Details

Autor(en) / Beteiligte

• Niyomsatian, Korawich
• Gyselinck, Johan J. C.
• Sabariego, Ruth V.

Titel

Experimental Extraction of Winding Resistance in Litz-Wire Transformers-Influence of Winding Mutual Resistance

Ist Teil von

• IEEE transactions on power electronics, 2019-07, Vol.34 (7), p.6736-6746

Ort / Verlag

New York: IEEE

Erscheinungsjahr

2019

Link zum Volltext

• IEEE_Xplore

Quelle

IEEE Electronic Library (IEL)

Beschreibungen/Notizen

• The extraction of winding resistance from impedance measurements needs a compensation of undesirable effects, e.g., core loss and distributed winding capacitance. This paper rigorously shows that the core loss (or core-loss resistance) measured with the two-winding method always includes the effect of the winding mutual resistance. At high frequencies, this effect becomes more prominent and can cause an overestimation of the measured core-loss resistance. As a result, the compensated winding resistances can be significantly underestimated. To mitigate this effect, this paper proposes to measure the core-loss resistance on an auxiliary 1:1 transformer with single-turn windings. Consequently, it is scaled to obtain the actual core loss. The proposed analysis and method is applicable to multiwinding systems. For validation, this paper considers a gapped transformer with litz-wire winding for high-frequency operations. The experimental results are validated against the results from its three-dimensional finite-element (FE) model. The litz-wire winding is considered in the FE model by means of a homogenization approach. With the method proposed in this paper, the experimentally extracted winding resistances become more accurate and are in good agreement with the FE results.