Retrofilling Application in 630 kVA Transformer with Synthetic Ester: A Field-Based Study

DOI

10.2991/978-94-6463-944-5_21How to use a DOI?

Keywords

2030 Corporate Commitment; Paper Insulation Ageing; Transformer Retrofilling; Paper Coupon; Synthetic Ester; Mineral Oil

Abstract

The sustainability agenda established under the 2030 corporate commitment framework supports the achievement of the Sustainable Development Goals (SDGs) at the national level, particularly in Indonesia. This commitment has directly motivated the authors to undertake research on these challenges by conducting a field-based study on the use of synthetic ester–based dielectric fluids as an alternative to mineral oil, which is limited by low biodegradability, reduced fire safety, and its contribution to accelerated transformer insulation ageing. However, most studies of ester performance have been restricted to laboratory conditions, often under accelerated ageing, which do not fully reflect in-service operating stresses. Field-based investigations that directly monitor the ageing of paper insulation in retrofilled transformers remain scarce, creating a gap in practical understanding of long-term performance and diagnostic interpretation. The present field experiment addresses this gap by evaluating the retrofilling of two 630 kVA transformers: one filled with mineral oil (Shell Diala S4) and the other retrofilled with synthetic ester (MIDEL 7131). Paper coupons were retrieved from the active parts, while fresh kraft and Thermally Upgraded (TU) paper samples were replenished for comparative monitoring. Baseline electrical diagnostics, including Degree of Polymerization (DP), Breakdown Voltage (BDV), and Dissolved Gas Analysis (DGA) were conducted before energization. The key contribution of this work lies in providing initial descriptive methodology for transformer retrofilling, highlighting procedures for coupon insertion, baseline characterization, and planned monitoring. This framework delivers practical insights for future large-scale retrofilling projects, offering greater confidence in their technical feasibility and reliability while supporting more robust and sustainable maintenance practices.

Copyright

© 2025 The Author(s)

Open Access

Open Access This chapter is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/), which permits any noncommercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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TY  - CONF
AU  - Robin Pranoto
AU  - Lesnanto Multa Putranto
AU  - Roni Irnawan
PY  - 2025
DA  - 2025/12/26
TI  - Retrofilling Application in 630 kVA Transformer with Synthetic Ester: A Field-Based Study
BT  - Proceedings of the International Conference on Sustainable Energy: Toward Energy Transition and Net-Zero Emission (ICOSE 2025)
PB  - Atlantis Press
SP  - 307
EP  - 322
SN  - 3005-155X
UR  - https://doi.org/10.2991/978-94-6463-944-5_21
DO  - 10.2991/978-94-6463-944-5_21
ID  - Pranoto2025
ER  -