US Patent No. 10,509,021

DIAGNOSING DEVICE FOR ON-LOAD TAP CHANGING APPARATUS, DIAGNOSING METHOD FOR ON-LOAD TAP CHANGING APPARATUS, AND DIAGNOSING DEVICE FOR TRANSFORMER


Patent No. 10,509,021
Issue Date December 17, 2019
Title Diagnosing Device For On-load Tap Changing Apparatus, Diagnosing Method For On-load Tap Changing Apparatus, And Diagnosing Device For Transformer
Inventorship Li Lu, Tokyo (JP)
Yoshio Hamadate, Tokyo (JP)
Toshiaki Rokunohe, Tokyo (JP)
Akira Yamagishi, Tokyo (JP)
Hideyuki Miyahara, Tokyo (JP)
Assignee Hitachi, Ltd., Tokyo (JP)

Claim of US Patent No. 10,509,021

1. A diagnosing device for an on-load tap changing apparatus having an insulating oil tank in which insulating oil is sealed, a changeover switching device that is disposed within the insulating oil tank and performs the tap changing operation of a tap winding, a tap selector that selects the tap position of the tap winding, and a polarity (transposition) changer that inverts the polarity of the tap winding or a winding connected to the tap winding,wherein the diagnosing device includes an arc discharge light detector that detects arc discharge light that is emitted at changing the tap position of the tap selector, and
wherein the degradation degree of the insulating oil is diagnosed based on the arc discharge light detected by the arc discharge light detector.