Progress Rail Joule Switcher

[Overmod]

Erik_Mag

My first guess is that a DC charging link would be at the battery voltage, charging time would be determined by how big a cable you would want to use. The ultimate limit is the battery itself, and presumably the battery will be charged at a rate conducive to many charge/discharge cycles.

The definition of 'battery voltage' here is what I meant by 'string voltage' -- I'm assuming that charging connections need not be the same as 'discharging' ones, so a nominal '1500V' battery might be a series/parallel combination of lower-voltage strings each with its own crossbar-switch connection to charging.  I think that is what you mean when you say

I would wonder if the batteries are set up so that you would have several battery packs running in parallel, each with a dedicated contactor to isolate the individual packs - which then would allow for multiple lower current cables.

I am assuming that any sensible large traction battery will be structured that way, especially if integrated with supercapacitor discharge management, and further with the ability to detect and as necessary 'switch out' cells that are defective, overheating, etc. or to rotate high discharge (analogous to how the GM Northstar handles LOCA 'limp-home' accommodation through selective cylinder activation).

An external connector that was hardwired to all of the batteries in parallel would be asking for trouble or a poor attempt to make a zeta pinch fusion reactor.

Nonetheless, provided you have an adequate current source (and competent cell cooling for the aggregate current and chemistry!) full parallel charge will give the shortest recharge time -- again, I think the discussions of the Tesla Megacharger covered many, if not most of the relevant issues by reasonably early on.  I do presume that the facility to be switched does in fact have access to high-amperage sources; the concern then becomes the trade off between time and current involved in sequential partially-parallel rather than full simultaneous parallel charging.

What I suspect might be used is rotating sequential fast-rate charge, with the 'addressing' being in part handled via the thermostatic measurement of cell temperature and its rate of change.  I believe many current lithium-ion chargers have temperature management so this is not 'new engineering'; the battery packs I was designing for a LSR motorcycle a few years ago were to be charged in strings this way.  The argument would then become whether to use more 'subdivision' of given discharge strings or conversion of the 110V power either via transformer or voltage-to-voltage conversion after rectification and filtering -- I would suspect the latter, although I don't know what the latest generation of 'plug-in hybrid' automobiles use for their 'wall charger' alternative.  The issue of trickle or float charging is, I think, related technically (although it remains to be seen if the Vale facility is set up in a way that allows the Jouse to move like an enormous Roomba to docking facilities with acceptably-low-voltage automatic connections).

Power electronics have advanced to the point that a connection to 4160V 3 phase power isn't entirely out of the question.

This vaguely disturbs me, as one of my prized college possessions was a 4160V switch removed from some improvement or other and 'adaptively reused' as a kind of theatrical prop when folks on commercial location shoots in Englewood started to get a bit too nosy about the layout of the house or its security system arrangements.  Further care would be needed in field connections and potential (no pun intended) arc flash -- you'd almost need powered connectors with active interlocks to be fully safe unless a full indoor 'dock' were built for the charging.  On the other hand, the 'hardest part' of 4160V charging, interruption of the charging current, would be limited by the state of charge reached by the cells and the charging controller, so accidental disconnection at the end of a cycle might be somewhat less traumatic...

[Erik_Mag]

Overmod

You don't charge a system like this at 110 or even 220V.

110V might be adeqaute to handle the self-discharge rate of the battery.

Erik will know more than I do about practical recharge time at ~1200 to 1500V, presumably at industrial grid current levels.  The principal limit ought to be cell cooling related, which I'd expect to be adequate on the Joule if Progress has indeed learned the lesson about discharge.  I'd be surprised if the practical charge time to battery-imposed limit is greater than about 45 minutes; I expect the unit is sized with sufficient overhead capacity that even 'overworked' it will have reliable 24hr run time and hence can be scheduled for regular run to and from a charging point.

My first guess is that a DC charging link would be at the battery voltage, charging time would be determined by how big a cable you would want to use. The ultimate limit is the battery itself, and presumably the battery will be charged at a rate conducive to many charge/discharge cycles.

I would wonder if the batteries are set up so that you would have several battery packs running in parallel, each with a dedicated contactor to isolate the individual packs - which then would allow for multiple lower current cables. An external connector that was hardwired to all of the batteries in parallel would be asking for trouble or a poor attempt to make a zeta pinch fusion reactor.

Power electronics have advanced to the point that a connection to 4160V 3 phase power isn't entirely out of the question.

[Overmod]

York1

Without fuel tanks, diesel engine, and generator, do the batteries take up all that room?

Looked at another way, you want as much 'battery' as you can afford.

In this particular case the Vale Joule does not have the full optional battery capacity installed, so I expect some of that long hood is either empty or has something else installed in it.  If cooling is liquid and competently designed there is little restriction on where in the locomotive the actual strings can go; it would be logical on a meter-gauge locomotive presumably bodied for North American clearances to have as much heavy equipment or battery in the area 'down low' below the frame and between the trucks as possible (comparable in part to the old GM 'skateboard' electric-car battery design) but I suspect EMD has done its DFM so that all Joules have their battery architecture relatively 'in common'.

Note that more battery is better whether you actually deep-cycle it or not, and the aggressive cooling arrangements may add considerable volume to the 'assembled' battery as installed in the locomotive; it is also possible that some space is reserved for access or optimized modular packaging for ease in maintenance or repair.

[Overmod]

Interesting that almost everything about this locomotive refers to the initial publicity blitz that Progress sent out around mid-July... often so word-for-word that we can 'flip around the dial' and see whose editors are lazy or not.  I have so far not seen any technical discussion of the Joule at all, although it was promised in the press release.

Interestingly EMD only filed trademark on JOULE for locomotives in early July.

The unit has only been working in Brazil since late September, so perhaps not enough experience to comment on practical performance.  Amusingly it was delivered with a tarp covering it because the owner wanted a publicity 'big reveal'; the long hood has a Pakistani-bus color scheme "100% ELETRICA" supergraphic on it now.

It appears to me that EMD has tumbled to the understanding that aggressive battery cooling is a major key to practical use in flat switching just as it is for high performance in road vehicles.  There are radiator openings each side and I would presume a system of pumped liquid coolant through the cells as installed.  Depending on climate I'd expect this to 'double' with onboard heating to keep the battery at reasonable temperature.

You don't charge a system like this at 110 or even 220V.  A reasonable guide for what EMD and Vale will use can be found in the Tesla Megacharger (for trucks) where the battery 'strings' are charged in parallel, priportional to the nominal voltage per string.  (This is something just over 300V for many electric cars; I would predict it to be around nominal DC-link voltage for EMD's regular AC production locomotives if they have their production heads screwed on right). 100% ELETRICA means there is no onboard charging engine, something I expect they will eventually provide (using carbon-neutral renewable-derived fuel of course) when they have a little experience with 80-20 charge limits or the current equivalent for these actual cells -- EMD likely has fancy voltage-to-voltage conversion to extend "run time between recharges" but I predict that will be highly counterproductive in the long run for battery longevity if actually regularly used as such.  It will be interesting to see whether EMD has incorporated some or all of the DC-specific charging equipment on the locomotive, making only a connection to commercial grid power necessary at charging points (which is I think what I'd do on a locomotive in a heavy industrial facility) and whether there is a nominally lower-voltage charging mode for 'emergency' recovery using something like a mobile generator or starting cables from another locomotive.

Erik will know more than I do about practical recharge time at ~1200 to 1500V, presumably at industrial grid current levels.  The principal limit ought to be cell cooling related, which I'd expect to be adequate on the Joule if Progress has indeed learned the lesson about discharge.  I'd be surprised if the practical charge time to battery-imposed limit is greater than about 45 minutes; I expect the unit is sized with sufficient overhead capacity that even 'overworked' it will have reliable 24hr run time and hence can be scheduled for regular run to and from a charging point.

[York1]

I don't know anything about these, so this may be a silly question.

How does a locomotive with batteries compare in size with a normal diesel?

Without fuel tanks, diesel engine, and generator, do the batteries take up all that room?

[SD60MAC9500]

 

MidlandMike

I wonder if it is narrow gauge?  It's on 3-rail track, and the loco in the background looks bigger.

 

 

Brazil operates a tri gauge network; 1600mm, 1435mm, and 1000mm. Vale leases lines using; 1600mm, and 1000mm gauge. Yes this is a NG unit.

 

 

 

[MidlandMike]

I wonder if it is narrow gauge?  It's on 3-rail track, and the loco in the background looks bigger.

[caldreamer]

OK, i plug it in.  How long does it take to charge at 110 volts???

[SD60MAC9500]

 

zugmann

"Oh crap... I forgot to plug in the swticher before I left!"

 

Yeah there's no mention of how it's charged. I'd assume plug in. 

 

[zugmann]

"Oh crap... I forgot to plug in the swticher before I left!"

[SD60MAC9500]

 

Here it is! The Progress Rail battery switcher for Vale Mining in Brazil. Progress is claiming this unit can operate up to 24 hrs without charge depending on duty cycles.

 

Here's a link to the article