TY - JOUR
T1 - Low-frequency eddy current testing using HTS coil driven by PWM inverter
AU - Sasayama, Teruyoshi
AU - Enpuku, Keiji
N1 - Funding Information:
This work was supported in part by the Cross-Ministerial Strategic Innovation Promotion Program (SIP), Cabinet Office, Government of Japan.
Publisher Copyright:
© 2019 IOS Press and the authors. All rights reserved.
Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2019
Y1 - 2019
N2 - When testing ferromagnetic materials such as iron, low-frequency eddy-current testing (LF-ECT) is used to avoid the skin effect. However, the drawback of LF-ECT is that the signal becomes weak at low frequencies. Furthermore, when the specimen is covered with protective materials, the signal becomes even weak, owing to the large lift-off. To overcome these drawbacks, we utilize a high-temperature superconducting (HTS) coil and a pulse-width modulation (PWM) inverter in the LF-ECT method. Using an HTS coil and a PWM inverter, strong currents are conducted, and the change in the coil resistance can be easily measured. The small impedance change of the HTS coil is detected by using a Maxwell bridge. The result demonstrates that a steel plate thickness of up to 20 mm can be estimated based upon the measurements of the change in the coil resistance, even when the lift-off is 98 mm.
AB - When testing ferromagnetic materials such as iron, low-frequency eddy-current testing (LF-ECT) is used to avoid the skin effect. However, the drawback of LF-ECT is that the signal becomes weak at low frequencies. Furthermore, when the specimen is covered with protective materials, the signal becomes even weak, owing to the large lift-off. To overcome these drawbacks, we utilize a high-temperature superconducting (HTS) coil and a pulse-width modulation (PWM) inverter in the LF-ECT method. Using an HTS coil and a PWM inverter, strong currents are conducted, and the change in the coil resistance can be easily measured. The small impedance change of the HTS coil is detected by using a Maxwell bridge. The result demonstrates that a steel plate thickness of up to 20 mm can be estimated based upon the measurements of the change in the coil resistance, even when the lift-off is 98 mm.
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U2 - 10.3233/JAE-171117
DO - 10.3233/JAE-171117
M3 - Article
AN - SCOPUS:85063347279
SN - 1383-5416
VL - 59
SP - 1275
EP - 1282
JO - International Journal of Applied Electromagnetics and Mechanics
JF - International Journal of Applied Electromagnetics and Mechanics
IS - 4
ER -