Effect of Loads and Other Key Factors on Oil-Transformer Ageing: Sustainability Benefits and Challenges

Abstract

Transformers are one of the more expensive pieces of equipment found in a distribution network. The transformer's role has not changed over the last decades. With simple construction and at the same time mechanically robust, they offer long term service that on average can reach half a century. Today, with the ongoing trend to supply a growing number of non-linear loads along with the notion of distributed generation (DG), a new challenge has arisen in terms of transformer sustainability, with one of the possible consequences being accelerated ageing. In this paper we carefully review the existing studies in the literature of the effect of loads and other key factors on oil-transformer ageing. The state-of-the-art is reviewed, each factor is analysed in detail, and in the end a smart transformer protection method is sought in order to monitor and protect it from upcoming challenges.

Grey Relational Analysis for Insulation Condition Assessment of Power Transformers Based Upon Conventional Dielectric Response Measurement

“…Unfortunately, it is a fact that the electrical and mechanical properties of the transformer oil-paper insulation system become aging gradually due to the combination stresses of the mechanical vibration, thermal, electrical, oxygen, water and other factors, in the long-term service process [4][5][6][7][8]. Historically, the applications of oil sample analysis (OSA) in terms of equilibrium relationships between insulating oil and cellulose insulation, dissolved gas analysis (DGA), dielectric loss factor (DLF) and insulation resistance (IR) have been commonly used for performing non-destructive condition monitoring of transformer insulation [9][10][11][12]. However, the OSA technique only presents limited knowledge about the aging status of transformer solid insulation.…”

Nonlinear Autoregressive Neural Network Models for Prediction of Transformer Oil-Dissolved Gas Concentrations

“…In order to enable a comparison regarding prediction accuracy and validity we adopted the same evaluation criteria of [1]:…”

“…As the transformer is one of the most important unit of an electrical system, it is natural that efforts are made to preserve its integrity and increase its availability [1]. For these purposes, maintenance policies and procedures are planned and applied to ensure the least interruption of such equipment [1][2][3].…”

“…For these purposes, maintenance policies and procedures are planned and applied to ensure the least interruption of such equipment [1][2][3]. In fact, any failure in this equipment can affect the whole network, compromise other elements in the grid and generate significant economic impacts [1,2].…”

Oil Movement In Closed Environment Of Distribution Transformer Tank Problem Simulation

“…To consider the generalized differential Navier-Stokes equation with assumptions that are embodied into its mathematical model, the analysis of oil natural movement in the transformer tank closed environment is usually applied, Godina, R. et al (2015). It is known that the presence of internal sources of heat flow in the windings and magnetic circuit the temperature field distribution…”