TY - JOUR
T1 - 500 kVA medium-frequency core-type amorphous transformers with alternately wound sheet winding for offshore DC grid
AU - Kurita, Naoyuki
AU - Hatakeyama, Tomoyuki
AU - Kimura, Mamoru
AU - Nakamura, Kenji
AU - Ichinokura, Osamu
N1 - Funding Information:
The authors would like to thank K. Ando, K. Nakanoue, and K. Sato for their great support on the design and assembly of the MFTs. The authors also gratefully acknowledge the contribution of Dr. K. Onda to this research activity. This paper is based on the results obtained from a project commissioned by the New Energy and Industrial Technology Development Organization (NEDO).
Publisher Copyright:
© 2019 The Institute of Electrical Engineers of Japan.
PY - 2019
Y1 - 2019
N2 - This paper describes a low winding loss design methodology to develop a real-scaled medium frequency transformer (MFT) for an isolated DC-DC converter to be used in a DC-interconnected offshore wind farm system. We assembled a core-type 500 kVA MFT consisting of a lap-joint amorphous wound core and windings with a primary Cu sheet and divided secondary Cu sheets, wound alternately in turns. Then, we compared its loss performance with that of a conventionally designed MFT. The alternately wound winding structure suppressed the medium-frequency proximity effect between the Cu sheets and the in-plane eddy current due to the fringing flux crossing the edges of the sheets and fixtures, and the winding loss at 3 kHz was 61% lower than that of the conventional MFT. In addition, we propose and discuss an accurate estimation method for the winding loss of core-type MFTs, considering the in-plane eddy current loss at the edge of the Cu sheets based on the finite element method.
AB - This paper describes a low winding loss design methodology to develop a real-scaled medium frequency transformer (MFT) for an isolated DC-DC converter to be used in a DC-interconnected offshore wind farm system. We assembled a core-type 500 kVA MFT consisting of a lap-joint amorphous wound core and windings with a primary Cu sheet and divided secondary Cu sheets, wound alternately in turns. Then, we compared its loss performance with that of a conventionally designed MFT. The alternately wound winding structure suppressed the medium-frequency proximity effect between the Cu sheets and the in-plane eddy current due to the fringing flux crossing the edges of the sheets and fixtures, and the winding loss at 3 kHz was 61% lower than that of the conventional MFT. In addition, we propose and discuss an accurate estimation method for the winding loss of core-type MFTs, considering the in-plane eddy current loss at the edge of the Cu sheets based on the finite element method.
KW - Lap-joint amorphous core
KW - Leakage flux
KW - Multi-winding
KW - Offshore wind farm
KW - Proximity effect
KW - Winding loss
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U2 - 10.1541/ieejjia.8.756
DO - 10.1541/ieejjia.8.756
M3 - Article
AN - SCOPUS:85072578194
SN - 2187-1094
VL - 8
SP - 756
EP - 766
JO - IEEJ Journal of Industry Applications
JF - IEEJ Journal of Industry Applications
IS - 5
ER -