Видео

You mean the Bx6 not the Bx12

@@goofyahhnerdyy Apologies, I don't take any requests. However, that car's sound has already been posted here by my fellow: ruclips.net/video/hHyP-9I8Y3s/видео.htmlsi=aHtLq1S19fHkvG8u

@@ebaraexpress7260 Oh i forgot about that video, oops.

Thanks for watching! Yes generally 3-level IGBTs are quieter than 2-level ones. Also I have posted other SEPTA cars, so hope you will also enjoy that!

patentimages.storage.googleapis.com/16/8c/08/82d1ed6e25c222/JP2006197798A.pdf P. 6 Lines 12-17 "However, the previously known unipolar modulation method cannot achieve a voltage pulse smaller than the minimum output pulse width determined by the minimum on-time of the switching device in the region where the inverter frequency is low and minute output voltage control is required (near the starting point of the VVVF control region), As shown by the dashed line in Figure 2, a voltage larger than the command will be output." In order to resolve this problem, dipolar modulation has been applied for 3-level inverters.

@@ebaraexpress7260 Oh I see, so when the train is just starting to move dipolar is used because a low voltage cannot be achieved with unipolar, then it switches to unipolar after more voltage is needed due to efficiency 👍

He doesn’t accept any requests

@@w_avor I'm just using a 100mH inductor, and then do the craft for attaching lines to earphone jack so that can be connected to the IC recorder.

It has DC motors, probably not applicable

@@QuarioQuario54321 dc motors cant use this?

@@calypso_the_freak correct

That would be from the Random Carrier Frequency Modulation(RCFM) which is quite rare to find in GTO-VVVF drives, I think a few Alstom Pendolinos have it too but besides that, this might be the only GTO with RCFM to my knowledge.

Oh thanks

Is there pcfm gto vvvf

@@minecraft_javjavatonkoonca8109 Yes! Theres a good number of PCFM GTO-VVVF in fact produced by companies such as Toyo Denki and Holec just to name a few, most of which are found in either Europe or Japan.

Thanks

This doesn’t apply to chopper. Only AC

@@QuarioQuario54321 That’s incorrect. The chopper generates a PWM frequency that can be picked up by an inductor. Resistance/cam control cannot be recorded because it is changing the voltage with resistors rather than using PWM.

I tried 5 years ago, however failed to get the ideal sound (smooth transition from async to 1P with less noise). Instead, you can refer to this video posted by other creator: ruclips.net/video/gpLRxpE3gSs/видео.html

Thank you! That kind of noise might be caused by contact between wheels and a rail, or if that train is running in a third rail section, then that should be caused by the rubbing between the contact shoe and the conductor rail.

Maybe that is because you see lines around 2700Hz and 3300 Hz, but they are from input AC side (there was a bold line around 3000 Hz so I reduced by a notch filter, however these edge components are still remaining here) and not from the inverter. Also, if that kind of modulation you mentioned is applied, there should be components for 750 Hz and 1250 Hz, but not visible here. Moreover, Mitsubishi hadn't used that kind of modulation until late 2000s. Therefore, I think this is 500 Hz with 70 % dipolar rate.

@@ebaraexpress7260 The pulses in the waveform (not the spectrum) seems to be equally spaced, but the pulses in the twice frequency bipolar mode occur in pairs, so it is suspected to be a 250Hz quadruple dipolar mode.

⁠@@CR400AF-B When determining a PWM mode, we rely more on the spectrum than on the waveform. Since we cannot remove noise components from the displayed waveform results, it is difficult to judge the mode. Also, there are some cases that inductor recorded data is more like a phase current than line-to-line voltage, which causes confusion for judging the mode; on the other hand by spectrum we can judge from both phase current and line-to-line voltage, since they are showing similar results: yuppi5.hateblo.jp/entry/pwm2 So, for this case, since I give more weight to the fact that there is no 750 Hz and 1250 Hz spectrum shown, let me conclude this as 500 Hz. Anyway I'm so interested in the way you guessed.

@@ebaraexpress7260 Your analysis is reasonable. From the spectrum, it looks more like the E2 series, and 500Hz is also a reasonable switching frequency for 3300V IGBT devices during motor start-up. Indeed, when doing moharadio on many China high-speed trains, the superposition of multiphase currents and noise makes it difficult for me to see the waveform clearly.

いやぁ、乗れなかったです💦

Sound like keio 9000

英語使っているいもさん貴重すぎる(笑)あざす！

If you are mentioning the pulse mode after async, that is not W3P, maybe a type of 5P.

Could it be HOP-5?

@@dabee1884 It's possible. I think some newer Hitachi inverters use it.

@@dabee1884 Since HOP is more a recent development, and has different waveform, I guess this is other type of 5P.

​@@ebaraexpress7260 This should be W5P, but it is a little different from Siemens' W5P. Someone has already given a comparison chart on Bilibili.

Unfortunately, I didn't have a chance to ride Class 465/9 at that time...

@@ebaraexpress7260 btw dym coming to qld aus to recored some of my home trains

@@ebaraexpress7260 When would you think to do the 465/9?

@@ebaraexpress7260if you want the sound files I was able to get some recordings of the /9 variant about a month ago with an inductor. Unfortunately I don't have the same software you have to process it

@@jeremyzorek Oh really? I would like to discuss with you about that topic, would you send a DM via X Account (if you have) or contact vvvftokyu2000[at]gmail.com then?

Excuse me, what does "enchanting table language" mean in this sentence...?

@@ebaraexpress7260 Its a very complex language in minecraft enchanting table

Wtf

This is not Aramaic language this vvvf sound

Carrier-sync modulation I believe

i THINK the pulses are still widening AND the carrier is increasing. it's not as obvious on this particular spectrogram trace, but i've seen others where the two diverging frequency lines on the graph that represent the carrier widen out way quicker while still increasing. at least until it goes FULLY synchronous, then i t looks and sounds like the pattern is locked. it's a weird hybrid of async and sync that i keep seeing more and more on these spectrogram vids, mostly on vf drives of Japanese make. they always seem to be the ones that innovate this tech i'm also pretty sure that they were the first ones to implement a random carrier, at least as far as i'm aware, which i find fascinating. i have a small 1/4hp Fuji Electric vf drive at home that lets you select three levels of carrier scrambling! it's not truly random but it has the same effect of making a buzzing sound instead of a constant ringing

It slowly increases the carrier frequency but it is not synced to the output frequency. I recorded the Osaka Metro 20 Series with the replacement inverters and they also sound similar to this.