US4148087A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Distance relay for electric power transmission lines
Assignee: Individual
•
Filing: 1977-04-20
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Granted: 1979-04-03
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Expires: 1997-04-20
Abstract
Abstract A distance relay system for a three-phase electric power transmission line comprises means for producing positive, negative and zero sequence symmetrical component voltages from the phase voltages of the line, and means for producing positive, negative and zero sequence voltage drops from the corresponding sequence currents and impedances of the line. Zero sequence current in a parallel line and the mutual impedance between the lines may be taken into account. Predetermined ratios of the sequence voltages and changes in the voltage drops are used to produce a distance factor K corresponding to the ratio of the distance to a fault on the line and the length of the line. The single equation for K applies to all ten fault conditions that can occur on the line. A fault signal is produced when K lies between predetermined fault values. The faulted phase of single phase to ground faults may be identified. Particular expressions for K are given.
Inventors
- 👤 Arun G. Phadke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:23
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/38; H02H3/387
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
145 words
A distance relay system for a three-phase electric power transmission line which comprises (a) means responsive to the phase voltages of said three-phase transmission line for producing positive, negative and zero sequence symmetrical component voltages corresponding thereto, (b) means responsive to respective phase and zero sequence currents of said three-phase transmission line and the positive and zero sequence impedances of the line for producing positive, negative and zero sequence symmetrical component voltage drops, (c) means for producing predetermined ratios of said positive, negative and zero sequence voltages and substantial changes in said positive, negative and zero sequence voltage drops, (d) means utilizing said ratios for producing a distance factor corresponding to the ratio of the distance to a fault on said line and the length of the line, (e) and means for producing a fault signal when said distance factor lies between predetermined fault values.
Claim 2
Dependent Claim
145 words
A distance relay system for a three-phase electric power transmission line which comprises (a) means responsive to the phase voltages of said three-phase transmission line for producing positive, negative and zero sequence symmetrical component voltages corresponding thereto, (b) means responsive to respective phase and zero sequence currents of said three-phase transmission line and the positive and zero sequence impedances of the line for producing positive, negative and zero sequence symmetrical component voltage drops, (c) means for producing predetermined ratios of said positive, negative and zero sequence voltages and substantial changes in said positive, negative and zero sequence voltage drops, (d) means utilizing said ratios for producing a distance factor corresponding to the ratio of the distance to a fault on said line and the length of the line, (e) and means for producing a fault signal when said distance factor lies between predetermined fault values.
Claim 3
Dependent Claim
56 words
A distance relay according to claim 1 in which said predetermined ratios include k 3 = ΔV o /ΔV 1 where ΔV o and ΔV 1 are the changes in zero sequence and positive sequence voltage drops, respectively, and means for utilizing the phase angle of k 3 to produce a signal identifying a faulted phase.
Claim 4
Dependent Claim
31 words
A distance relay according to claim 1 in which said distance factor is substantially equivalent to the factor K where ##EQU25## and the quantities are as set forth in Table 1.
Claim 5
Dependent Claim
62 words
A distance relay according to claim 3 in which the values of k o and k 2 are substantially zero when ΔV o and ΔV 2 are substantially zero, respectively, and the maximum value of k L is limited to a predetermined value yielding a value of K greater than said predetermined fault values under normal operating conditions of the transmission line.
Claim 6
Dependent Claim
51 words
A distance relay according to claim 4 in which, when either ΔV o or ΔV 1 is zero or small, the value of k o ' is set to a predetermined value yielding a value of K greater than said predetermined fault values under normal operating conditions of the transmission line.
Claim 7
Dependent Claim
40 words
A distance relay according to claim 5 in which the maximum value of k 1 is limited to a predetermined value producing a value of K greater than said predetermined fault values under normal operating conditions of the transmission line.
Claim 8
Dependent Claim
55 words
A distance relay according to claim 1 in which said distance factor is substantially equivalent to the factor K where ##EQU26## and the quantities are as set forth in Table I, and in which a said fault signal is produced when the distance factor K lies between zero and a predetermined value less than unity.
Claim 9
Dependent Claim
30 words
A distance relay according to claim 7 including means for utilizing the phase angle of k 3 = ΔV o /ΔV 1 to produce a signal identifying a faulted phase.
Claim 10
Dependent Claim
39 words
A distance relay according to claim 7 including means for utilizing the phase angle of k 3 = ΔV o /ΔV 1 and a value of k 2 ' of unity to produce a signal identifying a faulted phase.
Claim 11
Dependent Claim
42 words
A distance relay according to claim 1 in which said distance factor is substantially equivalent to the factor K where ##EQU27## and the quantities are as set forth in Table I with ΔV 1 substantially equal to said positive sequence voltage drop.
Claim 12
Dependent Claim
30 words
A distance relay according to claim 10 in which the values of k o and k 2 are substantially zero when ΔV o and ΔV 2 are substantially zero, respectively.
Claim 13
Dependent Claim
149 words
A distance relay system for a three-phase electric power transmission line which comprises (a) means responsive to the phase voltages of said three-phase transmission line for producing positive, negative and zero sequence symmetrical component voltages corresponding thereto, (b) means responsive to respective phase and zero sequence currents of said three-phase transmission line and the positive and zero sequence impedances of the line and to the zero sequence current and mutual impedance of an adjacent parallel transmission line, (c) means for producing predetermined ratios of said positive, negative and zero sequence voltages and substantial changes in said positive, negative and zero sequence voltage drops, (d) means utilizing said ratios for producing a distance factor corresponding to the ratio of the distance to a fault on said line and the length of the line, (e) and means for producing a fault signal when said distance factor lies between predetermined fault values.
Claim 14
Dependent Claim
149 words
A distance relay system for a three-phase electric power transmission line which comprises (a) means responsive to the phase voltages of said three-phase transmission line for producing positive, negative and zero sequence symmetrical component voltages corresponding thereto, (b) means responsive to respective phase and zero sequence currents of said three-phase transmission line and the positive and zero sequence impedances of the line and to the zero sequence current and mutual impedance of an adjacent parallel transmission line, (c) means for producing predetermined ratios of said positive, negative and zero sequence voltages and substantial changes in said positive, negative and zero sequence voltage drops, (d) means utilizing said ratios for producing a distance factor corresponding to the ratio of the distance to a fault on said line and the length of the line, (e) and means for producing a fault signal when said distance factor lies between predetermined fault values.
References Cited (Backward Citations)
US2879454A
Cited
US3379936A
Cited
US3413523A
Cited
US3339115A
Cited
US3337774A
Cited
US3538384A
Cited
US3430103A
Cited
US3612989A
Cited
US3569785A
Cited
US3526761A
Cited
US3651377A
Cited
US3723864A
Cited
US3599044A
Cited
US3735204A
Cited
US3732464A
Cited
US3800215A
Cited
US3731152A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-04-02 | 1982-10-02 | 1983-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-02 | 1986-10-02 | 1987-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-02 | 1990-10-02 | 1991-04-03 | $7700.00 | Window Closed / Lapsed |