scholarly journals Frequency Diagnostics of Insulating System of Power Transformers

2020 ◽  
Vol 16 (1) ◽  
pp. 1-7
Author(s):  
Miroslav Gutten ◽  
Daniel Korenciak ◽  
Peter Brncal ◽  
Roman Jarina

AbstractThe paper presents experimental diagnostics of the oil-paper insulating system of power transformers using progressive frequency method. The first part of the paper deals with the basic information about diagnostics of power oil transformers. The second part of the paper deals with the use of frequency domain spectroscopy (FDS) for power oil transformers. This method is used in the analysis of insulating condition of power transformer with the system of oil-paper. It was found that the results of these tests are highly influenced by the operating temperature during the experimental measurement. Moisture and conductivity between the insulating transformer paper and oil in an insulating system are highly dependent on the temperature. In the other part, the paper presents experimental results of the diagnostic measurement for a real traction oil transformer at different operating temperatures and states (with oil and without). Finally, the paper presents comparative measurement among several autotransformers with the same power. In experimental measurements, the correlation between the measured values and the operational aspects of the individual oil autotransformers are shown.

2019 ◽  
Vol 10 (4) ◽  
pp. 353-359
Author(s):  
M. Gutten ◽  
M. Šebok ◽  
D. Korenčiak ◽  
P. Brnčal ◽  
M. Kubiš ◽  
...  

The first part of paper deals with the base information about diagnostics of power transformers. In this part are presented differently insulating methods, for example method of recovery voltage method, method of polarization and depolarization currents and chromatographic analysis.The second part of paper deals use of method of frequency domain spectroscopy for oil power transformers. This method is used in analysis insulating condition of power transformer with system of oil-paper. It was found, that the results of these tests are highly impacted by the operating temperature during the experimental measurement. Moisture and conductivity between insulating paper and oil in an insulating system are highly dependent from temperature.In the other part, the paper presents experimental results of the frequency diagnostic measurement for a real single-phase traction transformer 110/27 kV at different operating temperatures and states (with oil and without).Finally in the last part, the paper presents comparing frequency insulating measurements among several the same single-phase transformers 110/27 kV.


2011 ◽  
Vol 128-129 ◽  
pp. 190-195
Author(s):  
Hua Lin Liu ◽  
Yin Bo Zhan ◽  
Xiao Lei ◽  
You Yuan Wang ◽  
Hua Rong Zeng ◽  
...  

As we know, the TF method is more sensitive to changes in the power transformers at higher frequencies. Although measurement based on low voltage impulse (LVI) is definitely faster than that based on swept frequency method (SFM), the available frequency band is narrow because of the typical microsecond impulse. In this paper, the characteristics of the nanosecond impulse in the frequency domain were investigated. A test System based on Nanosecond low voltage impulse was developed. The proposed method was applied to a 10kV/100kVA distribution transformer in the laboratory. Measurement results with two different impulses were compared.


1976 ◽  
Vol 41 (4) ◽  
pp. 523-529 ◽  
Author(s):  
Daniel R. Boone ◽  
Harold M. Friedman

Reading and writing performance was observed in 30 adult aphasic patients to determine whether there was a significant difference when stimuli and manual responses were varied in the written form: cursive versus manuscript. Patients were asked to read aloud 10 words written cursively and 10 words written in manuscript form. They were then asked to write on dictation 10 word responses using cursive writing and 10 words using manuscript writing. Number of words correctly read, number of words correctly written, and number of letters correctly written in the proper sequence were tallied for both cursive and manuscript writing tasks for each patient. Results indicated no significant difference in correct response between cursive and manuscript writing style for these aphasic patients as a group; however, it was noted that individual patients varied widely in their success using one writing form over the other. It appeared that since neither writing form showed better facilitation of performance, the writing style used should be determined according to the individual patient’s own preference and best performance.


2008 ◽  
Vol 1 (2) ◽  
pp. 187-199
Author(s):  
KATHRYN WALLS

According to the ‘Individual Psychology’ of Alfred Adler (1870–1937), Freud's contemporary and rival, everyone seeks superiority. But only those who can adapt their aspirations to meet the needs of others find fulfilment. Children who are rejected or pampered are so desperate for superiority that they fail to develop social feeling, and endanger themselves and society. This article argues that Mahy's realistic novels invite Adlerian interpretation. It examines the character of Hero, the elective mute who is the narrator-protagonist of The Other Side of Silence (1995) , in terms of her experience of rejection. The novel as a whole, it is suggested, stresses the destructiveness of the neurotically driven quest for superiority. Turning to Mahy's supernatural romances, the article considers novels that might seem to resist the Adlerian template. Focusing, in particular, on the young female protagonists of The Haunting (1982) and The Changeover (1984), it points to the ways in which their magical power is utilised for the sake of others. It concludes with the suggestion that the triumph of Mahy's protagonists lies not so much in their generally celebrated ‘empowerment’, as in their transcendence of the goal of superiority for its own sake.


Vestnik MEI ◽  
2020 ◽  
Vol 6 (6) ◽  
pp. 82-90
Author(s):  
Dmitriy I. Panfilov ◽  
◽  
Mikhail G. Astashev ◽  
Aleksandr V. Gorchakov ◽  
◽  
...  

The specific features relating to voltage control of power transformers at distribution network transformer substations are considered. An approach to implementing high-speed on-load voltage control of serially produced 10/0.4 kV power transformers by using a solid-state on-load tap changer (SOLTC) is presented. An example of the SOLTC circuit solution on the basis of thyristor switches is given. On-load voltage control algorithms for power transformers equipped with SOLTC that ensure high reliability and high-speed operation are proposed. The SOLTC performance and the operability of the suggested voltage control algorithms were studied by simulation in the Matlab/Simulink environment and by experiments on the SOLTC physical model. The structure and peculiarities of the used simulation Matlab model are described. The SOLTC physical model design and its parameters are presented. The results obtained from the simulating the SOLTC operation on the Matlab model and from the experiments on the SOLTS physical model jointly with a power transformer under different loads and with using different control algorithms are given. An analysis of the experimental study results has shown the soundness of the adopted technical solutions. It has been demonstrated that the use of an SOLTC ensures high-speed voltage control, high efficiency and reliability of its operation, and arcless switching of the power transformer regulating taps without load voltage and current interruption. By using the SOLTC operation algorithms it is possible to perform individual phase voltage regulation in a three-phase 0.4 kV distribution network. The possibility of integrating SOLTC control and diagnostic facilities into the structure of modern digital substations based on the digital interface according to the IEC 61850 standard is noted.


2011 ◽  
Vol 2011 (1) ◽  
pp. 5-28
Author(s):  
Jens Bonnemann

In ethics, when discussing problems of justice and a just social existence one question arises obviously: What is the normal case of the relation between I and you we start from? In moral philosophy, each position includes basic socio-anthropological convictions in that we understand the other, for example, primarily as competitor in the fight for essential resources or as a partner in communication. Thus, it is not the human being as isolated individual, or as specimen of the human species or socialised member of a historical society what needs to be understood. Instead, the individual in its relation to the other or others has been studied in phenomenology and the philosophy of dialogue of the twentieth century. In the following essay I focus on Martin Buber’s and Jean-Paul Sartre’s theories of intersubjectivity which I use in order to explore the meaning of recognition and disrespect for an individual. They offer a valuable contribution to questions of practical philosophy and the socio-philosophical diagnosis of our time.


2020 ◽  
Vol 10 (3) ◽  
pp. 43-57
Author(s):  
See Seng Tan

Abstract: The longstanding effort to develop a people-based regionalism in Southeast Asia has been shaped by an inherent tension between the liberal inclination to privilege the individual and the community under formation, on the one hand, and the realist insistence on the primacy of the state, on the other. This article explores the conditions and constraints affecting ASEAN’s progress in remaking Southeast Asia into a people-focused and caring community in three areas: disaster management, development, and democratization (understood here as human rights). Arguably, the persistent gap in Southeast Asia between aspiration and expectation is determined less by political ideology than by the pragmatic responses of ASEAN member states to the forces of nationalism and protectionism, as well as their respective sense of local and regional responsibility.Resumen: El esfuerzo histórico para desarrollar un regionalismo basado en las personas del sudeste de Asia ha estado marcado por una tensión fundamental entre la inclinación liberal de privilegiar el individuo y la comunidad y la insistencia realista sobre la primacía del estado. Este artículo explora las condiciones y limitaciones que afectan el progreso de la ASEAN en la reestructuración de Asia sudoriental en una comunidad centrada en el cuidado de las personas en: gestión de desastres, desarrollo y democratización (i.e., derechos humanos). La brecha persistente en el sudeste asiático entre la aspiración y la expectativa está determinada por las respuestas pragmáticas de los miembros de la ASEAN sometidos a las fuerzas del nacionalismo y proteccionismo, así como su respectivo sentido de responsabilidad local y regional.Résumé: L’effort historique pour développer un régionalisme fondé sur les peuples en Asie du Sud-Est a été marqué par une tension fondamentale entre l’inclination libérale qui privilégie, d’une part, l’individu et la communauté et, d’autre part, l’insistance réaliste sur la primauté de l’État. Cet article explore les conditions et les contraintes qui nuisent aux progrès de l’ANASE dans le cadre d’une refonte de l’Asie du Sud-Est en une communauté centrée et attentive aux peuples dans trois domaines : la gestion des désastres, le développement et la démocratisation (en référence aux droits humains). Le fossé persistant en Asie du Sud-Est entre les aspirations et les attentes est vraisemblablement moins déterminé par l’idéologie politique que par les réponses pragmatiques des États membres de l’ANASE soumis aux forces du nationalisme et du protectionnisme ainsi que par leur sens respectif de la responsabilité locale et régionale.


2010 ◽  
Vol 27 (3) ◽  
pp. 1-23 ◽  
Author(s):  
Marie-Luisa Frick

Against the background of the trend of Islamizing human rights on the one hand, as well as increasing skepticism about the compatibility of Islam and human rights on the other, I intend to analyze the potential of Islamic ethics to meet the requirements for vitalizing the idea of human rights. I will argue that the compatibility of Islam and human rights cannot be determined merely on the basis of comparing the specific content of the Islamic moral code(s) with the rights stipulated in the International Bill of Rights, but by scanning (different conceptions of) Islamic ethics for the two indispensable formal prerequisites of any human rights conception: the principle of universalism (i.e., normative equality) and individualism (i.e., the individual enjoyment of rights). In contrast to many contemporary (political) attempts to reconcile Islam and human rights due to urgent (global) societal needs, this contribution is solely committed to philosophical reasoning. Its guiding questions are “What are the conditions for deriving both universalism and individualism from Islamic ethics?” and “What axiological axioms have to be faded out or reorganized hierarchically in return?”


2019 ◽  
Vol 70 (6) ◽  
pp. 2105-2107
Author(s):  
Gheorghita Popa ◽  
Olimpiu L. Karancsi ◽  
Maria Alexandra Preda ◽  
Marius Cristian Suta ◽  
Lavinia Stelea ◽  
...  

Our study aimed to determine pain levels and the state of welfare connected to laser-based procedures in the treatment of patients diagnosed with uncontrolled glaucoma. The study group included 100 eyes of 100 patients diagnosed with glucoma, 50 of them being treated with micropulse transscleral laser cyclophotocoagulation, and the other 50 eyes being treated with continuous transscleral laser cyclophotocoagulation. We used visual analog scale to gather information from each patient. After analysing the individual information the following results were obtained: the pain level for the micropulse transscleral laser cyclophotocoagulation was 60.23 mm, signifying moderate pain; and the pain score for the continuous transscleral laser cyclophotocoagulation was 76.34 mm, corresponding to moderate-intense pain. Pain level generated by minimally invasive laser procedures is discussed.


2020 ◽  
Vol 67 (1) ◽  
pp. 42-47
Author(s):  
Anatoliy I. Sopov ◽  
Aleksandr V. Vinogradov

In power transformers, energy losses in the form of heat are about 2 percent of their rated power, and in transformers of large power centers reach hundreds of kilowatts. Heat is dissipated into the environment and heats the street air. Therefore, there is a need to consume this thermal energy as a source of heat supply to nearby facilities. (Research purpose) To develop methods and means of using excess heat of power transformers with improvement of their cooling system design. (Materials and methods) The authors applied following methods: analysis, synthesis, comparison, monographic, mathematical and others. They analyzed various methods for consuming excess heat from power transformers. They identified suitable heat supply sources among power transformers and potential heat consumers. The authors studied the reasons for the formation of excess heat in power transformers and found ways to conserve this heat to increase the efficiency of its selection. (Results and discussion) The authors developed an improved power transformer cooling system design to combine the functions of voltage transformation and electric heating. They conducted experiments to verify the effectiveness of decisions made. A feasibility study was carried out on the implementation of the developed system using the example of the TMG-1000/10/0.4 power transformer. (Conclusions) The authors got a new way to use the excess heat of power transformers to heat the AIC facilities. It was determined that the improved design of the power transformer and its cooling system using the developed solutions made it possible to maximize the amount of heat taken off without quality loss of voltage transformation.


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