1) The document presents a seminar on controlling a switched reluctance machine operating in generating mode using a microcontroller. 2) A mathematical model of the switched reluctance machine is developed using analytical modeling techniques to determine flux linkage and inductance. 3) A power converter circuit, rotor position and speed sensors, and control feedback system are modeled in MATLAB and interfaced with a microcontroller. 4) The microcontroller is programmed to control the speed and current of the switched reluctance generator based on the mathematical model and simulations.

1. SEMINAR PRESENTATION
BRUNO GODSPOWER SABASTINE
PROJECT SUPERVISORS
PROF. ENGR. C. M NWOSU
DR. C. J. NNONYELU

2. TITTLE
MICROCONTROLLER BASED
CONTROL OF A SWITCHED
RELUCTANCE MACHINE OPERATING
IN GENERATING MODE.

3. INTRODUCTION
Switched Reluctance Machine is a variable drive that runs by reluctance torque. It is
simplest form of an electrical machine. It consist of a stationary part, the stator and a
moving part, a magnetic rotor with saliency. The rotor and the stator are made of steel
laminations, and only the stator poles have windings concentrated around it. The rotor
has no windings and brushes. The windings on one of the stator pole are connected in
series with the opposite stator to form one phase.
It can operated both as a generator and a motor depending on its inductance profile.
It is simple in design and cheaper in cost. It has wide range of application in household
appliances, aerospace, wind energy technology and hybrid electric vehicle

4. STRUCTURE OF A SIMPLE 8 STATOR (4PHASE), 6 POLES, A
CLASS CONVERTER DRIVE CIRCUIT AND IGBT

5. STATEMENT OF PROBLEM
Switched Reluctance Machine is gaining competitive edge in the variable drive
applications. This is due to its unique features when compared to other existing
variable drives. But it is still being faced with the problem of Torque ripple and
acoustic noise. This problem is either caused mechanically through the design
process or electrically due to improper control of the relationship between the flux
linkages, rotor angle position and current
Radial forces affecting the motor resulting from the mechanical design of the
machine and the nonlinear distribution of flux linkage and high amount of stator
current, result from electrical design control are the major causes of Torque ripple
and acoustic noise.

6. AIM AND OBJECTIVES OF THE PROJECT
The aim of this work is to control the
speed and current of a Switched
Reluctance Machine operating in
generating mode using microcontroller

7. SIGNIFICANCE OF THE STUDY
Switched Reluctance Machine is gaining competitive edge as a
generator in wind energy systems when compare to other existing
generators and in variable drive application. Minimization of
torque ripple will improve the efficiency and the performance of
the machine and will give the machine more edge and acceptance
over other existing wind energy generator and variable drives use
in hybrid electric vehicle and aerospace industry.

8. BRIEF LITERATURE REVIEW
Switched Reluctance Machine started to gain more attention at the end of the 20th century. Its
operation principle had already been known since 1838 but didn’t find practical use because of
unavailability of fast power electronic switches for switching. The first switched reluctance machine
used mechanical switches and it was employed by the British Navy during the world war II to perform
remote positioning of the guns on ship. The rapid development of the power electronic devices in the
1960s gave life to its development.
Lawrenson in 1980 laid the foundation for the practical design of the switched reluctance machine
drive. Other notable researchers such as Unnewehr and Koch, Wager and lang contributed to the
development of different configuration of the machine drive

9. KNOWLEDE GAP
Torque ripple still serve as a major problem facing
development and commercialization of switched reluctance
machine. Many control topologies has been introduced to
eliminate torque ripple, but each has only reduced it to a
certain percentage. I intend reduce the effect of harmonics
in switched reluctance machine operating in generating
mode.

10. METHODOLGY
SRM
Positio
n
sensor
Power
conver
ter
Gate
pulse
DC
supply
Speed
Regula
tor
Microc
ontroll
er
Output

11. METHODOLOGY
Below are outline steps used in achieving the work
i. Mathematical modelling of the switched reluctance machine
ii. Linking of Proteus to MATLAB Library
iii. MATLAB modelling of;
a. Power converter circuit
b. Rotor Angle position sensor
c. Rotor Speed sensor
d. control feedback system
e. Interfacing microcontroller to the control loop
iv. Programming of the microcontroller
v. Result and Analysis

12. MATHEMATICAL MODELLING
• Switched Reluctance Machine can either be model using either the Look-up table
approach or mathematically. Mathematical model can either be done through
• i. Analytical modelling technique
• Inductance based modelling technique
In this project I will be using the Analytical Modelling Technique

13. MATHEMATICAL MODEL
• When voltage is supplied to an electrical motor, it produces speed or rotation
ELECTRIC MOTOR
Voltage Speed or Rotation
MagneticCircuit
ElectricalCircuit MechanicalCircuit
voltage
current torque
Speed
Integrator
Magnetic
Characteristics
TorqueCharacteristics MechanicalSection
Torque,speed,
position
Voltage
Flux Linkage Current
RotorPosition

14. ANALYTICAL MODELLING TECHNIQUE
• ∅ 𝑖, 𝜃 = 𝑎1 𝜃 [1 − 𝑒 𝑎2 𝜃 𝑖 ] + 𝑎3(𝜃)𝑖……………………………….1
• This expansion summarizes the magnetic characteristics over all rotor position and current.
• Where ∅(𝑖, 𝜃) = is the flux in the function of current and rotor position
• The unknown parameter 𝑎1, 𝑎2 𝑎𝑛𝑑 𝑎3 dependent upon the rotor position
• Expanding equation 1
• ∅ 𝑖, 𝜃 = 𝑎1 𝜃 − 𝑎1 𝜃 𝑒 𝑎2 𝜃 𝑖 + 𝑎3(𝜃)𝑖
•
• Incremental inductance
• 𝐼 𝑖, 𝜃 =
𝜕∅ 𝑖,𝜃
𝜕𝑖
= −𝑎1 𝜃 𝑎2 𝜃 𝑒 𝑎2 𝜃 𝑖 + 𝑎3 𝜃 … … … … … …… … . . 2
• 𝑢𝑛𝑠𝑎𝑡𝑢𝑟𝑎𝑡𝑒𝑑 𝑝ℎ𝑎𝑠𝑒 𝑖𝑛𝑑𝑢𝑐𝑡𝑎𝑛𝑐𝑒
• Neglecting the exponential function
• 𝐿 𝜃 = −𝑎1 𝜃 𝑎2 𝜃 + 𝑎3 𝜃 … … … … …… … … … … .3
• From equation 3
• 𝑎1 𝜃 𝑎2 𝜃 = 𝑎3 𝜃 − 𝐿 𝜃 … …… … … … … 4
• Dividing both side by 𝑎1 𝜃
• 𝑎2 𝜃 =
𝑎3 𝜃 −𝐿 𝜃
𝑎1 𝜃
… … … … …… … … … 5
• 𝑎1 𝜃 , 𝑎1 𝜃 𝑎𝑛𝑑 𝐿 𝜃 𝑎𝑟𝑒 𝑑𝑒𝑡𝑒𝑟𝑚𝑖𝑛𝑒𝑑 𝑓𝑟𝑜𝑚 𝑡ℎ𝑒 𝑒𝑙𝑒𝑣𝑒𝑛 𝑝𝑎𝑟𝑎𝑚𝑒𝑡𝑒𝑟𝑠 𝑠ℎ𝑜𝑤𝑛 𝑖𝑛 𝑡ℎ𝑒 𝑡𝑎𝑏𝑙𝑒 𝑏𝑒𝑙𝑜𝑤

15. ANALYTICAL MODELLING TECHNIQUE

16. MATLAB MODEL

17. ROTOR ANGLE POSITION SENSING

18. POWER CONVERTER CIRCUIT

19. REFERENCES
• S.A. Nasar, “DC Switched Reluctance Motor", Proceedings of the Institution of Electrical Engineers, vol.166, no.6, June, 1996.
• D.Susitra, E.Annie Elisabeth Jebaseeli and S.Paramasivam, “Switched Reluctance Generator - Modeling, Design,
Simulation, Analysis and Control A Comprehensive Review”, international journal of computer applications (0975-8887),
volume 1, No. 2
• Raheel Muzzammel, Omer Ahmed Sajid, Mudassar Manzoor, Adnan Qayyum and Adil Shahzad, “Performance Analysis of
Switched Reluctance Motor for 24/7 Working Enviornment”, https://www.researchgate.net/publication/329842378
• Arthur Radun, “Switched Reluctance Generators and Their Control”, https://www.researchgate.net/publication/329842378
• M. Divandari and B. Rezaie, “Fuzzy Logic Control of Switched Reluctance Motor
• Drives”, http://dx.doi.org/10.5772/63642
• M. Moallen and C.M. Ong, “performance characteristics of switched reluctance motor drives”,(1989). Department of Electrical
and Computer engineering, technical reports, paper 667