Zero sequence harmonic filter

Zero Sequence Current in Power System

Zero Sequence Current

Computer, SMPS power supplies, Single Phase UPS and Electronic devices, and LED lighting create triplen harmonic current, also called third harmonic or zero sequence harmonic; which unlike the normal current and also the industrial harmonic currents, do not get cancelled at neutral but get added and triple at neutral. That's why such load types have very high neutral current. All odd multiples of third harmonics i.e.