Economy and Quality, higher working flux density of power system equipments(transformers) , with the advent in CRGO, is the main cause for generating third harmonics in system, could be reduced by lowring operating point, so operation remain in linear region of BH curve......
Yes. There is the presence of 3rd harmonic in phase-to-neutral voltage but not in the line-to-line voltage. This is because the inverter limbs are phase shifted by 120deg and under this condition, 3rd harmonic voltage of one limb is cancelled by the 3rd harmonic voltage of the other limb in line voltage between the two. A 3-wire connection to load without neutral does not give a path for any 3rd harmonic current to flow through the lines.
Maybe you use an wye connected transformer (or motor).
The neutral point of the wye connection should not be grounded.
The 3rd harmonic voltage appeares its neutral-to-ground.
Even the neutral is not grounded, a small amount of 3rd harmonic current flows through the stray capacitance and/or insulation resistance and also in some cases through the instrument transformer or voltage divider primary circuit for measuring line-to-ground voltages.
This small 3rd harmonic current is superimposed to the fundamentl current and flows through the line.
Modern higher flux density, system equipment are generating third harmonics in voltage waveform due to flat top flux wave form, even for magnetizing current without loading....
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