The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 23, 2007
Filed:
Oct. 21, 2004
Takashi Shinmoto, Tokyo, JP;
Yuji Urabe, Sakura, JP;
Tatsuya Murofushi, Sakura, JP;
Tatsuya Ogawa, Tokyo, JP;
Takashi Shinmoto, Tokyo, JP;
Yuji Urabe, Sakura, JP;
Tatsuya Murofushi, Sakura, JP;
Tatsuya Ogawa, Tokyo, JP;
Fujikura Ltd., Tokyo, JP;
Abstract
An insulation degradation diagnostic device () comprises a current transformer (), a first amplifier (), a first high-pass filter (), a low-pass filter (), a second amplifier (), a second high-pass filter (), and a discharge judgement section (). The current transformer () has a filtering function, with an amount of attenuation of −60 dB or less and a slope characteristic of −5 dB/oct or less at a commercial frequency and detects a current flowing through a grounding conductor (). The first amplifier () amplifies a current signal from the current transformer (). The first high-pass filter () removes a low frequency component from an amplified current signal. The low-pass filter () removes a high frequency component from a current signal from which the low frequency component has been removed. The second amplifier () amplifies a current signal from the low-pass filter () to a predetermined level. The second high-pass filter () extracts a signal corresponding to a discharge current caused by a partial discharge from the current signal amplified in the second amplifier (). The discharge judgement section () judges whether or not a partial discharge has occurred in a cable () based on the signal extracted in the second high-pass filter ().