Lead-Lag Compensators

Lead Compensator

The lead compensator has the following form:

On the RLD, you can identify it as a pole to the left of a zero.

The lead compensator:

• Reduces the settling time
• Increases the stability region
• Increases the steady state error

Lag Compensator

The lag compensator has the following form:

On the RLD, you can identify it as a pole to the right of a zero (both are close to 1 on the unitary circle).

The lag compensator:

• Increases the settling time
• Reduces the stability region
• Decreases the steady state error