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Provning av reläskydd med intermittentfunktion

Hägg, Jakob (2011) In CODEN:LUTEDX/TEIE EIE920 20111
Industrial Electrical Engineering and Automation
Abstract
The Division of Industrial Electrical Engineering and Automation, IEA, at LTH is
participating in the research project DLAB, sponsored by E.ON. The goal of this project is to gain more understanding of the problems arising from increased cablification of Swedish medium voltage distribution grid and to develop an electric power laboratory.
More and longer cables have increased the capacitive earth fault current, which in combination with Petersen coil system increase the risk for more intermittent earth faults. The intermittent earth fault is a sequence of ignitions and extinctions of earth faults. Cause of error can be poor insulation in cable connections or cracked overhead line insulators. The use of more and longer cables also... (More)
The Division of Industrial Electrical Engineering and Automation, IEA, at LTH is
participating in the research project DLAB, sponsored by E.ON. The goal of this project is to gain more understanding of the problems arising from increased cablification of Swedish medium voltage distribution grid and to develop an electric power laboratory.
More and longer cables have increased the capacitive earth fault current, which in combination with Petersen coil system increase the risk for more intermittent earth faults. The intermittent earth fault is a sequence of ignitions and extinctions of earth faults. Cause of error can be poor insulation in cable connections or cracked overhead line insulators. The use of more and longer cables also increases the demands on the feeder protection relay and instrument transformers accuracy.
This thesis aims to improve the understanding of protective relay testing with different types of ground faults. The work has included the construction of test equipment with a performance that allows testing of the key features in a modern feeder protection relay, particularly the function of transient earth fault detection.
Two different methods are used to test the relay protections, namely playback of
generated fundamental signals and of real disturbance recordings. The equipment has been used to test two different radial feeder protection relays,
namely, ABB RXHL421 and REF615. The testing of the directional earth-fault protection shows that they mostly follow the settings. However, the test of the operating characteristics shows that they differ slightly from the intended characterization. The transient earth-fault protection in REF615 was tested with transients from disturbance recordings. The protection did not start for all transients, it is however hard to draw a direct conclusion of the protection performance from this test. The reason for this is that there is no possibility to change the settings of the protection but also because no other corresponding transient earth-fault protection has been tested. (Less)
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author
Hägg, Jakob
supervisor
organization
course
EIE920 20111
year
type
H3 - Professional qualifications (4 Years - )
subject
publication/series
CODEN:LUTEDX/TEIE
report number
5284
language
English
id
3632571
date added to LUP
2015-12-11 12:22:17
date last changed
2015-12-11 12:22:17
@misc{3632571,
  abstract     = {The Division of Industrial Electrical Engineering and Automation, IEA, at LTH is
participating in the research project DLAB, sponsored by E.ON. The goal of this project is to gain more understanding of the problems arising from increased cablification of Swedish medium voltage distribution grid and to develop an electric power laboratory.
More and longer cables have increased the capacitive earth fault current, which in combination with Petersen coil system increase the risk for more intermittent earth faults. The intermittent earth fault is a sequence of ignitions and extinctions of earth faults. Cause of error can be poor insulation in cable connections or cracked overhead line insulators. The use of more and longer cables also increases the demands on the feeder protection relay and instrument transformers accuracy.
This thesis aims to improve the understanding of protective relay testing with different types of ground faults. The work has included the construction of test equipment with a performance that allows testing of the key features in a modern feeder protection relay, particularly the function of transient earth fault detection.
Two different methods are used to test the relay protections, namely playback of
generated fundamental signals and of real disturbance recordings. The equipment has been used to test two different radial feeder protection relays,
namely, ABB RXHL421 and REF615. The testing of the directional earth-fault protection shows that they mostly follow the settings. However, the test of the operating characteristics shows that they differ slightly from the intended characterization. The transient earth-fault protection in REF615 was tested with transients from disturbance recordings. The protection did not start for all transients, it is however hard to draw a direct conclusion of the protection performance from this test. The reason for this is that there is no possibility to change the settings of the protection but also because no other corresponding transient earth-fault protection has been tested.},
  author       = {Hägg, Jakob},
  language     = {eng},
  note         = {Student Paper},
  series       = {CODEN:LUTEDX/TEIE},
  title        = {Provning av reläskydd med intermittentfunktion},
  year         = {2011},
}