Howtosignalprocessing
- What causes right half plane zero?
- Why are right half poles unstable?
- Does the system become unstable when the zero enters the right half of the s plane?
What causes right half plane zero?
In other words, the output current is 180° out of phase with a. This is the circuit effect which is mathematically the right- half-plane zero. It dominates when the signal frequency is relatively high so that the inductor current cannot change significantly.
Why are right half poles unstable?
If any pole has a positive real part there is a component in the output that increases without bound, causing the system to be unstable. In order for a linear system to be stable, all of its poles must have negative real parts, that is they must all lie within the left-half of the s-plane.
Does the system become unstable when the zero enters the right half of the s plane?
The poles move towards the zeros and if there are zeros in the right half plane, the tendency for the system to become unstable is higher because finally the pole will assume the position of the zero. Such a system would be called a non-minimum phase system, and they are quite common.
