TY - GEN
T1 - Improved thin heating coil structure of copper foil feasible for induction cookers
AU - Umetani, Kazuhiro
AU - Mishima, Tomohiro
AU - Hiraki, Eiji
AU - Hirokawa, Takayuki
AU - Imai, Makoto
AU - Sadakata, Hideki
N1 - Publisher Copyright:
© 2018 IEEE.
Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2018/12/26
Y1 - 2018/12/26
N2 - Litz wire is widely utilized for heating coils of the induction cookers to suppress the proximity effect. However, low space factor of the Litz wire often significantly increases the heating coil height, which may be an obstacle of wide-spread of the induction cookers. In order to overcome this problem, a preceding study has proposed a heating coil structure of the copper foil, which suppresses the proximity effect without using the Litz wire. The preceding study has proven effective suppression of the proximity effect, when the material to be heated is placed to cover the heating coil. However, this heating coil structure still suffers from large A C resistance, when the material to be heated does not exist or partially covers the heating coil. Furthermore, the ferrite walls, installed to suppress the proximity effect, need larger height than the coil, hindering effective reduction of the total heating coil height. The purpose of this paper is to propose an improved heating coil structure. The proposed heating coil structure further incorporates a thin layer of low-permeability soft-magnetic material covering the top of the coil. This layer enables elimination of the proximity effect regardless of the existence or the disposition of the material to be heated. Furthermore, this layer enables the ferrite walls to have the same height as the coil, thus further reducing the total heating coil height. The F E M based simulation was carried out to verify the operating principle of this structure. The result supported reduction of the heating coil height and effective suppression of the A C resistance regardless of the existence and the disposition of the material to be heated.
AB - Litz wire is widely utilized for heating coils of the induction cookers to suppress the proximity effect. However, low space factor of the Litz wire often significantly increases the heating coil height, which may be an obstacle of wide-spread of the induction cookers. In order to overcome this problem, a preceding study has proposed a heating coil structure of the copper foil, which suppresses the proximity effect without using the Litz wire. The preceding study has proven effective suppression of the proximity effect, when the material to be heated is placed to cover the heating coil. However, this heating coil structure still suffers from large A C resistance, when the material to be heated does not exist or partially covers the heating coil. Furthermore, the ferrite walls, installed to suppress the proximity effect, need larger height than the coil, hindering effective reduction of the total heating coil height. The purpose of this paper is to propose an improved heating coil structure. The proposed heating coil structure further incorporates a thin layer of low-permeability soft-magnetic material covering the top of the coil. This layer enables elimination of the proximity effect regardless of the existence or the disposition of the material to be heated. Furthermore, this layer enables the ferrite walls to have the same height as the coil, thus further reducing the total heating coil height. The F E M based simulation was carried out to verify the operating principle of this structure. The result supported reduction of the heating coil height and effective suppression of the A C resistance regardless of the existence and the disposition of the material to be heated.
KW - AC resistance
KW - Copper loss
KW - Induction heating
KW - Proximity effect
KW - Skin effect
UR - http://www.scopus.com/inward/record.url?scp=85061522910&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85061522910&partnerID=8YFLogxK
U2 - 10.1109/IECON.2018.8591462
DO - 10.1109/IECON.2018.8591462
M3 - Conference contribution
AN - SCOPUS:85061522910
T3 - Proceedings: IECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society
SP - 3503
EP - 3508
BT - Proceedings
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 44th Annual Conference of the IEEE Industrial Electronics Society, IECON 2018
Y2 - 20 October 2018 through 23 October 2018
ER -