Effect of adding zeros to a control system

Addition of zeros to the transfer function has the effect of pulling the root locus to the left, making the system more stable.

1. What are the effect of adding a zero to a system?
2. What is the effect of a zero on a controller response?
3. Do zeros affect system stability?
4. What is the effect of addition of zeros on root locus?

What are the effect of adding a zero to a system?

2. Addition of zero increases the stability. Explanation: Zero is defined as the root of the numerator of the transfer function and addition of zeroes increases the stability as the speed of response increases.

What is the effect of a zero on a controller response?

Adding a LHP zero to the transfer function makes the step response faster (decreases the rise time and the peak time) and increases the overshoot. Adding a RHP zero to the transfer function makes the step response slower, and can make the response undershoot.

Do zeros affect system stability?

zeroes do not influence the stability or the asymptotic transient behavior of the system unless they precisely cancel a pole.

What is the effect of addition of zeros on root locus?

If we include a zero in the open loop transfer function, then some of root locus branches will move towards left half of 's' plane. So, it will increase the control system stability. In this case, the damping ratio δ increases.