THIS REPORT IS BASED ON THE SIMULATION OF DC SERIES MOTOR CHARACTERISTICS AND THIS REPORT IS PREPARED WELL ACCORDING TO THE NORMS AND THE REPORT ALSO CONTAINS A MATLAB SIMULINK OF THE DC MOTOR DESIGN AND THE RESULTS ARE ALSO PLOTTED IN THIS REPORT AND THE DESCRIPTION ALSO ABOUT THE REPORT IS ALSO PREPARED WELL IN THIS REPORT AND THIS IS USEFUL FOR THE ENGINEERING STUDENTS

1. Project Report
On
Simulate DC Seriesmotor characteristics and summarise your observations
Submitted as a part of Second Year First Semester curriculum of
BACHELOR OF TECHNOLOGY
IN
ELECTRICAL AND ELECTRONICS ENGINEERING
By
Mr.P.EswarSai 18981A0237
Mr.P.Mohan 18981A0238
Ms. P.Supriya 18981A0239
Mr. P. Nithesh Kumar 18981A0240
Mr. P.Sanjay Kumar 18981A0241
Under the Supervision of
Mr.M.Srikanth
Associate Professor
Department of Electrical & Electronics Engineering
Raghu Engineering College
(Autonomous)
Accredited by NBA & NAAC with ‘A Grade, Permanently Affiliated JNTU
Kakinada
Dakamarri (v), Bheemunipatnam Mandal, Visakhapatnam, Andhra Pradesh
531162

2. Dec – 2019
RAGHU ENGINEERING COLLEGE
Department of Electrical and Electronics
Engineering
CERTIFICATE
This is to certify that case study entitled as “Simulate DC series motor
characteristics and summarise your observations” submitted by Mr.P.Mohan
(18981A0238), Ms.P.Supriya(18981A0239), Mr. P.NitheshKumar(18981A0240), Mr.P.Sanjay
Kumar(18981A0241) as a part of Second Year First Semester Curriculum of
Under Graduate Program in Electrical & Electronics Engineering at Raghu
Engineering College.
Faculty Member Head of the department
Mr.M.Srikanth Dr P. Sasi Kiran Associate Professor
Professor

3. Objective:-Simulate DC Series Motor Characteristics and
Summarise Your Observations.
DC Motor:-
• There are two types of DC motors based on the construction such
as self-excited, and separately excited.
• Similarly, self-excited motors classified into three types namely
DC series motor, DC shunt motor, and DC compound motor.
• The main function of this motor is to convert electrical energy to
mechanical energy.
Working Principle:-
The working principle of this motor mainly depends on electromagnetic
law, which states that whenever a magnetic field is formed in the region
of current carrying conductor & cooperates with an outside field, then
the rotating motion can be generated. Once the series motor is started,
then it will give utmost speed as well as torque slowly with high speed.
DC Series Motor:-
• The DC Series Motor is similar to any other motor because the
main function of this motor is to convert electrical energy to
mechanical energy.
• The operation of this motor mainly depends on the
electromagnetic principle.
• Whenever the magnetic field is formed approximately, a current
carrying conductor cooperates with an exterior magnetic field, and
then a rotating motion can be generated.

4. Components used in DC Series Motor:-
• The components of this motor mainly include the rotor (the
armature), commutator, stator, axle, field windings, and brushes.
• The fixed component of the motor is the stator, and it is built with
two otherwise more electromagnet pole parts.
• The rotor includes the armature and the windings on the core
allied to the commutator.
• The power source can be connected toward the armature
windings throughout a brush array allied to the commutator.
• The rotor includes a central axle for rotating, and the field winding
must be able to hold high current due to the larger quantity of
current throughout the winding, the larger will be the torque
produced with the motor.
• Therefore the motor winding can be fabricated with solid gauge
wire.
• This wire does not permit a huge number of twists.
• The winding can be fabricated with solid copper bars because it
assists in simple as well as efficient heat dissipation generated
accordingly by a large amount of current flow during winding.

5. DC Series Motor Circuit Diagram:-
In this motor, field, as well as stator windings, are coupled in series by
each other. Accordingly the armature and field current are equivalent.
• Huge current supply straightly from the supply toward the field
windings.
• The huge current can be carried by field windings because these
windings have few turns as well as very thick. Generally, copper
bars form stator windings.
• These thick copper bars dissipate heat generated by the heavy flow
of current very effectively.
• Note that the stator field windings S1-S2 are in series with the
rotating armature A1-A2.

6. Speed Control of DC Series Motor
The speed control of DC motors can be attained by using the two
following methods
 Flux control Method
 Armature-resistance Control Method.
Characteristics of DC series motors
Torque vs. armature current (Ta-Ia)
• This characteristic is also known as electrical characteristic.
• We know that torque is directly proportional to the product of
armature current and field flux, Ta ∝ ɸ.Ia.
• In DC series motors, field winding is connected in series with the
armature, i.e. Ia = If.
• Therefore, before magnetic saturation of the field, flux ɸ is
directly proportional to Ia.
• Hence, before magnetic saturation Ta α Ia2
.
• Therefore, the Ta-Ia curve is parabola for smaller values of Ia.
• After magnetic saturation of the field poles, flux ɸ is independent
of armature current Ia.
• Therefore, the torque varies proportionally to Ia only, T ∝ Ia.
• Therefore, after magnetic saturation, Ta-Ia curve becomes straight-
line.
• The shaft torque (Tsh) is less than armature torque (Ta) due
to stray losses. Hence, the curve Tsh vs Ia lies slightly lower.

7. • In DC series motors, (prior to magnetic saturation) torque increases
as the square of armature current, these motors are used where high
starting torque is required.
Speed vs. armature current (N-Ia)
We know the relation, N ∝ Eb/ɸ
• For small load current (and hence for small armature current)
change in back emf Eb is small and it may be neglected.
• Hence, for small currents speed is inversely proportional to ɸ. As
we know, flux is directly proportional to Ia, speed is inversely
proportional to Ia.
• Therefore, when armature current is very small the speed becomes
dangerously high. That is why a series motor should never be
started without some mechanical load.
• But, at heavy loads, armature current Ia is large. And hence, speed
is low which results in decreased back emf Eb.
• Due to decreased Eb, more armature current is allowed.
Speed vs. torque (N-Ta)
This characteristic is also called as mechanical characteristic. From the
above two characteristics of DC series motor, it can be found that
when speed is high, torque is low and vice versa.

8. Simulation:-
The dc series motor circuit in the matlab Simulink
And the results are plotted below.

9. The results are shown below
Torque vs armature current result
Speed vs armature current

10. Speed vs torque
Observations:-
 Low field winding resistance.
 Thicker field winding with less no of turns.
 High starting torque.
 Low starting current.
 Armature generally wave wound.
 When different load torque are applied the maximum phase
current is in a steady state.
Conclusion:-
As the armature current increases, the series field receives the
same increase, intensifying the magnetic flux and torque. ... The
most important characteristic of a dc motor is the inverse
relationship between its torque and speed. That is, at low speed
torque is high and at high speed torque is low.

11.  The dc series motor reaches steady state having constant rotation
speed after transient period not exceeding 1.5s in most loading
cases.
 The maximum phase current in transient state is 370A for less than
0.2s