The Design Of Portable SF₆Purity Analyzer Based On The Principle Of Infrared Light Absorption

In recent years, with the rapid development of power industry in our country.Gas Insulated totally enclosed combined electrical equipment (Gas InsulatedSwitch-gear GIS) is becoming more and more widely used in electric power system.And the arc extinction and insulation characteristics of GIS electrical eq uipment de-pend entirely on the purity of SF6gas filled in the equipment. If the SF6GIS gasequipment in the mixed with impurities, not up to standard, then the equipment ofarcing and insulating performance will drop sharply. Which results in the decrease ofstrength of SF6switch pressure, the breaking capacity of breaker decline, make acircuit breaker failure causing massive blackout accident and serious economic loss-es. This paper completed a design of portable SF6purity analyzer based on the prin-ciple of infrared absorption spectrum which can quickly and accurately detection thepurity of SF6gas. This paper mainly introduces the principle of measurement,the an-alyzer software, hardware design and error compensation algorithm. Practice provesthat the equipment can accurately detect the purity of SF6gas in the GIS equipmentor a gas cylinder.This design completed the purity of gas analyzer using high-performance infra-red sensor for gas measurement, External independent high resolution A/D chip toensure the conversion precision of the sensor output signal. The main control chip isMega128of AVR series which is a high-performance microcontroller, Extendedmemory chip makes the SF6purity analyzer can save a large amount of historicaldata. PC via a serial port can view the historical data of the purity analyzer, also canset the parameters of the purity analyzer. Purity analyzer using new OLED displays,reasonable interface design and button type operation to ensure the good hu-man-computer interaction. Using a new type of intelligent power management tec h-nology, greatly extended the instrument work time and makes the work more co n-venient.Through a lot of experimental data summed up the calibration error handlingand sensor calibration algorithm greatly increases the precision of the instrument and environmental adaptability. From hardware to software design and the selection ofpiping material gas path through experiment contrast, ensure the instrument canwork reliable. Finally, the test data of SF6gas purity proved this design of portableSF6purity analysis instrument measuring accuracy reaches the expected target, theinstrument can be used as a portable high precision instrument SF6gas concentrationin the detection of electrical equipment.