Power generation industry is most important in any country all over the world. By and large entire economy of the country depends upon its capacity to generate power. During the last decade a lot of accidents took place in this industry and causes of these accidents/explosions remained unexplained. Recently with the advent of latest technology in the fields of analysis, it has been possible to point out the possible cause of explosion in the power stations.
In oil-filled equipment, such as power transformers, which is mainly a mixture of hydrocarbons, failures are inevitable if proper care is not taken. With the use of transformer, the oil starts degrading due to various factors such as ageing of the oil, overvoltage, environmental condition, overheat and numerous unknown factors. In the process of degradation lot of lower hydrocarbons like methane, ethane, acetylene, ethylene etc. are produced along with some permanent gases like CO, CO2 and H2. These mixtures in sealed environment can cause an explosion.The gases depend upon the condition of the oil and hence, it is extremely vital to monitor the concentration of these explosive gases in the running transformer.
In interpretation of the results obtained for a particular transormer, due regard should be given to the following factors before arriving at a specific conclusion:
Date of commissioning of the transformer.
Loading cycle of the transformer.
Date on which the oil was last filtered.
Early diagnosis and periodic monitoring of the condition of oil-filled electrical equipment used in generation and distribution of power can improve reliability and availability of power. DGA is an unique condition monitoring tool and has given significant benefits in the form of major reductions in unscheduled transformer failure, reduced maintenance, and reduced cost of repairs.
(Some inaccuracy is always associated with laboratory DGA measurements of transformer oil, which may affect the gas ratios, concentration differences and other calculation upon which transformer condition assessment and fault diagnosis by DGA are based.)