Patent EP0718948A2 successfully refreshed from Google Patents.
EP0718948A2
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EP
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Circuit interrupter providing protection and waveform capture for harmonic analysis
Assignee: Eaton Corp
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Filing: 1995-12-06
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Granted: —
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Expires: 2015-12-06
Abstract
Abstract A circuit breaker (1) with a digital trip unit (15) has a protection mode (89) and a waveform capture mode (87) of operation. In the protection mode (89), an equivalent sampling technique based upon pairs of samples spaced 90 electrical degrees apart with a pattern of delays between pairs is used to digitize the waveforms in the protected electrical system (3). Synchronous sampling is used in the waveform capture mode (87). The value of each sample is monitored (77, 79) in the waveform capture mode (87) and a transfer is made back to the protection mode (89) if a threshold value indicating an overcurrent condition is exceeded. The percentage total harmonic distortion, and per harmonic distortion for harmonics, up to and including the 27th are sequentially presented on a display (21) on the front panel of the circuit breaker (1) and can be transmitted along with the raw waveform data to a remote processor.
Inventors
- 👤 Joseph Charles Engel
- 👤 Gary Francis Saletta
- 👤 Richard Arthur Johnson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 15:39
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/08; G; G01; G01R; G01R21/00; G01R21/133; H02H3/093; H02H3/0935; H02H1/00; H02H1/0007; H02H3/02; H02H3/04; H02H3/50
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
117 words
A circuit interrupter (1) for interrupting current in an electrical system (3), said circuit interrupter comprising: separable contacts (25) interrupting said current when opened; sensing means (7, 9) sensing waveforms in said electrical system including at least one current waveform; sampling means (13) sampling said waveforms sensed by said sensing means at sampling instants to generate digital samples of said waveforms; and processing means (15) having protection means (31-69) operating in a protection mode (89) to trip said separable contacts open in response to a selected current/time characteristic of said current waveform repetitively determined from said digital samples, and waveform capture means (71-85) operating in a capture mode (87) to store said digital samples of said waveform.
Claim 2
Dependent Claim
57 words
The circuit interrupter (1) of Claim 1 wherein said waveform capture means (71-85) operating in said capture mode (87) includes monitoring means (77, 79) monitoring digital samples of said current waveform generated by said sampling means and transferring operation to said protection means (31-69) operating in said protection mode (89) when said current samples satisfy predetermined conditions.
Claim 3
Dependent Claim
36 words
The circuit interrupter of Claim 2 wherein said monitoring means (77, 79) transfers operation to said protection means (31-69) operating in said protection mode (89) when a magnitude of said current samples exceeds a predetermined threshold.
Claim 4
Dependent Claim
56 words
The circuit interrupter (1) of Claim 2 wherein said processing means (15) comprises sampling instant generating means (97, 75) generating sampling instants at a first sampling rate for said protection means (31-69) operating in said protection mode (89), and at a second sampling rate for said waveform capture means (71-85) operating in said capture mode (87).
Claim 5
Dependent Claim
42 words
The circuit interrupter (1) of Claim 4 wherein said sampling instant generating means (97, 75) generates said sampling instants at an equivalent sampling rate to produce said first sampling rate, and at a synchronous sampling rate to produce said second sampling rate.
Claim 6
Dependent Claim
39 words
The circuit interrupter (1) of Claim 5 wherein said sampling instant generating means (97) generates sampling instants in pairs spaced 90 electrical degrees apart and with adjustable delays between successive pairs of samples to generate said equivalent sampling rate.
Claim 7
Dependent Claim
37 words
The circuit interrupter (1) of Claim 6 wherein said monitoring means (77, 79) transfers operation to said protection means (31-69) operating in said protection mode (89) when a magnitude of said current samples exceeds a predetermined threshold.
Claim 8
Dependent Claim
29 words
The circuit interrupter (1) of Claim 5 wherein said processing means (15) includes means (137) performing harmonic analysis on said digital samples generated in said waveform capture mode (87).
Claim 9
Dependent Claim
38 words
The circuit interrupter (1) of Claim 8 wherein said means (137) performing harmonic analysis generates individual harmonic values for a plurality of harmonics and wherein said processing means (15) includes display means (21) displaying said individual harmonic values.
Claim 10
Dependent Claim
55 words
The circuit interrupter (1) of Claim 1 wherein said processing means (15) comprises sampling instant generating means (97, 75) generating sampling instants at a first sampling rate for said protection means (31-69) operating in said protection mode (89), and at a second sampling rate for said waveform capture means operating in said capture mode (87).
Claim 11
Dependent Claim
44 words
The circuit interrupter (1) of Claim 10 wherein said first sampling rate generated by said sampling instant generating means (97) is an equivalent sampling rate, and wherein said second sampling rate generated by said sampling instant generating means (75) is a synchronous sampling rate.
Claim 12
Dependent Claim
51 words
The circuit interrupter of Claim 10 wherein said sampling instant generating means (97, 75) generating samples at said first sampling rate generates pairs of samples 90 electrical degrees apart, and in generating samples at said second sampling rates generates samples synchronously at a rate of more than four samples per cycle.
Claim 13
Dependent Claim
28 words
The circuit interrupter of Claim 12 wherein said sampling instant generating means (97) provides adjustable time delays between successive pairs of samples generated at said first sampling rate.
Claim 14
Dependent Claim
39 words
The circuit interrupter (1) of Claim 12 wherein said waveform capture means (71-85) includes means (77, 79) monitoring current sample magnitude and transfers operation to said protection means (31-69) when said magnitude of said current samples satisfies predetermined conditions.
Claim 15
Dependent Claim
81 words
A circuit interrupter (1) for interrupting current in an electrical system (3), said circuit interrupter comprising: separable contacts (25) interrupting current in said electrical system (3) when opened; means (13) generating digital samples of waveforms in said electrical system including said current; and processing means (15) tripping said separable contacts (25) open in response to a selected current/time characteristic of said current determined from said digital samples, and generating an output representing harmonic content of said waveforms from said digital samples.
Claim 16
Dependent Claim
38 words
The circuit interrupter (1) of Claim 15 wherein said processing means (15) comprises means (137) generating individual harmonic values for individual harmonics of said waveforms from said digital samples and display means (21) displaying said individual harmonic values.
Claim 17
Dependent Claim
18 words
The circuit interrupter (1) of Claim 16 wherein said display means (21) sequentially displays said individual harmonic values.
Claim 18
Dependent Claim
31 words
The circuit interrupter (1) of Claim 16 wherein said processing means (15) further includes metering means (91) generating representations of power related parameters of said electrical system from said digital samples.
References Cited (Backward Citations)
No citation records indexed.
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