Concerning realism

[Aldarion]

After the excitament of the launch comes some concearns.

 

First off all, Simrail is absolutly amazing and I do not regret buying on day one.

That said, i have to note one  thing I have not experienced yet... slipage.

I have been driving almost exclusivly the Eu07 (it has my favourite driving style and frankly it's what made me buy the sim) and I have yet to experience slipage when starting to move. And believe me I do tend to tend to use a lot of 'taps' from the beggining.

Also, will there be more statistics related to the mileage and time we use any of the different traction loco's availabe?

Any hope in the future to have a saving feature for the finalk report?

[weezzah]

On the EU07 you're also limited to how much power you can tap in, and maybe it's not prone to wheel slip because of that? I'm not a real EU07 driver so I wouldn't know.

But if you set full power on the TRAXX then you can experience kN fluctuations on the main display, which I assume indicates wheel slip? Hard to tell visually from the model.

And agreed on the save function. I believe there are threads on here requesting said feature.

[pschlik]

I've definitely experienced wheel slip on the EU07. It can be tricky if you aren't expecting it, as the only indicator is a white light on the desk and there's no automatic control of slip. If you don't see that light you can easily reach full power while only moving 70 kph because all that power is going into spinning some of the axles really fast.

If you really want to cause wheel slip, use the EU07 (EP07's higher gear ratio gives it less tractive effort, making it harder to slip) and set it to high current mode so you can draw 750 amps when starting. That'll get things spinning.

[-1PARA-AlexKall]

I tried this in the prologue missions with the Traxx and wheel slip was modeled already back then. I have experienced it many times, especially on wet tracks and some of the older routes with the freight trains, where there are fairly long inclines, especially with the low blue wagons. But yes, more prevalent on the more modern locomotives; Traxx and Dragon as they can deliver more power.

[weezzah]

2 hours ago, pschlik said:

the only indicator is a white light on the desk

Nice, thanks for sharing. Found a video showing a wheel slip and the white light you were talking about:

 

[SurvivorSean]

I've had the white light come on.  Normally I would blow out the circuit before it got that far.  There are some steep grades.  1 is by a bridge on the coal route.  I noticed someone mentioning this in the last 24 hours and ran out of time at lunch to reply.  But indeed I experienced the same issue in the play test.

I should've posted it as a bug (but I had some posts about it in general I think).

Thanks

Sean

[Skully]

As pschlik said: in the sim, put her in high current. Ramp up throttle while keeping amps just below 700 and put her in shunt 6 at throttle 28 immediately. This works for both cargo and passenger trains. 😄

You can observe the traction wheels spinning externally. Either lower the power and/or use antislip to get her to move.

I don't see a bug here but I might be missing something.

[Aldarion]

Than you so much for sharing this.

I guess I have been lucky so far, since I have yet to drive in the rain. If that's the case in no time I will experience that... or maybe if some heavier ECE consists happen to come.

[Aldarion]

On 1/17/2023 at 9:40 AM, Skully said:

As pschlik said: in the sim, put her in high current. Ramp up throttle while keeping amps just below 700 and put her in shunt 6 at throttle 28 immediately. This works for both cargo and passenger trains. 😄

You can observe the traction wheels spinning externally. Either lower the power and/or use antislip to get her to move.

I don't see a bug here but I might be missing something.

Funny you mention that.

I only use shunting after throttle 43. I've never actually seen or read about the drive style of this EU07 but instinctively I have driven her like I drive my regular 'tap' french locomotive with 32 taps and 5 shunts... but in 25kV@50hz. In this case Alsthom's manual clearly states the shunts only to be used after throtlle 30. All drivers I know state they do not know what happens ifshunts are used in lower thrrottle, but being shunts what they are (they result in magnetic field reduction) I belive  that using shunts at lower throttle have a negligible effect, since they are effective when electric motor is at it's  higghest rotational speed...

[Skully]

The 07s have two traction motors. At throttle 28 one is engaged fully.

[Aldarion]

oh I see. I was thinking that it the transition between parallel and series.. well..it is, sort of

[Gazz292]

I'm sure the EU07 uses both motors all the time (one per bogie) but in the 1-28 notches they are in series and 29 - 43 notches are in parallel?   that's the normal way to do it in DC motor trains,

 

So the 1 - 28 notches the power goes into one motor, then out and into the other motor before going to the rail return, so they share the 3Kv input and each motor see's 1.5Kv and turn slower,
then when you get past notch 28 they are connected in parallel, so both motors receive 3Kv each and turn faster.

Hence why one ammeter shows the 2 motors series connected with upto 600 / 750 amps, then when you go to parallel connection each motor can have it's own ammeter, so you now need to add their readings together to get the total current drawn... upto 1200 amps in parallel notches.. 600 amps per motor / meter.

 

With the EU07 in the sim, the field weakening / shunt lever should do nothing whilst the resistors are in circuit (notches 1 - 27, and 29 - 42)  but if you've used it in the series notches it wont advance into the parallel stages until the field weakening / shunt lever is put back to zero (or if you have switched to high current.. as that's for the series notches only)

 

If hauling a heavy freight, then using the field weakening / shunt lever in the series notches is often needed, with a passenger train i don't bother, and only use the lever when i want to get to max speed in notch 43,
But if i want to hold the speed at about 90 km/h, if notch 43 and no field weakening / shunt is too much current (~220) making you over speed, dropping back to notch 28 and using the lever can often get you cruising along nicely at about 90 km/h, with about 180 amps or so.

 

Not sure if Polish train drivers are told to drive in the zig/zag / see saw method German drivers are, which is to :  power on to get upto speed, then power off and coast for a bit, power back on when you've lost about 5km/h, as this was found to me more efficient than running at a constant current draw for the speed.. which is what the modern thyristor / IBGT mosfet based motor controllers do....
So the old 'bang - bang' method of motor control used less electricity.

 

[bprog]

EU07 has Bo'Bo' configuration, which means two motors per bogie, one motor per axle. EE541A have nominal voltage of 1500V, so in each bogie two motors are connected in series. Up to position 28. bogies themselves are connected in series, and on later positions - in parallel.

The field weakening lever is mechanically blocked from used when not in position 28. and 43. (and also 0.). It would work, but it is done to encourage reaching position 28. or 43. (without resistors) instead of weaking the field while on resistive position.

As you say, passenger trains often skip weaking field on position 28. since it accelerates much quickly and you can go from 28. to 43. easily enough. With heavy cargo you need to use it, to prevent overheating of the resistors.

As far as I have gathered - old train drivers, in years of Polish People Republic were encouraged to use zig-zag/see-saw method, as it was deemed most energy efficiend. Nowadays it has come under debate, and I think continuous low power might be encouraged nowadays, to ensure more smooth experience for passengers, but I don't have any proof for that.

For my understanding see-saw method would make sense on resistive positions but what's the loss on non-resistive positions? Eco-driving in a car means maintaining more or less steady rpms, and experimental "coasting mode" is regarded obsolete in modern cars, AFAIK.

[Gazz292]

Re: the se saw / zig zag power method, it was something i read about modern German trains,  something about the continuous steady power used more electricity than getting upto speed then coasting, then powering back upto speed etc.

There's also something about the use of 2 loco's uses less power together than a single one,

[Królik Uszasty]

There is more than one topic, so my answer is in points.

1. The slipping needs still a small fix. For know the ahesion of wheel-rail is set for a very very good condition, so it is not that easy to slip with EU07. Adhesion doesn't change with weather yet. It still needs some conception work, but priorities for now are obvious bugs and the most lacking features. For EU07 you should try "high current" setting without "load compensation" or high current with 1-2 shunting position in parallel connection - AFAIR the needed current is nearly 600 A. But when you switch load compensation on, you can reach up to 700 A in EU in series connection (up to last resistive position - 27th) and it would be rather nearly impossible to slip in EP  in that range.

2. Shunting handle is not blocked - you can use it freely on every controller position. It is forbidden to use shunting on resistive position by electrical way.

3. Energy efficient driving is very wide topic, but it needs one assumption - what is required time to travel from A to B. With 2 locos you can have the same driving time (and mean velocity), but less energy used as you accelerate faster and it saves some time you can spend on longer coasting before braking.

[Schyrsivochter]

On 1/18/2023 at 1:35 PM, Gazz292 said:

Not sure if Polish train drivers are told to drive in the zig/zag / see saw method German drivers are, which is to :  power on to get upto speed, then power off and coast for a bit, power back on when you've lost about 5km/h, as this was found to me more efficient than running at a constant current draw for the speed.. which is what the modern thyristor / IBGT mosfet based motor controllers do....

So the old 'bang - bang' method of motor control used less electricity.

Never heard of that, never noticed anything like it when riding any electric train here in Germany. I’d have thought that with modern semiconductor-controlled three-phase motors the difference would be negligible. Why would they all have automatic speed control if it were inefficient? Maybe it applies only to old locomotives with series-wound motors and transformer tap changers? Or maybe it’s diesel trains – internal combustion engines, as should be common knowledge, are most efficient at or near full load, and least efficient at light load or no load (idling). Not sure what bprog means about coasting in modern cars being obsolete, by the way. After all, coasting in gear often means you’re not consuming any fuel at all, provided the engine RPM is high enough.

Not sure what an ‘IBGT MOSFET’ is supposed to be, by the way. Thyristors, insulated-gate bipolar transistors (IGBTs), and metal-oxide-semiconductor field-effect transistors (MOSFETs) are three distinct kinds of semiconductor devices with fairly different characteristics.