Nyquist Plot
1. How Nyquist Plot can be affected by the time delays?
The Nyquist plot undergoes a phase lag due to time delays. It can cause Nyquist Plot to rotate anticlockwise and reduction in the phase margin leads to decrease in the stability.
2. Why is the phase of a Nyquist plot continuous at the -180° point?
It continues at -180° due to the principle of causality. The Nyquist plot crosses through the point (-1, 0), which causes a phase shift of -180° since a system’s output cannot react before the input.
3. Can a system with no unstable poles be unstable according to the Nyquist Stability Criterion?
The Nyquist Stability Criterion states that a system cannot be unstable unless it also includes unstable poles. The number of unstable poles corresponds with the number of encirclements in the Nyquist plot.
Nyquist Plot
A Nyquist plot is a graphical representation used in control engineering. It is used to analyze the stability and frequency response of a system. The plot represents the complex transfer function of a system in a complex plane. The x-axis represents the real part of the complex numbers and the y-axis represents the imaginary part. Each point on the Nyquist plot reflects the complex value of the transfer function at that frequency.
- Nyquist Stability Criteria
- Important Terminologies of Nyquist Plot
- How to draw Nyquist Plot?
- Stability analysis using Nyquist Plot
- Solved Example of Nyquist Plot
- Advantages of Nyquist Plot
- Disadvantages of Nyquist Plot
- Application of Nyquist Plot
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