Mumbai University > Electronics Engineering > Sem 4 > Linear Control Systems

Topic: Compensators and Controllers

Difficulty : Low

Marks : 5M

LEAD COMPENSATOR:

Pole-zero Plot:

1) Lead compensator is a high pass filter, so it amplifies high frequency noise signals.

2) Transfer function of lead compensators is

$G_{C}= \alpha \cfrac{(1+T_{s})}{1+\alpha T_{s}}$ where $0 \lt \alpha \lt 1$

Effect of lead compensator:

1) The velocity constant is usually increased.

2) Relative stability improves.

3) Phase margin increased.

4) The bandwidth is increased.

5) Reduces the amount of overshoot.

LAG COMPENSATOR:

Pole-zero Plot:

1) Lag compensator is a low pass filter, so high frequency noise signals are attenuated.

2) Transfer function of lag compensators is

$G_{C}(s)= \cfrac{(1+T_{s})}{1+\beta T_{s}}$ where $\beta \gt 1$

Effect of lag compensator:

1) Decrease in bandwidth.

2) Phase margin increased.

3) The response will be slower.

4) Transient state will be poor.

5) Steady state response is increased.