides of the same technology. Both use magnetic fields and coiled wires, but in different configurations. Regenerative braking systems take advantage of this duality. Whenever the electric motor of a hybrid car begins to rotate reverse direction, it becomes an electric generator or dynamo. This generated electricity is fed into a chemical storage battery and used later to power the car at city speeds.

9Apparatus required-DC MOTOR POWER SUPPLYWHEELSHAFTSWITCH5 WATT BATTERYBULB

10DC MOTORPermanent magnet type Voltage- 12 voltPower-120 wattSpeed-1700 rpmMass-5kgCurrent-7.5 A

11EXPENDITURESno. ITEMQUANTITYCOST1DC MOTOR 127002BATTERY17003WHEEL13004SHAFT MATERIAL11005SWITCH12006MACHINING WORK-200TOTAL420012Benefits of regenerative brakingReduction of pollutionIncrease in engine lifeBreaking is not total lossWear ReductionReduction in pollutionRailway vehicle The Delhi Metro saved around 90,000 tons of carbon dioxide (CO2) from being released into the atmosphere by regenerating 112,500 megawatt hours of electricity through the use of regenerative braking systems

Regenerative brakes have been able to improve the performance of engines.This has been exhibited in the Motor sport industry The system used by F! cars is called K. E. R. S (Kinetic Energy Recovery System)

Increase engine efficiencyBreaking is not total lossConventional brakes apply friction to convert a vehicles kinetic energy into heat. In energy terms, therefore, braking is a total loss: once heat is generated, it is very difficult to reuse. The regenerative braking system, however, slows a vehicle down in a different way.

Wear ReductionAn electric drive train also allows for regenerative breaking which increases Efficiency and reduces wear on the vehicle brakes. Limitations of regenerative braking systemThe regenerative braking effect drops off at lower speeds, therefore the friction brake is still required in order to bring the vehicle to a complete halt.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 wheelsConclusion 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 miraculous 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. Hence regenerative braking plays an important role in fuel consumption and also in the field of speed Thank you