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    Biological Insulating Liquids - Safe, Sustainable, Environmental-Friendly
    (2024-01-01)
    Pagger, Ernst
    ;
    Pattanadech, Norasage
    ;
    Muhr, Michael
    ;
    Tieber, Michael
    ;
    Kongdang, Peeraphong
    Because of the aim for safe, sustainable, and environmentally friendly production, transmission, and distribution of electricity, the use of biological insulating liquids is increasing. This is reflected in the increasing number of suppliers of these liquids and the quantities being used in electrical equipment. Due to their chemical and physical properties, they are superior to conventional mineral oil in important areas. Due to their biological origin and the significantly lower energy input during production, they have a much lower CO<inf>2</inf> footprint compared to other insulating liquids. Insulating liquids produced by cracking fats and oils are not included in this article.
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    Biological Insulating Liquids: New Insulating Liquids for High Voltage Engineering
    (2023-01-01)
    Pagger, Ernst Peter
    ;
    Pattanadech, Norasage
    ;
    Uhlig, Frank
    ;
    Muhr, Michael
    This book describes the state-of-the-art use of biological insulating liquids in detail. In recent years, more and more transformers filled with esters have been put into operation. This is because people recognize the benefits of ester liquids in terms of their fire safety (high flash and fire points) and environmental characteristics, judging from their biodegradability, their low CO2 footprint (only valid for natural ester) and their beneficial interactions with solid insulation, etc. One of the main reasons is that the water adsorption and absorption characteristics of these liquids are excellent and very different compared to mineral oil. The today’s discussion about climate change and global warming is an additional driver for using natural ester. Another advantage is that transformers filled with biological insulating liquids can operate with an overload of up to 150%. This is advantageous in the case of volatile energy generation from wind and solar power and in the supply of electrical energy for electromobility. Liquid inside electrical equipment is the lifeblood that serves both as a dielectric and a cooling medium. Some properties of these liquids differ from mineral oil, which had to be considered in the transformer design. The dielectric liquid is always in direct contact with transformer materials; therefore, the interaction should be very well understood, especially when retrofilling an existing mineral oil filled device. There are several natural ester fluids derived from various seeds and fruits on the market, and their properties may differ more or less. In the book, the most important properties of the different biological insulating fluids and mineral oil are compared. Ester fluids have already found their way into various standards. The condition of the device can be verified very well from the contents of the insulating liquids. For analysis and testing, the same equipment and devices that are commonly used for mineral oil are used for ester liquid. The chemical and physical behaviors of ester fluids compared to mineral oil are different. This must always be considered when interpreting test results stemming from ester fluids. The book is a guideline for students, original equipment manufacturers, users, laboratories and authorities in the use of biological insulating liquids.
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    Partial Discharges (PD): Detection, Identification, and Localization
    (2023-01-01)
    Pattanadech, Norasage
    ;
    Haller, Rainer
    ;
    Kornhuber, Stefan
    ;
    Muhr, Michael
    PARTIAL DISCHARGES (PD) - DETECTION, IDENTIFICATION AND LOCALIZATION Explore state-of-the-art partial discharge measurement techniques In Partial Discharges (PD) - Detection, Identification and Localization, a team of distinguished electrical engineers delivers a comprehensive treatment of the behavior, modeling, measurement, monitoring, localization, and evaluation of partial discharges. It includes coverage of all major advancements in the field that have occurred over the last few decades. It also discusses partial discharge phenomena, detection methods, and strategies for analyzing and processing collected data. Mechanisms of insulation failure are explored, as is the denoising of partial discharge measurement data and the localization of partial discharge in large, high-voltage equipment. Non-electric principles and procedures are discussed, and the book offers a variety of tables, figures, and photographs to illustrate the concepts discussed within. Partial Discharges(PD) also provides: • A thorough introduction to the physical behavior of partial discharges, including their causes and classification • Comprehensive modeling of partial discharge behavior, including classical and dipole discharges • Practical discussions of the measurement of partial discharges, including the electrical method, partial discharge decoupling, and pre- and post-processing of partial discharges • In-depth examinations of the monitoring of partial discharge behavior, including methods and realization Perfect for electrical engineers engaged in electrical power engineering, Partial Discharges (PD) will also earn a place in the libraries of research and development specialists employed in the manufacturing, quality testing and operation of electrical systems.
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    How Water Affects the Properties of Insulating Liquids
    (2020-10-25)
    Pagger, Ernst
    ;
    Muhr, Michael
    ;
    Pattanadech, Norasage
    ;
    Kongdang, Peeraphong
    ;
    Tieber, Michael
    Water has a great influence on the properties of insulating liquids, but this influence does not always have the same impact on the insulation system. Depending on what kind of insulating liquid is used the influence can be more or less. Liquids with a higher water absorption and adsorption capacity are less susceptible to changing liquid properties compared to insulating liquids like mineral oil. This paper provides results of how properties of viscosity, refractive index, breakdown voltage and moisture equilibrium in transformer paper-liquid systems change in relation to the water content.
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    Alternative Insulating Fluids - Interpretation of Test Results
    (2020-09-01)
    Pagger, Ernst Peter
    ;
    Muhr, Michael
    ;
    Rapp, Kevin
    ;
    Pattanadech, Norasage
    In recent years, more and more transformers filled with esters have been put into operation. This is because people recognize the benefits of ester fluids in terms of their fire safety (high flash- and fire points) and environmental characteristics, judging from their biodegradability, their low CO2 footprint (only valid for natural ester) and their beneficial interactions with solid insulation, etc. Ester fluids have already found their way into various standards. For analysis and testing the same equipment and devices that are commonly used for mineral oil are used for ester liquid. The chemical- and physical behaviors of ester fluids compared to mineral oil are different. This must always be considered when interpreting test results stemming from ester fluids.
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    Comments on PDIV testing procedure according to IEC 61294
    (2017-11-29)
    Pattanadech, Norasage
    ;
    Muhr, Michael
    —In this paper, partial discharge inception voltage (PDIV) and partial discharge (PD) activity of mineral oil with water content of 4 ppm are investigated. The PDIV test procedure was performed according to IEC 61294. Then, the PDactivitywas recorded for 1 minute at 1.1 PDIV level. The investigation wasconducted with a needle – plane electrode and a needle –sphere electrode by which different tip radius needles, plane electrodes, and various diameter sphere electrodes were used for the experiments. The PDIV and PD activity test results are reported in this paper. It was found that PDIV strongly depends on the electrode configuration and the gap distance. From the experiments,PDIV values of some electrode systems were not obtained due to the problems of breakdown events occurring during the experiments.Theparticular patterns for PDIV testing to explain the possibility PD and breakdown events which may occur during PDIV testing in accordance with IEC 61294 are developed. The particular patterns for PDIV testingare divided into four cases as the followings: The first PD pulse coexisting with PDIV, the low risk of breakdown for PDIV experiment, the medium risk of breakdown for PDIV experiment and the high risk of breakdown for PDIV experiment. In case of the very simple case PDIV and the lower risk of breakdown for PDIV experiment, the PDIV can be detected without breakdown occur. However, in the case of the medium risk of breakdown for PDIV experiment breakdown may take place before or after the PDIV is detected. In the case of high risk of breakdown for PDIV measurement, breakdown takes place easily during performing the PDIV experiment.Therefore, the exact PDIV valuesare not be obtained for such cases. To avoid the breakdown events which may occur during PDIV experimentaccording to IEC 61294 was performed, the combined PDIV measurement was recommended. Besides, PDIV testing with the combined PDIV method provided the lower PDIVwhich was closer to the theoretical PDIV compared with testing in accordance with IEC61294.