Compensator Design by Pole-Zero Adjustment for DC Motor

Abstract

The thesis work mainly relies upon designing of compensator especially lag compensator which can be incorporated into the system in order to improve the response of dc motor without affecting the other parameters. Compensators are specially designed under some design constraints like settling time, rise time, peak overshoot and steady state error. Improving steady state error is the key parameter which has to be taken under consideration. By suitable choice of dc motor constants, transfer functions of open loop and closed loop system are constructed and the corresponding open loop response and closed loop response is observed. The mathematical formulation of transfer function and location of poles and zeros has also been studied. The stability of the system can be analyzed by plotting poles and zeros on the root loci plot. Different compensators are designed by choosing suitable values of poles and zeroes by hit and trial method and the corresponding response curves of different compensators are compared. The closed loop response of dc motor with PID control has also been studied. In order to calculate gain margin and phase margin, bode plot has been plotted. MATLAB is used in order to study different parameters and to plot different response curves.