IRJET- Optimization of Required Power for an Electric Vehicle
Presentation
1. 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
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2. Identification 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
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3. Literature 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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4. 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 4
5. FINDINGS 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)
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6. objectives
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.
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7. Analysis 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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8. 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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9. 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
relationship
Fg = m.g.sin(a)
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10. Analysis 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
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12. Fuel Consumption due to Rolling Resistance
Let'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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13. 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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15. Result
Development of drive cycle for vehicle in Simulink
Potential of recovering 30% of energy (from calculations)
Improved fuel economy by 7%
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