Q8Power Quality and FACTS
Question
2 marks
Q.8. Define the term Notching. [2]
Answer
Notching is a periodic voltage disturbance caused by the normal commutation process of power electronic converters (such as line-commutated rectifiers and inverters) when current is transferred from one phase to another.
During commutation, a momentary short circuit occurs between two phases, producing a notch in the voltage waveform. Since it occurs during every cycle, notching is classified as a steady-state waveform distortion and its severity is analyzed using its harmonic spectrum rather than as a transient.