Transformer Condition Control: Advanced and Traditional Technologies

ISBN-13: 9783030831974 / Angielski / Twarda / 2021 / 168 str.

Vasily Ya Ushakov; Alexey V. Mytnikov; Valeriy A. Lavrinovich

Spis treści

Chapter 1. Failure reasons of power transformers

1.1. Analysis of failure statistics of transformer structural elements

1.2. Technical and economic consequences of disruption of the normal operation of transformers

1.3 Aging (degradation) of insulation

1.4. Violation of the integrity of transformer windings

 

Chapter 2 Traditional technologies for condition monitoring of high-voltage transformer

2.1 Non-electrical control methods

          2.1.1 Physical and chemical control methods

                   2.1.1.1 Chromatographic analysis of dissolved gases (GDA)

                   2.1.1.2 Physical and chemical indicators for assessing the state of                            paper insulation of power transformers in operation

          2.1.2 Vibration control

2.2 Electrical test methods

          2.2.1 Insulation monitoring using partial discharges (PD) registration

                   2.2.1.1 Methods for registering PD

                   2.2.1.2 Technical implementation of the idea of ​​insulation diagnostics           by registering PD

          2.2.2 Measurement of no-load losses

          2.2.3 Measuring the transformation ratio

          2.2.4 Insulation resistance monitoring of transformer windings

          2.2.5 Measurement of ohm’s resistance of windings

          2.2.6 Monitoring by changes in resistance (inductance) short circuit

 

Chapter 3 Diagnostics of the condition of transformer windings by probing pulses of microsecond duration

3.1 Physical foundations and stages of development of impulse diagnostics

3.2 Development of pulse diagnostics technology

3.3 Frequency analysis as a development of impulse diagnostics

 

Chapter 4 Diagnostics of the transformer winding condition by probing pulses of nanosecond duration 

4.1 Physical prerequisites for increasing the efficiency of the technology of pulse diagnostics (PD) by reducing the duration of the probe pulse.

4.2 Development of PD on physical and mathematical models of a power transformer

          4.2.1 Development a physical model of a power transformer

          4.2.2 Turn-to-turn short circuit detection

          4.2.3 Passage of the probing pulse through the windings of the physical model of the transformer

                   4.2.3.1 Passage of the probing pulse through the LV winding

                   4.2.3.2 Passage of the probing pulse through the HV winding

          4.2.4 Determining the radial and axial displacement of the winding turns

          4.2.5 Regularities of the response formation with different methods of winding connection

          4.2.6 Experimental investigation of the diagnostic capability under operating voltage

          4.2.7 Study of the influence of the probing pulse parameters on the sensitivity of the diagnostic procedure

          4.2.8 Research of power transformer PD on a mathematical model

4.3 Diagnostic complex realizing PD technology in nanosecond mode.

          4.3.1 Object characterization and experimental procedure

          4.3.2 Choice of efficiency criteria

4.4 Comparison of FRA efficiency and PD technology

          4.4.1 Diagnostics by nanosecond pulse

          4.4.2 Diagnostics by FRAX-150 device

          4.4.3 Diagnostics of a defect of the "axial displacement of turns" type in the HV winding of phase "A" by probing with nanosecond pulses

          4.4.4 Diagnostics of a defect of the "axial displacement of turns" type in the HV winding of phase "A" by the FRA method

4.5 Single-stage technology of pulse defectography.

          4.5.1. Single-step winding condition monitoring

          4.5.2. Implementation of single-stage defectography

          4.5.3 Comparison of spectra of pulses applied to an undamaged winding

4.6 Monitoring the winding condition in ON-LINE mode

Conclusion

 

Appendix 1 Development of a schematic diagram and a prototype of a probe pulse generator

Appendix 2 Development and approbation of programs for testing and processing of diagnostic results

O autorze

Alexey V. Lavrinovich was born on 10 October 1986. He received the M.S. degree in Electrical Engineering from Tomsk Polytechnic University in 2008. From 2008 up to 2017, he worked as researcher and engineer in High Current Electronics Institute, Tomsk, doing research with high voltage pulsed power. Since 2017 he has been working in Tomsk research and design institute of oil and gas, Tomsk, Russia. His research interests focus on power transformer diagnostics and providing of high voltage equipment stable work.     

Valeriy A. Lavrinovich was born on 7 November 1948. He received the Ph.D. degree in 1985 from High Current Electronics Institute of the Russian Academy of Sciences (Tomsk, Russia) and the Doctor of Science degree in 2005 from Tomsk Polytechnic University (Tomsk, Russia). Both dissertations are dedicated to investigation and elaboration of high-voltage vacuum spark gaps and commutators. From 1989 to 1998 he was the director of Russian Research Institute of Electrotechnical Industry. Now he is a professor at the Department of Electrical Power Engineering Systems and High Voltage Engineering of Tomsk Polytechnic University. He is the laureate of Russian Government Prize in the area of Science and Technology. Professor Lavrinovich published more than 90 scientific articles. His research interests focus on pulsed power and electrical power engineering systems.

Alexey V. Mytnikov was born on 2 June 1966. He received the M.S. degree in Electrical Engineering from Tomsk Polytechnic University in 1988. He received the Ph.D. degree in 2001. He is an Associate Professor of Power Engineering Institute, Tomsk Polytechnic University (Tomsk, Russia). His research interests focus on power transformer diagnostics, high voltage technologies and engineering pedagogics. Also, he provides full range of special courses for bachelor and master teaching specialization “High Voltage Power Engineering”, including lectures, practices and workshops. New technology of winding condition control, which is based on the nanosecond probing impulses, is the result of his experimental work. New diagnostic complex has been designed and engineered. Simulations are a useful tool but as Hippocratos once said: “Clever man is not who knows a lot, but whose knowledge is useful”. I follow this motto now.  Associate Professor Alexey V. Mytnikov published more than 70 scientific articles.

Vasiliy Ya.  Ushakov was born in Kazakstan, 1939. He received Ph.D. degree in 1965 and Doctor of Science degree in 1973 from Tomsk Polytechnic University, Tomsk, Russia. Currently, he is a Professor of School of Power and Power Engineering at the Tomsk Polytechnic University. In different years, he held the following positions: the Head of High Voltage Department of the Tomsk Polytechnic University (TPU), the Head of High Voltage Research Institute at TPU, the Vice-rector for Research of TPU, the Head of Regional Resources Saving Centre. He has many years of experience teaching special disciplines (“High-voltage engineering”, “Electrical engineering. Current state, problems and perspectives”, “Energy saving in the enterprises of fuel and energy complex”) in Russian and in English (including abroad – South Korea, spring 2005) and the course "Professional English" for Russian-speaking students. He has published over 300 scientific articles and 24 monographs and textbooks (four of them in Springer Verlag), received 38 invention certificates and patents. Under his leadership, 34 candidate and 6 doctoral dissertations were defended. He is currently a member of the Editorial Board of the journal “Russian Physics” and participant of Dissertation Council in the Tomsk branch of Russian Academy of Sciences.

Blurb

This book is devoted to one of the main problems of modern electrical power engineering—power transformer diagnostics. The first three chapters discuss the fundamentals: The first chapter presents the physical reasons for power transformers’ failures and the technical and economic consequences of disruption of the normal operation. The second chapter reviews the standard technologies for monitoring the state of the high-voltage transformers. The third chapter tells about monitoring the condition of transformer windings based on the pulse method.

The fourth chapter presents the technologies for transformer windings condition controlled by means of nanosecond pulses. The stages of improving the pulsed method based on a short probing pulse of the nanosecond range, the results of experiments on identifying the radial and axial displacements of the winding, studies of the effect of the duration and shape of the probing pulse on the sensitivity of the diagnostic procedure, and the stages of developing a mathematical as well as physical model of a power transformer are consistently presented.