How electric trains work and why they make interesting sounds
HTML-код
- Опубликовано: 2 дек 2024
- Electroboom 101:
• ElectroBOOM101
Narrated, edited and fact-checked by Zack
Credits:
@xoticclipsyt , The Engineering mindset, Arduino website, Beno, Electroboom
Before you comment saying "What about this other type of train?", I only provided examples of different sounds, not just explaining that one. Every model of train is different and going over them all would make the video 10 hours long, so use the examples I mentioned to figure out the sounds, it'll be a combination of what I talked about
So happy you managed to fit in the musical train
I love that musical train. It literally sounds like music notes rising in pitch.
@@Pethrenne some of the older Montreal metro have a similar sound. Forgot the tech in those however.
@@threeparots1it’s called a current chopper.
Keikyu N1000 Siemens GTO is one of them though they are ded.
@@737Garrus Sounds like they deliberately used the major scale for choosing the carrier frequency.
i am so glad someone engineering train motors thought, "it's gotta be in steps anyway, so why not make it a major scale?"
i've never been on a train before but I am happy knowing this exists
Oh mate, you gotta go on one at some point! Are you based in the US by any chance? If so, I'd recommend the M7 units on the Long Island Railroad and the Metro North
@@zfrailways I'm in the southeastern US. I have been on the monorail at Disney World and the train at my local zoo, but public transportation in my state is almost non-existent. I'll have plenty of opportunities if and when I go to the Netherlands one day though
@@NotGabe001 I also live in southeastern US (Louisiana specifically), and we have a zoo with a train as well, but other than that I've never really been on any trains before my trip to Japan this past summer for a study abroad program. The trains there were wondeful!
🤯 there are people with internet access that have never been on a train
@@UloPe not very surprising considering the entire USA
There is a video of a Taurus hauling freight, and sounding like an orchestra as its motors adjust to avoid slip.
can you get me the ID?
@@brunoais the video is called "Taurus make music" iirc, RUclips won't let me post links here
@@WildWildWeasel Found it! It's Q_bF1Wb_pSE
All Taurus make that sound.
@@rogeriomonteiro760 not all Taurus make it, the newer ones are dead silent.
Love the picture of a ironing board to represent a 700 class, a distinct touch sir.
That made me laugh.
What was the joke there?
PS: some googling later is it the shape of the seats?
@dawsum11 Not so much their shape, but they are really hard & compared to like "sitting on an ironing board".
No passenger would agree that they are suitable to be used in a train.
@@TheRip72 Sadly, living on the GN, I (and my posterior) are well versed with the pain of 700 seats.
Came here to say that
Fun Fact: the sound the ÖBB 1016/1116 also known as DB BR 182 or Taurus makes as it speeds up from 0 was indeed an Easteregg placed by the Engineers at Siemens who programmed the GTO's to sound like that. However with new Software versions this iconic sound is being phased out and some locomotives don't do it anymore.
That's sad that they're being updated
What a disgrace. I thought that could have been a marketing advantage of those "musical" trains.
A fun Easter Egg! I wondered if an engineer was a sax player given it sounds… very much like that.
Then I wondered if they could’ve reached a similar sound mathematically, making a total coincidence given the maths behind tuning systems. Reading this comment, especially that newer engineers aren’t keeping it up, makes me go back to thinking some dude tooted a few notes and wrote down what a frequency counter told him the frequency was!
That's the BR 183 or ÖBB 1216 who make the different sound. Thanks to the fact that those are based on the BR 189.
reminds me of those videos of Metalica on a CNC. You could play music on a train.
I would never tire of the musical scaled one. Those tones were carefully calibrated to the notes of a musical scale.
not so carefully
@@kefsound I’m laughing so hard. RUclips is arguing school. Masters degree.
The octave is fine and even the third is good (not a sharp third like on piano and guitar, maybe ever ever ever so slightly flat without going and getting a computer to confirm). Sounds like a wind instrument going up diatonically.
However, past the octave, it gets flatter and flatter. This is to be expected I suppose, you start getting into the matter of which frequencies work best for the motors rather than having leeway in the step spacing during the initial ramp.
I suppose it’s questionable whether they’re even intended to be heard as part of the scale past the octave, but since they were still stepped I interpreted them as a 9th, 10th, etc. Keeping up the wind instrument comparison, it’s like someone used to blowing the low notes doesn’t have enough air speed for higher notes (and they come out flat).
Maybe they programmed in a specific frequency multiplier each time, which was only ever so slightly flat but not enough to throw off the ears, until the error compounded after the octave. Okay yeah, on another listen, the 6th and 7th are also a little flat (and indeed by slightly more than the 3rd). The 10th is really noticeable, but it’s the “11th” that absolutely jumped out to my ear as way off from the rest of the pattern and that’s the first “drone note” of constant-carrier operation. So maybe it isn’t “part of the scale” at all.
@@kaitlyn__L It sounds like you may be a pianist, accustomed to a tempered instrument. Besides the piano and a few percussion instruments, the entirety of a symphony orchestra’s temperament is human-chosen. Even my instrument, the fretted guitar, is regularly played in such a way as to temper the scalar intervals of the key signature being used.
My original comment btw, was merely regarding an amusing use of musical intervals outside of actual instrumental playing.
@@artysanmobile nope! Woodwinds, accustomed to just-intonation.
This is exactly what I wanted to know for so long and had nobody I could ask. The sounds trains make always made me wonder what causes them to sound the way they do and how it was different between vehicle generations. I realize it is quite quirky to be curious about it but I love to learn about the things that surround us and that we use every day. Thanks, you really made my day today!
that's it, I'm gonna get diagnosed for reals.
we are acustic
HAHAHA
Tell me the prescription
Already there
8:20 it's nice that the trains community finally got the recognition they deserve with the IGBTs 😂
Ayyyyy!
A Class comment. :) (From someone who identifies as old train repair guy)
This is a IGBT safe space
1:15 The current actually changes direction twice per period, so at 50 Hz it reverses 100 times per second
Sorry about that, thankfully it wasn't too important of a thing to get wrong for what came later.
@@zfrailwaysi was on an azuma and noticed fhe motor sounded like a dual tone klaxon siren or a large bench planer startin up. Its a nice sound
@@zfrailwaysIt was like a long one phase siren ramp up. I like when you dont hear that buzz like an arc welder instead the resinance on some of the trains sound awesome when they sound like V12 racing cars or are musical. Its almost like a robot singing scales
Excellent work on this explanation! I'm glad to see a fellow railfan who actually understands & appreciates the electrical engineering of the inverter/drive side of things, which I find to be the most fascinating & the core tech powering modern trains/locos.
A few details I'd like to rectify with your inverter terminology tho. The modes you refer to as "PWM/Pattern/Regular/Normal" have different names we use to describe them accurately. They are all 'PWM Modes', but are either referred to as 'Asyncronous' or 'Syncronous' operation stages. An Asyncronous mode can be 'Fixed' to a single carrier frequency, OR have a set 'Frequency Range', as well as multiple asyncronous 'Stages', either in 'Steps' (E.g. like the singing/musical Taurus), OR multiple Stages of Asyncronous Ranges. Most trains with lower gearing/lower top speeds only use one Asyncronous Stage. Then we always move to 'Syncronous' operation Stages, usually between 2-8 of those. Syncronous Modes/Stages are that nice smooth variable tone produced once the train gets up to speed (Sync), to avoid the elctromagnetic slip & excessive inrush current. Also, the 'gear change' sounds you hear, in Syncronous Modes specifically, are the 'Pulse Count' changing per mode change based on speed. These Pulse Counts are the equivilant in the inverter as to the 'Pole Count' (# of North/South magnet pairs) in a Syncronous motor. More poles=more Torque/acceleration, less pole count=higher HP/top speeds
A great resource to learn & play with inverter tuning/modes & operation is an Android App called "OTTOTETSU". It is a free inverter simulator app which you can replicate inverter calibrations & operate them to produce their resulting signals as sound generated. 🧑✈️🗝🛤🚦🚊🚋🚋🚋
I have made a profile for my favorite inverter sound of my local lightrail, the Siemens S70 Ultrashort SD8 LRV on the San Diego Trolley. Have a listen & have a try yourself. Thanks again & have a good one!
I'll definitely get the app, it sounds cool
Ah, thank you! I did some electrical in school but mainly did physics in uni and have had music as a lifelong hobby. So this video brought together a bunch of aspects I hadn’t combined before. But I found the mode names a bit confusing. Especially that “pattern mode” naming scheme for what I associate as PWM in class-D type operation (or similar but fully quantised).
When you mention modulating the pulse count, does that mean there’s essentially (in musical terminology) not just one sequencer modulating the pulse with but also adjusting the length of the pulse train sequenced in?
@@kaitlyn__L No way, my background is in music as well! I have an Associates in 'Audio Production', but always wished I studied EE/Physics or Music Theory. I started my career out as a Live Sound Engineer & CMV/CDL Truck Driver for a Sound, Lighting, Stage & Music Rental business here in San Diego, than moved to public transit/rail.
The 'Pulse Count' modulating per different modes is more akin to 'harmonic distortion' in sound reproduction, as I understand it. You are making the same fundamental frequency, but with more overtones for Acceleration/Torque, then transitioning to 'pure sine wave' to minimize back-EMF for Speed/HP. Sort of serves the same purpose of the 'Flux Weakening' or 'Field Weakening' featute in some motor Controllers/Inverters.
Now I may be off the dot here honestly as I don't have experience (yet 😉) Engineering, Programming or Manufacturing rail traction inverters, so this is the edge limit of my clear knowledge, as we are not even REMOTELY trained, educated or required as a Train Engineer to know this level of detail about the equipment we operate
@@RailManSD oh, cool! Thank you so much for the detailed answer. That makes a lot of sense! (Especially as modulating PWM through its entire range noticeably accentuates various overtones.) Are they “proper” harmonics, or can they be totally arbitrarily spaced (inharmonics) by the PWM controller?
@@kaitlyn__L I believe "Proper" Harmonics. I believe it is using the principal of 'Beat Frequencies' to create the varying/sweeping 'Fundamental' frequency. So 'Pulse Count' would more accurately in musical science be referred to as 'Overtone/Undertone Count' I suppose. Also, keeping in mind we are dealing with square waves instead of sine, saw, triangle of music/sound. Finally, I should have used the term "Harmonic TFS" (Temporal Fine Structure), instead of "Harmonic Distortion", as "Distortion" implies a destructive interferance rather than a constructive interfetance
What have you done. Now im gonna be listening to every train i will ever travel on to try and recognise the humming pattern.
You're welcome :)
I am very happy to see there are people doing this void of knowledge. I'm an EE student myself and find train traction sounds to be very interesting and not talked about enough. One thing I would've liked to see mentioned is a tap-changer.
Though not in use on UK railways as far as I am aware, my home country India does use a lot of trains that still run on tap changers (yes even EMUs). The newer ones are IGBT VF Drives, but I still like the old units. I'm not sure how you could explain it in a video though, you have to feel it. The best way I can describe it is that every few seconds, there is a slight tug you feel that pulls you slightly faster.
Apparently the z3 trams here in melbourne use thyristor choppers, but they do feel like they jerk a bit while accelerating. It's probably just the 70s control system.
Also, I assume it's changing motor taps, a bit like star/delta starters, which seems like the most obvious way to change impedance without using resistors but also rather annoying to engineer.
@@ArchieHalliwell The difference between what you are describing and a tap changer is that when you're in a tap changer driven, there are periodic, regular, very small jerks. And there are a lot of them. It is particularly noticeable on an EMU (I had the unfortunate experience of riding on one of them which had a damaged arm so every time the driver changed tap the motor would disconnect and reconnect which was awful). It is very small, usually periodic jerks. You can usually hear the tap changer clicking away as the gears move to change taps.
Also, I wouldn't expect a tram to have enough space to actually fit a tap changer (depends on power output so who knows maybe)
The early BR AC units had DC series-wound motors, but used a combination of tap-changer and series/parallel & field weakening control.
The Dutch VIRM sets also have a slight tug like this with their VFDs when the carrier frequency changes, but it's quite unusual to find this for modern power electronics based setups, usually the torque is controlled quite steadily. Also, I'd say modern traction systems are generally quite underappreciated in the railfan circles, it may not be all mechanical like with steam, but there's a lot of interesting stuff that goes on under the hood.
You want people walk around and talk about train traction?
Seriously?
I finally know why the older Montréal metro trains have a 3-note rising hum when accelerating. Great video!
And also why the original MR-63 Montreal Metro trains made clicking sounds as they began accelerating and finished decelerating!
If anyone is interested for German parallels as we have a big train enthusiast community:
Traditional GTO • BR420/421, BR111, BR112, BR142
GTO w/ pulse dropping • BR423 GTO, BR425
IGBT • literally every modern loco, every ICE (besides the unmodernised ICE 1 & ICE 2)
Very nice examples for PWM fixed -> PWM raising -> Pattern • ICE 3, ICE 3V, ICE 3neo
Edit: I think the ICE 4(412) does the same as the class 385 Hitachi Javelin
Was BR143 also a GTO? Heard something...
@@demil3618 Yeaaa one of those humming ones from the start of the video :D
The BR143 uses DC motors with resistors
@@zfrailways Ah thanks.
And where would we place BR120?
I'm guessing GTO but it's very quiet for that.
I rode a gear switching metro in Germany once, and wondered why it sounded like that 😎
Now i know the model too hehehehe
13:30 The cool thing about the Taurus is that each traction motor is independently controlled. So, when starting a heavy train, the little wheel slips (and the inverters trying to handle them) make it sound like a harmony
There is a video of that happening and it sounds legendary
The VIRM in the Netherlands is also very recognisable by it's Pattern Pulse Dropping when accelerating from a standstill. Thanks for explaining!
Or DDZ coming to a standstill (1:15 -- ruclips.net/video/DLN-8zujcX4/видео.htmlsi=VV1JG_ipj7Yf8FTx&t=75)
Yeah, I wanted to mention that one as well. Listening inside the train, the electronics/coils make these weird melodies during acceleration, with nagging tones that are unfortunately not on some usable musical scale. 🎶
ruclips.net/video/I_qH75Evc1w/видео.htmlsi=gtHM3PRWn68AToK5
@@wolflouis_official how can one post RUclips links without the reply being auto-deleted?
Lol @@nkronert
It is great to see someone actually illustrating DC current flowing in the right direction!
Back in 2000, I worked in a paint factory with many huge electric mixers. I always thought that the sound of an F1 car going through the automatic gears was simply an automatic gear box. I now stand corrected - fantastic video!
Good video! Helsinki Metro M100 has the best sounds imo along with the Siemens Taurus. M100 series uses the Strömberg VF drive, and are the oldest production EMUs with VF controlled induction motors in the world (1980). Strömberg engineers nailed it at the first try, and they’re still operational with the original inverter technology.
Almost 30 years ago I worked at Brush Electrical Machines on an experimental 3 phase AC motored locomotive for Network South East, which used a D.C. powered third rail. Brush was competing with another company.
The motors were driven by a three phase inverter that utilised Gate Turn Off thyristors which were controlled by a PWM system implemented in software on a 68000 microprocessor. Another 68000 acted as the controller with all the various control laws implemented in software both for traction and regenerative braking.
Did you help develop the Brush 465 VFD? If so, you did an amazing job
That "doremifa" inverter sound, music to my ears, literally :D
13:53 Columbia Pictures Intro
My guy this video was phenomenal, thanks so much for making this. Love the real life footage of all the different speeds and what not. The OBB one really cracked me up hahah
That 700 lmfao
yeah or one of its seats lol
Absolutely amazing!! Very happy u mentioned IGBT, for those who are interested, there is another type of drive. Newer high power trains like the swiss RABe502 and the 2007 tgv150 record train as well as some experimental locomotives like the FS e403 use PMSM. Or permanent magnet synchronous motors, these differ from regular 3 ph induction motors as they are way lighter but need more complex control algorithms. I am not sure about the next part, but from experience working with PMSM and the sound that the RABe502 makes I imagine they are using a control algorithm called FOC, or field orientation control. Where a positioning sensor inside of the motor is used to get its position allowing the inverters to apply current directly on the correct winding resulting in much higher torque than 3ph induction motors. If anyone watching knows if this theory is correct It would be interesting to know.
14:15 sure they sampled that for crazy frog
Lol probably
10:47 - Sounds like an F1 car from the 1990s launching from the grid.
@@Bandicoot803 you should listen to the Vancouver Skytrain Mark 1 trains. Due to the linear induction motors used, the “gear” or F1 sound is really pronounced. A sound with a lot of character that people will likely miss a little when they see gone.
@@threeparots1 Just seen a video from 1991. The VFD designers were pretty much ahead of their time, very impressive. Also wondered why they have this wide third rail. Not for grid power, but traction for the linear motors underneath the bogies. Clever!
@@Bandicoot803I always thought this was what people referred to as the third rail as well. It turns out the is system is a forth rail system as there are two contact for power. One being power and the other is a better ground as the linear induction motor tend to lift the train on acceleration from a stop and cant rely solely on the steel wheels. Also the flanges on the steel wheels are taller for this reason as well.
One of the other interesting-sounding electric locomotives is the Czech series 162/3. Its frequency is 33 and ⅓ hz, 100 hz and 300 hz sawtooth wave, and at higher speeds it switches back to 100 hz, but into a square wave. You can find a pretty good cabviews from this locomotive here on RUclips, for a good quality audio recording.
The CQ310 type used in the original Atlanta subway had an absolutely amazing sound, interior and exterior. Constant whirring pitch changes, relays clacking and more. You would have to find video from late 70s or early 80s to hear it. They did an overhaul in the 80s and replaced all the motors and controllers with much quieter versions that lost all their personality. A further overhaul replaced the motors again with ones that somehow sound like most of the other US subway systems. It's nothing like it used to be.
You were 3 years late with this knowledge. But it's always nice to iron it out. Thank you for making a video which was needed a very long time ago.
Amazing, thank you for creating this very interesting deep dive with all these amazing examples. Must have taken a lot of investigation.
As a kid in the mid 80's I built my own PWM speed controller for my electrical off road RC car, because I did not like the energy waist and bulkiness of a varistor & servo based speed controller.
The robotic "music" it produced was a nice side effect.
Some errors in this video:
1. Says that you can't use single-phase or fixed-frequency AC for traction motors -- as a matter of fact, that's the way the first AC-powered trains (both electric locomotives and EMU trains) worked, going back to the very early 1900s. They used a DC motor design modified to work passably well on low frequency AC, with voltage controlled by a transformer having a tap changer, running on _low-frequency_ single-phase AC That is why the the German and Scandinavian railways use 15000 V @ 16+2/3 Hz (in some cases changed to 16.7 Hz when generated electronically instead of directly or through motor-generators as was originally done); likewise, that is why the parts of the US Northeast Corridor that still have their original electrification (along with the former Reading Railroad commuter lines now run by SEPTA) have 11000 V @ 25 Hz. This has the disadvantage of requiring a heavier transformer than you would need with mains frequency (50 Hz or 60 Hz). It is even _possible_ to use single-phase mains-frequency AC current directly to run traction motors designed appropriately for this -- SNCF actually did this with their BB 13000 locomotives running on 25000 V @ 50 Hz in the mid-to-late 1950s, when they were trying to figure out the best AC electrification scheme. Those locomotives accompanied 3 other classes: BB 12000 which used DC motors fed through mercury-arc rectifiers, CC 14000 which used DC motors fed through rotary converters, and CC 14100 which used 3-phase AC motors fed through rotary converters. Class BB 12000 won the competition for becoming the basis of new designs (except with mercury-arc rectifiers soon being supplanted by silicon rectifiers), but all classes worked well enough to have long service lives.
2. Says that you can't used fixed-frequency 3-phase AC for traction motors. Starting in 1908, Italian State Railways in fact did exactly that on a large scale for their northern electrification, with 2 phases being supplied through double overhead wires at 3400 V @ 15.4 Hz or thereabouts and the running rails acting as the 3rd phase, although they also tried a variant supplied with some higher voltage (I think somewhere in the vicinity o 12000 V) @ 42 Hz (their mains frequency until after World War II) with a step-down transformer to supply the motors and gearing to reduce the speed to the side-rod drive jackshafts. Starting was not very efficient, and running speeds were limited, but the system worked well enough to last into the early 1970s in Italy, and a handful of isolated lines using similar systems persist in other countries to this day using some form of 2-wire 3-phase electrification. Another variant, used by the Hungarian State Railways before World War II, as well as the Virginian and Norfolk and Western Railroad in the US, was to supply single-phase current as 11000 V @ 50 Hz (Hungary) or 25 Hz (US) to a rotary converter which produced 3-phase current for the traction motors.
3. Says that electronic control of current began to be used in the 1980s. In fact, thyristors started to be used in traction systems at least as far back as the 1960s -- the Pennsylvania Railroad/Penn Central/Amtrak original Metroliner EMUs had thyristors in the tap changers of their transformers (presumably for smoother transitions), and some locomotives of the era had thyristors doing the entire job of controlling current to the traction motors, with an experimental German diesel-electric locomotive using a variable-frequency drive inn the very late 1960s, and SNCF locomotives and TGV power cars were using synchronous motors (requiring a type of VFD) in the 1970s. And I am personally witness to the Boeing USSLRV (usually just called LRV) light rail vehicles that Boston's MBTA had starting in the late 1970s (although I did not get to see them until 1982) using DC motors with electronic chopper control (between that chopper and the low-voltage power supply chopper, these things sounded like they were powered by tortured ghosts with terminal indigestion).
I was going to make a similar comment, but luckily I checked the earlier comments and you have already covered it. Strangely, when I studied electrical engineering in the late 60s, the college lecturer made the same mistake as the video so I had to point out that single phase commutator motors were in common use in Germany, Austria and Switzerland where the traction supply was 15kV at 16 2/3Hz.
@@MervynPartin So that mistake goes back a long way . . . Don't get me wrong, running a universal series motor on AC current isn't as good as running it on DC (for one thing, think about how hot a universal series motor in an AC-powered electric drill gets), but it certainly works.
Addition to my previous post: San Francisco also had (a slightly modified version of) the Boeing USSLRV light rail vehicles for a long time as well (although I didn't get to see them there), acquired at approximately the same time. They weren't very good in Boston or San Francisco (the reliability was awful), but they still lasted for decades (even with the awful reliability, although eventually Boston managed to solve a subset of the problems with a rebuild).
@@Lucius_Chiaraviglio I do have a HO model of one of the Boston Boeing LRVs in my display cabinet, but that was an unreliable model, too. None of the actual LRVs were still in service on the Green Line during my last visit to Boston in 1995.
@@MervynPartin Strange that you wouldn't have seen them in 1995, because their last revenue run was on March 16, 2007 (and I saw them myself up to not too long before then), and they had been present in considerable numbers before then, and the rebuild (of 55 of them) was in 1996 through 1997. They were kept in service until then because the MBTA Type 8s were even worse, not only being unreliable in general but also derailing (and although this has been partially mitigated since then, we had one derail just yesterday, with the cause officially unknown last I heard, although somebody thought it was a switch changing under it, although from the photo it looks like that would have caused the derailment to be noticeably earlier). I did get to see and even board one of these that was kept into the 2010s as a rerailer car (including a great number of hydraulic jacks stored inside), and they also kept 2 others for a while as work cars, but those are all gone (as of some time in 2020), because they couldn't keep them running.
According to Wikipedia, their last USSLRVs ran in late 2001 (when our MBTA originally wanted to retire theirs, but see above), but I didn't get to see that.
@@Lucius_Chiaraviglio Thanks for that reply. I am surprised that some were still in service then. I never saw any at the time, just the Japanese built cars (I don't remember the manufacturer's name).
I did not know that derailing was common.
I was fascinated by the system- it had more character and was easier to use than some modern systems like Washington. We did not have enough time in Boston to explore fully during our short vacation, although we did use Commuter Rail from North Station, and other lines on the "T".
On my previous visits to Boston, I was very busy in the port. Not relevant to the topic, but I did find the local people to be very friendly and helpful. I liked Boston very much.
Most American trains with DC motors are basically silent or only produce a high-pitched sound
Thank you for this video, a much needed thing! There might be a little gap in the explanation: How do we actually HEAR the sounds? I hope my english terminology is sufficient:
Currents in conductors cause magnetic fields as they flow through them. The on and off switching also turns those magentic fields on and off, and those magnetic fields around conductors physically tug on the conductor and other magnetic materials, like the train chassis. Those frequencies of the magnetic fields directly correspond to the sound that you hear as airwaves.
Or simply: Every lose part around such a conductor becomes a LOUDSPEAKER.
The older nerds beyond us may know this from the flybacks of old tube monitors and TV sets and that 15.6 kHz whining sound
While I'm sure _some_ sound comes from the wiring, I imagine most of it comes from the motor itself, with the changing torque on the rotor causing vibration.
@user2C47 There is very small amount of torque pulsation due to sine-shape current in difference with block commutation of bldc for example 🤷🏻♂️
We have this kinda thing in theatre too with the dimmed tungsten lamps! The forward phase dimming that cuts off the beginning part of the cycle (traditionally with triacs/thyristors, now with IGBTs) naturally causes there to be multiples of the base frequency in the current (because the wave shape is modified and a wave of any shape can be described as an addition of various frequency sine/cosine waves). Because this makes the filaments of the lamps and the coils in the dimmers vibrate, a very distinct buzzing can be heard both from the lamps and the dimmers. For me, this is an intersection of multiple interests of mine because I've been into everything that is sound synthesis/overtone series for many years and I'm also into lighting design, and, as of recent, electronics. Anyways, it sounds buzzy because it has these overtones, just like a sawtooth wave synthesizer sounds buzzy compared to a sine wave one. Of course, the buzz varies by intensity, and because different types of lamps are constructed in different ways, they buzz at different intensities.
This is correct and it is called the Lenz effect.
I lived in Switzerland for a couple of years and I've always wondered about the sounds trains make. I never imagined someone would take the time to explain this very specific topic. Thanks a lot man, also kudos to the algorithm for knowing me so well 😂
Very nicely explained video!
Though i would like to add that The clip you chose for the ÖBB 1016/1116 is not the full sequence. There are two more frequency changes happening at ~60 Km/h before fixing the PWM.
I never knew that 🙀
Are those changes stepped as well? I noticed the notes after the octave seemed a bit off, but I wasn’t sure if they were “out of the scope of the scale” or not. If they step further up, then interpreting the final tones musically is still valid 😅
@@kaitlyn__L They dont really sound like music notes at all by that point. But they are still very diddferent compared to the rest.
The Holec sound is also characteristic of the Dutch V-IRM intercity train built by Bombardier, they have the nickname "bagpipes" for doing so. You can hear the Siemens sound very clearly on newer Eurostar (Siemens Velaro) trainsets. I work on industrial VFD systems and those often have a fixed carrier frequency of 4-16kHz. Our applications stay in PWM mode permanently, even under full load.
Winner of my RUclips Video of the Year Award 2024 - yes it’s the start of October, but we have our winner 🏆
Thanks a lot! We all feel honoured 🎖
@@zfrailways It's now November, and I want to double down on it. Every time I've caught a train since this video came out, I want to watch this video again. And I've sent the link to 2 or 3 people who have mentioned when a train engine sounds interesting. Thank you again for making this!!
@14:59 💡 that must be where the Tron light cycle sound must be inspired by. Thank you, really interesting stuff. We use these trains so casually, and only rarely appreciate what makes them move after all. I used to wonder why trains sound so differently. It's a lot clearer now.
Maybe a dumb question, if I may: why does the first train at 0:18 have a different head light on each side? Is that on purpose, or just bad maintenance?
In Britain, trains have different headlight modes for day and night. Day time is when the marker lights (at the sides) are on and the train's right side headlamp is on, and in night mode the left headlamp is on. This is so that drivers coming the other way don't get blinded at night, because trains drive on the left here
@@zfrailways thank you
Afaik this is mostly on older stock, newer units seem to have two headlights rather than one headlight one marker light.
@@RJ-ge1kz interesting, thank you!
1:20 No: 60Hz means the current changes direction 120 times a second. The Hz tells you how often the complete cycle ("there and back again") happens in a second, and the current changes direction twice each cycle
Thank you, I’m an electrical engineer and I studied VF drives 10-12 years ago at the university in Milan. Since then I never heard about it until I saw your video. You make me remember me on the train listening the sounds and trying to guess what was happening.
The „shut up insulin pump“ felt VERY relatable lol
That is one brilliant piece of information, thank you so much for it! I know a little bit about PWM and Thyristors but this is the first time I actually understood how the different modes work together to make a motor spin. Also: hard love for getting interrupted by an insulin alert. Cheers, a fellow T1D train nerd.
I could see the drive patterns for the Hitachi stock being picked because they're the most pleasant sounding, the sound profile just seems far less harsh than all the other options standing next to one pulling away. Obviously its still an aesthetic change rather than a performance one but you get choices like that all the time.
I somewhat agree, although to me the most pleasant sounding one is the Brush Traction 465
The reason so many of the VFDs use increasing PWM frequency as they accelerate is because the motors draw very large currents (for the same output power) when they're at low speeds, and switching transistors on/off at high currents wastes a lot of energy as heat. Thus, lower switching frequencies -> less heat wasted in the transistors.
At higher speeds, they run at lower currents, so power losses from switching aren't as big of a concern. However, slower switching will generate more heat in the motor and wiring due to the current ripple (The current through the motor increasing/decreasing in each pulse of the PWM), so it's more efficient overall to run at higher frequency.
Pattern mode sounds amazing, and it's not something you hear much anymore with modern VFDs/inverters. I had no idea it was so common in trains!
Thanks so much for this - very well explained. I visited Vancouber, British Columbia for the World's Fair in 1986. They built a commuter rail system for that event. It used a linear motor drive system and articulated trucks. It sounded different from any of these and of course had no geartrain noise. But it did have a "gear change" sound like most of your examplesy. Might be interesting for you to look into. I didn't know anything about VFD then, I just knew enough to understand I was hearing the coils pulsing.
These train are still in operation, the ones that make that noise are the Mark 1 trains. They are scheduled to be all be retired by 2027. The noise is high tended by the linear induction motors. I believe they plan on keeping one heritage set. They have been very reliable. New cars are larger and longer and have AC, but they sound boring.
@@s2snider UTDC GTO system on that one. For its time it was/is still quite and advanced system. Not super popular, but ended up being pretty reliable.
Very nice video! I’ve waited for a long time that somebody talked on RUclips about the sound of electric trains. You deserved my subscription!
Yeah, I think it's a good environment for learning English.
Where I grew up, the trams had chopper controllers which made a pretty cool buzzing sound
the early Washington DC metrorail trains had those. When riding in them, you could hear the choppers buzzing
Cool. The Düwag Stadtbahnwagen M always made a nice buzzing sound.
Yeah we had the Düwag M8C ones
Great, straightforward explanation and very informative. Thanks for putting this together.
Nice video, I liked that there was a lot of different real life examples. However, this is something that I have put a lot of research into and have a strong knowledge on, so I have a few things which I would like to comment on, feel free to provide discussion on them:
01:47 Its not really to do with efficiency, AC motors have always been more efficient than DC as they don't use brushes. Its more to do with the fact that they really only generate usable torque when the supplied frequency is similar to the rotation of the motor (something which you touched on afterwards).
02:23 I wouldn't have thought that its to do with inrush current. More being able to control the speed. Generally with DC motors, more voltage means more torque. Surely if it can't handle a certain amount of power to begin with, then it wouldn't be able to sustain that amount of power at higher speeds???
02:49 Bypass??? The way resistance works is that the more resistors you have in parallel the lower the resistance (ohm's law), this is usually how they work, they increase the number of resistors in the bank until it can then be bypassed.
06:24 Technically you can have a VF drive on any type of motor, works in a similar way with PWM managing the speed (this one is really nit picking).
10:34 Didn't the 323s get their VFD replaced?? They just used the same patterns (not my specialty so likely to be wrong)
This ISN'T a dig. The video was great. There's just so much misinformation surrounding this topic I felt the need to add some of my own thoughts. Of course, I could be wrong too, hence why I ask that you reply with why you disagree and I will try provide evidence to support my claims.
On the motor inrush current, it is a problem because a 200 ton train at a stand, sometimes even with a small amount of brake on, is gonna draw a lot of current. The current will decrease over time as the motor speeds up because there's less load on it. And I was talking about series resistors when mentioning bypassing them one by one, I maybe should've cleared that up. Yes, the 323s now have IGBTs but with the original programming (thank god)
The resistors are in series, not parallel, hence the camshaft being used to bypass them.
Also, class 320, 318 and other similar units don't use GTOs but regular thyristors. This is possible thanks to the AC power supply, as the alternating supply current will switch off the thyristor automatically. This is why southern region used EMUs with camshafts for longer, as the use of thyristor control wasn't possible until the introduction of the GTO.
"Pure" PWM only became commonplace with the introduction of the IGBT, I don't know of any GTO VF driven train that uses it. If you listen to class 465s or the 1996 stock you will also hear pattern pulsing throughout. Class 323s aren't unique for that, but they are for the amount of "gear changes."
No VF drives on the class 195, those are diesel-mechanical units with a 6-speed transmission.
@@MihkelKiil that's so weird. I've only ever heard of resistor banks?? Hence the shunt, series, parallel. Surely using a camshaft is a less common way of doing it. Using a resistor bank is so much easier.
With DC motors, there is usually a reduced amount of available power as the speed rises, although some applications used “field weakening” to mitigate that. Some diesel locos with electric transmission were better than others to that extent.
This was awesome! I have wondered about the sounds for years! Thank you 😊
Great intro of the sounds, thanks! But what where is the sound radiated from? Is it the coils of the engine?
The sound is made by the motors themselves, but the reason they make those sounds is because of how the vf drive controls them
It's everything that resonate loud enough to be heared. It's a physical phenomenon known as "synchronicity" (that's what make laterally wobbling the Millenium Bridge in London in the early 2000s, everyone was forced by the bridges moves to walk at same time and pace, which act as an wave amplifier, worsening the situation but i digress a bit)
If you go under a really high-voltage powerline (at least 200 000V (you can found it often near high voltage substations)), when you hear the current huming, you actually hear the whole conductor "shaking" at the current frequency cause it's so powerful that it act as a speaker...
@clementclarisseclemen3d708 for large radio transmitters, up close you can hear the coils vibrating out the sound which is being transmitted. I saw this on a video, I'll see if I can find it...
@@zfrailways not just the motors, also the controllers
When you're outside under a high voltage power line, pay attention to the sound coming from the wires. It's either 50 or 60Hz, so it produces a very low, continuous buzzing sound. Now imagine the frequency was a lot higher, so it wouldn't sound like buzzing anymore and it would be higher pitched. If the frequency varies, so does the pitch.
Now imagine that the wires are inside metal boxes which resonate with the sound. It's not just coming from a single component in the locomotive, like in a car the engine noise comes from the explosions in the cylinders, the wheel noise comes from the wheels, etc. It comes from everywhere in the locomotive where the wires are installed from the controllers to the motors and is influenced by the internal layout of the locomotive.
What a neat video, thanks!
The scale-pattern from the ÖBB 1016 is deliciously ominous.
Also, during the outtakes, I instinctively reached for my insulin pump when I heard yours beeping, then laughed and laughed.
I've had a few fellow diabetics do that, including myself when I was proof watching the video before uploading
Always felt those E cars would be way better if they were a lot simpler and made noises like these trains
Yes, they would also be a lot safer because you'd actually be able to hear them
The reason why they don't make the noises is because they're battery-powered, so their motors and energy supply are DC
@@WildWildWeasel Most modern trains have a DC bus too. The electronics (GTO or IGBT) switch the DC on and off to create a pseudo-waveform that the AC motors use, as explained in the video. Third rail trains (750v DC) take the DC straight from the rail, whereas 25Kv AC trains additionally have a transformer and rectifier to covert the AC to DC. On an AC train, DC can also be directly fed to the PWM/VFD drive, bypassing the transformer and rectifier, this is how the dual voltage units found around Londion work.
@@WildWildWeaselmost modern evs use inverters and ac motors. But their lower system voltages and power levels allow them to use mosfets rather than igbts or gtos, which can practically switch at 25+kHz no problem, so you simply won't hear it.
Recently sic-mosfets have made it possible to even do this on megawatt scales, so even a train drive could be almost silent. Even then though, a manufacturer may still opt to switch slower because it saves some power.
The electric buses in York sound like they are taking off when they reach about 30. Really surprised how loud they are. I kind of expected electric bus to be quiet. Anything but! Sound isn't very nice. I wish they made that musical train sound!
This is the CLEAREST explanation I have ever seen on this subject. _Beno_ explained it well but perhaps with too much detail but here, everything is just so concise and logically explained with really good examples, and their sequence of operation.
Interestingly, in Japan there's a whole hobby dedicated to building DIY VF drives
Yes, I actually saw beno's videos while researching this and they're very technical, which is why I tried to make this one so that anyone can understand. Thanks for the kind words!
@@zfrailways Not just kind words from me - proof is in the pudding: 1.05K subs, this video has been up 1 month, and as of now you have received 104K views!! That's incredible!
What do trains on AC overhead lines do? Do they convert it to DC and use PWM/Pattern mode, or do they use some kind of frequency converter magic?
+1 on this...
AC is better at being transported over long distances, so to me, id make sense to build overhead lines with AC, even if I were to have to rectify it on the locomotives themselves. I mean, cars do this, they dont have dynamos, they have alternators. Its in the name, "alternator" as in it creates an alternating current. Its just easier and cheaper to slap 4 diodes on it (and some smoothing caps, etc...) than to put in a heaver and more complex dynamo.
It depends. old trains with DC motors commonly used mechanical converters that converted AC to DC, modern DC trains mainly use electric rectifiers that convert AC to DC.
AC motors are split between single phase and 3 phase motors. single phase motors use the overhead power directly altough only with low frequency (mainly 13,7 Hz) 3 phase motors the most modern and common types convert the single phase AC with H-bridges to 3 phase AC.
The main advantage of H-Bridges are that they can generate a three-phase current with a variable frequency, which means that the motors can be switched continuously and braking energy can be fed back into the network (regenerative brake) and is not wasted on Braking resistors. They also support an emergency brake mode which short circuits the motor and transfers the energy into heat.
Trains usually convert the AC from overhead to DC
And most mainline trains here in continental Europe use 25 kV AC @50 Hz like many main lines in the UK, or 15 kV AC @16 2/3 Hz (mostly Germany, Sweden, and Norway). The single phase AC is converted by power electronics to a variable three phase supply to AC traction motors on modern stock as described here.
Modern trains convert to DC and then basically do the same thing described in the video. In fact, the two locos from ÖBB and DB run at 15kV, 16.7Hz AC.
Older locos had a variable transformer to regulate the voltage. There you can varry the count of windings being used on the primary or secondary side.
The musical upscaling of the ÖBB BR 1016 gives me goosebumps everytime I hear it. ICE trains (unfortunately I don't remember right now, which version) do the same beatiful melody when accelerating. Knowing, that there are 5000HP at work in there gives me additional goosebumps too. For me, this are by far the most favorite and most advanced electric locomotives out there, giving the sound and power they make. The 1016 is an incredible beast of a locomotive, used in double traction freight and passenger operation, capable of multiple power standards, AC and DC from 1KV up to 50KV from 16,6Hz to 50 and 60Hz. Variants of it run all over Europe and even in the U.S. Also I have nice memories that connect me to them, since I was working on them as a technician, installing schedule and track information systems in the driver cab several years ago.
I really do like them too. If you ask me, they're even better than the Vectrons
The ICE with the same melody, is the ICE 1 (BR 401).
Very good video, as an engineer I appreciated a lot to know these several control systems and their sounds.
The SIEMENS Eurosprinter "Taurus" locomotives are unique!
I've worked in the forklift industry for over 40 years. The old electric trucks that used thyristors always sung a tune, especially Lansing Bagnals.
1:18 trains often run on other frequencies. E.g. the German railway uses 16⅔ Hz and is therefore completely independent from the "normal" of the 50 Hz net.
Sorry about this! I maybe should've made it a bit clearer that I was referring to electricity at home.
I had no idea. This was a GREAT video. I always love coming across someone eleses hyper focus that I never thought about before.
That was a really interesting video thanks so much for making it. A lot of information though and i feel a lot went in one ear and then went out the other so i might have to rewatch to properly digest ig
I knew some of the things regarding the DC locos and learned a lot that I didn't know about the AC drives . I enjoyed your video .
This vid made me sub to you. Greetings from Poland! We also had resistor, thyristor, and igbt startup! Wish you rare train shots!!!
Fascinating and informative video. Thanks. I'm sure the acoustics of the station roof have a role in accentuating it, but I always love the sound of departing Eurostar trains out of St Pancras Intl. It sounds like a spacecraft taking off!
The 425 S-Bahn of DB Regio AG Mitte/S-Bahn Rhein-Neckar here in Germany also use the VFD system. Always lovely when all the trash bins on the train start vibrating when it hits a certain frequency.
10:14 - I thought this was a departure alarm 🤯😂
Amazing! Forgot about motors themselves, but thanks
The motors themselves make the sound, the vf drive controls what sound they make
Great video! Interesting to see the development of the power control units
The Helsinki metro's M100 also has a very similiar sound to the class 323. Very iconic sound to me
I'm from Buenos Aires and a couple of trains from our subway (Alstom Metropolis 300 series and CNR Citic 200 series) make that "gear changing" sound and I always wondered why they did until now, but they are slightly different from the ones shown here, they start with a fixed high pitch, then they switch to a higher pitch and then they go into regular pattern, I wonder if the system is any different from these or what
Anyway, you answered one of my biggest questions about electric trains, great video!
hey Z&F team! just stumbled upon this gem of a video, subscribed pronto! it's music to my ears, and your technical breakdown of the sounds adds the cherry on top.
here in São Paulo (Brazil) we have some sweet sounding trains too, it's like a string quartet warming up! keep up the awesome work, 1000-sub coming soon! cheers
There have been many modifications of the electrical equipment of the Tatra T3 tram. The original PCC based accelerator was replaced by various thyristors and later transistors. Even asynchronous AC motors and controllers were fitted in a few vehicles. The first thyristor prototype was finished in 1971 and the new equipment was shipped from 1976. Different types were developed over the years, using GTO, IGCT/IGBT, RCT... Even with the same thyristors, there were different sound characteristics based on the modulation and physical installation (varied between operators). The sounds produced by the entire electrical equipment (including cables, coils, brake resistors, etc.) varied a lot too. Sometimes even between two vehicles using the same modification of any specific design. Škoda trolleybuses from the 1980s are another example, there were two variants of "thyristor sounds".
Amazing video mate, this is so well put together I couldn't resist giving it a like ^^
My favourite electric train sound is the class 319 where you can clearly hear the pulse width slowly changing as it departs. Very musical. In fact you can hear an almost identical sound in the opening few seconds of the song “A New” by Little Dragon, played on a keyboard synth. Before I was into trains I used to listen for the “Little Dragon” train departing London Bridge.
It was just last Saturday while changing trains at Woking that I was wondering why the express train that I was leaving sounded so different to the suburban service I was boarding. Thanks for the information.
For a splendid example of "musical" motors may I cite the example of the older trains on the Montreal Metro.
I've heard them, realised they are different and the migration has been in blocks of a few years before the next sound type arrives. Now I begin to understand how and why. Many thanks.
The F1 car gear change sound of the class 323 was the sound of my childhood taking the train to the nearest city.
Thank you, I finally got the answer to the "gear change" sound I heard on trains more than 10 years ago!
Brilliant excellent I been working on trains for many years and never thought about it this way .your vid was shared with me by my 11yr old son , it's all he seems to be interesting in Trains amazing Thanks
The older helsinki metro trains built in the 1980 make that "gear changing" sound when accelerating and breaking. I've always wondered what is actually going on there, thanks for the explanation :D
This is an amazing video. I never thought anything of those sounds, now I know exactly how they're made!
At 5:30 I believe the low frequency hum is the transformer, but after a few seconds you can also hear a higher frequency hum which I think is the thyristor
The thyristors pulse at the same frequency as the transformer, so it gets louder as the train starts
Clicked on this out of intrigue because I just finished my final project on AC motor control for high-speed trains. Really interesting video! I'm no pro by ANY means so may be wrong, but (11:35) there are practical reasons to increase the PWM carrier frequency as motor speed increases. There are losses associated with unnecessarily high carrier frequencies called switching losses. Depend on the scenario, you can save a significant amount of energy and improve motor performance by starting low and increasing the carrier frequency. Most VFD's on modern trains will alter the carrier frequency like that at low speeds to improve energy efficiency.
i LOVE the pattern dropping sounds, i don't remember which specific vehicles use (or used) it but to me it's extremely nostalgic.
Great explanation! Some constructive criticism I guess: 7:27 you mention that pulses are dropped as the frequency gets too high, leading to the gear shifting sound. I would have LOVED to see some visual explanation here for this pulse dropping, it felt like we just glossed over it and went straight to the examples. I needed to rewind to figure out what you meant :)
FINALLY, an explanation as to why trains make that we we we we we we/wa wa wa wa wa sound. Thanks!
This is absolutely brilliant and will go viral (amongst us train nerds) imo. Answers questions I never knew to ask!
Take time to deliberate, but when the time for action has arrived, stop thinking and go in.
I think early PWM experiements like the 70s with chopper control would have been a nice topic to have added to the video. Also the topic of Direct Torque Control used in the 101, 146 and 185 german locos would have been nice but overall really great video.
Your video and benos seems to be the only ones explaining this really interesting system. But made simple to understand for train enthusiasts.
Cheers 👍
This was fascinating and really explains well how electric trains work. I have sent this video to a friend in America who will love this as we often discuss why one electric train sounds one way, and another sounds another way. Oh and I have subscribed, looking forward to catching up on your other work
Great work. I’ve searched for this information for a while. It’s one of those thing I have mused about at Clapham Junction station. I did electrical and electronic engineering for my qualifications about 40 years ago but that is a long time ago. Thanks for the refresh.
I have a real fascination with why vehicles sound the way they do so this was really interesting to me. Thanks so much for the deep dive 👍
This is it! I don't understand everything yet, but this is what I wanted to know about sounds coming from electric trains! Thanks for sharing your knowledge.
Good to see your diagram of a battery powered DC circuit had the current flowing from negative to positive, as most people assume it goes the other way 👍
The sweetest electric train sound is heard from the German ICE II trains. They sounds like someone playing a saxophone.
My era stopped at DC traction motors with series/shunt switching and resistor banks. I did wonder about PCM at the time but the control circuitry had to catch up. Excellent stuff
I was hoping the Jubilee line would be covered as those units have a very odd sound indeed and I've heard it said that they've gotten odder with age, but perhaps that's a myth? In any case, what a great video, thank you. I'm sure I'm not the only one who's spent years commuting on these trains and always wondered why they sound so distinct.
Because the 1996 tube stock (Jubilee line) is so similar to the 465/9, I put the 2 together
I remember first going on that line and being fascinated by the unusual noise.