Research on Harmonic Characteristics of Typical Single-Phase Non-Linear Loads

Aiming at the current situation that the waveform distortion in the low voltage distribution system was getting increasingly serious because of the wide use of single-phase non-linear loads,a large amount of harmonic tests had been carried on at different voltage conditions,the harmonic amplitude and phase spectrum were studied and researched.Referring to the load distribution situation in residential and office buildings,the equipments mentioned above were grouped,the harmonic situation of different combination was measured,the dispersion effect of all harmonic current due to phase angle diversity of different equipment was proved.Furthermore,zero sequence current ratio was proposed as an index of neutral line cross-section selection in residential and office buildings.