As for the wide application of arc suppression coil to the grounding in neutral point of mine high voltage grid,
grid leakage fault rules and harmonic characteristics of the neutral point grounding system through arc suppression coil
are analyzed, the selective leakage protection program “zero-sequence voltage starts, fifth harmonics of grid zerosequence
voltage and zero-sequence current are extracted for phase comparison” is proposed, and corresponding fifth
harmonic extraction circuit and power direction discrimination circuit are designed. The experimental results show that
the protective principle applies not only to the neutral point insulated power supply system, but also to the power supply
system in which neutral point passes arc suppression coil, which can solve selective leakage protection problems under
different neutral grounding ways, improving the reliability of selective leakage and guaranteeing the stability of the action
value.
A 30-GHz class-F23 oscillator in 28nm CMOS using harmonic extraction and achieving 120 kHz 1/f3 corner
