Market-oriented power distribution system requires a well-planned budget with
scheduled preventive and corrective maintenance during a replacement of
units that are in an unsatisfactory condition. In recent years, the concept
of the transformer health index as an integral part of resource management
was adopted for the condition assessment and ranking of ETs. However,
because of the lack of regular measurement and inspections, the confidence
in health index value is greatly reduced. The paper proposes a novel
methodology for the ET condition assessment and the lifetime increase
through the establishment of priorities for control and maintenance. The
solution is based on the upgraded health index, where the confidence to the
measurement results is calculated using Evidential reasoning algorithm based
on Dempster - Shafer theory. A novel, two - level hierarchical model of ET
health index is proposed, with real weighting factors values. This way, the
methodology for ET ranking includes the value of available information to
describe ET current state. The proposed methodology is tested on real data
of an installed ET and compared with the traditional health index
calculation.
Power transformer health index estimation using evidential reasoning