A SEMINAR ON DESIGN & ANALYSIS OF REGENERATIVE BRAKING SYSTEM UNDER THE GUIDANCE OF PROF. NILESH SHINDE Presented by SHIVDATTA REDEKAR NITIN SARGAR SOHAIL SHAIKH BHARAT WAGH 1
1 A SEMINAR ON DESIGN & ANALYSIS OF
REGENERATIVE BRAKING SYSTEM
UNDER THE GUIDANCE OF PROF. NILESH SHINDE
Presented by SHIVDATTA REDEKAR
NITIN SARGARSOHAIL SHAIKHBHARAT WAGH
2Identification of problem
Challenges across world on Climate change & Reducing Carbon Emission
Automotive industry's challenges- facing strict emission norms
The price increase of petroleum based fuel
Various research and development efforts for energy conservation & sustainable development methods
3Literature study • One third (21 to 24%) energy is
consumed during brake. • Research by Volkswagen has
shown that a hybrid drive with both ECE and ICE offers fuel saving of over 20% compared purely electric.
• A vehicle operated in the main city for such vehicles the wastage of energy by application of brake is about 60% to 65%.
Fig. shows energy utilization at wheels for heavy loaded truck and bus
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Fig. shows energy dissipation on wheels during braking
Fig. shows the total braking force, regenerative braking force and braking force on front wheels
ENERGY DISSIPATION IN RBS
5FINDINGS IN LITERATURE STUDY
The average efficiency of energy recovery of the system was 66%. (HER)
Regarding to the energy recovering potential of the system, simulation results indicated that 32 to 66% of braking energy can be recuperated.
The variation is due to the losses of load variation. High potential of energy recovery and it is worth to apply for
commercial vehicle. (COURTESY: Journal of Science and Engineering Technology, Vol. 7, No.4, 2011)
6objectives
To study the basic design of RBS To identify obstacles occurred while implementing RBS To analyze RBS in terms of cost effectiveness, feasibility,
efficiency To carry out simulation in suitable software. To validate analyzed result on proposed model by carry out
testing To evaluate an efficient system for future study.
7Analysis of Forces acting on vehicles The amount of mechanical energy consumed by a vehicle when driving a
pre-specified driving pattern mainly depends on three effects: the aerodynamic friction losses the rolling friction losses the energy dissipated in the brakes. The elementary equation that describes the longitudinal dynamics of a road
vehicle has the following form
M(dv(t)/dt)= Ft(t) − (Fa(t) + Fr(t) + Fg(t))
The traction force Ft is the force generated by the prime mover minus the force that is used to accelerate the rotating parts inside the vehicle and minus all friction losses in the powertrain
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Aerodynamic friction losses Usually, the aerodynamic resistance force Fa is
approximated by simplifying the vehicle to be a prismatic body with a frontal area Af . Fa(v) = ½.q.Af.Cd.v
Figure : Schematic representation of the forces acting on a vehicle in motion
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Rolling friction losses • The rolling friction is modeled as Fr = Cr.m.g.cos(a) rolling friction coefficient Cr depends vehicle speed v, tire pressure p, and road
surface conditions.
Uphill driving force The force induced by gravity when driving on a non-horizontal road is conservative and considerably influences the vehicle behavior. In this text this force will be modeled by the relationshipFg = m.g.sin(a)
10Analysis on vehicle
2001 Toyota Camry Specifications city mileage4: 0.103 Liter/km empty mass5: 1420 kg CD6: 0.29 Frontal Area: 2.42 m2
Coefficient of Rolling Resistance: 0.015
11Drivetrain Modelling in Simulink
12Fuel Consumption due to Rolling ResistanceLet's assume the car is carrying one passenger (70 kg) and a full tank of gas (40 kg).
Force of rolling resitance=(Coff of rolling resitance)(mass)(g) =(0.015)(1420+70+30)(9.81) =223N Work done against the rolling resistance=(force of rolling resistance)(distance) =223*1000 =223KJ Energy per liter= amt of joules/amt of lits Amt of lits = amt of joules/energy per lit = 892/32 = 0.028L Work done against air resitance=1/2*p*Acar *Cdv =1/2 (1.3*2.42*0.29*1000*14) =89.4KJ
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Efficiency=work output/fuel energy input Fuel energy input=Work output/Efficiency =89.4/25% =357.6KJ Energy per liter=amt of joules/amt of lits Amt of lits=amt of joules/energy per lit =357.4/32 =0.011L
Consumption due repeated acceleration= total camry fuel consumption-fuel consumed by rolling resistance –fuel consumed by air drag
=0.103-0.028-0.01 =0.064 L/KM
This tells us that repeated acceleration is responsible for about 0.064 / 0.103 = 62% of the city fuel economy.
For regenerative braking system, we could recover 70% of this energy, thereby saving (70%) (62%) = 43% of the total city fuel economy!
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METHODOLOGYStudy of
Regenerative Braking System
Study of braking
component
CurrentScenario of
RBS
Literature review
Developing drive
schedule in Simulink
Analysing forces on vehicles
Fabrication of Prototype Testing Consult with
guideFinalize project
1 2 3 4 5
6 7 8 9 10
15Result
Development of drive cycle for vehicle in Simulink Potential of recovering 30% of energy (from calculations) Improved fuel economy by 7%
16References
1. http://auto.howstuffworks.com/auto-parts/brakes/brake-types/regenerative-braking.htm
2. http://www.hybridcars.com/components/regenerative-braking.html3. http://www.hybridcars.com/related-technologies/hydraulic-hybrids.html European Automobile manufacturing association, Economic report for
2007 (9/28/2008) Bosch Automotive Handbook – Rev. 7 – John Wiley & sons – (2007) Air Resource Board – Estimation of average vehicle average lifetime &
miles of travel - (Sept. 2004)