Article
Engineering, Electrical & Electronic
Sunuwe Kim, Jongmin Park, Wongon Kim, Soo-Ho Jo, Byeng D. Youn
Summary: This paper proposes a new framework, BDD, which combines Duval's method with deep neural network (DNN) for power transformer fault diagnosis using dissolved gas analysis (DGA). The proposed method overcomes the issue of unlabeled DGA data by using pseudo-labeling information and incorporates parameter transfer learning for diagnosing sparse labeled DGA data. The experiments show that the BDD method outperforms existing methods in terms of fault diagnosis accuracy.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2022)
Review
Engineering, Electrical & Electronic
Mohd Syukri Ali, Ab Halim Abu Bakar, Azimah Omar, Amirul Syafiq Abdul Jaafar, Siti Hajar Mohamed
Summary: This review paper summarizes the discoveries made about dissolved gas analysis (DGA) conventional methods around the decade. It provides a brief introduction of DGA and reviews various fault detection methods such as the Key Gases Method, Duval Triangle Method, Duval Pentagon Method, and Ratio Methods. The paper highlights the importance of enhancing the reliability and accuracy of each DGA method in the diagnostic process to prevent further damage to transformers.
ELECTRIC POWER SYSTEMS RESEARCH
(2023)
Article
Multidisciplinary Sciences
Haw Jia Yong, Mohd Fairouz Mohd Yousof, Rahisham Abd Rahman, Mohd Aizam Talib, Norhafiz Azis
Summary: An oil-filled transformer requires proper maintenance for long-term operation. Dissolved gas analysis (DGA) is the best diagnostic method for assessing the condition of oil-immersed transformers. Machine learning algorithms can classify DGA data into normal and faulty conditions, based on IEEE limits and the Duval pentagon method. The use of data resampling techniques improves the accuracy of predictions for imbalanced data.
ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Electrical & Electronic
Michel Duval, Jerzy Buchacz
Summary: The new sub-zones of Duval Pentagons 1 and 2 allow for the detection of dangerous arcing faults in the paper insulation of transformers and distinguishing them from arcing faults in oil.
IEEE ELECTRICAL INSULATION MAGAZINE
(2022)
Article
Engineering, Electrical & Electronic
Rahman Azis Prasojo, Muhammad Akmal A. Putra, Ekojono, Meyti Eka Apriyani, Anugrah Nur Rahmanto, Sherif S. M. Ghoneim, Karar Mahmoud, Matti Lehtonen, Mohamed M. F. Darwish
Summary: Power transformers are critical and expensive assets in the power system. Dissolved gas analysis (DGA) is an important test to ensure system reliability by detecting fault types through analyzing dissolved gases in transformer oil. The graphical Duval pentagon is a widely used DGA interpretation technique, but has limitations in handling large amounts of data. This study proposes a machine-learning-based fault identification model using the Random Forest algorithm with SMOTE preprocessing, achieving high accuracy and consistency in fault diagnosis.
ELECTRIC POWER SYSTEMS RESEARCH
(2023)
Article
Engineering, Electrical & Electronic
T. Manoj, C. Ranga, Sherif S. M. Ghoneim, U. Mohan Rao, Saad A. Mohamed Abdelwahab
Summary: Various fault diagnosis techniques in oil immersed power transformers have been studied for the past two decades and are well documented in the literature. Among these techniques, the Duval triangle method (DTM) is reported to be the most prominent. In this study, a new approach combining three Duval triangles with triangular membership functions (MFs) is proposed for fault diagnosis.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2023)
Article
Green & Sustainable Science & Technology
Anu Kumar Das, Dayal Ch Shill, Saibal Chatterjee
Summary: This paper examines the application of natural esters and new vegetable oils as alternatives to conventional mineral oils in the electric utility. It focuses on the dielectric performance and environmental safety of coconut oil, and discusses its sustainability and market potential.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2022)
Article
Engineering, Electrical & Electronic
S. Gopakumar, T. Sree Renga Raja
Summary: Transformer defects are defined by their severity, and this paper proposes a novel method to assess the severity of PT problems by integrating GL, GR, and DGA interpretation. The proposed method shows good agreement with earlier methods but with better sensitivity, and it also incorporates a DL-based CNN model and HHO method to make the evaluation process more efficient.
JOURNAL OF ELECTRICAL ENGINEERING & TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Josue Rodriguez, Jose Contreras, Carlos Gaytan
Summary: This study evaluates the gas generation of a new soybean-based natural ester liquid in distribution and power transformers through lab-scale testing, and discusses predicting transformer fault types using different diagnostic methods. Results show that overheating issues in natural esters are associated with ethylene, while high energy faults and partial discharge faults are linked to acetylene and hydrogen, respectively. The Duval triangle method is confirmed as the most reliable approach for diagnosing natural ester liquids.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2021)
Article
Chemistry, Physical
Bo Gao, Yanan Fang, Kai Liu, Haojie Yin, Yonghong Zeng, Guangning Wu
Summary: In this paper, molecular dynamics simulations were performed to study the thermal decomposition mechanism and product distribution of synthetic ester oils. The results show that the initial decomposition reaction is ester bond cleavage, followed by decarboxylation reaction and beta-C bond cleavage. The main decomposition products are CO2, C2H4, and some C2 and C3 species. The study of the generation process of these dissolved gases provides a theoretical basis for the research on the DGA method of synthetic ester oil.
CHEMICAL PHYSICS LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Yusuf Cilliyuz, Yunus Bicen, Faruk Aras, Guzide Aydugan
Summary: The use of natural esters as an insulating liquid has become popular since the early 2000s. While studies emphasize their environmental friendliness and safety, there is still a need for further experimental verification regarding their effectiveness in delaying the aging of cellulosic insulation material.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2021)
Article
Engineering, Electrical & Electronic
Matias Meira, Carlos Verucchi, Raul Alvarez, Leonardo Catalano
Summary: This study investigates the gas formation mechanisms of paraffinic-type mineral oil and soybean-based natural ester under thermal faults. Different gas profiles are generated for the two types of oils, with natural ester showing significant differences at low temperatures. The chemical structures of the natural ester behave similarly to carbon structures of mineral oil at temperatures above 700 degrees C.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2021)
Article
Chemistry, Physical
Binghao Chen, Ziming Su, Zhenbin Du, Mingyuan Ma, Junjie Zhang, Chao Tang
Summary: This study analyzes the kinematic viscosity and oxidation stability of mixed oils composed of rapeseed oil and palm fatty acid ester (PFAE). The results show that the addition of PFAE reduces the kinematic viscosity of the mixed oil. The presence of short chain oil molecules in the mixed system decreases the internal friction between oil molecules, resulting in improved performance.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Chemistry, Physical
Peipei Zhao, Mingcong Tang, Dongzhi Zhang
Summary: This paper performs simulations to investigate the sensing performance of different metal-modified PdSe2 for five dissolved gases in transformer oil. The results show that Rh-PdSe2 has the best desorption for H-2 at room temperature and can be used as a candidate material for H-2 detection. PdSe2 also shows good adsorption and desorption performance for H-2 and C2H2 at high temperatures, making it suitable for gas detection in high-temperature environments. This work provides a theoretical basis and preliminary ideas for experimenters.
APPLIED SURFACE SCIENCE
(2022)
Article
Energy & Fuels
Jiaxin Liu, Zijian Zhao, Yuanchen Zhong, Chenchen Zhao, Guogang Zhang
Summary: This paper presents a time series forecasting model based on the SARIMA model to predict the dissolved gas concentration in power transformer oil. The SARIMA model shows the most accurate and stable performance in predicting the trend component of the gas, and considering external factors improves the accuracy of the predictions.
Article
Physics, Applied
Donglin Liu, Qiang Liu, Zhongdong Wang
Summary: Understanding the pre-breakdown phenomenon in dielectric liquids, known as streamers, is crucial for the application of liquids in high voltage and power dense devices. The stable propagation velocity of the second mode streamer is a key characteristic, with recent research showing that limiting the electron saturation velocity can greatly impact the streamer propagation velocity.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Hanwen Ren, Haoyu Gao, Chengqian Li, Qingmin Li, Zhongdong Wang
Summary: This paper investigates the effect of different voltage types on the space charge characteristics inside solid insulation, revealing that the charge amount is mainly determined by input power and the injected charge depth is shallow. Results under unipolar conditions are frequency-independent, while charge amount under bipolar conditions is negatively correlated with frequency.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2021)
Article
Engineering, Electrical & Electronic
Hanwen Ren, Yasuhiro Tanaka, Hiroaki Miyake, Kazuki Endo, Qingmin Li, Haoyu Gao, Chengqian Li, Zhongdong Wang
Summary: Pulse wave voltages result in more accumulation of positive charge inside polyimide compared to DC voltages, with higher space charge under negative voltages above 50 Hz and most distortion under negative voltage at 500 Hz. The distribution of accumulated charge tends to stabilize when the duty ratio exceeds 50%.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2021)
Article
Engineering, Electrical & Electronic
Shuhang Shen, Qiang Liu, Zhongdong Wang
Summary: The experimental study focused on analyzing the spatial characteristics of Mach-cone shaped shockwaves generated by streamers in mineral oil and synthetic ester. The results showed that the appearance of Mach-cone shaped shockwave is an effective indicator of actively propagating streamer channel. Voltage levels did not have a significant impact on the observed shockwave parameters.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2021)
Article
Engineering, Electrical & Electronic
Hanwen Ren, Yasuhiro Tanaka, Hiroaki Miyake, Qingmin Li, Haoyu Gao, Chengqian Li, Zhongdong Wang
Summary: The study investigated charge phenomena under sine and half-wave sine voltages within the frequency range of 500 Hz. Experimental results showed that the amount of accumulated charge depends on the voltage's waveform and frequency parameters, with lower frequency conditions resulting in more charge accumulation.
Article
Engineering, Electrical & Electronic
Hanwen Ren, Qingmin Li, Haoyu Gao, Chengqian Li, Sihong Cheng, Zhongdong Wang
Summary: The proposed optical method for space charge measurement, based on ellipsometry detection principle and the photoelastic effect of the sensor, shows potential in providing high signal-to-noise ratio, terahertz bandwidth, and nanometer spatial resolution. The mathematical relationship derived indicates that the light intensity difference measured can linearly represent the elastic force generated from space charge. The built ellipsometry detection system demonstrates fast measurement speed and accurate tracking of elastic waves, confirming the feasibility and effectiveness of the proposed method.
IEEE SENSORS JOURNAL
(2021)
Article
Engineering, Electrical & Electronic
Haichuan Yu, Shuhang Shen, Qiang Liu, Zhongdong Wang
Summary: The uniformity of electric field has a significant impact on the breakdown mechanisms of dielectric liquids. This study identifies and quantifies the transition field factor boundary between streamer initiation and propagation mechanisms. Different methods are introduced and applied to derive the transition field factor boundaries for mineral oil under positive and negative lightning impulses. The results suggest that the negative transition field factor boundary is lower than the positive one, indicating a polarity-dependent effect on breakdown mechanisms.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2021)
Article
Polymer Science
Hanwen Ren, Qingmin Li, Yasuhiro Tanaka, Hiroaki Miyake, Haoyu Gao, Zhongdong Wang
Summary: The study investigates the space charge phenomena of a solid polymer under thermal and electrical stresses with different frequencies and waveforms, providing insights into the characteristics of charge accumulation under different voltage and temperature conditions.
Article
Engineering, Electrical & Electronic
ShengJi Tee, Qiang Liu, Zhongdong Wang, Fikri Hafid, Pierre Tournet
Summary: Asset management of instrument transformers (ITs) has been gaining attention, and this study investigates failure causes of a family of combined measuring ITs through temperature profile simulations and consideration of moisture migration behavior in an oil-impregnated paper insulation system. It is found that temperature differences and relative saturation hysteresis during summer could lead to lower dielectric strength and failures, while factors such as in-service age, operating voltage level, and environment also influence failure rate.
Proceedings Paper
Engineering, Electrical & Electronic
S. Y. Matharage, Q. Liu, Z. D. Wang, G. Wilson, Y. H. Kim, R. Martin
PROCEEDINGS OF THE 2020 3RD IEEE INTERNATIONAL CONFERENCE ON DIELECTRICS (ICD 2020)
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
Donglin Liu, Qiang Liu, Zhongdong Wang
2020 IEEE CONFERENCE ON ELECTRICAL INSULATION AND DIELECTRIC PHENOMENA (2020 IEEE CEIDP)
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
Shuhang Shen, Ying Xu, Qiang Liu, Zhangdong Wang
2020 IEEE CONFERENCE ON ELECTRICAL INSULATION AND DIELECTRIC PHENOMENA (2020 IEEE CEIDP)
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
D. Liu, Q. Liu, Z. D. Wang
PROCEEDINGS OF THE 21ST INTERNATIONAL SYMPOSIUM ON HIGH VOLTAGE ENGINEERING, VOL 2
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
Xiaozhou Mao, Shuntao Ji, Zhongdong Wang, Paul Jarman, Andrew Fieldsend-Roxborough, Gordon Wilson
PROCEEDINGS OF THE 21ST INTERNATIONAL SYMPOSIUM ON HIGH VOLTAGE ENGINEERING, VOL 1
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
S. Y. Matharage, S. Liu, Q. Liu, Z. D. Wang
PROCEEDINGS OF THE 21ST INTERNATIONAL SYMPOSIUM ON HIGH VOLTAGE ENGINEERING, VOL 1
(2020)
