href="https://www.litres.ru/author/serafima-zayceva-5994195/?lfrom=203296966&ffile=1">Т. Н., Зайцева С. Е., Смирнова Е. В., Тинигина Л. А., English reader for technical students Английский язык, Учебно-методическое пособие, – М.: ЛИТРЕС, 2018, с. 66.
[6] Khrennikov, A. Yu., (1998). Measuring device of the inductive transformer short-circuit impedance”, Patent of Russian Federation, № 96110718 А.
Луговая А. Л. Английский язык для студентов энергетических специальностей: Учебное пособие/А. Л. Луговая. – М.: Высш. шк., 2009. – 150 с.
[7] Fogelberg, T., Girgis, R. S., (1994). ABB power transformers – a result of merging different technologies with prospects for significant future advancements”, International Simposium "Electrotechnics – 2010", Moscow, vol. 1, 56–59.
[8] Balakrishnan, V. A study of short-circuits in large power transformers, Electrical India, 1989, Vol. XXIX, № 4, 87–91.
[9] Бухарова Г. П. Техническое чтение для энергетиков: Методическое пособие по английскому языку для студентов 1, 2 курсов энергетических специальностей дневной и заочной форм обучения / сост. Г. П. Бухарова. – Ульяновск: УлГТУ, 2004–112 с.
[10] Lech, W., Tyminski, L. Detecting transformer winding damage – the low voltage impulse method, Electrical Review, 1966, № 18, 23–27.
[11]Галиахметова А. Т., Лутфуллина Г. Ф. English for energy industry. Английский язык для энергетических специальностей: Учебное пособие /, А. Т. Галиахметова, Г. Ф. Лутфуллина. – Казан. гос. энерг. ун-т, 2014–152 с.
[12] Malewski, R., Khrennikov, A. Yu., Shlegel, O. A., Dolgopolov, A. G. (1995). Monitoring of Winding Displacements in HV Transformers in Service, Reports of CIGRE Working Group 33.03. Italy, Padua.
[13] Khrennikov, A. Yu., (1999). Short-circuit performance of power transformers. Test experience at Samaraenergo Co and at Power Testing Station in Togliatti, including fault diagnostics, Reports of CIGRE Study Commitee 12 Transformers. Hungary, Budapest.
[14] Трухан, Е. В. Английский язык для энергетиков: учеб. пособие /Е. В. Трухан, О. Н. Кобяк. Минск: Выш. шк., 2011–191 с.
[15] Khrennikov, A. Yu., (2000). Power transformer's fault diagnostics at Samaraenergo Co, including FRA/LVI method, Reports from School of Math. and System Engineering, Vaxjo University, Sweden, № 43, ISSN 1400–1942.
[16] Khrennikov, A. Yu., (2005). Short-circuit performance of power transformers. Transformer testing experience for reliability’s increase of electric power supply, Reports of CIGRE Colloquium, Comitee A2., Moscow.
[17] Khrennikov, A. Yu., Goldshtein, V. G., Skladchikov, A. A., (2010). The analysis of a condition of overhead lines of power transmission 6–500 кV, Power plants, № 5.
[18] Khrennikov, A. Yu. (2012). New «intellectual networks» (Smart Grid) for detecting electrical equipment faults, defects and weaknesses. Smart Grid and Renewable Energy, February, Volume 3, Issue 1, 159–164. http://www.scirp.org/journal/sgre/
[19] Khrennikov, A. Yu., (2013). Smart Grid technologies for Detecting Electrical Equipment Faults, Defects and Weaknesses. Workshop on Mathematical Modelling of Wave Phenomena with applications in the power industry, Linnaeus University, Växjö.
[20] Khrennikov, A.Yu., Mazhurin, R. V., Radin P. S., (2014). Infra-red and ultraviolet control, LVI-testing, partial discharges and another diagnostic methods for detection of electrical equipment’s faults, defects. Journal of Multidisciplinary Engineering Science and Technology (JMEST) (ISSN: 3159–0040), Volume 1, Issue 4, 184–189. http://www.jmest.org/vol-1-issue-4-november-2014/
Chapter 2. Diagnostics and Transformer Testing Experience by LVI/FRA Methods
Abstract
LVI-testing, FRA and short-circuit inductive reactance measurements are sensitive to detecting such typical transformers winding faults as buckling, axial shift and other. It is given an algorithm of the frequency spectral analysis. The examples of diagnostics by LVI-testing, frequency spectral analysis of capacity range from 20 to 400 MVA and voltage range from 35 to 220 kV transformers and autotransformers are showed in service and during short-circuit testing. The studies are carried out for dependency of LVI oscillograms and signal spectra of power transformer winding of one type manufacturing.
Keywords: Short-circuit, Testing Laboratory, Winding fault, Electrodynamic deformation, Low voltage impulse method
2.1. Introduction
Power transformers are one of the basic parts in the circuitry of power transmission and delivery. Therefore, the interest to perfection of the power transformers' fault diagnostic methods is increased. The repairs of power transformers and other electrical equipment are carried out, using diagnostic measurement results.
LVI-testing, FRA and short-circuit inductive reactance measurements are sensitive to detecting such typical transformers winding faults as buckling, axial shift and other. The 70 units of 25–240 MVA 110–500 kV power transformers have been checked by low voltage impulse (LVI) method. A few power transformers were detected with winding deformations after short-circuit with aperiodical short-circuit current.
The idea of the application of an apparatus of frequency spectral analysis (FRA) for diagnostics of defects and damages of transformer-reactor electrical equipment belongs to R. Malewski, which proposed to use frequency spectra or transfer function of winding on the oscillograms of current and voltage for the analysis of the state of the transformer.
2.2. LVI-Testing and FRA Method for 250 MVA/220 kV Transformer Diagnostic
Significant amplitude-frequency changes with value to 1,5 Volts in the LVI- oscillograms, corresponding to radial deformations in LV winding of phase A, were occurred during the short-circuit tests of phase A of 250 MVA/220 kV transformer after short-circuit shot with 85 % value of transient (aperiodic) current. Conclusion was made about the impossibility of conducting further transformer testing (Figure 7) [by 1–4].
a) for LVI-testing
