Article
Polymer Science
Pierre Delliere, Nathanael Guigo
Summary: Hydrolytic furan ring opening is utilized to open biobased furanic molecules into levulinic-like platform molecules. The quantitative assessment of ring opening in furanic macromolecules, which has been considered as a side reaction, has not been conducted. This study highlights the concept of monitoring furan ring opening during polymerization using poly(furfuryl alcohol) (PFA). The investigation reveals that a significant amount of carbonyl species is formed during the polymerization process, introducing the concept of degree of open structure (DOS). Polymerizing furfuryl alcohol (FA) in a 50% aqueous solution doubles the fraction of opened structures, reaching up to 15% of opened furanic entities. The accessibility of carbonyls in PFA is influenced by steric hindrance.
Article
Energy & Fuels
Sherif S. M. Ghoneim
Summary: The aging of power transformers can cause various defects and damages in the insulating system, particularly in the insulating paper. Statistical tools can be used to establish a connection between the DP and testing parameters of transformer samples to determine the status of the insulating paper and the remaining life percentage.
Article
Engineering, Electrical & Electronic
Jian Hao, Chenyu Gao, Xin Chen, Dawei Feng, Qian Wang, Ruijin Liao
Summary: Gas generation behaviors of the TEMO oil-paper insulation system under overheating faults and discharge faults were investigated, showing higher content of H-2 and C2H6 compared to conventional mineral oil systems. A diagnosis model based on oil dissolved gas analysis was proposed for the TEMO-paper insulation system, which was proven effective in detecting faults such as low-temperature overheating, lightning impulse and surface flashover.
ELECTRICAL ENGINEERING
(2021)
Article
Engineering, Electrical & Electronic
Yiyi Zhang, Xinyang Mao, Xingtuo Zhang, Chuqi Xu, Gang Wang, Sheng Li
Summary: Frequency domain spectroscopy (FDS) is widely used in insulation evaluation of power transformers, but conventional FDS has the drawback of long test duration. To address this issue, a novel iFDS method is proposed to reduce test duration through signal superposition and waveform prediction, and improve accuracy through excitation parameter design, test process optimization, and time-frequency-domain data processing. Experimental results demonstrate that iFDS is a superior method for both saving time and accurate testing.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2022)
Article
Engineering, Electrical & Electronic
Yongqiang Wang, Ziqi Wang, Zhuo Zeng, Ruoyu Fei, Jing Shang
Summary: The study found that thermal aging makes it harder to extinguish sparks in the oil-paper insulation, with a gradual impact on the development of partial discharge. It also reduces the insulation performance between layers and accelerates carbon trace growth.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2021)
Article
Chemistry, Analytical
Anantawat Kunakorn, Sarawuth Pramualsingha, Peerawut Yutthagowith, Phethai Nimsanong, Supat Kittiratsatcha
Summary: This paper introduces an effective technique for assessing the insulation conditions in power transformers, focusing on oil-immersed paper insulation commonly used in transformers. The technique utilizes advanced transformer sensing and monitoring, employing dielectric response sensing to estimate degrees of polymerization (DP) and percentages of moisture content (PMCs) in the oil-immersed paper insulation. The approach, based on weighted k-nearest neighbor regression, demonstrates superior accuracy and complexity compared to a previously developed method.
Article
Engineering, Electrical & Electronic
Enze Zhang, Hanbo Zheng, Yiyi Zhang, Jiefeng Liu, Zhen Shi, Kuikui Shi, Chuansheng Zhang, Guangqi Shao, Chaohai Zhang, Harald Schwarz
Summary: The study showed that ethanol can be used as an effective indicator to monitor the aging behavior of insulating paper, with a strong correlation between ethanol content and temperature, moisture, and aging degree. By establishing a lifespan model based on the relationship between ethanol and the degree of polymerization, the performance of oil-paper systems can be assessed under laboratory conditions.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2021)
Article
Engineering, Electrical & Electronic
Daning Zhang, Xinyuan Feng, Zhi Yang, Haisong Xu, Jiongting Jiang, Haibao Mu, Guan-Jun Zhang
Summary: In this study, a testing platform was developed to investigate the mechanism of moisture's impact on epoxy-impregnated paper by integrating moisture diffusion, adsorption, and dielectric properties of insulating materials. The water diffusion characteristics of epoxy resin and epoxy-impregnated paper were analyzed using the Fick diffusion model and the Langmuir model, respectively. The vacuum vapor adsorption characteristics of the materials were examined using the Guggenheim-Anderson-de Boer equation to understand the form of water present within them. The dielectric response of materials with varying moisture levels was tested, and the characteristic frequency reflecting the water content of the epoxy-impregnated paper was extracted using the Extended Derivative Method.
IET GENERATION TRANSMISSION & DISTRIBUTION
(2023)
Article
Chemistry, Physical
Ming Li, Yating Pan, Lingyu Wan, Xinyu Hao, Tao Huang, Kaiyou Zhang, Wenjie Mai, Shuoping Chen, Aimiao Qin
Summary: Cellulose-derived materials have gained attention in advanced electronics for their abundance, low cost, light weight, and sustainability. This study presents a paper-based triboelectric nano-generator (TENG) using sisal cellulose as the friction layer. The effects of surface morphology, structure, and dielectric properties of sisal cellulose paper (SCP) on the TENG's output performance were discussed. It was found that SCP-TENG's electrical output can be improved and controlled by chemically modifying SCP with different polar groups, and a chemical sensor for detecting the degree of group substitution was successfully fabricated.
Article
Energy & Fuels
Pawel Zukowski, Przemyslaw Rogalski, Vitalii Bondariev, Milan Sebok
Summary: The aim of this study was to prepare and test a paper-oil insulation system according to CIGRE recommendations. It was found that the dimensions of the oil channel clearly affected the quality of the fitting process. By not taking into consideration real values of oil channel, the quality of the moisture content estimation was significantly improved.
Article
Engineering, Electrical & Electronic
Deepak Mishra, Arijit Baral, Sivaji Chakravorti
Summary: Oil-impregnated paper is the preferred insulation material for power transformers. Estimating insulation condition using polarization current profiles is time-consuming, so a proposed technique based on short-duration polarization current data is introduced to predict performance parameters related to paper insulation. The method is tested on measured data from various transformers to demonstrate its effectiveness.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2023)
Article
Engineering, Electrical & Electronic
Jiefeng Liu, Boshu Song, Enze Zhang, Heng Zhang, Yiyi Zhang, Hui Hwang Goh
Summary: This work proposes a two-stage residual lifespan prediction model for insulating paper based on methanol and furfural indicators. The changes in the contents of methanol and furfural in the oil are examined to determine two demarcation points for dividing the insulation's life into different aging stages. By coupling with the second-order aging kinetic equation, the two-stage residual lifespan model is obtained. The proposed model is proven to be valid with a mean absolute percentage error of 5.6% for insulating paper's residual lifespan when compared to the conventional method of using a single indicator.
IEEE TRANSACTIONS ON POWER DELIVERY
(2023)
Article
Engineering, Electrical & Electronic
Tao Zhang, Linduo Li, Yao Wang, Ning Zhang, Shijie Jiang, A. Abu-Siada
Summary: This article proposes a method for quantifying the health condition of power transformer insulation system using the concept of resistor and fractional calculus. The dielectric model and parameter identification method are presented. The influence of moisture and aging on the dielectric model parameters is studied, showing a strong correlation between relaxation time and water content.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2022)
Article
Engineering, Electrical & Electronic
Ivan Semenov, Carsten Leu
Summary: The effect of high dc-fields on the ac-dielectric response in cellulosic insulating papers was investigated. Complex permittivity measurements were performed in a frequency range from several Hz to 1 MHz using a custom-made dielectric test setup. Non-impregnated and oil-impregnated papers with different water contents were examined. The real and imaginary components of the complex permittivity showed a significant increase at lower frequencies when a high dc-field was applied simultaneously. The magnitude of the increase depended on the water content of the paper and the amplitude of the applied electric field. It is proposed that ionic motions in hydrated cellulose caused by the high dc-field affected the complex permittivity within a frequency range determined by the time constants of ionic species movements.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2023)
Article
Computer Science, Information Systems
Daniel Perez-Rosa, Belen Garcia, Juan Carlos Burgos
Summary: In the past decade, there has been a growing interest in developing and testing dielectric nanofluids for electrotechnical purposes, with potential applications in transformer insulation. While nanofluids show promise in improving the reliability of transformers and transformer design, more research is needed to understand their interaction with other elements of the transformer insulation system. This study focuses on analyzing the effect of nanoparticles on the dielectric response of oil and oil-paper insulation in laboratory conditions, providing insights for potential future applications of nanofluids in transformer insulation.
Article
Energy & Fuels
Rahman Azis Prasojo, Harry Gumilang, Suwarno, Nur Ulfa Maulidevi, Bambang Anggoro Soedjarno
Article
Energy & Fuels
Teguh Kurniawan, Craig A. Baguley, Udaya K. Madawala, Suwarno, Nanang Hariyanto, Yuana Adianto
Article
Engineering, Electrical & Electronic
Winanda Riga Tamma, Rahman Azis Prasojo, Suwarno
Summary: This study explores the health index method for assessing transformer condition, focusing on the decreasing rate as an important factor. Data from 150 kV power transformers provided by an Indonesian electric company were analyzed. The correlation between operating age and health index value as well as the decreasing rate was observed, showing a tendency for the health index value to decrease as transformers age, leading to a proposed risk assessment methodology for transformers.
Article
Energy & Fuels
Yuana Adianto, Craig Baguley, Udaya Madawala, Nanang Hariyanto, Suwarno Suwarno, Teguh Kurniawan
Summary: A novel charge scheduling strategy is proposed in this paper to address the needs of vertically structured power systems without relying on time-of-use pricing. By providing a decision-making framework that considers the considerations of transmission and distribution network operators and allowing for dynamically changing charging loads through timely forecast updates, the strategy demonstrates its effectiveness in a case study.
Article
Engineering, Electrical & Electronic
Ekojono, Rahman Azis Prasojo, Meyti Eka Apriyani, Anugrah Nur Rahmanto
Summary: Dissolved gas analysis is a powerful tool for monitoring the condition of power transformers. The graphical Duval triangle method is one of the most reliable fault identification methods. This study compares six commonly used machine learning algorithms and validates the proposed model using a validation dataset, demonstrating its reliability and usefulness in fault identification for a large number of transformers.
ELECTRICAL ENGINEERING
(2022)
Article
Energy & Fuels
Bryan Denov, Syarif Hidayat, Ali Suwarno, Reynaldo Zoro
Summary: This paper discusses the problem of lightning in modern society, with a focus on its impact on Indonesia. Due to its geographical location in the tropics, Indonesia experiences frequent lightning phenomena. By installing magnetic tape to record direct lightning peak currents, the author obtains lightning characteristics for several provinces in Indonesia and proposes a method for collecting lightning data. These unique lightning characteristics can assist in designing lightning protection systems that match the local conditions, ultimately minimizing the impact of lightning damage.
Article
Computer Science, Information Systems
Dhanu Rediansyah, Rahman Azis Prasojo, Suwarno, A. Abu-Siada
Summary: This paper proposes a method to accurately assess the health condition of power transformers while handling data uncertainty through the application of artificial intelligence techniques. Utilizing data collected from 504, 150-kV transformers, AI models were established and seven AI algorithms were investigated, with the RF model showing the best performance in predicting power transformer HI with an accuracy of 97.3%.
Article
Computer Science, Information Systems
Rahman Azis Prasojo, Suwarno, A. Abu-Siada
Summary: The article introduces a certainty level model for transformer insulation system health index to address data uncertainty issues. By investigating the impact of data unavailability on health index results, a method for predicting oil interfacial tension is proposed. The robustness of the model is validated through assessing the health condition of six in-service power transformers.
Proceedings Paper
Engineering, Industrial
Devi Hendriyono, Tian-Hua Liu, Muhammad Syahril Mubarok, Suwarno
2020 IEEE 29TH INTERNATIONAL SYMPOSIUM ON INDUSTRIAL ELECTRONICS (ISIE)
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
Trinurkalid Sumarwoto, S. Morita, T. Kawashima, N. Hozumi, Suwarno
PROCEEDINGS OF THE 21ST INTERNATIONAL SYMPOSIUM ON HIGH VOLTAGE ENGINEERING, VOL 2
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
Tobias Kinkeldey, Tobias Muenster, Peter Werle, Suwarno, Kai Haemel, Joerg Preusel
PROCEEDINGS OF THE 21ST INTERNATIONAL SYMPOSIUM ON HIGH VOLTAGE ENGINEERING, VOL 1
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
Rahman Azis Prasojo, Nur Ulfa Maulidevi, Bambang Anggoro Soedjarno, Suwarno
4TH INTERNATIONAL CONFERENCE ON CONDITION ASSESSMENT TECHNIQUES IN ELECTRICAL SYSTEMS (CATCON 2019)
(2019)
Proceedings Paper
Computer Science, Information Systems
Yulia Erina Sari, Alvin D. S. Ritonga, Suwarno
PROCEEDING OF 2019 INTERNATIONAL CONFERENCE ON ELECTRICAL ENGINEERING AND INFORMATICS (ICEEI)
(2019)