Hemwati Nandan Bahuguna Garhwal University 2005 B.E Electrical and Electronics Engineering automatic control system - Question Paper

1. The characterstic formula of a system is provided by: 5(s^6)+8(s^5)+12(s^4)+20(s^3)+100(s^2)+150(s)+200=0 Determine the stability of the system using Routh-Hurwitz criterion.
2. elaborate the following? discuss with examples: (i) Gain margin (ii) Phase margin (iii) Polar plots
3. Consider a unity feedback system with open loop transfer function: G(s)=20(s+1)/s(s+5)(s^2+2s+10) Draw the Bode plot and determine the gain margin and phase margin.
4. Sketch the root locus plot of a unity feedback system with the open loop transfer function: G(s)=k/s(s+2)(s+4) obtain the range of values of K for which the system has damped oscillatory response. What is the greatest value of K which can be used before continuous oscillations occur?Also determine the frequency of continuous osillations. Determine the value of K so that the dominant pair of complex poles of the system has a damping ratio of 0.5.
5. explain the effect of adding (i)a pole and (ii)a zero,to the system transfer function.
6. explain the Nyquist stability criterion with suitable examples.
7. What is the basic concept of control system compensation ? elaborate the different kinds of compensation schemes used in control systems?

Earning:   Approval pending.