edwin_m
Veteran Member
But would the smaller but more numerous feeder stations actually be cheaper in areas where there is a suitable grid connection to build a large one?
There must be pretty huge advantages for the supply and distribution side, as you lose the mis-balance between phases which is typical of existing supplies.But would the smaller but more numerous feeder stations actually be cheaper in areas where there is a suitable grid connection to build a large one?
I think that's the reason it can work on lower voltage feeders where the phase imbalance would be too big relative to the capacity of the supply.There must be pretty huge advantages for the supply and distribution side, as you lose the mis-balance between phases which is typical of existing supplies.
Electrical engineering is improving all the time so I do have high hopes for further improvements.This is interesting! I wonder if there is the capacity(now or in future) for the DNO to 'mix' the balance of the supply in real time at these types of feeders to balance the overall three phase system in the local area? a win-win for all concerned if it is possible!
The new 400kV grid supplies also use all 3 phases*. This a big difference from the old 132kV onesThere must be pretty huge advantages for the supply and distribution side, as you lose the mis-balance between phases which is typical of existing supplies.
There’ll probably be an element of ‘not invented here’ to get past, I expect.
AIUI the problem in north Northumberland always was the lack of a useful grid supply, of any description, as there was no significant population or industry to justify a major supply for non-railway purposes. The supply from Lynemouth power station was apparently poor quality because it’s normal base load was the Alcan smelter.The new 400kV grid supplies also use all 3 phases*. This a big difference from the old 132kV ones
*Connecting them up and earthing them is very different which caused Alstom some grief at Pudding Mill Lane and Kensal Gas work feeders while connecting up the new co-located pairs of Crossrail and NR feeds (Twin independent 400kV feeds at each).
400kV has many advantages if there is a convenient substation next to /near by the line (e.g. Kensal (ex-) Gas Works) but the costs can be huge if there isn't a suitable 400KV supply let alone substation.
The new approach also means you need a spare 33kV DNO circuit which can also be a rare as hen's teeth in some areas you want to electrify or reinforce.
South Wales has plenty of easy 400kV supply opportunities.
Similarly there is nothing much (Grid or spare DNO circuits) in large parts of east Sussex hence part of the reason Uckfield has never been electrified.AIUI the problem in north Northumberland always was the lack of a useful grid supply, of any description, as there was no significant population or industry to justify a major supply for non-railway purposes. The supply from Lynemouth power station was apparently poor quality because it’s normal base load was the Alcan smelter.
The first post lists a new “ASP” at Longniddry - but that’s an abbreviation not explained yet. Perhaps it’s Ancillary Supply Point, but don’t quote me. Otherwise Longniddry is listed as a Mid Point Track Sectioning Cabin (MPTSC).This may not be relevant to this thread, but I was past Longniddry at the weekend and noticed a new concrete pad just to the East of the station. Anyone know what for? I wondered whether it was a sectioning cabin?
Longniddry is still an MPTSC, but the ASP is indeed an Ancillary Supply Point. AmcoGiffen were contracted to install new signalling power supplies at all interlockings from Edinburgh to Berwick, and an Ancillary Supply Point is the TSC 'equivalent' (as I understand it) of the signalling power supply network.The first post lists a new “ASP” at Longniddry - but that’s an abbreviation not explained yet. Perhaps it’s Ancillary Supply Point, but don’t quote me. Otherwise Longniddry is listed as a Mid Point Track Sectioning Cabin (MPTSC).
Thanks for explaining. So are the alterations or additions to signalling PSPs and ASPs a necessary part of the whole upgrade, or is it more like a sensible time to do the work, while civils and electrical contractors are around anyway?Longniddry is still an MPTSC, but the ASP is indeed an Ancillary Supply Point. AmcoGiffen were contracted to install new signalling power supplies at all interlockings from Edinburgh to Berwick, and an Ancillary Supply Point is the TSC 'equivalent' (as I understand it) of the signalling power supply network.
Principal Supply Points (PSPs) are the equivalent of feeder stations, and are different from PSBs which either mean Power Signal Box or Panel Signal Box! (it's wrecked my head a few times I can tell you)
As the works were undertaken in 2017, I think it was a case of "while you're here..." for AmcoGiffen. It might have been a small part of the signalling power supply upgrade, which may or may not be separate to the traction power supply upgrade. I don't know for certain as I'm not on either project!Thanks for explaining. So are the alterations or additions to signalling PSPs and ASPs a necessary part of the whole upgrade, or is it more like a sensible time to do the work, while civils and electrical contractors are around anyway?
Found an AmcoGiffen web page describing their work:As the works were undertaken in 2017, I think it was a case of "while you're here..." for AmcoGiffen. It might have been a small part of the signalling power supply upgrade, which may or may not be separate to the traction power supply upgrade. I don't know for certain as I'm not on either project!
they report that it’s IEP related.
There is also the advantage that if all substations were connected through SFCs, you can potentially operate with all 25kV systems in parallel in the style of DC systems.But would the smaller but more numerous feeder stations actually be cheaper in areas where there is a suitable grid connection to build a large one?
That sounds as though it could be a big step forward, although I'm not that clued-up on high voltage engineering. It would be really helpful if you could perhaps give an example or two of where this would make a difference, and why. Many thanksThere is also the advantage that if all substations were connected through SFCs, you can potentially operate with all 25kV systems in parallel in the style of DC systems.
This would make it possible to share demand from trains on a route with all substations on the route.That sounds as though it could be a big step forward, although I'm not that clued-up on high voltage engineering. It would be really helpful if you could perhaps give an example or two of where this would make a difference, and why. Many thanks
There is also the advantage that if all substations were connected through SFCs, you can potentially operate with all 25kV systems in parallel in the style of DC systems.
Thanks HSTEd. Sounds like the way forward. Presumably there's a "but" somewhere, with "but it's expensive" being my first guess, with "but implementation is disruptive and requires lengthy possessions" being my second. What is standing in the way of rolling this out?This would make it possible to share demand from trains on a route with all substations on the route.
Indeed with clever design and control of the static converters you can share demand between substations to maximise utilisation of capacity and even in response to general grid loading conditions.
The SFCs are more able to control fault currents than regular equipment, by virtue of having total control of the phase, voltage and current flow through the converter.How would you control the prospective fault current levels in this interconnected HV system?
Thanks HSTEd. Sounds like the way forward. Presumably there's a "but" somewhere, with "but it's expensive" being my first guess, with "but implementation is disruptive and requires lengthy possessions" being my second. What is standing in the way of rolling this out?
A very new looking piece of steelwork has appeared by Nene F.S. in the last week or so...
View attachment 78354
Looks like this'll replace the old disconnectors.
Within 9ft of the Overhead? You'd be Dazed & Confused to try that!Half expecting to see a Zeppelin moored to that!
I think that QWs at the thinner spots (SFCs at Marshall Meadows & Hambleton Jn) might be installed first to reduce the phase imbalance in the supply, and also see a lot more disconnected boosters to increase the power throughput (with Return Screening Conductors going in new signalling troughs). Not sure what GRIP the second phase is at, so it might yet also go over to a 25-0-25 Autotransformer system - but one that doesn't necessarily need to rely on 275kV/400kV National Grid connections.There’s a new press release here:
...about the phase 2 work contract being awarded, with completion by 2024.East Coast Mainline increases power supply with £216.2M contract award - VolkerRail
The East Coast Mainline (ECML) Power Supply Upgrade is to power forward into its second phase, bolstered by a £216.2M contract award for the Rail Electrification Alliance.www.volkerrail.co.uk
So if this is still required to operate more electric services through the Northumberland Gap, (amongst other areas), then how can the First open access service using pure EMUs work? Will there have to be “quick wins” at certain power trouble spots?
(The press release is from Volker, but I think it’s referring to the whole consortium - including Siemens for the power conversion hardware such as the new SFCs.)
I think it refers to my earlier use of “Quick Wins”! I don’t think it’s a standard abbreviation...SFCs - Static Frequency Converters
QWs - please remind me again
There’s a new press release here:
...about the phase 2 work contract being awarded, with completion by 2024.East Coast Mainline increases power supply with £216.2M contract award - VolkerRail
The East Coast Mainline (ECML) Power Supply Upgrade is to power forward into its second phase, bolstered by a £216.2M contract award for the Rail Electrification Alliance.www.volkerrail.co.uk
So if this is still required to operate more electric services through the Northumberland Gap, (amongst other areas), then how can the First open access service using pure EMUs work? Will there have to be “quick wins” at certain power trouble spots?
(The press release is from Volker, but I think it’s referring to the whole consortium - including Siemens for the power conversion hardware such as the new SFCs.)
Ah, then all those bi-modes that the others have should help a lot...First East Coast have confirmed access rights for their trains (that aren’t yet operating), but ‘some other’ operator(s) have only contingent rights for some of their trains (that are operating).
Ah, then all those bi-modes that the others have should help a lot...