KINETIC ENERGY RECOVERYSYSTEM

COLLEGE OF ENGINEERING AND TECHNOLOGY , AKOLA

Sant Gadge Baba Amravati University, Amravati[2015-2016]

DEPARTMENT OF MECHANICAL ENGINEERING

Presented By…Nivrati A. Malve

Guided By..Prof. Y. P. Tidke

Contents

Introduction History of KERS KERS working schematics Elements of KERS Types KERS Graphs Advantages Disadvantages Applications Conclusion References

KERS - Introduction

The acronym KERS stands for Kinetic Energy Recovery System. The device recovers the kinetic energy that is present in the waste heat created by the car’s braking process. It stores that energy and converts it into power that can be called upon to boost acceleration.

Basically, it’s working principle involves storing the energy involved with deceleration and using it for acceleration. That is, when a car breaks, it dissipates a lot of kinetic energy as heat. The KERS stores this energy and converts this into power.

KERS - History

In development since 90’s . It was first introduced to the general public through the 2009 series of Formula one motor sport.

KERS builders, Flybrid Systems demonstrated a working Formula One-spec device at the Autosport International show. (24kg , 400kj energy capacity, power boost-60kw).

FIA introduced KERS in 2009 series to Increase Overtaking and also as defensive tool to block faster car

But many F1 teams Opposed it , as it was an Expensive system, so it was banned in 2010 season

But with improvements and increase in manufacturers for KERS it was reintroduced in 2011.

KERS – Working Schematics

Basic Elements of KERS

In essence a KERS systems is simple, you need a component for generating the power, one for storing it and another to control it all. Thus KERS systems have three main components: 1. The MGU (Motor/Generator Unit)2. The PCU (Power Control Unit)3. The batteries/flywheel. (Power Storage Unit)

Basic Elements of KERS

1. MGU (Motor/Generator Unit):• Its a single unit which has both motor-

generator rotor coils wound around a single rotor, and both coils share the same outer field coils working in two modes.

• The MGU both creates the power for the batteries when the car is braking, then return the power from the batteries to add power directly to the engine, when the KERS button is deployed.

Basic Elements of KERS

2. Power Control Unit ( PCU ) It serves two purposes, to invert & control the switching of current from the batteries to the MGU and to monitor the status of the individual cells with the battery.

Basic Elements of KERS

3. Power Storage Unit (Flywheel/Batteries) • It stores power for immediate usage and

gives power as and when required. Flywheel used in Mechanical KERS and Batteries are used in Electrical KERS.

Types of KERS

The KERS can be divided in the way they convert the energy and how that energy is stored within the vehicle. Depending on this, KERS has three types: 1. Mechanical Kinetic Energy Recovery

System2. Electrical Kinetic Energy Recovery System3. Hydraulic kinetic energy recovery system

Mechanical KERS

• The concept of transferring the vehicle’s kinetic energy using flywheel energy storage was postulated by physicist Richard Feynman in the 1950.

• The mechanical KERS system has a flywheel as the energy storage device and it does away with MGUs by replacing them with a transmission to control and transfer the energy to and from the driveline.

Mechanical KERS

Electrical KERS

• In electrical KERS, braking rotational force is captured by an electric motor / generator unit (MGU) mounted to the engines crankshaft.

• This MGU takes the electrical energy that it converts from kinetic energy and stores it in batteries. The boost button then summons the electrical energy in the batteries to power the MGU which in turn powers boosts the driveline

Electrical KERS

Advantages of Mechanical KERS

Over Electrical KERS

• In electrical KERS , energy has to be converted twice , where as in Mechanical no need of conversion. Hence electrical energy conversion efficiency is 31- 34 % where as in mechanical KERS its 70%

• Lithium-ion batteries take 1-2 hours to charge completely due to low specific power hence not good for F1 , so they use Super Capacitor.

• Chemical batteries heat up during charging process and could cause the batteries to lose energy over the cycle or worse even explode.

• Energy lose in Electrical KERS is more , Whereas not so much in Mechanical KERS

hydraulic KERS

Axial piston unit +Gear box pumpHydraulic pressure accumulatorPressure relief valve

Hydraulic KERS - where braking energy is used to accumulate hydraulic pressure which is then sent to the wheels when required.

Components

Energy recovery system comparison

KERS in Road Cars

• Transport Buses in Sverdon, Switzerland (1950)

• Honda Civic Hybrid(2002)• Ford Escape Hybrid(2005)• Jaguar XF sedan • Porsche 918 RSR variant concept car

(2011)• Hybrid car: mahindra e-20,Maruti ciaz.• Flywheel kers in BICYCLE

Advantages of KERS

• Reduced CO2 Emissions/Pollutants• Enhanced Performance• Environmentally Sound• High power capability• Light weight and small size with Long

system life• Completely Safe and a Truly Green

Solution• High efficiency Storage and Recovery

Limitations of KERS

• Only one KERS for car which has only one braking system.

• 60 kw is the maximum input and output power of the KERS system.

• The energy recovery system is functional only when the car is moving.

• The recovery system must be controlled by the same electronic control unit.

• If in case the KERS is connected between the differential and the wheel the torque applied to each wheel must be same.

• It is very costly. Engineers are trying hard to make it more cost effective.

Conclusion• It’s a technology for the present and the

future because it’s environment-friendly, reduces emissions, increases efficiency and is highly customizable and modifiable. Adoption of a KERS may permit regenerative braking and engine downsizing as a means of improving efficiency and hence reducing fuel consumption and CO2 emissions.

• The KERS have major areas of development in power density, life, simplicity, effectiveness and first and foremost the costs of the device. Applications are being considered for small, mass-production passenger cars, as well as luxury cars and Trucks.

References• International journal of scientific and engineering research

Volume 5, Issue 1, January- 2014 ISSN 2229-5518• Automotive Engineering International Online, “Volvo Spins

Up Flywheel Technology Research,” http://www.sae.org/mags/aei/9924, June 19, 2011

• WikiPedia/Kers• Barr, A., Veshagh, A. Fuel Economy and Performance

Comparison of Alternative Mechanical Hybrid Powertrain Configurations. SAE 2008 International. Number 2008-01-0083.

• http://www.oxbridgewriters.com/essays/engineerin/kers.php

Queries….

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