# What is a non minimum phase zero?

## What is a non minimum phase zero?

Non-minimum Phase systems are causal and stable systems whose inverses are causal but unstable. Having a delay in our system or a model zero on the right half of the s−plane (aka Right-Half Plane or RHP) may lead to a non-minimum phase system.

## Can we draw Bode plot for non minimum phase system?

Yes, of course! Non-minimum phase (NMP) systems appear either when a NMP element (such as transport lag) is present in the system or may be when an inner loop is unstable. One can draw Bode plot for NMP systems, but the magnitude and phase-angle plots are not ‘uniquely related’.

What is a zero in Bode plot?

For a = 0—that is, a pole or a zero at s = 0—the plot is simply a straight line of 6 dB/octave slope intersecting the 0-dB line at ω = 1. In summary, to obtain the Bode plot for the magnitude of a transfer function, the asymptotic plot for each pole and zero is first drawn.

### How do you know if a transfer function is non minimum phase?

The difference between a minimum phase and a general transfer function is that a minimum phase system has all of the poles and zeroes of its transfer function in the left half of the s-plane representation (in discrete time, respectively, inside the unit circle of the z-plane).

### What do you mean by minimum and non minimum phase systems give an example of each?

Minimum phase system: It is a system in which poles and zeros will not lie on the right side of the s-plane. In particular, zeros will not lie on the right side of the s-plane. Non-minimum phase system: It is a system in which some of the poles and zeros may lie on the right side of the s-plane.

What are the differences between minimum and non-minimum phase system?

#### Which of the following transfer function belongs to non-minimum phase system?

1.7 Non-Minimum Phase System: Delay Time delay systems are of non-minimum phase behavior. The transfer function of the time delay factor is G3(s)=exp(−τs), where τ is the delay.

#### What are poles and zeros s plane?

A pole-zero plot can represent either a continuous-time (CT) or a discrete-time (DT) system. For a CT system, the plane in which the poles and zeros appear is the s plane of the Laplace transform. In this context, the parameter s represents the complex angular frequency, which is the domain of the CT transfer function.

What is the difference between minimum and non minimum phase function?

## What are the zeros of H1 and H2 in Bode plots?

The images below show the Bode plots for (note the sign of the middle term in the numerator is different) The zeros of H1(s) are at s=-0.5±j9.987 (a negative real part, the left half of the s-plane; a minimum phase zero) and the pole of H2(s) is at s=+0.5±j 9.987 (a positive real part, the right half of the s-plane; a non-minimum phase zero).

What is an example of a non minimum phase system?

One common example of non-minimum phase systems are systems with right-half plane (RHP) zeros, although this is not the only situation where non-minimum phase systems occur . The tricky thing about non-minimum phase systems is that they have the same Bode magnitude plots as minimum phase systems .

### What is the difference between Bode phase plot and Bode magnitude plot?

The only difference is that the Bode phase plot for a non-minimum system has more phase than for a minimum system . Put another way, while every magnitude plot will display a high frequency asymptote with slope -20 (n-m) dB/dec, only minimum phase systems will display a phase plot with a high frequency phase asymptote at -90 (n-m) degrees .

### What is the minimum phase zero of H1 and H2?

The zero of H 1 (s) is at s=-10 (a negative real part, the left half of the s-plane; a minimum phase pole) and the pole of H 2 (s) is at s=+10 (a positive real part, the right half of the s-plane; a non-minimum phase zero). H 1 (s) is plotted as a solid blue line, and H 2 (s) as a dotted pink line.