[Inductor-Recorded Traction Motor Sound モハラジオ録音] British Rail Class 465 [Hitachi IGBT-VVVF]

Описание: #モハラジオ #TractionMotorPWMSound #Class465

00:00 Title & Introduction
00:05 File#1: Station to Station - 1
01:46 File#2: Station to Station - 2

Car Type:
British Rail Class 465

VVVF:
Hitachi 2-Level IGBT-VVVF

Sound Characteristics:
Pattern:
Asynchronous (750 Hz Constant → 1050 Hz → 1800 Hz) → Advanced PWM → Wide 3P → 1P

Asynchronous carriers have the same transition as Class 395.
Class 395 video:
   • [Inductor-Recorded Traction Motor Sound モハ...  
However, since the volume increases momentarily at the beginning, it seems that unlike Class 395, it uses sensorless control.
Moreover, there is also another pulse mode existing between asynchronous modulation and wide 3P. Looking at the waveform, the number of pulses appears to be 5, but it is different from the 5P that Hitachi used in the GTO era, and from the HOP5P that Hitachi has been using frequently in recent years. It is something that has not been found in other VVVFs made by this manufacturer. Maybe this pulse mode will also appear in the Class 395 (DC section mode)...?
In the first file, this pulse mode appears both at acceleration turn-off and braking turn-on (from 0:50). On the other hand, in the second file, since the inverter frequency is higher both at acceleration turn-off and braking turn-on (from 3:20), so the modulation rate scope that would normally be synchronous multi-pulse mode is entirely replaced by asynchronous modulation, like other Hitachi 2-level IGBTs.
This recording was also conducted on the floor in front of the door of the motor vehicle, as shown in the last screen. Although there is less constant noise like Class 395's recordings, since the recording was made in the third rail section (DC 750V), there is frequent noise that seems to be caused by the rubbing between the contact shoe and the conductor rail.

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.
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 September 2023.
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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