DTC

1. Design of Fuzzy logic based
Sliding Mode Controller for
Indirect Vector Control of
Induction Motor
Submitted by :
Nalini
Guided by : Srini Naik

2. Contents
• Introduction
• Literature Survey
• Technology Used
• Mathematical Modeling
• Project Specification
• Future Scope

3. Introduction
• The traditional way to control the speed of
induction motors is the V/Hz-control
• Low dynamic performance
• In applications like sensorless drives and
rolling mills quick torque response is
required.
• Desire to replace induction drives led to
vector control

4. What is Fuzzy logic based vector control?
• Fuzzy logic based Vector control implies that an ac
motor is forced to behave dynamically as a dc motor
by the use of feedback control.
• Always consider the stator frequency to be a variable
quantity.
• Think in synchronous coordinates.
• There are two approaches to vector control:
Direct field oriented current control
Indirect field oriented current control

5. Literature Survey
• Dynamic model of Induction motors for vector
control by Dal Y. Ohm Drivetech, Inc., Blacksburg,
Virginia.
• A Novel Fuzzy Logic Controller for Indirect Vector
Control Induction Motor Drive by Yang Liyong, Li
Yinghong, Chen Yaai and Li Zhengxi, Shijingshan,
Beijing, China.
• Fuzzy logic based speed controller for vector
controlled cage induction motor drive by Sanjiv
Kumar, Bhim Singh, J.K. Chatterjee,New Delhi

6. Fuzzy logic based Vector Control
• The technique of vector control based on
separating out the two basic function of stator
current.
• The current is controlled in the d- direct and q-
quardarure directions.
j
ref ref ref
s sd sq
i i
 
i
magnetization
Torque production

7. Fuzzy Sliding Mode Controller for induction motor
Fig- block diaram of Fuzzy Sliding Mode Controller for induction motor

8. Mathematical Modeling
• In the controller two inverse transforms are
performed:
1)From the synchronous d-q to the stationary
d-q reference frame;
2) From d*-q* to a*, b*, c*.

9. A few of the salient features of Fuzzy Sliding Mode Controller
for induction motor are:
•The frequency e of the drive is not controlled (as in scalar
control). The motor is “self-controlled” by using the unit vector to
help control the frequency and phase.
•There is no concern about instability because limiting within the
safe limit automatically limits operation to the stable region.
•Transient response will be fast because torque control by iqs does
not affect flux.
•Vector control allows for speed control in all four quadrants
(without additional control elements) since negative torque is
directly taken care of in vector control.

10. EXPECTED RESULTS

11. EXPECTED RESULTS

12. EXPECTED RESULTS

13. Indirect vector control based induction motor

14. Induction motor Speed

15. Reference Speed and Actual speed

16. Fuzzy logic based Sliding Mode Controller for induction motor
torque anr torque reference 2
torque anr torque reference 1
torque anr torque reference
stator voltages
stator currents
speederror 1
speederror
speed and speed reference
n
flux trajectory
flux Table
Timer
T
Satur
PI
In1 Out1
NN
PHIr
Is
speed error
Induction Machine
model
TL
Uabc
Te
n
Is _abc
Ir_abc
Is _aB
Ir_aB
PHIs
PHIr
Gain 1
1/5
Gain
-K-
Fuzzy Logic
Controller
Fcn
f(u)
Demux
Demux
Demux
DTC
T
Tf
flux
PHIs
Uphase
Uline
0

17. Fuzzy logic controller

18. Dynamic response of motor speed using FLC based sliding mode control

19. conclusion
The Proposed concept has successfully demonstrated the
application of the proposed fuzzy sliding mode control system
to an indirect field-oriented induction motor drive for tracking
periodic commands.
The design and description of the classical fuzzy logic based
sliding mode controller (SMC) is presented in detail.
Then, the fuzzy logic control is used to mimic the hitting
control law to remove the chattering.
The developed fuzzy logic control with sliding mode control of
induction motor drive shows fast response, smooth
performance, and high dynamic response with speed changing
and transient conditions.