Why the frequency variation is negative in the curve of instantaneous frequency vs time for the faulted phase current?

1. Can instantaneous frequency be negative?
2. How are instantaneous phase and frequency related?
3. What is instantaneous frequency in frequency modulation?
4. Why is instantaneous frequency important?

Can instantaneous frequency be negative?

Negative frequency arises often when doing the instantaneous frequency calculation on IMF. The Intrinsic Mode Function characterized by its smoothly oscillatory nature enjoys good properties of Hilbert Transform. The major one is the ruling out of negative frequency which arises often for non-IMF signals.

How are instantaneous phase and frequency related?

1 Instantaneous magnitude and phase. holds for a sinusoidal function. The angular frequency ω or for the frequency creates the sensation of pitch by hearing the sound of the wave. The pitch goes higher as the frequency increases; the sensation of pitch is in proportion to the frequency on the logarithmic scale.

What is instantaneous frequency in frequency modulation?

Instantaneous frequency is defined as the sinusoid frequency in a short window that fits the seismic trace around the corresponding time.

Why is instantaneous frequency important?

The instantaneous frequency (IF) of a signal is a parame- ter which is often of significant practical importance. In many situations such as seismic, radar, sonar, communications, and biomedical applications, the IF is a good descriptor of some physical phenomenon.