Field diagnosis methods for determining the insulation health index for power transformers

Summary

Power transformers are critical and expansive components in the electrical grids for both utilities and industry. Failures of power transformers resources can cause severe damage the, as well as financial damages for electrical companies. Therefore on-site transformer testing and diagnosis was introduced in order to help analysis the problems during the operating conditions. For power transformers this can mean continuous operation over the life extension of the asset at full load or even more since redundant transformer assets are not available. Large power transformer failures which are associated with irreversible internal damage can be catastrophic and may cause consequential damage to adjacent substation equipment which has further safety and environmental implications. Accessories such as bushings, tap changers, cooling systems and instrumentation can play a very important role in reliability of the transformer. With regards to the design of accessories a special emphasis should be placed on high reliability and minimization of the maintenance requirements. With regards to the design of accessories a special emphasis should be placed on high reliability and minimization of the maintenance requirements. With continuous rise in power demand and consequent rise in required transformer ratings design requirements for, transformer accessories become ever more stringent. With increasing loads, the risks of thermal degradation are also increased with potential explosion in extreme cases. The management of the aging transformers overload has become a very important issue in the utilities. This paper describes the various condition diagnoses for oil immersed transformers in the Egyptian network and condition assessment methods available to provide engineers with the information necessary to make decisions on the future of the power transformers.

Additional informations

Authors

Howland

Keywords

Power transformers, Diagnostic techniques, Transformer windings, Insulation damage, Failures