Optimization of Various Natural Ester Oils Impregnated Nomex Paper Performance in Power Transformer Applications under Different Ageing Conditions

Abstract

Vegetable oils are being considered as the potential replacements to mineral oils because of their better natural execution and for their high fire point. In spite of the fact that these fluids have been utilized as a part of appropriation transformers, it is as yet a huge advance to receive vegetable oils in control transformer because of high cost and abnormal state of well being and unwavering quality required in benefit for these units. Vegetable oils such as honge oil (HO), neem oil (NO), mustard oil (MO), punna oil (PO) and castor oil (CO) offer the reasonable option for mineral oil. It is expected that the greater part of the un-matured oil could fulfil the base necessity of dielectric protection fluids in the transformer. This paper concentrated on the impact of maturing on the electrical and physicochemical properties of HO, NO, MO, PO and CO. Fixed maturing tests have been set at 90°C for 30 days, 60 days and 90 days. Prior to the maturing procedure, the examples were dried in a vacuum broiler under the pressure of 0.8kPa at 85°C for 48 hours keeping in mind the end goal to evacuate the dampness content in the oils. At that point, the oils were impregnated with the Nomex paper and keep on ageing for choosing the span time. The electrical properties (relative permittivity, dielectric misfortunes, resistivity and breakdown quality), mechanical properties (thickness and elasticity) and substance properties (dampness and corrosiveness) of the oils were estimated all through the maturing time frames. It can be reasoned that the research center quickened warm maturing test uncovers that every single vegetable oil in this examination are safe towards oxidation in light of the steady thickness and low corrosiveness estimations of vegetable oils all through the maturing term even with the nearness of oxygen. The AC breakdown voltages of vegetable oils can in any case conform to the prescribed furthest reaches of new Vegetable oil set by ASTM 6781 even after subjected to maturing. From the results, it may be concluded that the proposed vegetable oils can be used as the alternatives for mineral oil.

Surface Degradation of Oil-Immersed Nomex Paper Caused by Partial Discharge of High-Frequency Voltage

“…As a result, the backbone of the benzene ring structure for aramid molecular is broken, which causes the molecular weight of the aramid molecular to decrease, affecting the mechanical properties of the oil-impregnated Nomex paper. [22][23][24][25] Figure 8 shows the content of carbon and oxygen in oilimpregnated Nomex paper based on EDS. It can be seen that the atomic and mass percentage of carbon are the lowest and the atomic and mass percentage of oxygen are the highest for the blank sample.…”

“…It can also be observed that the position and shape of the diffraction peaks before and after PD degradation remain basically unchanged, and that only the intensity of the diffraction peak changes. In order to further analyze the influence of high frequency on the aggregation structure of oil-paper insulation, the integral method [23][24][25] has been used to calculate the crystallinity of the paper, as shown in Table II. The corresponding calculation formula is expressed as:…”

Transformer Oil Generation and Regeneration Techniques Based on Recent Developments (A Review)

“…The silica gel device as a dehumidifier in the transformer is a function of the load and environmental conditions. In addition, the volume of the dehumidifier is determined by the same factors [21,22]. The types of tests of these oils are divided into four categories including at least 28 typical tests according to the following cases.…”

Investigation of Dielectric Properties of Indigenous Blended Ester oil for Electric System Applications

“…The impact of electrical and physicochemical properties of different vegetable oils with different ageing has been studied [6]. Due to lack of oxidative stability, the vegetable oils are less exposed as dielectric in transformer application [7].…”