Assessment of the effect of commercial vegetal oils on Kraft paper ageing through mechanical characterization

Abstract

Vegetal oils are considered a suitable substitute of mineral oil, widely used in power transformers as insulation liquid and cooling. Due to the fact that more and more power transformers containing this alternative insulating fluids are being constructed it is needed the development of mathematical aging models which help to predict transformer failures. The continued performance of power transformers depends on the condition of its paper insulation mainly. In this sense, this paper analyses Kraft paper degradation through the loss of its mechanical strength. Accelerated thermal ageing test of the paper in two different vegetal oils were carried out at three temperatures during diverse periods of time, in order to obtain information on the kinetics of the ageing degradation of the paper. The evolution of the mechanical properties of paper failure are analysed as a function of temperature and ageing time. Finally, the results obtained are compared with the traditional method of degradation analysis, based on the degree of polymerisation (DP) measurement.

Rancang Bangun Sel Uji Penuaan Termal Dipercepat Sistem Isolasi Transformator

“…Sampel minyak dan kertas dipanaskan menggunakan chamber eksperimen kaca yang dimasukkan kedalam oven. Penelitian [4] membahas efek penuaan thermal minyak vegetal melalui karakterisasi thermal menggunakan chamber eksperimen stainless yang dimasukkan kedalam oven. Penelitian [5] membahas penuaan thermal sistem isolasi transformator menggunakan chamber eksperimen stainless dilengkapi dengan thermocouple, dengan pemanas oven listrik.…”

Effect of the Thermal Characteristics of Dielectric Fluids on the Loading Capacity of a Power Transformer

“…The insulating materials and fluids used in these machines accelerate the speed of their degradation when their temperature is high [3]. As has been shown in multiple scientific tests already published, biodegradable dielectric fluids reduce the aging rate of the solid components of the insulation systems, compared to the behavior of conventional mineral oils [4]. Another advantage to keep in mind is that the combination of biodegradable dielectric fluids and hightemperature solid insulation makes it possible to build large transformers within the weight limits of the trucks used in their transport [5].…”

Experimental investigation on creep characteristic of the spacer between winding turns of power transformers

“…The windings contact each other with the creeping and breaking of the spacer and leads to lack of cooling in the region. In this case, the enamel layer around the copper windings melts due to overheating and a short circuit fault occurs (Farinas et al, 2016; Fernandez-Diego et al, 2018).…”