Experimental Detection of Transformer Excitation Asymmetry through the Analysis of the Magnetizing Current Harmonic Content
The presence of a low DC voltage in a power grid produces an excitation asymmetry for the distribution transformers, resulting in unwanted half-cycle saturation that may impair transformer safety, reliability and efficiency, especially in increasing the reactive power, stray losses and iron losses. This paper highlights a diagnostic method based on the phase value of the particular even harmonics of a transformer excitation current as the basic marker of an excitation asymmetry. In order to achieve a straightforward insight into the nature of even harmonics behaviour, a novel method of decomposition an excitation current waveform into its unhysteretic (pure magnetization) and hysteretic components has been included in the harmonic analysis.
Authors retain copyright and grant the journal the right of the first publication with the paper simultaneously licensed under the Creative Commons Attribution 4.0 (CC BY 4.0) licence.
Authors are allowed to enter into separate, additional contractual arrangements for the non-exclusive distribution of the paper published in the journal with an acknowledgement of the initial publication in the journal.
Copyright terms are indicated in the Republic of Lithuania Law on Copyright and Related Rights, Articles 4-37.