[Inductor-Recorded Traction Motor Sound モハラジオ録音] 800 Series Shinkansen

#モハラジオ #TractionMotorPWMSound #800Series

00:00 Title & Introduction
00:05 File 1: Acceleration
02:45 File 2: Braking
05:32 Appendix

Car Type:
JR Kyushu 800 Series Shinkansen

VVVF:
Toshiba 3-level IGBT-VVVF

Sound Characteristics:
Pattern:
Asynchronous (Dipolar Modulation → Unipolar Modulation) → Multi-Pulse Mode → 1P
Asynchronous Mode Carrier Frequency:
①Set a random modulation spread spectrum between upper limit 1000 Hz and lower limit 750 Hz → 1000 Hz.
②Only for the dipolar modulation part, set the carrier frequency to 1/2 compared to the setting of ①.
③For the dipolar modulation, the most emphasized component is around four times the carrier frequency.
　On the other hand, for the unipolar modulation, the most emphasized component is around twice the carrier frequency.
　This factor and the factor ② make the most emphasized components sound connected.

Asynchronous carrier transition is similar to other Toshiba 3-level IGBTs to which spread spectrum is applied: "upper spreading limit = constant, lower spreading limit = increases with increasing inverter frequency". Therefore, during acceleration, the average carrier frequency rises and reaches 1000 Hz while the diffusion width is narrowed. However, as explained in the "Appendix" section, the 800 Series has a higher carrier frequency for the lower spreading limit than the JR Tokai Series 313 (1st and 2nd batch trains), resulting in a higher overall sound.
(Click below for the 313 Series VVVF:)
https://vvvfdb.stars.ne.jp/vvvf_data/...
After the carrier frequency reaches 1000 Hz, it transitions to a synchronous multi-pulse mode instead of rapid rising asynchronous mode, even though it was introduced in 2003. It then transitions to 1-pulse, but it sounds quite massive.
This massive one-pulse mode is frequently used in (supposedly) Toshiba's VVVF for Shinkansen, and will appear in the video I will post in the future.
The sound files are from the 800-0 series. I recorded both 800-0 and 800-1000 series, but there was no difference in sound between them.
The source that this VVVF is made by Toshiba is as follows.
https://www.global.toshiba/content/da...

The AC traction PWM sound shown in this video is recorded by a sensor. This sensor is made by myself just using a 100 mH inductor.
Regarding the files used, notch filters and low-pass filters are applied to the one immediately after recording to reduce unnecessary noise components.
Due to the resolution of the spectrogram software, the frequency displayed in this video may include some error. Thank you for your understanding.
This sound is recorded in May 2022.
Sorry, I am NOT taking requests for recordings.

Posted by Ebara Express
X (Available in Japanese; translate please!):
https://x.com/VVVF_tokyu2000
Website "VVVF Database" (Available in Japanese; translate please!):
https://vvvfdb.stars.ne.jp
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