Applications of distance relays on distribution networks
Applications of distance relays on distribution networks
(OP)
Hi All,
I'm interested in hearing your opinions on using distance relays on distribution networks - how common is it, do you use it mostly as primary or backup, what are the expectations as far as the operating time is concerned (is ~30ms acceptable for Zone1), are you trying to use it on networks with a lot of distributed generation (with all the problems related to variable amount of DG that can be connected at one time)?
Thanks in advance,
Peter
I'm interested in hearing your opinions on using distance relays on distribution networks - how common is it, do you use it mostly as primary or backup, what are the expectations as far as the operating time is concerned (is ~30ms acceptable for Zone1), are you trying to use it on networks with a lot of distributed generation (with all the problems related to variable amount of DG that can be connected at one time)?
Thanks in advance,
Peter






RE: Applications of distance relays on distribution networks
RE: Applications of distance relays on distribution networks
David Castor
www.cvoes.com
RE: Applications of distance relays on distribution networks
RE: Applications of distance relays on distribution networks
RE: Applications of distance relays on distribution networks
So the 21P has Zone 1 set to reach back to the utility substation?
RE: Applications of distance relays on distribution networks
The other issue to consider is: Why use it? Transmission systems are typically configured to loop through a series of intermediate substations, each with its own system of breakers. In this case, distance relaying provides a method of tripping the closest breaker to the fault.
The case of distribution with multiple sources (DG, for example) is one possible application, but I think directional power schemes seem to be more popular, at least for the small DG systems I'm familiar with.
RE: Applications of distance relays on distribution networks
RE: Applications of distance relays on distribution networks
RE: Applications of distance relays on distribution networks
RE: Applications of distance relays on distribution networks
It's been about 10 years since I have done commissioning work in that region. IIRC, it was a 2 zone step distance scheme, therefore I would guess it was ~80%/120%, or something in that neighborhood. The generation sites I was involved with were mostly landfill gas applications by some of the more well established players and some less in that market.
There were many heated discussions between the OEMs of packaged he sets and the local utility on relaying requirements.
RE: Applications of distance relays on distribution networks
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RE: Applications of distance relays on distribution networks
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RE: Applications of distance relays on distribution networks
@m3ntosan:
Yes, by distribution I mean networks up to 132kV. I'm surprised you mention cables as well - I was under impression that for cables it's mostly current diff.
RE: Applications of distance relays on distribution networks
For 110 kV cables, in Eastern Europe you'll find old analogical distance protection RD110, from former Democratic Germany Republic, by EAW Berlin and differential protection, DZL from former Soviet Union, using pilot cable, these two as main protections and E/F or O/C as backup.
Also, you'll find important 110 kV s/s without BBP, using zone 1 extension or zone 2 override to protect the busbars from remote ends, with a fairly high level of generation embedded into 110 kV network. BFP with 500 ms setting at 110 kV in Eastern Europe, you won't find BFP in the UK at 132 kV level.
May you grow up to be righteous, may you grow up to be true...
RE: Applications of distance relays on distribution networks
RE: Applications of distance relays on distribution networks
110kV-132kV is not so distribution, its sub-transmission.
OK, its not so important.
BBP and BFP ( bus bur and breaker failure protection) are depend on the country code/standards or economical reason.
Actually, 21, Distance protection in radial O/H lines or cables with one source is not so used.
DZL is 87L, DZL is russian transcription of differntial line protection, based on the pilot wire or fiber optic connection between ends.
As usually, all depends