Affiliation:
1. Research and Production Enterprise RUTAS LLC; National University of Science and Technology MISIS
Abstract
The aim was to study the effect of switching modes on the power of supply transformers in electrical networks up to 1000 V on the multiplicity of switching overvoltages, as well as to develop recommendations for their reduction. The study was carried out during switching of supply transformers in networks up to 1000 V. Vacuum contactors were used to study overvoltages arising during switching of supply transformers. Overvoltages were recorded using an RDN-1000 active divider and a Tektronix TDS2024B digital oscilloscope. The RC circuit capacitance was measured by a Mastech MY6243 digital LC-meter. To limit switching overvoltages, RC quenchers based on RC circuits were used, reducing not only the switching pulse amplitude, but also the rate of the switching pulse voltage rise. In addition, RC quenchers lack fading zones under high-frequency switching pulses. The capacitance of the primary winding of the transformers under study was measured. An increase in the transformer power was found to lead to a decrease in the multiplicity of switching overvoltages, when the transformer is disconnected from the mains. Under a 1.5-fold increase in the power of the transformer, its inductance and wave impedance decreases. As a result, when the same capacitance is connected to the transformer terminals, the wave resistance in more powerful transformers will be reduced to a larger extent (by 3 to 6 times), thus providing a more effective overvoltage limitation. The conducted experimental studies confirmed the effectiveness of RC circuits in limiting switching overvoltages.
Publisher
Irkutsk National Research Technical University
Reference21 articles.
1. Kuz'min S.V. Use of power transformers for localization of higher harmonics in 0.4 – 10 kV power supply systems. In: Energoeffektivnost' sistem zhizneobespecheniya goroda: Trudy vserossiiskoi nauuchno-prakticheskoi konferentsii = Energy efficiency of city life support systems: Proceedings of All-Russian Scientific and Practical Conference. 2009, Krasnoyarsk. Krasnoyarsk; 2009, vol. 1, p. 268-270. (In Russ.).
2. Bebikhov Yu.V., Egorov A.N., Matul G.A., Semenov A.S., Kharitonov Ya.S. Search of ways to improve the efficiency of application of high-voltage frequency-regulated electric drive in conditions of mining production. Estestvennye i tekhnicheskie nauki = Natural and Technical Sciences. 2018;8:228-234. (In Russ.).
3. Brykalov S.M., Balyberdin A.S., Trifonov V.Yu., Zasukhin R.V. Key approaches to energy efficiency improvement at large manufacturing companies. Energobezopasnost’i energosberezhenie = Energy Safety and Energy Economy . 2020;5:10-18. (In Russ.).
4. Shevyrev Y.V., Shevyreva N.Y. Improvement of voltage waveform in power supply systems with dynamic rectifier in mineral mining and processing industry. Gornyi Zhurnal. 2019;1:66-69. https://doi.org/10.17580/gzh.2019.01.14.
5. Egorov A.N., Semenov A.S., Fedorov O.V. The practical experience of the application of the frequency converter power flex 7000 in the mining industry. In: Trudy Nizhegorodskogo gosudarstvennogo tekhnicheskogo universiteta imeni R.E. Alekseeva. 2017;4:86-93. (In Russ.).