Estimation of water content in a power transformer using moisture dynamic measurement of its oil

Abstract

Careful monitoring of high voltage equipments and diagnosing the critical conditions before they lead to a disaster are prerequisites of condition-based maintenance. Moisture content in a transformer is regarded as one of the major factors in diagnosing its conditions. It causes many problems for a power transformer including electrical breakdown between either its windings or one winding with neutral, increase in the amount of partial discharge and sundry minor problems. Since paper insulation of a power transformer carries large portion of water content, determining moisture content in this part of the transformer is essential. However, the problem is that the direct measurement of moisture in paper is impossible. Therefore, various methods have been proposed to measure the moisture content in a transformer but each one has its limitations. In this study, an approach is introduced to measure water content in a transformer by analysing the moisture dynamics in oil, tracking its variations and analysis of parameters such as temperature, without necessity of disconnecting the transformer from the power grid. High Voltage

Reliability assessment of distribution system using fuzzy logic for modelling of transformer and line uncertainties

“…Among them, moisture in oil is the most common reason of transformer's failure in short and log terms. Moisture causes breakdown in windings and it also increases discharges [27]. In this study, the amount of moisture in the oil of a transformer is considered as exposure to the risk index.…”

Leveraging sensory data in estimating transformer lifetime

“…Moreover, amongst different aging factors of transformer insulation, such as insulation moisture, oxygen amount, internal temperature, and electrical stress, aging of a transformer highly depends on the thermal degradation of the insulation during its normal life cycle. Thus, the primary aging factor is transformer's internal temperature, specifically at the hottest-spot, which is a function of transformer's loading and ambient temperature [6]- [8].…”

Frequency Domain Spectroscopy for Non-Uniformly Distributed Moisture Detection in Transformer Bushings

“…Moisture ingress into the bushing through leaky gaskets or other openings leads to approximately 90% of all bushing failures [2]. The insulation properties of a bushing can also be severely degraded by moisture in an OIP system, leading to nonuniformly distributed moisture faults in the bushings [3][4][5]. Therefore, it is exceedingly important to detect these nonuniformly distributed moisture faults in a bushing.…”