[Inductor-Recorded Traction Motor Sound モハラジオ録音] Class 923-3000 Shinkansen

#モハラジオ #TractionMotorPWMSound #DoctorYellow #Class923 #T5

00:00 Title & Introduction
00:05 File 1-1: Type 1 Acceleration
06:18 File 1-2: Type 1 Braking
09:08 File 2-1: Type 2 Acceleration
17:54 File 2-2: Type 2 Braking
21:16 Manufacturer Presumption (Short Version)

Car Type:
JR West Class 923-3000 Shinkansen

VVVF:
Hitachi/Toshiba? 3-level IGBT-VVVF

Sound Characteristics:
[Type 1]
Pattern:
Asynchronous (Dipolar Modulation → (Continuous Transition) → Unipolar Modulation) → Multi-Pulse Mode (3-Pulse Mode) → 1P
Asynchronous Mode Carrier Frequency:
500 Hz (Dipolar Modulation) → (Continuous Transition) → 1000 Hz (Unipolar Modulation)
For the dipolar modulation, the most emphasized component is around four times the carrier frequency.

[Type 2]
Pattern:
Asynchronous (Dipolar Modulation → Unipolar Modulation) → Multi-Pulse Mode → 1P
Asynchronous Mode Carrier Frequency:
500 Hz (Dipolar Modulation) → 1000 Hz (Unipolar Modulation)
For the dipolar modulation, the most emphasized component is around four times the carrier frequency.

For more detailed information on the reasons for presuming each manufacturer, please see the "Manufacturer Presumption" section for each comparison targets.
JR East E2-1000 Series (Presumed as Hitachi):
   • [Inductor-Recorded Traction Motor Sound モハ...  
JR West 700-7000 Series (Presumed as Toshiba):
   • [Inductor-Recorded Traction Motor Sound モハ...  

Others:
The Class 923 includes the Class 923-0 (T4 formation) belonging to JR Central and the Class 923-3000 (T5 formation) belonging to JR West.
The traction system of this T5 formation is also based on the 700 Series C formation (700-0 series) designed by JR Central, not the 700 series B formation (700-3000 series) or E formation (700-7000 series) designed by JR West.
(In other words, it is highly likely that the VVVF PWM applied to the T5 formation was used almost as is in the C formation.)
However, for the Type 2 in this video, the PWM setting is almost the same as that of the Type 2 of the E formation, but it seems to enter the CVVF range at a higher inverter frequency, perhaps considering the difference in gear ratio.
In addition, there should be other CIs made by Fuji Electric on the C formation, but unfortunately no such sound was caught from the T5 formation.
These sound sources were recorded during the "Doctor Yellow Experience Ride Plan" (Okayama → Hakata) held on October 15, 2024.
During the "free time" which you can move freely inside the car, there are two stops as shown below, and the sound source is actually recorded in the following order.
1. Arrival at Hiroshima Station (File 1-2)
2. Departure from Hiroshima Station (File 1-1)
3. Arrival at Shin-Iwakuni Station Detention Line (File 2-2)
4. Departure from Shin-Iwakuni Station Detention Line (Reverse) (File 2-1)

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, the extra noise components has been reduced from the ones saved immediately after recording.
Due to the resolution of the spectrogram software, the frequency displayed in this video may include some error. Thank you for your understanding.
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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