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XP for neutral sections


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  • 9 months later...
  • SIMRAIL Team

If it was the case... Most of the neutral sections are there just in case, and running them at full power won't do anything in the real life. There are even some placed in the middle of a platform. Other than that, it's a good idea to give points for either running them in the neutral or failing to do so, but it's a small thing to maybe add in the future.

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2 hours ago, Atoka220 said:

Or just have actual voltage dropouts and if you drive under it without cutting power, the MCB should pop, giving you some work to fix your mistake

voltage drops are active in the sim now,  people are tripping the overload due to icy overhead wires reducing the voltage available to the loco, 

so hopefully having things happen if you forget to move the controller to zero when passing a neutral section can be added easily. 

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1 hour ago, GoppelPL said:

If it was the case... Most of the neutral sections are there just in case, and running them at full power won't do anything in the real life. There are even some placed in the middle of a platform. 

Ahh
That's new info to me. Here we have our uttermost respect to neutral section signs as shorting 2 phases of 25kVac together is pretty bad 😁

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Wait, so you don't have a neutral section between them?

Here in Italy we have both 3kV DC, like in Poland, and 25kV AC (on high speed lines), like you.

Under 3kV DC, sections are normally connected via a normally closed disconnector, so the voltage difference between the end of a section and the beginning of the next one is always zero; therefore, no special caution is required when passing under them, except under special circumstances which must be notified to every train with a dispatch.

This makes me wonder why in Poland you need to cut off the power: are your sections not normally connected?

Under 25kV AC we have many neutral sections, most of them are kept powered so it's like they don't even exist, but some of them will have 0V for a few dozen meters (don't know how many exactly) to insulate one phase from another. These neutral sections are activated or deactivated depending on the current demand on the national electric grid, which trains help to balance by using more or less of each of the three phases. At any rate, you're required to lower the pantograph, which is done automatically since we're talking about modern high speed trains, but there is a section of neutral overhead wires between the phases. Does this section not exist in Hungary?

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In hungary we have either air insulated 'phase limits' where a neutral wire is brought in, the phase is raised away from the panto, has 2 section insulators with a very short (1-2m) neutral wire inbetween them and it's lowered down again and the neutral wire is brought away and out

Or section insulated ones where there are only 2 section insulators that the pantograph can slide on and have the same very short neutral wire (if there is a neutral wire)

We only need to turn off the MCB when passing them, pantograph is only lowered if there's a specific sign for it (which is usually pointed out in a written order)

But unlike you, our trains are 40 to 60 years old and only do 120km/h max
Well of course we have some more modern ones for show off going 160 near the austrian border 😆

These sections however can only be activated when needed, such as a locomotive got stopped and is now stuck under the neutral section. Or if there's an outage on one phase, 2 sections of wire can be closed short and now there'll be one phase across both sections until it gets fixed. Normally, the neutral sections are never energized - but can be when needed

Of course we only study about 25kV 50Hz here so i'm not familiar with dc overhead wire systems

Fazishatar.jpg

fazis2.jpg

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  • 2 weeks later...

In the UK, we also have two electrification systems (25kV AC overhead, and 750V third rail) - and historically a third (1500V DC overhead) which was retired in 1984 with the closure of the Woodhead Line.  This doesn't include various metros and tramways which have their own special systems.

On both the 750V and 1500V DC systems, electrical sections can be powered by multiple substations simultaneously, with most of the load of any given train effectively falling on the nearest substation, or on the two either side of its position if it's about halfway between them.  In some places on the third-rail system, there are "section gaps" with the third rail removed over a distance longer than the connected shoes of any locomotive or multiple-unit in service, to ensure that the rail can be depowered without accidentally being shorted to its neighbour.

1500V locomotives routinely ran with both pantographs raised to reduce wear due to arcing, and there was one location where it was required that the three nearest substations were switched in and no other trains were operating in that area before particular trains could start away - due to extreme gradients, they were double-headed and also double-banked from behind, so a total of four locomotives were starting at once.  It was apparently common for one substation to be switched out, but the section of line it normally powered would be supplied by feed-through from the neighbouring substations.  Isolation switches were provided, but normally kept closed to allow this feed-through, which also made it easier for descending trains to regenerate power for ascending trains.

On the 25kV system, there are neutral sections about every 15 miles (25km) where the supply is taken from a different phase of the National Grid, balancing the load.  There is an insulated section between them which pantographs can run over without being lowered.  Either side of this neutral section, there are APC "magnets" (they might actually be tuned inductors) beside the track, which automatically prompt the main circuit breaker to toggle off and back on as the pantograph passes over them, ensuring that no significant arc is drawn over the gap.  It is considered good practice, but not strictly necessary, to reduce or cut power on approach to a neutral section, mainly to reduce the jerk to the train.  There are signs which prompt this to be done early enough for the older type of tap-changer locomotives, of which some are still in service for container freight traffic.  This system is designed to operate reliably at full express speeds, up to 140mph (225kph) in principle.

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Now that's a clever solution with the magnets

Here with our old fashioned way we have what are called 'ambush sections'
That means neutral sections in unexpected places and if someone doesn't have enough knowledge for that line, it can be pretty out of nowhere. And then panic, and begin the procedure of cutting power, shutting down loads and praying you have enough time to open the MCB before the actual neutral section lol
And well cutting power is fairly slow with our old 'position switch' type locomotives (don't know what it's exactly called in English) that take their precious time to run down the position switch till finally the contacts open and power is cut towards the motors.

You know one expects neutral sections to be near stations (as they usually are) but sometimes they can be out on the main line in the middle of nowhere 😅

Edited by Atoka220
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do the old loco's not have a rapid power off button? 

There's one in the EU07 / EP08's in SimRail,  it's the red button next to the wheel slip brake green mushroom button,  labelled 'open line contactors' 

I imagine it's only to be used in an emergency, and it might actually not be for what i am thinking, but i've used it a few times when i see a neutral section 50 meters infront of me and no way i'd get the wheel back round to zero in time.

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They have but it shuts down the entire thing and applies emergency brakes

Basically the driver puts the controller in the -- position and then motor contacts instantly open and the position switch begins its journey back to open position (as opposed to 0 where the position switch first runs down and then the contacts open)
And at the same time MCB is opened and pantograph is lowered and the loc begins emergency braking (and in some types it even sounds the horn)

It also results in an instantenous big jolt and a loss of power in the train so drivers really only use it in utmost emergency situations

ziliazdal.jpg

Edited by Atoka220
typo
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On 12/16/2023 at 3:07 AM, Gazz292 said:

do the old loco's not have a rapid power off button? 

There's one in the EU07 / EP08's in SimRail,  it's the red button next to the wheel slip brake green mushroom button,  labelled 'open line contactors' 

I imagine it's only to be used in an emergency, and it might actually not be for what i am thinking, but i've used it a few times when i see a neutral section 50 meters infront of me and no way i'd get the wheel back round to zero in time.

You can just turn off the main switch, that is always an option, but it's not very healthy for the loco to do so under power. Steering wheel tap changers don't have a lot of resistance to them though, they do the clicking sound, but you can still turn them for full rotation within half a second. Since the last patch you can just hold Num- and it will rotate rather quickly, or (at least before the patch you could) use Shift Num- to get to the nearest important position immediately. There are some shortcuts built in as in reality, so if the tap changer is set suddenly to zero, it does not have to go through individual notches down, but from I believe 27 it can jump to 1 immediately, for example. That speeds up the response of the engine to the controller a lot as well.

What Atoka220 describes is something different, that's an "oh sh*t" button that you press in case of imminent crash (in siemens loks it's the giant red mushroom at the end of the panel). When you see that you are about to have a crash that directly threatens your life, you slam the button and run into the engine room where surrounded by all the heavy equipment, your chance to survive is much higher. The button takes care of all the necessary steps to secure the loco for crash and rescue operations (mainly it ensures that you don't get killed by electricity right as you enter the engine room, turns off MCB, lowers pantograph, sounds horn, sets light into "stop by all means possible" signal, and applies all brakes; varying by the manufacturer). It is definitely not meant to be used in regular operation.

Edited by noirceur
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4 hours ago, noirceur said:

Since the last patch you can just hold Num- and it will rotate rather quickly, or (at least before the patch you could) use Shift Num- to get to the nearest important position immediately.

oh, i don't use the keyboard to drive trains 🙂 

   EU07MiniControllerWIP.gif.285a25db263d0315f12367ba4dac9c50.gif 

This controller is a work in progress, the reverser and shunt lever are not hooked up yet (i still have to print their gears to link them to the potentiometers and write the code for the arduino to convert positions to key presses

Only problem is, with the new input system and animations when moving the wheel, i can no longer send the 'move controller up / down' key event as fast as my mini wheel can be turned, or the controls in the sim miss the inputs.
So i have to send the key events with 70 millisecond gaps between them so the controls in the sim don't lose sync, so it takes a little longer than it should for the wheel in the sim to go to zero when i move my mini wheel down to zero, as can be seen in the GIF above.

 

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18 hours ago, Gazz292 said:

with the new input system and animations when moving the wheel, i can no longer send the 'move controller up / down' key event as fast as my mini wheel can be turned, or the controls in the sim miss the inputs.

Could you program it to send shift +/- when needed?

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