1
Arulmigu Meenakshi Amman college of Engineering
Vadamavandal-604410.
Prepared by,
V.Umapathy,
Prof. /EEE.
Imortant Questions and Answers
EE3015-CONTROL OF POWER ELECTRONICS CIRCUITS
Syllabus
1. UNIT I SIMULATION BASICS IN CONTROL SYSTEMS 6
Transfer Function-How to build transfer function, identify Poles, zeros, draw time response
plots, bode plot (Bode Plots for Multiplication Factors, Constant, Single and Double
Integration Functions, Single and Double Differentiation Functions, Single Pole and Single
Zero Functions, RHP Pole and RHP Zero Functions), state space modelling-transfer function
from state space Model.
2. UNIT II SYMBOLIC CALCULATIONS 6
Symbolic Variables - Symbolic Vector Variables, Commands for Handling Polynomial
Expressions - Extracting Parts of a Polynomial -. Factorization and Roots of Polynomials,
Symbolic Matrix Algebra - Operations with Symbolic Matrices - Other Symbolic Matrix
Operations.
3. UNIT III SLIDING MODE CONTROL BASICS 6
Introduction- Introduction to Sliding-Mode Control- Basics of Sliding-Mode Theory-
Application of Sliding-Mode Control to DC-DC Converters—Principle-Sliding mode control
of buck converter.
4. UNIT IV POWER FACTOR CORRECTION CIRCUITS 6
Introduction, Operating Principle of Single-Phase PFCs, Control of boost converter based
PFCs, Designing the Inner Average-Current-Control Loop, Designing the Outer Voltage-
Control Loop, Example of Single-Phase PFC Systems.
5. UNIT V CONTROLLER DESIGN FOR PFC CIRCUITS 6
Power factor correction circuit using other SMPS topologies: C’uk and SEPIC converter –
PFC circuits employing bridgeless topologies.
S.No. Description
Unit-I
, 2
SIMULATION BASICS IN CONTROL SYSTEMS
Prepared By: V Umapathy, Prof./EEE
Basic Concepts
Important Formula /
Concept Definition / Basic Idea Exam Tips
Key Points
A system that regulates the
Input → Controller → Two types: Open-loop
Control System output according to the desired
Plant → Output & Closed-loop
input.
Computer-based analysis of
MATLAB/Simulink Reduces design cost
Simulation system behavior before
commonly used and time
implementation.
Ratio of Laplace Transform of Applicable only to
Transfer
Output to Input with zero initial G(s)=Y(s)/U(s) Linear Time Invariant
Function (TF)
conditions. (LTI) systems
Order of Highest power of 's' in Example: S2+3S+2 → 2nd Determines system
System denominator polynomial. order dynamics
Values of 's' making
Poles Denominator = 0 Decide system stability
denominator zero.
Values of 's' making numerator Affect transient
Zeros Numerator = 0
zero. response
Ability of system to return to Stable if poles lie in Left LHP → Stable, RHP →
Stability
equilibrium after disturbance. Half Plane (LHP) Unstable
Multiplication factor affecting Changes amplitude, not
Gain (K) KG(s)
system response magnitude. pole locations
Most common test
Step Input Sudden change from 0 to 1. R(s)=1/s
signal
Used to determine
Impulse Input Instantaneous unit input. R(s)=1
impulse response
Used for steady-state
Ramp Input Linearly increasing input. R(s)=1/S2
error analysis
Transient + Steady-state Obtained using Step
Time Response Output variation with time.
response command
Transient Initial part before reaching Rise time, Peak time, Indicates speed of
Response steady state. Overshoot response
Steady-State Final output after transient
Final Value Theorem Determines accuracy
Response disappears.
Rise Time (Tr) Time required to reach 0–100% Smaller is better Indicates speed
, 3
(or 10–90%) of final value.
Peak Time Time taken to reach first Used in second-order
Depends on damping ratio
(Tp) maximum peak. systems
Maximum
Maximum output beyond final Higher damping
Overshoot Percentage overshoot
value. reduces overshoot
(Mp)
Settling Time Time required to remain within
Smaller value preferred Indicates stability speed
(Ts) ±2% or ±5% of final value.
Steady-State Difference between desired and Lower error indicates
ess=R(∞)−C(∞)
Error (Ess) actual output after long time. better accuracy
Transfer Function Modelling
Concept Explanation Key Formula
Build Transfer Represent system using numerator and denominator
G(s)=N(s)/D(s)
Function coefficients
First Order TF One pole system K/Ts+1
Second Order TF Two pole system
Pole-Zero Map Graphical representation of poles and zeros MATLAB: pzmap()
Step Response Output due to unit step input MATLAB: step()
MATLAB:
Impulse Response Output due to impulse input
impulse()
Bode Plot Basics
Component Magnitude Slope Phase Shift Important Point
Constant Gain K 20logK20\log K20logK dB 0° Horizontal line
Single Integrator (1/s) −20 dB/decade −90° Always decreasing
Double Integrator (1/s²) −40 dB/decade −180° Faster decrease
Single Differentiator (s) +20 dB/decade +90° Increasing slope
Double Differentiator
+40 dB/decade +180° Rapid increase
(s²)
−20 dB/dec after break
Single Pole (1+sT) −90° Break at 1/T1/T1/T
frequency
Single Zero +20 dB/dec after break +90° Improves stability
, 4
frequency
Right Half Plane (RHP) Similar magnitude as LHP
Additional phase lag Unstable system
Pole pole
Right Half Plane (RHP) Same magnitude as LHP Phase lag instead of Non-minimum phase
Zero zero lead system
State Space Modelling
Concept Description Equation
State Variable Minimum variables representing system state x(t)
State Equation Describes state evolution x˙=Ax+Bu
Output Equation Relates output to states y=Cx+Du
A Matrix System matrix Determines dynamics
B Matrix Input matrix Shows control input effect
C Matrix Output matrix Maps states to output
D Matrix Feedforward matrix Direct input-output relation
State Space to TF Convert using matrix relation G(s)=C(sI−A)−1B+D
MATLAB Commands (Frequently Asked)
Purpose Command
Create Transfer Function tf(num,den)
Display Poles pole(sys)
Display Zeros zero(sys)
Pole-Zero Plot pzmap(sys)
Step Response step(sys)
Impulse Response impulse(sys)
Bode Plot bode(sys)
Root Locus rlocus(sys)
Convert State Space ss(A,B,C,D)
TF from State Space tf(sys)
Quick Revision Table
Term Remember
Pole Denominator root
Arulmigu Meenakshi Amman college of Engineering
Vadamavandal-604410.
Prepared by,
V.Umapathy,
Prof. /EEE.
Imortant Questions and Answers
EE3015-CONTROL OF POWER ELECTRONICS CIRCUITS
Syllabus
1. UNIT I SIMULATION BASICS IN CONTROL SYSTEMS 6
Transfer Function-How to build transfer function, identify Poles, zeros, draw time response
plots, bode plot (Bode Plots for Multiplication Factors, Constant, Single and Double
Integration Functions, Single and Double Differentiation Functions, Single Pole and Single
Zero Functions, RHP Pole and RHP Zero Functions), state space modelling-transfer function
from state space Model.
2. UNIT II SYMBOLIC CALCULATIONS 6
Symbolic Variables - Symbolic Vector Variables, Commands for Handling Polynomial
Expressions - Extracting Parts of a Polynomial -. Factorization and Roots of Polynomials,
Symbolic Matrix Algebra - Operations with Symbolic Matrices - Other Symbolic Matrix
Operations.
3. UNIT III SLIDING MODE CONTROL BASICS 6
Introduction- Introduction to Sliding-Mode Control- Basics of Sliding-Mode Theory-
Application of Sliding-Mode Control to DC-DC Converters—Principle-Sliding mode control
of buck converter.
4. UNIT IV POWER FACTOR CORRECTION CIRCUITS 6
Introduction, Operating Principle of Single-Phase PFCs, Control of boost converter based
PFCs, Designing the Inner Average-Current-Control Loop, Designing the Outer Voltage-
Control Loop, Example of Single-Phase PFC Systems.
5. UNIT V CONTROLLER DESIGN FOR PFC CIRCUITS 6
Power factor correction circuit using other SMPS topologies: C’uk and SEPIC converter –
PFC circuits employing bridgeless topologies.
S.No. Description
Unit-I
, 2
SIMULATION BASICS IN CONTROL SYSTEMS
Prepared By: V Umapathy, Prof./EEE
Basic Concepts
Important Formula /
Concept Definition / Basic Idea Exam Tips
Key Points
A system that regulates the
Input → Controller → Two types: Open-loop
Control System output according to the desired
Plant → Output & Closed-loop
input.
Computer-based analysis of
MATLAB/Simulink Reduces design cost
Simulation system behavior before
commonly used and time
implementation.
Ratio of Laplace Transform of Applicable only to
Transfer
Output to Input with zero initial G(s)=Y(s)/U(s) Linear Time Invariant
Function (TF)
conditions. (LTI) systems
Order of Highest power of 's' in Example: S2+3S+2 → 2nd Determines system
System denominator polynomial. order dynamics
Values of 's' making
Poles Denominator = 0 Decide system stability
denominator zero.
Values of 's' making numerator Affect transient
Zeros Numerator = 0
zero. response
Ability of system to return to Stable if poles lie in Left LHP → Stable, RHP →
Stability
equilibrium after disturbance. Half Plane (LHP) Unstable
Multiplication factor affecting Changes amplitude, not
Gain (K) KG(s)
system response magnitude. pole locations
Most common test
Step Input Sudden change from 0 to 1. R(s)=1/s
signal
Used to determine
Impulse Input Instantaneous unit input. R(s)=1
impulse response
Used for steady-state
Ramp Input Linearly increasing input. R(s)=1/S2
error analysis
Transient + Steady-state Obtained using Step
Time Response Output variation with time.
response command
Transient Initial part before reaching Rise time, Peak time, Indicates speed of
Response steady state. Overshoot response
Steady-State Final output after transient
Final Value Theorem Determines accuracy
Response disappears.
Rise Time (Tr) Time required to reach 0–100% Smaller is better Indicates speed
, 3
(or 10–90%) of final value.
Peak Time Time taken to reach first Used in second-order
Depends on damping ratio
(Tp) maximum peak. systems
Maximum
Maximum output beyond final Higher damping
Overshoot Percentage overshoot
value. reduces overshoot
(Mp)
Settling Time Time required to remain within
Smaller value preferred Indicates stability speed
(Ts) ±2% or ±5% of final value.
Steady-State Difference between desired and Lower error indicates
ess=R(∞)−C(∞)
Error (Ess) actual output after long time. better accuracy
Transfer Function Modelling
Concept Explanation Key Formula
Build Transfer Represent system using numerator and denominator
G(s)=N(s)/D(s)
Function coefficients
First Order TF One pole system K/Ts+1
Second Order TF Two pole system
Pole-Zero Map Graphical representation of poles and zeros MATLAB: pzmap()
Step Response Output due to unit step input MATLAB: step()
MATLAB:
Impulse Response Output due to impulse input
impulse()
Bode Plot Basics
Component Magnitude Slope Phase Shift Important Point
Constant Gain K 20logK20\log K20logK dB 0° Horizontal line
Single Integrator (1/s) −20 dB/decade −90° Always decreasing
Double Integrator (1/s²) −40 dB/decade −180° Faster decrease
Single Differentiator (s) +20 dB/decade +90° Increasing slope
Double Differentiator
+40 dB/decade +180° Rapid increase
(s²)
−20 dB/dec after break
Single Pole (1+sT) −90° Break at 1/T1/T1/T
frequency
Single Zero +20 dB/dec after break +90° Improves stability
, 4
frequency
Right Half Plane (RHP) Similar magnitude as LHP
Additional phase lag Unstable system
Pole pole
Right Half Plane (RHP) Same magnitude as LHP Phase lag instead of Non-minimum phase
Zero zero lead system
State Space Modelling
Concept Description Equation
State Variable Minimum variables representing system state x(t)
State Equation Describes state evolution x˙=Ax+Bu
Output Equation Relates output to states y=Cx+Du
A Matrix System matrix Determines dynamics
B Matrix Input matrix Shows control input effect
C Matrix Output matrix Maps states to output
D Matrix Feedforward matrix Direct input-output relation
State Space to TF Convert using matrix relation G(s)=C(sI−A)−1B+D
MATLAB Commands (Frequently Asked)
Purpose Command
Create Transfer Function tf(num,den)
Display Poles pole(sys)
Display Zeros zero(sys)
Pole-Zero Plot pzmap(sys)
Step Response step(sys)
Impulse Response impulse(sys)
Bode Plot bode(sys)
Root Locus rlocus(sys)
Convert State Space ss(A,B,C,D)
TF from State Space tf(sys)
Quick Revision Table
Term Remember
Pole Denominator root
