Rahat Ullah Khan et al. / International Journal of Engineering Science and Technology
Vol. 2(3), 2010, 312-316
ANALYSIS OF INNOVATIVE APPLICATIONS OF
SINGLE DC MOTOR IN SERIES AND
SEPARATELY EXCITED MODE FOR HYBRID
ELECTRIC SOLAR CAR
Rahat Ullah Khan#1
Mohd. Arif Khan#2
Huma Arjumand#3
#1&2 Department. of Electrical Engg., KIET, Ghaziabad,-201 206 email - rahatkhan@kiet.edu,
mdarif27@rediffmail.com.
#3 Department. of Electrical Engg., Ideal Institute of Technology, Ghaziabad, email –
huma_arjumand@rediffmail.com
Abstract
In this paper an innovative technique is proposed to run a DC series motor and converting it into D C separately
excited as and when required to do regenerative braking and controlling a loaded car. In this scheme we are
proposing on alternate energy source for driving the car i.e. solar PV Cell based battery charging system. The
implication, basic concept and limitations of this concept are discussed. Also the mode of operations including
analysis and operating conditions is also discussed. The simulation results are provided to validate the concept.
I.
INTRODUCTION
Automobiles, which has become a major part of our life also consumes non-renewable fuels like diesel or petrol
which are costly to run, hazardous to environment and also limited for future use. For eliminating all these
future problems related to automobile’s future we need to design some future vehicles, just like our solar car
which is a good renewable automobile which is cheap to run, environment-friendly and for which unlimited
energy resource is available.
Today in this running world most of the energy requirements are done by compensating non-renewable
energy resources. For eliminating all the future problems we need to make proper use of our precious nonrenewable resources available to us in present for that the best way is to find renewable alternatives for them and
thus conserving them too.
Solar energy stands form a major part of available renewable energy resources. Same is for automobiles which
have become a major part of our life also consumes non-renewable fuels like diesel or petrol which are costly to
run, hazardous to environment and also limited for future use.
For eliminating all these future problems related to automobile’s future we need to design future
vehicles just like solar car which is renewable energy based automobile which is cheap to run, environmentfriendly and for which unlimited solar energy source is available.
The simple approach done in running our solar car is to receive solar energy and convert its maximum
part into electrical energy by photovoltaic and storing it as D.C. and using this stored energy to run and control a
D.C. Motor to run the car.
The most important and intresting part of this analysys is the Innovative Application of DC Motor in Series and
Seperately Excited Mode, while we are moving and in the mean time of switching from one mode to another
mode we also have an option to get the regenrative braking system in which we may store the energy generated
in various speed modes.
II.
1.
2.
3.
4.
MILESTONES OF THE ANALYSIS
Mechanism of converting motor from series to separately excited & vice-versa.
Optimum Use of the solar energy available.
Making the environment free of all green house gases
Commute at very low running cost.
ISSN : 0975-5462
312
Rahat Ullah Khan et al. / International Journal of Engineering Science and Technology
Vol. 2(3), 2010, 312-316
Fig 1 Schematic representation of Basic assembly of different components
Fig. 1 represents the schematic of the basic mechanism of the proposed technology for the solar energy
conversion, maximum power point tracker, potentiometers for voltage measurement, battery bank for idle
condition charging and running and motor changing from series to separately excited and separately excited to
series operation with the help of speed sensors and PLCs.
III.
DESCRIPTION
We impose or cast solar panels on the top of our car which gives them maximum surface area of exposure to
sunlight. These photovoltaic cells convert solar energy into electrical energy which we will be store in dc
tubular battery bank (which are light in weight) and the process of receiving of direct current and charging
battery bank in done by means of the M.P.P.T (Maximum Power Point Tracking) type charge controller to
minimize loss and also to improve efficiency.
We will also add some capacitors to our battery bank to improve the charging capacity of our batteries .Now this
battery bank will supply rated direct current to the rated series motor required to run the wheels and hence the
car .
To control the car we need to control the motor for which we will use a motor controller or drive which will be
used to do regenerative braking, controlling speed of the car and also to start and stop the car.
To run the car we need a high starting torque for which dc series motor is most suitable but for regenerative
braking we need a separately excited DC motor so to overcome this problem we propose to connect the dc series
motor with a PLC and an another field coil and connecting this in such a way that we will start and run our
motor with dc series and set a speed limit crossing which PLC will automatically cut series winding and in very
short time i.e. in seconds connect separately excited field winding in running conditions at same parameters thus
making it separately excited and vice versa.
This may improve the car performance and also gives a concept to utilize single motor for dual purpose and
also charge auxiliary battery by regenerative braking thus making maximum use of energy and hence offering
maximum efficiency of the system
MOTOR SWITCHING
In the motor switching we are taking a DC motor circuit apparatus comprising of two field coils and an
auxiliary battery and PLC switching circuit with digital speedometer and analyzer circuit in this apparatus we
will connect according to the given circuit diagram .
On switching on the main power supply and starting and running this motor the digital speedometer takes the
rpm speed reading to the analyzer circuit which according to the set value gives a process signal to the PLC
circuit which will send a process signal (that whether the speed of car is in limits of series motor or separately
ISSN : 0975-5462
313
Rahat Ullah Khan et al. / International Journal of Engineering Science and Technology
Vol. 2(3), 2010, 312-316
excited) and according to which PLC switch on and off the connections thus making motor series to separately
excited or vice-versa.
Advantages of motor switching with the help of PLC:1.
It helps in improving the vehicle efficiency.
2.
It also proves to be economical and easier to use where both series and separately excited motor needs to
be worked for completing a single job under given conditions.
This technology will make apparatus very compact as both operation of series and separately excited if done by
single motor.
PLC Switching Circuit
M
Velocity Sensor
Analyzer Circuit
Auxiliary
Battery
Battery
Fig 2 circuit diagram for motor switching
Fig 2 describes the logic of operation with the help of analyzer circuit taking input from velocity sensor
and giving signals to the PLC and switching devices, responsible for the motor changing from series to
separately excited and separately excited to series operation with the help of speed sensors and PLCs,
auxiliary batteries are provided to be used in emergency conditions only when there is no solar power is
present. Another battery is provided to give separate excitation to separately excited motor.
Advantages of this system
1. To get a high starting torque.
2. To do regenerative braking.
3. To get an auxiliary Battery charged by regenerative braking for emergency use.
4. Conditions of operation:
5. We use the single motor for all three purposes i.e. DC Series, Separately Excited and as well as for
Regenerative breaking.
6. We change the motor without affecting external inertia which is due to the weight of the car.
7. This inertia we assumed that will be providing the flux continuity to both of the working condition.
8. If the motor is running at constant speed and is in the separately excited mode then small intervals
of not accelerating i.e. not breaking mechanically or manually, will be providing the regenerative
braking.
Fig 3 Speed Vs Torque
ISSN : 0975-5462
314
Rahat Ullah Khan et al. / International Journal of Engineering Science and Technology
Vol. 2(3), 2010, 312-316
curve
Fig4 Matlab model for the DC series motor to DC separately excited mode
IV. SIMULATION RESULTS
Fig. 3 shows the simulated results of Speed Vs Torque Curve. It shows that the motor is in standstill
condition when we close the switch the motor is in series mode the starting torque is very high, kink of the curve
represents the switching and after changing the mode the torque linearly increases with increase in speed.
Fig.4 shows the MATLAB/SIMULINK model of the proposed scheme and all the blocks represents their
usual meanings.
V. FUTURE WORK
As we all know that today there is a great and large crisis of non-renewable sources of energy and so we need
to compensate our requirements with renewable sources of energy for that we need renewable and nonconventional sources based appliances and so is the solar car whose future is very widely distributed and
wisely and wholly illuminated .It is definitely a future car and will be accepted by each and every family in
this world but it presently needs some more innovations and research to be done.
Our solar car model proves to be better as:1. Widely and commercially acceptable.
2. It is very safe.
3. It may eliminate many problems Such as power losses.
4. The dual purpose application may be used for other applications in industry as it is saving one complete
motor.
5. It can also serve as an electric car.
VI- CONCLUSION:
By using this technique we may be able to use single dc motor for the dual purposes applications.
Simulation results are showing that the speed achieved is very high and the torque desired is also adequate. This
technology also encourages users because of the innovative multipurpose applications of single dc motor in
various modes resulting cost reduction and increasing the efficiency. Proposed scheme of PLC also an added
advantage as it offers the fast switching and reliable operation. In future we may use microcontrollers in place of
PLC {Programmable Logic Controllers}.
VI. REFERENCES
[1]. Project solaris university of delhi india.html
[2]. About solar car.html for nsit solar project
[3]. CEL electronics have provided us with the technical specifications about solar panels.
[4]. Curtis motor controllers website for the controller figure and other salient features. http://curtisinst.com/
ISSN : 0975-5462
315
Rahat Ullah Khan et al. / International Journal of Engineering Science and Technology
Vol. 2(3), 2010, 312-316
[5].
[6].
[7].
[8].
[9].
[10].
From www.maruti800.com, www.indiacar.com, reference for the specifications of various standard parts.
technical data for tubular batterieshttp://www.exideindustries.com/
http://mnes.nic.in/ and http://www.indiasolar.com
Title:Vehicle motor switching apparatus Document Type and Number:United States Patent 5165006
http://www.patentstorm.us/patents/5165006.html
Nakanishi Nobuyuki, Kato Satoshi, Hattori Yoichi, “Research of vehicle dynamics for solar car”, Proceedings JSAE Annual
Congress Journal Code: S0434A ISSN: 0919-1364, vol. no.121-05, page 19-22, 2005.
[11]. Richard A. Cullen President Blue Sky Energy, Inc. AT www.blueskyenergyinc.com.
[12]. Prof. Krishna Vasudevan, Prof. G. Sridhara Rao, Prof. P. Sasidhara Rao, Indian Institute of Technology Madras.
http://nptel.iitm.ac.in/courses/IIT-madras/Electrical_Machines_I /pdfs/2_8.pdf
ISSN : 0975-5462
316