Overview of the power transformer park and diagnostic methods in Latvia

Reliability of a power system depends on its equipment. As power transformers are essential elements in substations, reliability of power transmission system largely depends on their operating and technical conditions. Therefore complicated maintenance strategies are applied including various diagnostic methods and a thorough evaluation of the acquired results. Although diagnostic tests aid the evaluation of the technical condition, the risk assessment of a particular transformer is the next step in order to ensure certain reliability level. The risk assessment approach applicable for transformers in power transmission system in Latvia is proposed in this paper.