Hybrid electric vehicle
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Transcript of Hybrid electric vehicle
Contents
Part I: what is a hybrid vehicle
Part II: Need for a hybrid
vehicle
Part III: Concept of
hybridization
Part IV: Architectures of
Hybrids
Part I :What is hybrid vehicle
Any vehicle which combines two or
more sources of power to operate is
called hybrid vehicle
Examples :
diesel – electric
gasoline - electric
HEV,EV?
A traditional vehicle has sole
propulsion by ICE or diesel engine
EV - Electric Vehicle, battery (or
ultra capacitor, fly wheels) operated
only. Sole propulsion by electric
motor
An HEV (Hybrid Electric Vehicle) is
a vehicle which involves multiple
sources of propulsions
Part II :Need for the hybrid
vehicle
Rising petrol/diesel prices
Pollution and the resultant global
warming
Noise
Part III: Concept of hybridization?
Multiple sources of power
Making ICE work in most efficient
range
Sizing of motor and ICE lower
compared
to conventional vehicles and EV
Modes of operation
Part IV: Architectures of
Hybrids
According to the method the energy sources are arranged
Parallel HEV: Multiple propulsion sources can be
combined, or drive the vehicle alone with one of the
energy sources
Series HEV: Sole propulsion by electric motor, but
the electric energy comes from another on board
energy source, such as ICE
Power split : it is a parallel and series hybrid
vehicle which additionally uses power spliter
Parallel hybrid
Fuel tank which supplies gasoline
to the engine
Set of batteries that supplies
power to electric motor
Both the engine and electric motor
can turn the transmission system
at the same time and the
transmission system then turns the
wheels
Parallel (cont.) When the Alternative power unit (APU) is
OFF the vehicle runs as an electric vehicle
When the APU is on the controller divides the
power between drive trains(propulsion) and
Batteries ( Energy storage)
Under acceleration more power is allocated to
drive train than batteries . During Idle or low
speed more power is allocated to batteries
The batteries provide Additional power to the
drive train and also to power auxiliary system
such as Air conditioner and heater
Advantages
ICE operation can be
optimized, with motor assist
or share the power from the
ICE
Flexible in configurations
and gives room for
optimization of fuel
economy and emissions
Reduced engine size
Possible plug-in hybrid for
further improved fuel
economy and emission
reduction
Disadvantag
e
Complicated control strategy
Complex transmission
SERIES HYBRID Similar to an parallel hybrid with an on board
generator
The vehicle runs in a Battery like a pure
electric vehicle until the battery reach the pre
determined discharge level
At that point the APU turns ON and Starts
Recharging the Battery
The APU is ON until the Battery recharged to
its predetermined level
The APU never directly powers the vehicle
The time duration of APU ON depends on the
size of the battery and APU itself
Since the APU is not directly connected to the
drive train it can run on its operating
condition. Hence fuel economy is more and
pollutant emission is low as compared to IC
Advantages
IC Engine mostly run at
optimal speed and
torque
IC Engine can be
turned OFF in zero
emission zone
Low floor possible
Low fuel consumption
High fuel efficiency
Disadvantag
es
Many energy
conversion so more
energy loss
Additional weight/cost
due to increased
components
POWER SPLIT HYBRID
It is also called as series-parallel hybrid
Here the power transmission some times is shared according to requirement
If the battery utilises complete power then it is called as series architecture
If the power shared among the engine and battery then it is called parallel architecture
Power is shared by a power splitter which is simply called as planetary gear set
Advantages Disadvantages
IC Engine can
be turned OFF
IC Engine
speed can be
chosen by
adjusting
generator speed
Power vicious
may leading to
low efficiency
Relatively
complex
Expensive
Key advantages of HEVs Optimize the fuel economy
– Optimize the operating point of ICE
– Stop the ICE if not needed (ultra low speed and stops)
– Recover the kinetic energy at braking
– Reduce the size (hp and volume) of ICE
Reduce emissions
– Minimize the emissions when ICE is optimized in
operation
– Stop the ICE when it’s not needed
– Reduced size of ICE means less emissions
Quiet Operation
– Ultra low noise at low speed because ICE is stopped
– Quiet motor, motor is stopped when vehicle comes to
a stop, with engine already stopped
– Reduced maintenance because ICE operation is
optimized, less hazardous material, fewer tune ups,
longer life cycle of ICE
– Fewer spark-plug changes
– Fewer oil changes
– Fewer fuel filters, antifreeze, radiator flushes or
water
pumps
– Fewer exhaust repairs or muffler changes
Key Concerns of HEVs High initial cost
– Increased components such as battery, electric machines,
motor controller, etc.
Reliability concern
– Increased components, especially power system, electronics,
sensors
Warranty issues
– Issues on major electric components
– Dealership and repair shop not familiar with new components
Safety: high voltage system employed in HEV
Key concerns(cont.) Short Driving Range- Range anxiety
Recharging takes much longer time than refueling gasoline-lack of charging infrastructure
Battery pack takes space and weight of the vehicle which otherwise is available to the people
Grid load
ICE + Electric motor = Propulsion