High voltage power transformer condition assessment considering the health index value and its decreasing rate

Abstract

A health index method is a useful tool for the transformer assessment condition. This method has been used in several previous studies. However, most of them have not observed the health index decreasing rate as an aspect to improve the transformer condition assessment. A health index method with different approaches is proposed, considering the values and decreasing rate to assess the transformer condition. Inspection data from in‐service and out‐of‐service 150 kV power transformers provided by the Indonesian electric company are included. The correlation between operating age and Health Index value and Health Index decreasing rate was also observed. With increasing operation age, the Health Index value tends to decrease with a correlation coefficient R 2 of 0.631. Further analysis was conducted to power transformers with historical data of 3 years or more, which showed that the tendency of the Health Index value decreasing rate is higher with older transformers. This paper also illustrates the Health Index analysis of 35 out‐of‐service transformers, resulting in a more suitable Health Index value compared to the previous approach. This study proposes the transformer risk assessment based on its health index value and the decreasing rate.

Implementasi Metode Scoring Matrix dalam Menentukan Indeks Kondisi Minyak Isolasi pada Transformator Daya 150 kV

“…Berdasarkan hasil penelitian-penelitian sebelumnya, isolasi minyak transformator memiliki penilaian yang berbeda-beda tiap parameter yang mana memunculkan kesimpulan atau pemahaman yang berbeda pula terhadap kondisi transformator [7] [2]. Eksperimen lain menganalisis sifat-sifat minyak isolasi yang mana sebagian besar dari mereka melaporkan bahwa keasaman memiliki dampak terhadap usia transformator [8].…”

“…SM = Scoring Matrix S = Nilai parameter Scoring W= Nilai parameter Weighting Metode agregasi weighted-average ini yang banyak digunakan oleh penelitian terdahulu [7]. Jumlah parameter yang digunakan dinyatakan oleh n. Penilaian skor sebuah parameter dinyatakan dalam Si.…”

Thermofluidic investigations of oil natural transformer: Closed‐loop modelling and experimental validation

“…Excessively high HSTs (e.g. over 98°C) can cause accelerated transformer degradation and even catastrophic failure [6,7]. An accurate prediction of the HST and its location can effectively evaluate the load capacity and extend the remaining service lifetime of a transformer [8,9] and thus has attracted broad attention from industrial and scientific communities.…”

Machine Learning Methods for Transformer Health Based on the Degree of Polymerization of Insulating Paper

“…It turns out that the DP decreases as the insulating paper ages and wears out, which indicates the possibility of the transformer's insulation collapsing and not performing with the required efficiency. Testing the oil and insulation paper periodically is a preventive measure for the continuity of operation of the transformer, and failure to maintain periodic tests may lead to catastrophic failures in the operation of the transformer [10,11].…”