Question

What is the effect of phase-lag compensation on the performance of the servo system?

(a) For a given relative stability, the velocity constant is increased

(b) For a given relative stability, the velocity constant is decreased

(c) The bandwidth of the system is increased

(d) The time response is made faster

The question was posed to me during an interview.

Question is taken from Design Considerations for Higher-Order Systems in division Time Response Analysis, Design Specifications and Performance Indices of Control Systems

Answer 1

Correct option is (a) For a given relative stability, the velocity constant is increased

Easiest explanation: Phase lag compensation is an integrator. It reduces the steady state error. Velocity constant = 1/ (steady state error). So, the velocity constant is increased.