US5600527A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit interrupter providing protection and waveform capture for harmonic analysis
Assignee: Eaton Corp
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Filing: 1994-12-22
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Granted: 1997-02-04
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Expires: 2014-12-22
Abstract
Abstract A circuit breaker with a digital trip unit has a protection mode and a waveform capture mode of operation. In the protection mode, 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. Synchronous sampling is used in the waveform capture mode. The value of each sample is monitored in the waveform capture mode and a transfer is made back to the protection mode 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 on the front panel of the circuit breaker and can be transmitted along with the raw waveform data to a remote processor.
Inventors
- 👤 Joseph C. Engel
- 👤 Gary F. Saletta
- 👤 Richard A. Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:28
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: 13
Claim 1
Independent Claim
153 words
A circuit interrupter for interrupting current in an electrical system, said circuit interrupter comprising: separable contacts interrupting said current when opened; sensing means sensing waveforms in said electrical system including at least one current waveform; sampling means sampling said waveforms sensed by said sensing means at sampling instants to generate digital samples of said waveforms including current samples of said at least one current waveform; and processing means having protection means operating in a protection mode 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 operating in a capture mode to store said digital samples of said waveform, wherein said processing means comprises sampling instant generating means generating sampling instants at a first sampling rate for said protection mode, and at a second sampling rate for said waveform capture means operating in said capture mode.
Claim 2
Dependent Claim
153 words
A circuit interrupter for interrupting current in an electrical system, said circuit interrupter comprising: separable contacts interrupting said current when opened; sensing means sensing waveforms in said electrical system including at least one current waveform; sampling means sampling said waveforms sensed by said sensing means at sampling instants to generate digital samples of said waveforms including current samples of said at least one current waveform; and processing means having protection means operating in a protection mode 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 operating in a capture mode to store said digital samples of said waveform, wherein said processing means comprises sampling instant generating means generating sampling instants at a first sampling rate for said protection mode, and at a second sampling rate for said waveform capture means operating in said capture mode.
Claim 3
Dependent Claim
41 words
The circuit interrupter of claim 1 wherein said first sampling rate generated by said sampling instant generating means is an equivalent sampling rate, and wherein said second sampling rate generated by said sampling instant generating means is a synchronous sampling rate.
Claim 4
Dependent Claim
49 words
The circuit interrupter of claim 1 wherein said sampling instant generating means 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 5
Dependent Claim
27 words
The circuit interrupter of claim 3 wherein said sampling instant generating means provides adjustable time delays between successive pairs of samples generated at said first sampling rate.
Claim 6
Dependent Claim
34 words
The circuit interrupter of claim 3 wherein said waveform capture means includes means monitoring current sample magnitude and transfers operation to said protection means when said magnitude of said current samples satisfies predetermined conditions.
Claim 7
Dependent Claim
202 words
A circuit interrupter for interrupting current in an electrical system, said circuit interrupter comprising: separable contacts interrupting said current when opened; sensing means sensing waveforms in said electrical system including a least one current waveform; sampling means sampling said waveforms sensed by said sensing means at sampling instants to generate digital samples of said waveforms including current samples of said at least one current waveform; and processing means having protection means operating in a protection mode 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 operating in a capture mode to store said digital samples of said waveform, wherein said waveform capture means operating in said capture mode includes monitoring means monitoring digital samples of said current waveform generated by said sampling means and transferring operation to said protection means operating in said protection mode when said current samples satisfy predetermined conditions, wherein said processing means comprises sampling instant generating means generating sampling instants at a first sampling rate for said protection means operating in said protection mode, and at a second sampling rate for said waveform capture means operating in said capture mode.
Claim 8
Dependent Claim
202 words
A circuit interrupter for interrupting current in an electrical system, said circuit interrupter comprising: separable contacts interrupting said current when opened; sensing means sensing waveforms in said electrical system including a least one current waveform; sampling means sampling said waveforms sensed by said sensing means at sampling instants to generate digital samples of said waveforms including current samples of said at least one current waveform; and processing means having protection means operating in a protection mode 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 operating in a capture mode to store said digital samples of said waveform, wherein said waveform capture means operating in said capture mode includes monitoring means monitoring digital samples of said current waveform generated by said sampling means and transferring operation to said protection means operating in said protection mode when said current samples satisfy predetermined conditions, wherein said processing means comprises sampling instant generating means generating sampling instants at a first sampling rate for said protection means operating in said protection mode, and at a second sampling rate for said waveform capture means operating in said capture mode.
Claim 9
Dependent Claim
39 words
The circuit interrupter of claim 6 wherein said sampling instant generating means 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 10
Dependent Claim
37 words
The circuit interrupter of claim 7 wherein said sampling instant generating means 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 11
Dependent Claim
32 words
The circuit interrupter of claim 8 wherein said monitoring means transfers operation to said protection means operating in said protection mode when a magnitude of said current samples exceeds a predetermined threshold.
Claim 12
Dependent Claim
25 words
The circuit interrupter of claim 7 wherein said processing means includes means performing harmonic analysis on said digital samples generated in said waveform capture mode.
Claim 13
Dependent Claim
34 words
The circuit interrupter of claim 10 wherein said means performing harmonic analysis generates individual harmonic values for a plurality of harmonics and wherein said processing means includes display means displaying said individual harmonic values.
References Cited (Backward Citations)
US4291299A
Cited
US4709339A
Cited
US4672555A
Cited
US5060166A
Cited
US5224054A
Cited
US5233538A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-02-04 | 2000-08-05 | 2001-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-02-04 | 2004-08-05 | 2005-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-02-04 | 2008-08-05 | 2009-02-04 | $7700.00 | Window Closed / Lapsed |