[Serana]

I will work on the addition of electric locomotive selectors soon, so I am opening a discussion in order to collect ideas/remarks.


An electric locomotive may need several selectors. The most common are the following:
- Pantograph selector: a locomotive may raise the pantograph at the front or at the rear or both.
- Voltage selector: a locomotive needs to configure its systems in order to accept the right voltage from the overhead wire.
- Power limiter selector: on some lines, the power available on the overhead wire is limited. The locomotive must be able to limit its power consumption in order to not decrease too much the voltage.

All of these selectors must be scriptable in order to take the particularities of a locomotive into account.

The selectors will give information to the power supply classes in order to trigger the right pantograph and to limit the power of the locomotives.
The power supply classes will also receive information from the TCS in order, for example, to check that the right voltage is selected.

In order to give an idea of what will be available, here's the example of what's available on a TGV Atlantic:

The pantograph selector has 3 positions: normal, rescue, local.
The pantographs that are raised depends on the voltage selected on the voltage selector:
- 1500 V : normal => all pantographs are raised, rescue => all pantographs are raised, local => only the pantograph at the front of the train is raised
- 25000 V : normal => the rear pantograph of each EMU is raised, rescue => the front pantograph of each EMU is raised, local => only the pantograph at the front of the train is raised

The voltage selector has 3 positions:
- 1500 V
- 25000 V conventional line
- 25000 V high speed line

The power limiter has 3 positions: I, II and III.
Depending on the position of this selector, the position of the voltage selector and the number of EMU in the train, the locomotives are power limited to different values.

To answer a question of Chris sent by PM, at first, the power supply class won't be able to know if there is a voltage change on the route. But, with a few signals (for example, a Lower Pantograph signal with C# signal script), the TCS may forbid to raise the pantograph if the chosenvoltage is not the right one after the neutral section.

[Laci1959]

Quote

- Power limiter selector: on some lines, the power available on the overhead wire is limited. The locomotive must be able to limit its power consumption in order to not decrease too much the voltage.

This is called on some railways: Driver, i.e. a specialist.
Sorry.

[Csantucci]

In the Italian TCS scripts that I have written there is a provision to automatically lower and rise (the latter after driver enable) the correct pantograph depending on the line voltage. The points where to perform the operation are defined by INFO signals.

[keystoneaholic]

Would it be possible to add additional voltage positions for 3000 volts DC and 750 volts DC? The Eurostar sets run at 25Kv AC in UK, 25Kv AC on high speed lines in France, Belgium and the Netherlands, 3000v DC in Belgium and 1500v DC in the Netherlands. The original Eurostars also ran on 750v DC in the UK before the high speed line from London to Folkestone was opened. I believe that they may have retained this feature for emergency diversions. I'm not too sure about the newer trains. There are conventional EMUs in the UK which run on 750v DC third rail and 25Kv AC.

A number of the modern European freight locos are also multi-current, 1500v and 3000v DC, 15Kv AC (16 2/3 Hz) and 25Kv AC (50 Hz). Some of the most modern also have a 'last mile' (or should that be 'last kilometre') facility of a small diesel engine for slow speed movements in unelectrified tracks. I realise that this is all added complication, but if it is possible to build in 'hooks' to allow for developing these features even if they are not implemented immediately it could save a lot of rewriting code in the future.

I'd offer to help, but my coding skills were in COBOL, with a bit of BASIC thrown in. I tried to pick up 'C' but it went completely over my head, it felt like the lecturer lived on a different planet.

[darwins]

Related to the above - third rail. Not all electric trains have pantographs. It is quite annoying having to raise the pantograph of a train that uses a third rail system.

The old Eurostar sets as mentioned could use 750 v dc third rail as well as the three different overhead line voltages.

There were a small number of British locos that could take 750 v dc either from third rail or from an overhead line when in yards.

Also the French CC 6500 which originally used third rail rather than overhead on the Maurienne section.

[Weter]

Old-fashioned locomotives often had selectors for choosing motor groups arrangement (serial, mixed, parallel) or excitation field weakening.
Some functions could be combined with throttle handle, or we're automatically adjusted.

[Laci1959]

Quote

Old-fashioned locomotives often had selectors for choosing motor groups arrangement (serial, mixed, parallel) or excitation field weakening.

Hello

That's right. Parallel switching was used either to start or permanently in freight locomotives.
In the MÁV V43 locomotives, the gear switch ( throttle handle ) gave the speed and the shunt switch ( excitation field ) gave the force. It was available from 9th grade and had 4 positions.

Yours sincerely, Laci 1959

[Laci1959]

Quote

- 25000 V conventional line
- 25000 V high speed line

What is the difference in the design of the overhead line apart from fixing it?

[darwins]

Laci1959, on 26 November 2021 - 12:33 AM, said:

What is the difference in the design of the overhead line apart from fixing it?

The difference is the amount of current that an individual loco is allowed to draw. The result is that higher power is available on high speed lines.

[Laci1959]

So a larger cross-section work line and a support line. Higher power, possibly more densely distributed electrical substations.
I see. But these are outside the locomotive, independent of it.
I mean, the power consumption of the high-speed locomotive, the electronics, the winding of the motor, the values of the circuit fuses are scaled to the speed. Etc. But why switch to these when driving at a normal speed?
Or is it just replacing a pantograph and Google Translate having fun with me?

[darwins]

It sounds like you have got the idea. On normal routes less power available means the acceleration of the loco will be less. If this was not limited by on board control the results might be a damage to overhead line, reducing line voltage, tripping circuit breakers or otherwise having less power available for other trains sharing the route.

Having a selector in OR is interesting as previously we had to use two different eng files. Similar cases are passenger / freight gear ratios Passenger / Goods or Yard / Main Line and different braking systems - Air Goods / Air Passenger / Light Engine / Vacuum Braked / Vacuum Unbraked.
Choices
I thought there was also a Trello card for allowing options in eng files but I can't find one.

[Laci1959]

Quote

If this was not limited by on board control the results might be a damage to overhead line, reducing line voltage, tripping circuit breakers or otherwise having less power available for other trains sharing the route.

Thanks. I just understood. Thus, the switch is now legitimate.

[Weter]

Hello Darwin, Laci and all others.
First, I think, that moving on higher speed, indeed allows to draw more current from each point. (contact wire at this point will not be heated during too long time)
As like standing, or slow moving loco owe to use all of its pantos for dividing current, what prevents wire overheating, (causes the risqué of deformation or even burning of the wire)
Also, it might be different contact "ski" pressure on wire demanded, respecting of speed.
As well, different circuit-breaker threshold setting, as Laci noted.
I think, not sub-stations themself, but points of power-supply (where the power cable connected to contact wire)

Second.
Darwin have just gave to me an idea: if those "selectors" application is not limited to electric system, we could use that for pneumatic system, like braking modes (changing normal BP pressure for pass/goods or plain/mountain service) as well EP/automatic airbrakes
or for mechano-hydraulic transmissions (shunt-mainline mode)
Even for signaling/TCS switching/mainline mode, or signaled/coded routes.

[Serana]

About the selection of the HSL mode:


On high speed lines in France, UK, Belgium and Netherlands, the height of the overhead line is fixed to 5.08 m. This allows to activate a pantograph stop on the train that blocks the pantograph if it goes too high.
This can help not damaging the overhead line when the train is at high speed and some crosswind move the overhead line sideways a bit.
To activate or deactivate the pantograph stop, you have to lower the pantograph.

On TGV, this also change the power limit indeed. On conventional lines, you are limited to 7200 kW and, on HSL, you are limited to 9280kW (value for the most recent TGV).

keystoneaholic, on 25 November 2021 - 03:41 AM, said:

Would it be possible to add additional voltage positions for 3000 volts DC and 750 volts DC?

The voltage selectors can be so different for each type of rolling stock. In order to take into account the different positions, you will need a C# script for that.
In that script, you will be able to set any voltage you want.
For 750 VDC, you can consider in the engine configuration that pickup shoes are a type of pantograph.

Weter, on 25 November 2021 - 02:14 PM, said:

Old-fashioned locomotives often had selectors for choosing motor groups arrangement (serial, mixed, parallel) or excitation field weakening.
Some functions could be combined with throttle handle, or we're automatically adjusted.

For this, it will be a bit complicated since we currently don't use an accurate DC motor model. The different couplings and excitation field weakening will only be possible once this model is available. We would have to model also the rheostat.

[Laci1959]

Weter, on 26 November 2021 - 09:39 PM, said:

Second.
Darwin have just gave to me an idea: if those "selectors" application is not limited to electric system, we could use that for pneumatic system, like braking modes (changing normal BP pressure for pass/goods or plain/mountain service) as well EP/automatic airbrakes
or for mechano-hydraulic transmissions (shunt-mainline mode)
Even for signaling/TCS switching/mainline mode, or signaled/coded routes.

Hello.

ICIK's unofficial OR already knows this. There is a train derailleur and a load changer for the brakes. The former sets the operating speed of the brake.
In the window after F9, click on the car to display the list. Highlighting these settings in a different color. Its operation is almost similar to the EU07 Maszyna program. Only there can you get the train with random settings, and you have to check the cars and check the setting before you leave.