Features of magnetic fields produced by distorted or unbalanced systems of currents

As it is well known, at least in the low frequencies domain, generally considered up to 9 kHz, the power quality and electromagnetic compatibility are strongly connected. A poor power quality (as example, high level of harmonics, dips, voltage variations etc.) can lead to unwanted interferences in certain consumers, and reciprocally, a poor design or a badly chosen operation mode of a consumer supplied by a network can produce voltage distortions which can be quantified through power quality parameters. The paper goal is to find a relation between the harmonic currents' level and also an unbalanced system of currents flowing through a three-phase circuit and the surrounding magnetic field. A new concept is introduced, namely “total harmonic magnetic field distortion” and the lack of correlation between magnetic field and currents' distortion was studied theoretically and experimentally.