This document discusses hybrid electric vehicles (HEVs). It describes how HEVs can help reduce carbon emissions from transportation and assist with renewable energy integration. The document outlines the components and design considerations of electric vehicle (EV) and HEV systems, including different controller and powertrain options. It also discusses modeling vehicle dynamics and performance to optimize the torque-speed profile of electric motors. The goal is to meet driving requirements with minimum power. Finally, it examines the future potential of EVs and HEVs to address issues like rising fuel costs and dependence on non-renewable energy sources.

1. Hybrid Electric Vehicles
Subhash Mahla
Electrical Engineering Department
Baldev Ram Mirdha Institute of Technology, Jaipur
Subhashmahla93@gmail.com
Abstract: Electric vehicles (EVs) and renewable
energy sources offer the potential to
substantially decrease carbon emissions from
both the transportation and power generation
sectors of the economy. The fuzzy logic
controllers design to improve the performance
of the adaptive controller under different
driving condition. Mass adoption of EVs will
have a number of impacts and benefits,
including the ability to assist in the integration
of renewable energy into existing electric grids.
There is a growing interest in electric and
hybrid electric vehicles due to environmental
concerns. Recent efforts are directed toward
developing an improved system for electric and
hybrid-electric vehicles applications. This paper
is aimed at developing the system design
philosophies of electric and hybrid systems. The
vehicle’s dynamics are studied in an attempt to
find an optimal torque-speed profile for the
electric system. The combined storage unit is
composed by an ultra capacitors tank (UC) and
a battery unit (BU).
Keyword: electric grids, hybrid-electric vehicles,
fizzy controller, adaptive controller
I. INTRODUCTION
The concept of the electric vehicle (EV) was
conceived in the middle of the previous century.
After the introduction of the internal combustion
engine (ICE), EV’s remained in existence side by
side with the ICE for several years. The energy
density of gasoline is far more than what the
electrochemical battery could offer. Despite this
fact, the EV continued to exist, especially in urban
areas due to its self-starting capability. However,
soon after the introduction of the electric starter for
ICE’s early this century, despite being
energy-efficient and nonpolluting, the EV lost the
battle completely to the ICE due to its limited range
and inferior performance. Since then, the ICE has
evolved, improved in design, and received
widespread acceptance and respect. Although this
essentially is the case, EV interest never perished
completely and whenever there has been any crisis
regarding the operation of ICE automobiles, we
have seen a renewed interest in the EV. The early
air quality concerns in the 1960’s and the energy
crisis in the 1970’s have brought EV’s back to the
street again.
II. LITERATURE SURVEY
[1] A. Khanipour, K. M. Ebrahami and W. J.
Seale published “Conventional Design and
Simulation of an Urban Hybrid Bus” in
World Academy of Science, Engineering
and Technology Transactions,2006,
describing the study, design and
development of series hybrid bus
validating the fuel efficiency and emission
requirements. The simulation platform
used was ADVISOR, a Matlab / Simulink
platform. The validation of fuel efficiency
was performed on standard driving cycle
with observation of fuel consumption
reduction by 40 percent in their design.
[2] Sanghpriya H. Kamble, Tom V. Mathew
and G. K. Sharma, reported in
“Development of Real World Driving
Cycle: Case Study of Pune, India,” for
Central Institute of Road Transport, Pune,
India, 2010, describing the methodologies
of construction of driving cycles,
comparison of standard driving cycles
with formulation of acceleration,
declaration, cruise period for the city
Pune, India.
III. SPECIFICATIONS OF EV AND HEV
SYSTEM DESIGN
A. System Design Constraints:
Vehicle operation

2. consists of three main segments. These are: 1) the
initial acceleration; 2) cruising at vehicle rated
speed. These three operations provide the basic
design constraints for the EV and HEV drivetrain.
A drivetrain capable of meeting these constraints
will function adequately in the other operational
regimes. Refinements to these basic design
constraints are necessary for an actual commercial
product, but those are beyond the scope of this
paper. The objective here is to meet these
constraints with minimum power. The variables
defining the above design constraints are:
[1] Vehicle rated velocity.
[2] Specified time to attain this velocity.
[3] Vehicle maximum velocity.
[4] Vehicle mass and other physical
dimensions.
a) Initial Acceleration:
The initial acceleration force takes the vehicle from
standstill to its rated velocity, , in some specified
time, seconds. This force is supplied entirely by the
electric power train in an EV or series HEV. In a
parallel HEV, the acceleration force is supplied by
the electric power train in combination with the
ICE power train.
b) Cruising at Rated Vehicle Speed:
The electric motor provides the necessary
propulsion force at rated vehicle speed in the EV
and series HEV. On the other hand, the ICE of the
parallel HEV should be capable of delivering
enough force, without any help from the electric
power train, to overcome road load and cruise at
the rated vehicle speed on a grade of at least 3%. In
addition, there should be a margin of about 10%
power to charge the battery pack.
B. System Design Variables:
The main component
of the EV is its electrical power train. However, in
the HEV the propulsion system is a combination of
the electric motor and ICE. The electric propulsion
design variables are:
[1] Electric motor power rating.
[2] Motor rated speed.
[3] Motor maximum speed.
[4] The extent of constant power speed range
beyond the rated speed.
[5] Gear ratio between motor shaft and the
wheel shaft (transmission).
Designing an optimal torque-speed profile for the
ICE is beyond the scope of this paper. However,
assuming a typical ICE torque-speed profile, we
will specify the required ICE power by our design
procedure. Therefore, the design variables for the
mechanical propulsion system are:
[1] ICE siz.
[2] Gear ratio between ICE and the wheel
shaft.
As mentioned earlier, the main design objective is
to find the minimum drive weight, volume, and
cost that will meet the design constraints with
minimum power. EV system design is addressed
first. The HEV system design is then presented as a
modification of the EV system design
IV. PICK YOUR CONFIGURATION
Even settling on this type of HEV does not end the
choices.The wide variety of possible engine-battery
HEV configurations fall into two basic categories:
series and parallel. In a series hybrid, the
internal-combustion engine drives a generator that
charges the batteries, which power the electric
motor. Only this electric motor can directly turn the
vehicle’s driveshaft. In a parallel hybrid, on the
other hand, either the engine or the motor can
directly torque the driveshaft. A parallel HEV does
not need a generator, because the motor serves this
function. (When the engine turns the driveshaft, it
also spins the motor’s rotor when the clutch is
engaged. The motor thus becomes a generator,
which can charge the batteries.) Both the parallel
and the series hybrid can be operated with
propulsion power coming only from the battery
with power supplied only by the
internal-combustion engine (in a series hybrid, this
power must still be applied through the generator
and the electric motor), or with power from both
sources. One advantage of the parallel scheme is
that a smaller engine and motor can be used,
because these two components can work together.
Disadvantages of the parallel configuration include
the fact that the designer no longer has the luxury
of putting the internal-combustion engine anywhere
in the vehicle, because it must connect to the
drivetrain. In addition, if a parallel hybrid is
running electrically, the batteries cannot be charged
at the same time, because there is no generator. The
distinct features of the two types of HEV suit them
to different driving needs. Briefly: a series hybrid is
generally more efficient but less powerful than a
parallel HEV. So if the car is to be used for a daily
commute of 35 kilometres or less each way, and
perhaps the odd longer trip every now and then, a
series HEV will do just fine. On the other hand, if
the vehicle is to function and feel more like a
conventional, gasoline-powered car, then a parallel
hybrid may be necessary. Whereas a series hybrid
might very well suffice for a mission involving
many short trips a day (to make deliveries, say), a
parallel hybrid would be preferable for heavy
highway use, where bursts of speed are necessary
for passing. A parallel HEV can also usually
muster more speed on hills than a series hybrid, if
both have been designed basically for moderate
performance.

3. V. VEHICLE MODEL
Two different approaches to the HEV modelling
can be adopted: the backward- and forward-facing
modelling with respect to the physical causality
principles. The former makes the assumption that
the vehicle meets the target performance, so that
the vehicle speed is supposed known and the power
request is calculated using the kinematical
relationships imposed by the drivetrain.
Forward-facing modelling, on the contrary, takes as
inputs the driver commands and, simulating the
physical behaviours of each component, generates
the vehicle performance as output. The
backward-facing approach is beneficial in
simplicity and low computational cost, while
forward facing, requiring the resolution of the
differential motion equation of the vehicle, needs
more computational time. However, when the
vehicle modelling serves as a platform for the
implementation of the control strategy of an actual
vehicle, the forward-facing approach seems more
appropriate. In this way, the simulator reflects the
actual architecture of the vehicle and the control
strategy developed in the simulator can directly be
implemented in the actual vehicle. The open-circuit
voltage V1 is considered a function of the battery
state of charge (SOC), while the internal resistance
Rin is function of the SOC but also of the operating
mode (charging/ discharging). These functions are
available from experimental data published by the
constructor. The Driver module compares the
desired vehicle speed with the actual vehicle
velocity and, through a PI controller, calculates the
accelerator or brake commands. These signals are
sent to the Powertrain to calculate the tractive force
at the wheels. The actual vehicle velocity is then
calculated by considering the tractive force and the
total force needed to overcome the aerodynamic,
grade and rolling resistance. After the simulation is
completed, vehicle performance, such as fuel
economy, vehicle speed trace, SOC, engine and
electric machine operating points, can be displayed.
VI. FUTURE SCOPE
Urbanization has caused many affects on public
life. Presently, the daily activities are mainly
dependent on vehicles. So the density of vehicles in
city areas is increasing day by day. Mainly, many
of these vehicles are all dependent on non
renewable energy resources like petrol and diesel.
These resources are extinguishing day by day and
may not last long. People are also taking war in
certain countries because of oil crisis with political
instability. With all these factors, it’s seen that the
prices of oil going high day by day making the
common man’s life unbearable. Design and
development of automobile was not carried in a
single day. With several hands in picture, the
present automobiles are on roads. As vehicles have
become the phantom in human life, its design,
development and existence plays a major role in
present generation.
Since the invention of wheel in ancient age, the
development of automotives is one of its boons to
mankind. Throughout the generations, different
vehicular architectures were designed with several
propulsion techniques, with efficient utilization for
several applications. Categorization includes steam
engines, internal combustion engines and electric
vehicles.
VII. CONCLUSION
A design methodology for EV and HEV propulsion
systems is presented based on the vehicle

4. dynamics. This methodology is aimed at finding
the optimal torque-speed profile for the electric
power train. The design is to meet the operational
constraints with minimum power requirement. The
study reveals that the extended constant power
operation is important for both the initial
acceleration and cruising intervals of operation.
The more the motor can operate in constant power,
the less the acceleration power requirement will be
Several types of motors are studied in this context.
It is concluded that the induction motor has clear
advantages for the EV and HEV at the present. A
brushless dc motor must be capable of high speeds
to be competitive with the induction motor. The
switched reluctance motor may be superior to both
of these motors for vehicle application both in size
and cost. However, more design and evaluation
data is needed to verify this possibility. The design
methodology of this paper was applied to an actual
EV and HEV to demonstrate its benefits. Clearly,
the detailed design of a vehicle propulsion system
is more complicated than in our examples.
However, this methodology can serve as the
foundation of the detailed design.
VIII. REFERENCE
[1] A. Alison, “Searching for perfect fuel ... in
the clean air act,” in Proc. Environ. Veh.
Conf., Dearborn, MI, 1994, pp. 61–87.
[2] S. Barsony, “Infrastructure needs for EV
and HEV,” in NIST Workshop Advanced
Components for Electric Hybrid and
Electric Veh., Gaithersburg, MD, 1993,
pp. 14–23.
[3] A. F. Burke, “Hybrid/electric vehicle
design options and evaluations,” SAE
Paper #920447, Feb. 1992.
[4] A. Ralston and P. Rabinowitz, A First
Course in Numerical Analysis, 2nd ed.
New York: McGraw-Hill, 1978.
[5] H. A. Toliyat, K. M. Rahman, and M.
Ehsani, “Electric machines in electric and
hybrid vehicle applications,” in Proc. 1995
Int. Conf. Power Electronics, Seoul,
Korea.
[6] Chan CC. An overview of electric vehicle
technology. Proc of IEEE
1993;81(9):1202–13.
[7] Chau KT, Wong YS, Chan CC. An
overview of energy sources for electric
vehicles. Energy Convers Mgmt
1999;40(10):1021–39.
[8] Wakefield EH. History of the electric
automobile: hybrid electric vehicles.
Warrendale: Society of Automotive
Engineers; 1998.
[9] Wouk V. The hybrids are coming!
Proceedings of the 17th International
Electric Vehicle Symposium, 2000,
CDROM.