Published Paper Details:

Electricity is the backbone of any economy. Electrical energy is the indispensable force that drives all economic activity the greater the energy consumption, the more the economic activity, resulting in the emergence of growth. A steady growth in the economy is a prerequisite for any nation desirous of becoming a developed country. Demand of electricity in India is very high, to meet the growing demand, transformers are playing major role. As the demand of electricity increases, rate of failure of transformers & reactors is also increasing, below referred graph 1a & 1b & table 1 showing energy demand & requirement in India, (source: LGRB 2018-19 report of CEA). This paper based on statistical analysis of catastrophic failures of transformer & reactors. They are designed & constructed in such a way to serve at least 35 years, but they failed very earlier. For the study we have collected data from different utilities across India i.e 21 transformer & 4 reactors of different voltage class. All they are failed between 1st sept. 2015 to 31st Dec 2016. Transformer and reactors are one of the most expensive equipment�s of sub-station. Failure of these equipment�s is just like an ice burg and its impact is unbelievable such as unbalancing of transmission system grid, reliability of network and as well as huge revenue loss and take hundreds of man hour to restore the service and restoring cost i.e lum-sum 50-60K USD which includes cost of arrangement of new part or complete tank, T&P, filter machine, oil storage tank, dry air generator, dismantling of bushing, turrets, cooler units ,Vehicle & Crane for lifting & shifting of materials , dragging, shifting of new transformer, re-erection of bushing, turrets, cooler units, testing & also arranging a team of experts for identifying the root cause of failure. Around the world, utilities apply different approaches to estimate the actual stage of life of their assets. Two main methodologies can be distinguished here; bottom-up and top-down analysis. The bottom-up analysis focuses on the degradation and condition assessment of individual assets. The base for such an analysis is maintenance and diagnostics reports (e.g. DGA, PD-measurement, FRA, dielectric response), loading history and aging characteristics obtained through investigations performed on service-aged materials. The top-down analysis investigates the condition of the whole population by means of analytical tools (e.g. statistical distributions). In such approach, the information about number and ages of both failed and installed units are essential. Emphasis is put in this case on economic and strategic life-time assessment. Results of a top-down analysis are e.g. failure frequency, age of assets which are most likely to fail. However, both approaches have certain limitations, imposed by the differences in design and operating regimes. The main aim of this paper is to discuss modes of failure, causes of failures, service life, failure trend based on statistical analysis. Study of every failure is important, they provide a key information to design more reliable and efficient product.