Usage of nanotechnology based gas sensor for health assessment and maintenance of transformers by DGA method

Present day power system is essentially a complex mesh of various important components with power transformer as one of the key elements. For the reliability of power supply, a robust maintenance tool for power-transformer is highly essential. To cater for this demand a portable, online diagnostic device is developed which can record the temperature and quantify the concentration of some of the dissolved gases in transformer oil with the help of a non-invasive sensor fabricated by nanotechnology. After conditioning the signals, the data are transmitted to the nearest substation for storage in computer. For the purpose of analysis and health assessment of the transformers from a remote place, the computer is made accessible through network. From the data of five gases, different faults, if they are occurring inside the transformer, can be predicted. The fault diagnosis is performed by dissolved gas analysis (DGA), which is one of the proven methods widely used during the last two decades.

► In this work, an analyzer is developed using gas sensor fabricated from nanoparticles of zinc oxide.
► Usage of nanoparticles increases the sensitivity, reduces the response time and miniaturizes the sensor.
► Five gases hydrocarbon dissolved in the transformer oil are detected at different temperatures and quantified.
► The sensor is calibrated by gas chromatograph.
► A portable, online diagnostic module is designed for transformer by a non-invasive sensor.