THENI KAMMAVAR SANGAM COLLEGE OF TECHNOLOGY
KODUVILARPATTI, THENI – 625 534
DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING
Model Examination
Branch/Year/Sem/Sec : EEE/II/III
Date/Session : 19.5.2021/FN
Subject Code/Name : EC3351 /Control Systems
Time
: 3 Hrs
Max. Marks : 100
Answer All Questions
PART – A
(10×2=20)
1. What are the components of feedback control system?
2. What are the characteristics of feedback control system?
3. The closed loop transfer function of second order system is given by
. Determine the
damping ratio and natural frequency of oscillation.
4. Draw the graph of time domain specification.
5. What are the advantages of frequency response analysis?
6. Draw the bode plot of G(s)=K/sn
7. What is lead compensator? Give an example.
8. Define BIBO stability. What is the requirement of BIBO Stability?
9. What are the advantages of sate space analysis?
10. Write the state model of nth order system.
PART – B
(5X13= 65)
11. (a) Write the differential equations governing the mechanical system shown. Write the force
voltage and force current electrical analogous circuits and verify by writing mesh and nodal
analysis.
(OR)
(b) The block diagram of closed loop system is shown. Draw the signal flow graph and evaluate
the closed loop transfer function.
12. (a) A unity feedback controlsystem has an open loop transfer function G(S)= 10/s(s+2) . Find time
domain specifications for the step inputs of 12 units.
(OR)
(b) Derive the expression for under damped condition with necessary equations and graph.
13. (a) Sketch bode plot for the following transfer function and determine the system gain K for the
gain crossover frequency to be 5 rad/sec. G(s)=Ks2/(1+0.2s)(1+0.02s)
(OR)
(b) The open loop transfer function of a unity feedback system is given by G(s) =1/s 2 (1+s)
(1+2s).Sketch the polar plot and determine the gain margin and phase margin.
14. (a)The characteristic polynomial of the system is s7+9s6+24s5+24s4+24s3+24s2+23s+15=0.
Determine the location of roots on s-plane and hence the stability of the system.
(OR)
(b)The open loop transfer function of unity feedback system is given by
G(s)=K(s+9)/s(s2+4s+11) . Sketch the root locus of the system.
15. (a)Write the state equation for the system shown in figure in which x 1, x2.x3 constitute the state
vector. Determine the system is completely controllable and observable.
(OR)
(b)Construct a state model for a system characterized by the differential equation
d3y/dt3+6d2y/dt2+11dy/dt+6y+u=0. Give the block diagram representation of the state model.
PART – C
16. (a)Explain the design procedure of lag compensator with necessary equations.
(OR)
(b) Explain P, PI, PID, PD controllers in detail with necessary diagrams.
(1X15= 15)