Switched Reluctance M achines (SRM ) offer attractive attributes for automotive applications. Low cost, high reliability, and competitive weight and efficiency combine to make the switched reluctance (SR) motor drive a strong candidate for application in future electric vehicle (EV) propulsion systems. This paper proposes a methodology to determine separately the peak and continuous power ratings of a switched reluctance motor (SRM) for electric propulsion of an electric vehicle (EV).same machine have to deliver peak and continuous power for different road load condition of vehicle. Then gives switched reluctance design guidelines for battery operated electric vehicles. Finally, it presents the design and simulation of a switched reluctance motor power train.

1. Full Paper
Int. J. on Recent Trends in Engineering and Technology, Vol. 8, No. 2, Jan 2013
Design of Switched Reluctance Motor for Three
Wheeler Electric Vehicle
T.Dinesh kumar1 and M.Anand2
1
Department of EEE, PSG College of Technology, Coimbatore, India
Email: dineshkumarped@gmail.com
2
Department of EEE PSG College of Technology, Coimbatore, India
Email: and@eee.psgtech.ac.in
Abstract—Switched Reluctance M achines (SRM ) offer
attractive attributes for automotive applications. Low cost, high
reliability, and competitive weight and efficiency combine to
make the switched reluctance (SR) motor drive a strong
candidate for application in future electric vehicle (EV)
propulsion systems. This paper proposes a methodology to
determine separately the peak and continuous power ratings
of a switched reluctance motor (SRM) for electric propulsion
of an electric vehicle (EV).same machine have to deliver peak
and continuous power for different road load condition of
vehicle. Then gives switched reluctance design guidelines for
battery operated electric vehicles. Finally, it presents the
design and simulation of a switched reluctance motor power
train.
TABLE I. EV SPECIFICATIONS
Index Terms—switched reluctance motor, electric vehicle,
power rating
I. INTRODUCTION
The Automotive sector has undergone significant
changes in the last few decades. Major emphasis has been
placed on increasing efficiency, enhancing performance, reducing emissions, and developing a sustainable environment.
( ta), maximum slope or gradient (α ), rolling coefficient (Co),
This has led to an increased interest in the area of electric
EV frontal area (A , dragging coefficient (Cd), wheel radius (r),
vehicles (EVs) over the last decade In order to improve the
gear-box ratio(G). The EV specifications considered in this
effectiveness of an EV.There is a great demand for efficient,
paper are listed in Table I.
quiet, reliable, and cost-effective motor drives for propulsion
The vehicle speed is related to the electric motor speed
systems in electric vehicles. Owing to a rigid structure and
through the gear ratio and the wheel radius. All the results
the absence of magnetic source on the rotor, a switched reare reported in terms of the vehicle speed to eliminate the
luctance machine (SRM) is inherently robust and cost effecneed of considering the values of the gear ratio and wheel
tive. The performance of an electric machine can be described
radius (we assumed a single gear ratio as it is typical in EV).
by the following key parameters: 1) power density; 2) strucIn the analysis, the total losses are equal to the sum of the
tural integrity; and 3) manufacturing cost. The EV Technical
copper and total-iron losses. In the following sections, we
Specifications [1] and the NEMA Standard for Motors and
explain the procedure proposed for determining (sizing) the
Generators [2] address the rating (sizing) of electric motors
SRM ratings for EV propulsion.
used in an electric vehicle. Hence, they are used very appropriate throughout this paper. These standards require that
II. PROCEDURE FOR SIZING THE SRM
the peak and continuous power ratings be identified sepaIn a complete specification of the EV electric motor: 1) the
rately for a complete specification of an electric motor inpeak and continuous power ratings are identified separately
tended for electric propulsion of an EV. This paper presents a
and 2) the peak power is corrected according to the
detailed method to determine the two power ratings given
requirements imposed by all considered driving schedules
the vehicle specifications. A procedure for determining the
and operating conditions [3]. The peak power rating is also
peak power rating of the drive used for EV propulsion is
called the rated or continuous power; this might lead to overdescribed.
dimensioning of the electric motor although this approach
For a particular electric propulsion application, the EV
provides a safety margin.
main specifications are vehicle maximum mass (M), maximum
We can determine separately the peak power and
and rated speeds (Vev,max and Vev,r), acceleration times
31
© 2013 ACEEE
DOI: 01.IJRTET.8.2.55

2. Full Paper
Int. J. on Recent Trends in Engineering and Technology, Vol. 8, No. 2, Jan 2013
continuous power ratings by considering the EV
specifications, the SRM operation principles. Initially, the
peak power rating Pm,peak of the SRM (electric motor) is
calculated from the specified acceleration duty. We then
compare this value with: 1) , Pm,max the power for cruising at
the vehicle maximum velocity as well as , the powers required
when the EV is moving at: 2)Pm,g, 30km/hr on a 3% gradient
and ascending a 25% gradient at low speed. The value of
Pm,peak is changed to Pm,max or the highest Pm,g if any of
these values is greater than the initial value of of Pm,peak .
Continuous power rating Pm,cont of the electric motor
(SRM), is determine by driving the vehicle at maximum speed.
In other words, the SRM is capable of delivering this
Pm,cont at the chosen speed. The SRM temperature rise under
this continuous power rating should be within the limits specified in [4] for each class of insulation. Conventional auto
rickshaws are suited to the Indian environment. They are
small and narrow, allowing maneuverability on congested
roads. They have a top speed of 55 km/h or 34 mi/h and
generally carry one to four passengers and their cargo. Despite the apparent advantages in the vehicle design, auto
rickshaws present a huge pollution problem in major Indian
cities. This is due to poor vehicle maintenance and the use of
an inefficient engine with very little pollution control. For
better performance and efficiency we can go with electric
power for auto rickshaw. In this paper we are taken auto
rickshaw for selecting power rating, designing and development switched reluctance motor for battery operated electric
vehicle.
TABLE II. PEAK POWER AND CONTINUOUS POWER R ATING
IV. DESIGN OF SWITCHED RELUCTANCE MOTOR
Power developed in SRM is given by,
Pd = Ke * Kd * K1 * K2 * B * As * D2 * L * Nr
(3)
Here the stack length is assumed to be as the multiple or
submultiples of rotor bore diameter that is
L=K*D
(4)
For non-servo applications the range of K can be
0.25<K<0.7
For servo applications it’s usually the range given by
1<k<3
The specific electric loading is given by
As=stator current * No. of conductors
(5)
ΠD
As=2Tph * I * m
ΠD
m is the number of phases excited at a time in this design
taken as m=1 and I is the rms Current through the phase. The
specific electric loading in ampere conductors per meter is
usually in the range of: 25,000 < As<90000.
In this section switched reluctance motors is designed
by RMxprt. RMxprt uses a combination of analytical and
magnetic circuit equations to predict the performance of this
motor problem. RMxprt assumes the switched reluctance
motor operates with shaft position feedback to synchronize
the commutation of the phase currents with precise rotor
position single pulse operation is used phase excitation. In
the single pulse operation, each phase is energized at the
turn-on angle and switched off at the turn-off angle. The
difference between the turn-off and the turn-on angle is called
the dwell angle. RMxprt supports only switched reluctance
motors in which the number of stator poles is greater than
the number of rotor poles.
III. VEHICLE KINEMATICS
Force propelling the vehicle forward, traction force [4]
has to
 Overcome rolling resistance

overcome Aerodynamic drag
 Force needed to overcome when vehicle climbing
slope
 Accelerate vehicle
Power required for propulsion depends upon acceleration,
a=dv/dt m/s2.
(1)
Force required to propel vehicle is,
Ftr=Frr+Fad+Fg+Fa N
(2)
A. Srm Peak (Output) Power Rating
According to Indian road standard, acceleration for auto
rickshaw is a=0.65 m/s2, that is (0-30) km in 12.8 sec
 Accelerating from 0 to 30 kmph in 12.8 sec = 5.8 HP
 Maintaining 30 kmph in a 6% gradient = 5 HP.
 Cruising at the maximum vehicle velocity = 4.5 HP
Thus, the peak output power rating Pm, peak of the SRM is
specified as 5.8 HP, see Table 2.
V. MACHINE SPECIFICATION
The design specifications for the SRM comprise of the
required power output P in HP, speed N in rpm, allowable
peak phase current Ip in Ampere, and available supply voltage
V in volts for the system. Knowing the speed and power
output will automatically fix the torque to be developed by
the machine [5].Figure 1. Shows the geometry used 4 phase
SRM with 6 rotor poles and 8 stator poles. Motor dimensions
and design parameters are shown in table III.
Figure 2.shows flus linkage at various position with respect to current we can see that flux at unaligned position is
0.04 wb and at aligned position 0.08 wb.
B.Continuous (Output) Power Rating
The power requirements at the maximum vehicle velocity
of 55km/hr and for sustained speeds on gradients. The
continuous power rating Pm,cont of the SRM is specified as
4.5 HP at the SRM rated speed Table II .
© 2013 ACEEE
DOI: 01.IJRTET.8.2.55
32

3. Full Paper
Int. J. on Recent Trends in Engineering and Technology, Vol. 8, No. 2, Jan 2013
Figure 3. Efficiency vs speed
Figure 1. 8/6 Switched reluctance motor
TABLE III. MOTOR MAIN PARAMETERS
Figure 4. Output vs speed curve
A. Simulation Results
Figure 5. Torque vs speed
Figure 5.shows torque-speed characteristics of switched
reluctance motor. Starting torque should be high to propel
the vehicle. Chopper current control is applied to limit starting
current and also torque to requirement. Initial torque is locked
rotor torque which is limited because it causes sudden jurg
in vehicle. Torque produced is 50 Nm during acceleration
period, it varies for different road-load characteristics. For
maximum speed drive schedule torque is produced 7 Nm
required to propel vehicle.
Figure 6.shows inductance at aligned and unaligned
positions of stator-rotor pole.inductance profile starts every
45 degree in 8/6 configuration.since βr>βs,θ3-θ4>0 to
eliminate negative torque production by making current to
zero during this period.
Figure 2. Flux linkage at various position
Figure 3.shows efficiency at various speeds, during
acceleration efficiency is good maintained above 75% .for
different drive schedule efficiency is maintained minimum
above 68%.
Figure 4.shows output power of motor power needed
during acceleration in 5.8 HP but SRM machine is delivering
7 HP during acceleration which is enough to climb slope of
10% grading.
© 2013 ACEEE
DOI: 01.IJRTET.8.2.55
33

4. Full Paper
Int. J. on Recent Trends in Engineering and Technology, Vol. 8, No. 2, Jan 2013
Full Load Operation Data
Figure 6. Inductance profile
B.Design Data Sheet
As design and simulation process is completed data sheet
of design is generated.this data sheet provides about motor
operation lile full load and no-load operation.total material
consumption and copper consumption of winding will also
be generated.
General Gata
motor design parameters are generated in general data
sheet.
CONCLUSION
Presented an approach for determining the SRM power
ratings for a complete specification in an Electric propulsion
application. Efficiency still has to be increased that is done
by further analysis. Future work is the need to develop a
procedure to design a SRM so that the losses are limited to
the desired proportion of the total and the thermal duty is
kept low. Further analysis with different material and by
changing pole angle. Now a day’s permanent magnet motor
are replaced by major electric vehicle manufacturers as SRM
a perfect candidate for propulsion application.
REFERENCES
[1] Thomas Gyllendahl, David Tran, Development of an Auto
Rickshaw vehicle suspension, 2012.
[2] NEMA Motor-Generator standards, IEEE Industry
Applications, I999.
[3] Solar-Assisted Electric Auto Rickshaw Three-Wheeler,
Priscilla Munhall, Student Member, IEEE, M. Lukic Member
IEEE, Sanjaka G. Wirasingha Student Member, IEEE, YoungJooLee, Member, IEEE, and Ali Emadi, Senior Member, IEEE,
Vol. 59, No. 5, June 2010.
[4] Iqbal Husain, Electrical and Hybrid Vehicles – Design
Fundamentals,”CRC Press, 2003.
[5] Praveen Vijayraghavan, Design of Switched Reluctance
Motors and Development of a Universal Controller for
Switched Reluctance motor and Permanent Magnet Brushless
DC Motor Drives, November, 2001.
No- load Operation Data
© 2013 ACEEE
DOI: 01.IJRTET.8.2.55
34