Appeal No. 2002-2232
Application 09/174,032
37. A method of on-line analysis of location of partial
discharge events during operation of an a.c. power system in
which a.c. power is being applied through a cable to a load,
comprising the steps of:
(a) detecting the cable high frequency electromagnetic
pulses generated by partial discharge events in the power system
caused by continuing application of a.c. power to the system,
(b) analyzing said pulses detected in said step (a) in the
frequency domain to identify a frequency component of greatest
magnitude in said pulses and the frequency of said component,
(c) analyzing pulses detected in step (a) in the time
domain at the frequency of said component identified in said
step (b) to determine a phase relationship between said
frequency component and cycles of a.c. power in the system,
(d) identifying location of partial discharge events in the
power system as a function of said frequency component
identified in said step (b) and said phase relationship
identified in said step (c),
(e) determining a phase relationship between pulses
detected in said step (a) and the a.c. power being applied to
said system, and
(f) determining a type of fault in said system that causes
said partial discharge events as a function of said phase
relationship determined in said step (e).
31. The method set forth in claim 30 wherein said step of
filtering said high frequency pulses includes the steps of: (a1)
detecting high frequency signals in the surrounding atmosphere
within said selected frequency range, and (a2) subtracting said
signals detected in said step (a1) from said pulses.
The References
In rejecting the claims under 35 U.S.C. § 103(a), the
examiner relies upon the following references:
Rokunohe et al. (Rokunohe) 5,982,181 Nov. 9, 1999
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