PTI-P series photoacoustic spectroscopy based online monitoring system for gas in transformer oil applies advanced semiconductor laser technology and photoacoustic spectroscopy technology to the detection of gas in transformer, which can continuously monitor nine gases (hydrogen, methane, ethane, ethylene, acetylene, carbon monoxide, carbon dioxide, oxygen, nitrogen) and micro water in transformer group oil in real time. The system has high detection sensitivity and requires very little sample gas, thus greatly reducing the oil and gas separation time and shortening the measurement cycle; No carrier gas is required, which is convenient for equipment maintenance; No regular calibration is required; No preheating, fast detection time; Good stability, long service life, etc. From these characteristics, the application of photoacoustic spectroscopy is more suitable for the online monitoring system of dissolved gas content in transformer oil. Therefore, we developed an online monitoring system for gas content in transformer oil based on photoacoustic spectroscopy, committed to improving the performance of such online monitoring systems, and providing more reliable diagnostic data for transformer insulation fault diagnosis technology.

Technical principle:

A modulated semiconductor laser light source is used to emit light of a specific wavelength to irradiate the insulating oil sample to be measured in a closed photoacoustic cell. The sample absorbs light energy and de excites in the way of releasing heat energy. The released heat energy causes the insulating oil sample to generate periodic heating, which leads to periodic pressure fluctuations in the medium. These small pressure fluctuations can be detected by a micro sound pickup, and photoacoustic signals can be obtained by amplification. The central processing unit analyzes these photoacoustic signals through the data model, and finally obtains the content of fault gases of different components dissolved in the oil. The schematic diagram is as follows.

Design concept:

PTI-P6 photoacoustic spectroscopy based online monitoring system software for gas in oil adopts Vxworks6.8 operating system, embedded Sqilte3 database, IEC61850 communication protocol and other technologies with high real-time performance. The system has a multi task system for collecting and processing a variety of devices or sensors, and supports a variety of functional dynamic processing mechanisms such as Web browsing, data query, parameter revision, data remote transmission, etc.

Diagnostic module:

The DGA fault diagnosis module displays the diagnosis results in cubic diagram, TD diagram, David triangle and other ways, and has the function of studying and analyzing the trend of historical data.