Student Projects
Contact Information
University: Korea maritime university, Repulic of Korea
Team Member(s): hyeon-kyu Cha, hyun-min Lee, jeong-hak Moon, gi-woo Jeong
Faculty Advisors: professor Gyung-suk Kil
Email Address: dancar1412@nate.com
Project Information
Title: Acoustic Detection of Partial Discharges in Oil Filled Transformer
Description:
- Position of PD(partial discharge) inside oil transformers located using AE sensor and NI PXI
- PD measured and diagnosed during transformer’s operation.
Products:
- NI Hardware
- PXI-1042Q, PXI-5114,
- NI Software
- LabVIEW 2010
- NI Scope
The Challenge:
- Acoustic Detection of partial discharges in oil filled transformer using 3D graph.
- Diagnosis of PD occurring due to various factors inside transformers.
- Diagnosis of PD through non-electrical method without additional external coupling or short circuits on transformers.
- An all-time diagnosis system established enabling diagnosis during transformer’s operation.
- Position of PD located in 3D.
- Possibly applied to other heavy electric facilities.
The Solution:
PD position diagnosis system established as in Fig. 1
- Fig.1 System flow chart
Hard Ware
- AE sensor
- A device that converts acoustic signals into electric signals upon partial discharge.
- Locates PD positions in 3D using 5 sensors.
- Fig.2 AE sensor
- Discriminator Amplifier
Decoupling circuit
- AE sensors require decoupler as they use a single wire for both audio detection and power supply.
- A prototype decoupler was fabricated for separating the DC power source and acoustic signal to AE sensor and detection circuit, respectively..
Amplifier
- An amplifier circuit is required as acoustic signals from AE sensor are small in magnitude.
- An amplifier with gain of 40dB was fabricated.
- Fig.3 Prototype discriminator Amplifier
- needle to electrode system
- A needle-to-plane electrode system was used to simulate PD.
- Fig.4 Prototype discriminator Amplifier
Soft Ware
a. A Scope express was used to measure waveforms of acoustic signals.
b. Individual graph of acoustic signals is categorized into vertical or horizontal depending on the position of sensors.
c. Moving cursors on each graph enables individual setting.
d. Positions on coordinates are calculated from each value, and a 3D graph is displayed.
- Fig.5 VI interface
Fig.6 3D graph
Fig.4 Prototype discriminator Amplifier
Explain the benefits using LabVIEW and NI tools
- Users can acquire data and predict PD position easily.
- This system can be applied to variety of electric facilities.
Video link
