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Post by alpinejohn on Oct 18, 2018 7:48:05 GMT
I came across this video which sheds a lot of light on this technology.
Check out 4:10 in this video. So it seems VivaRail are clearly aware of the noise issue and know it is being created by some infernal electrickery gizmo - MOSFET IGBT STRING? Whatever that may be. I think the battery train idea is great, so I really hope they can find a quieter alternative or at least somehow reducing it to tolerable levels.
At 9.00+ the video explains the batteries are actually second hand from the IPMU whatever that was.
It seems VivaRail are however looking for better batteries, which might allow a better / faster charging, whether that will also help extend the range is interesting. Elsewhere in the video is the observation that the official quoted range is "conservative" - likewise the top speed of 60MPH could be exceeded with some tweaks to the battery controlling software.
At 12:00+ their comments about creating a shore based battery store unit which would allow the battery banks on the train to be rapidly recharged, seems a critical breakthrough. Inherently this resolves the mismatch between the desire to deliver a huge amount of power quickly in locations where power supply may be limited. By allowing power to be slowly reinstated into the shore batteries over many minutes/hours from a lower power capacity supply, they should also be able to draw in energy at optimum times (off peak) or more green sources.
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Post by Deleted on Oct 18, 2018 20:45:20 GMT
Thats a good video. I had to laugh at 1.20 ish when asked if it was AC or DC xD
AC batteries are not possible, and considering he said about the external charger, its going to be DC down the cable xD
Edit:
Finished the video, dumbed down a bit. Would love to ask my own questions.
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Post by spsmiler on Oct 18, 2018 20:49:31 GMT
I think you mean IPEMU, which stands for Independently Powered Electric Multiple Unit.
To set the scene for why the IPEMU concept was created, it is useful to look at the bus industry. In some towns and cities (Europe, USA, China) they have found that a cost-effective way to end the use of polluting fossil fuels and hence reduce urban air pollution is by using battery equipped electric buses which operate as part-time trolleybuses and part-time battery buses. The benefit of this is that they can electrify more bus routes without installing overhead wires for the entire system. The batteries are charged / topped-up whilst travelling in trolleybus mode. This is known variously as 'in-motion charging' and 'Slide-In'. (I see it as a great shame that London's transport planners prefer hybrid buses which still use diesel engines).
We know that here in the UK many people would like to see more railway electrification but that will never be financially viable for the quietest routes. So our railway industry trialled the in-motion charging concept with a battery equipped electric multiple unit. They chose to use a brand new train, perhaps because it would be easier to extend the principle to other trains of the same type, if desired. The train involved was Class 379 unit No.379 001 and this was given a type name of IPEMU.
re: the shore based battery units.... rival battery bus electrification technologies work on the principle of fast charging batteries on a stationary bus plus slow charging (and balancing the batteries) overnight. in Geneva they have trialled such a system known as TOSA which at bus stops can flash charge its batteries with a large amount of energy in top-ups as short as 15 seconds, which means that the process is about as quick as a short call at a bus stop for a few passengers to board / alight.
Fast charging technologies tend to use a special type of battery that is optimised for rapid recharging without suffering harm. The disadvantage of this type of battery is that often its energy density is a little lower than some other types of battery. However this does not matter as the basis for this trial is frequent top-up charging rather than a longer range between charges.
What is significant is that whilst the top-up charges are rapid and involve large amounts of energy, the TOSA bus stop charging facilities trickle charge energy from the local area grid - because this way the local community does not experience a voltage or power drop when the bus is recharging. I am not sure but suspect that they use capacitors at bus stops, as these are better at absorbing and rapid discharging of energy plus have a much longer operational life than batteries.
Whilst I do not know the people at Vivarail my expectation is that they have been watching the new (European) electric bus technologies with interest and see how their trains could benefit from using similar technologies.
Simon
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Post by norbitonflyer on Oct 18, 2018 21:43:46 GMT
The original battery unit (now preserved, and over 60 years old) was numbered in the dmu series (79998, 79999), which makes sense as DMUs are also "independently powered".
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Post by croxleyn on Oct 19, 2018 9:42:17 GMT
So, the whine is produced by the switching frequency of the transistors, being in the audio range. This is not surprising, as its a limitation of IGBTs. So the question has to be asked, is it the Electro-Magnetic filtering chokes themselves producing the whine, which should easily be cured, or (most likely) the motors themselves as they have the same elements of a loudspeaker, although careful design can minimise magnetostriction?
However, I believe the S-class uses the same principle of AC generation.
How did Bombardier get theirs so quiet?
It may be a compromise between the size of the E-M filtering components versus weight - the lower the operating frequency of a filter the heavier and bulkier it gets.
IGBT = Insulated Gate Bipolar Transistor.
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Post by alpinejohn on Oct 19, 2018 10:46:07 GMT
+1 to the above and thanks.
Indeed it makes me wonder how long before Bombardier decides to buy out VivaRail?
Apart from the noise, it already looks like VivaRail have a passable low volume product - at least until they run out of D Stock units to re-purpose.
However the big money will be in the follow-on generation of wholly new build trains. Doubtless all the major manufacturers have realised that electrification in the UK is not going to be universal any time soon. So units with last few mile capability to bridge the inevitable electrification gaps are going to have a big future especially once the anti fossil fuel consensus moves its focus on from road vehicles. With pretty much all new diesel and petrol cars (including hybrids) are apparently being banned from 2040 it seems unlikely that rail will be exempt.
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Post by AndrewPSSP on Oct 20, 2018 21:19:07 GMT
...I had to laugh at 1.20 ish when asked if it was AC or DC xD AC batteries are not possible... A while back, whilst doing some work for Electronics, someone asked whether batteries could be AC or DC. He got an hour detention and a fairly long rant on the concept of batteries and how different they are from the supply. 😂 |
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Post by Dstock7080 on Oct 30, 2018 12:12:28 GMT
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Post by Deleted on Oct 30, 2018 12:21:47 GMT
Did they ever manage to run any of their trains without problems?
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Post by brigham on Oct 30, 2018 16:07:02 GMT
Did they ever manage to run any of their trains without problems? It's a bit early yet. |
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Post by rincew1nd on Oct 30, 2018 16:42:35 GMT
Did they ever manage to run any of their trains without problems? You can't answer that question until they give up trying. It's a bit like asking if Bombardier have managed to run any of their new GOBLIN trains without problem! |
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Post by Deleted on Oct 30, 2018 17:39:56 GMT
It's just seems like these trains were on the market forever - not to mention that they in essence are extreme refurbs.
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cso
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Post by cso on Oct 30, 2018 18:03:04 GMT
The body is a refurb but I’m not sure the power etc is as it’s brand new I thought?
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Post by norbitonflyer on Oct 30, 2018 22:04:36 GMT
The body is a refurb but I’m not sure the power etc is as it’s brand new I thought? The bogies and traction motors are from the original units. Only the power supply feeding those motors (diesel or battery) is new. |
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Post by rincew1nd on Oct 30, 2018 22:10:55 GMT
But weren't they replaced not that long ago under LU ownership?
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Post by Deleted on Oct 31, 2018 4:39:03 GMT
The bogies were replaced under Metronet ownership supplied by Adtranz
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Post by Dstock7080 on Oct 31, 2018 6:28:17 GMT
The bogies and traction motors are from the original units. Only the power supply feeding those motors (diesel or battery) is new. Only the first diesel prototype 230.001 uses the original Brush LT118D motors, all subsequent conversations use new AC motors. |
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Post by alpinejohn on Oct 31, 2018 9:21:09 GMT
It's just seems like these trains were on the market forever - not to mention that they in essence are extreme refurbs. Perhaps a bit unfair - VivaRail was only formed in 2012 and at that stage they had no D stock units to assess whether their upcycling idea would work. Of the 230? carriages they purchased, the first D78 units were only actually withdrawn from service by LUL in January 2015. As you say this represents an extreme refurb. So before making any sales they had to carefully assess a representative sample of the units to determine if they were in a fit state for the project to be worth proceeding with. (Not something pertinent to an entirely new build). The units would however also need to be modified to meet accessibility rules, and then tested (crash?) to secure Network Rail clearance to just begin mileage accumulation, prior to any units ever getting into the hands of a train operating company, who would then need to arrange driver training etc. Like it or not in our safety focused world it takes years not weeks before any new units ever turn a wheel in fare paying service. Meantime VivaRail had to finance the costs involved - so they were obviously taking quite a big risk - but it is their own money to risk, so entirely their own decision to make. However potential buyers for D-Trains would probably choose to hold off placing firm orders unless/until they could see finished examples, or seek very significant discounts if their operations effectively become the operational test bed. Hence I doubt the Marston units will deliver huge profits to VivaRail. However despite "politicians" deciding these units were not suitable for Northern, (who's customers are now suffer chronic overcrowding), there is still a massive shortage of diesel rolling stock in the UK with Northern among the most severely affected. So I suspect that other train operating companies will be watching closely to see if VivaRail can quickly shake the bugs out of the Marston units. In which case speculative interest (Island Line) may quickly translate into follow on orders, and D-Train variants may start appearing all around the UK. |
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Post by 35b on Oct 31, 2018 10:33:35 GMT
I find that assessment unduly charitable, especially given the report on the fire at Kenilworth.
VivaRail have tenaciously presented their upcycling of near 40 year old trains as an economical option for operators, and have finally found buyers. Despite that, issues appear to remain and VivaRail are pursuing yet further forms of propulsion - a sign to me that the project was poorly founded.
The end result remains that these units have yet to appear in public service 18 months after final withdrawal from London Underground.
Elsewhere, we are seeing class 315 units of similar vintage carted straight to scrap.
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Post by norbitonflyer on Oct 31, 2018 10:41:44 GMT
The units would however also need to be modified to meet accessibility rules, and then tested (crash?) Indeed - crash tested However despite "politicians" deciding these units were not suitable for Northern, (who's customers are now suffer chronic overcrowding), there is still a massive shortage of diesel rolling stock in the UK with Northern among the most severely affected. Northern is still on course to get the first of its fifty-five new diesel units (class 195, ordered in 2016) in service in December, whilst the (three) D-trains have been put back to next year. |
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Post by Deleted on Oct 31, 2018 21:11:43 GMT
I think its unfair to call them refurbs. They are new builds practically. Having worked on the stock prior to vivarail, everything I would consider to have been an issue has been removed.
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Post by rincew1nd on Oct 31, 2018 23:47:41 GMT
I think its unfair to call them refurbs. <pedant> Assuming "refurb" is a contraction of refurbish: Given the above I think it can only be accurate to describe them as refurbs.</pedant> "Re-purposed" or "as good as new" might, perhaps, better ways to describe what VivaRail are doing! |
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Post by Chris M on Nov 1, 2018 0:01:39 GMT
Well the bodyshells are heavily refurbished, the engines and motors are new, the bogies are somwhere in between and I've got no idea about the wheels. So calling it a refurb is both accurate and inaccurate!
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Post by rincew1nd on Nov 1, 2018 0:40:04 GMT
"Better than what was"?
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Post by Deep Level on Nov 1, 2018 12:31:05 GMT
Overhaul?
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Post by miff on Nov 1, 2018 15:26:18 GMT
Rebuild.
Although the 230 includes D-stock shells and components it certainly isn’t D-stock any more.
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Post by brigham on Nov 1, 2018 17:26:11 GMT
Rebuild. Although the 230 includes D-stock shells and components it certainly isn’t D-stock any more. Bit like a Shackleton or a Nimrod, then? |
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Post by Deleted on Nov 1, 2018 19:31:52 GMT
Exactly like said above, when is something considered to be new/refurbed etc. Glad I got the chance to work on the D stock, always thought they were ugly looking, but somehow I would always be reminded of a stormtrooper. After working on them, you learn their quirks and are a lot of fun to maintain/work on.
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Post by alpinejohn on Nov 25, 2018 15:22:58 GMT
".. Northern is still on course to get the first of its fifty-five new diesel units (class 195, ordered in 2016) in service in December, whilst the (three) D-trains have been put back to next year[/a]."
I have delayed responding as last month I was not entirely sure where things were regarding the 195s?
However we are nearly at the end of November, and thus far Northern have yet to even agree testing arrangements with ASLEF let alone start them..
You have to be a real optimist to believe enough driver training on 195s will be complete in time for them to be in fare paying service this year. I think 2019 has even appeared in Northern tweets.
Oh and has the issue of their use on some services currently with guards been resolved?
As 230s, 195s and 710s all seem to show, you really should not expect a new or extensively refurbished train to come into service on time or without teething issues which will need follow up attention. For instance there are still quite a few S7s which need hardware/software updates so they can work with the proposed new signalling system whenever that magical system is actually deemed ready for use?
If nothing else it looks like 2019 will prove interesting.
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Post by patrickb on Nov 26, 2018 0:35:25 GMT
Looks like we'll be needing more buckets of concrete and fairy dust to get this magical system to work.
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