Q7Control System
Question
Q.7. What are the characteristics of phase-lead network?
Answer
A phase-lead network provides positive (leading) phase angle over a specific frequency range, has its zero closer to the origin than its pole, increases bandwidth and speeds up transient response, but amplifies high-frequency noise.
Key characteristics of a phase-lead network: it introduces a positive phase shift (phase lead) at frequencies between its zero and pole locations; on the pole-zero plot, its zero lies closer to the origin than its pole (i.e., |zero| < |pole|); it increases the gain crossover frequency and hence the closed-loop bandwidth, speeding up the transient response and reducing rise/settling time; it improves the phase margin, improving relative stability; and it acts approximately as a high-pass filter, so it increases susceptibility to high-frequency measurement noise.