GB188001A - Improvements in and relating to protective devices for electric circuits - Google Patents
Improvements in and relating to protective devices for electric circuitsInfo
- Publication number
- GB188001A GB188001A GB1168221A GB1168221A GB188001A GB 188001 A GB188001 A GB 188001A GB 1168221 A GB1168221 A GB 1168221A GB 1168221 A GB1168221 A GB 1168221A GB 188001 A GB188001 A GB 188001A
- Authority
- GB
- United Kingdom
- Prior art keywords
- faults
- phase
- phases
- transformers
- secondaries
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/26—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents
- H02H3/28—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at two spaced portions of a single system, e.g. at opposite ends of one line, at input and output of apparatus
- H02H3/30—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at two spaced portions of a single system, e.g. at opposite ends of one line, at input and output of apparatus using pilot wires or other signalling channel
- H02H3/307—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at two spaced portions of a single system, e.g. at opposite ends of one line, at input and output of apparatus using pilot wires or other signalling channel involving comparison of quantities derived from a plurality of phases, e.g. homopolar quantities; using mixing transformers
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Ac-Ac Conversion (AREA)
Abstract
188,001. British Thomson - Houston Co., Ltd., and Fitzgerald, A. S. April 22,1921. Protective arrangements of the Merz-Price type three-phase systems providing separate protection against faults between phases and against faults between any phase and earth as in Specifications 141,121 and 174,769 comprise current transformers in each phase the transformer in the middle phase consisting of two separate, parts the secondaries of which have half the output of those in the other two phases. Each one of the secondaries in the middle phase is connected across one of the secondaries in the outer phases, respectively. The secondaries are connected from end to end by pilot wires so that faults between two phases will cause currents to flow in two of the pilot wires, whereas faults between a phase and earth will cause current to flow in the other pilot wire. As shown in Fig. 2 applied to a three-phase distribution system similar current transformers 4, 6 are connected in two of the phases at each end and two transformers 5 are connected in the other phase at each end and have double the number of secondary turns and cores of half the cross-section of those of the transformers 4, 6. Transformers 4, 5 and 5, 6 are interconnected in separate circuits with a common point O and pilot wires interconnect equipotential points between ends. Faults between phases operate the relays 7 and faults to earth operate the relays 6. The adaptation to a circulating current system is shown in which a relay 8 between equipotential points of the pilot wires takes care of faults between phases and a relay 9 between the mid-point of the relay 8 and the middle pilot wire takes care of faults to earth.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1168221A GB188001A (en) | 1921-04-22 | 1921-04-22 | Improvements in and relating to protective devices for electric circuits |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1168221A GB188001A (en) | 1921-04-22 | 1921-04-22 | Improvements in and relating to protective devices for electric circuits |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB188001A true GB188001A (en) | 1922-10-23 |
Family
ID=9990738
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1168221A Expired GB188001A (en) | 1921-04-22 | 1921-04-22 | Improvements in and relating to protective devices for electric circuits |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB188001A (en) |
-
1921
- 1921-04-22 GB GB1168221A patent/GB188001A/en not_active Expired
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