Power quality in power supply systems of mining and processing enterprises in Russia

This paper investigates the effect of the load factor of frequency converters and thyristor converters on electrical power quality. Recommendations for reducing the influence of higher harmonics and switching overvoltages on the characteristics of electrical power are provided. Higher harmonics were measured by a PKK57 complex device for controlling electrical parameters and a digital oscilloscope of the Tektronix TDS 2024V type. Impulse switching overvoltages were recorded by an active resistance divider of the DNEK-10 type and the above-mentioned oscilloscope. The obtained data were processed by the Loginom 6.4 software and the methods of mathematical statistics. The lower threshold level of the load factor of frequency converters and thyristor converters was set equal to 0.8, at which the sinusoidal distortion of voltage curves correspond to the RF standard of electrical power quality. The suppression degree of higher harmonics from the 5th to 17th frequency by power transformers with a capacity of 250–6,300 kV. A ranged from 95 to 45%. The use of the ‘transformer–converter–electric receiver’ system as applied to the power supply systems of mining and processing enterprises was substantiated. It was shown that electric motors with a capacity of up to 2,500 kW inclusively require protection against switching overvoltages. Conventional RC-absorbers based on RC-circuits connected to the terminals of electric motors are shown to be highly efficient for protecting electric motors against switching overvoltages. Thus, the quality of electrical power in power supply systems of mining and processing enterprises in Russia can be ensured by frequency converters and thyristor converters with a load factor of 0.8 or greater. Provided that the transformer capacity does not exceed 1,000 kV. A, a more efficient and less expensive ‘transformer–converter–electrical receiver’ system is recommended. Effective protection of electric motors of up to 2,500 kW inclusive can be provided using the proposed conventional RC absorber, which maintains the overvoltage rate at a level not exceeding 1.7.

1. Kugusheva NN, Semenov AS, Yakushev IA, Pavlova SN. Technical and economic features of choice of frequency-controlled electric drives for technological units of diamond mining enterprises. Innovatsii i investitsii = Innovation & Investment. 2021;1:145–149. (In Russ.)

2. Brykalov SM, Balyberdin AS, Trifonov VYu, Zasukhin RV. Key approaches to energy efficiency improvement at large manufacturing companies. Energobezopasnost’ i energosberezhenie = Energy Safety and Energy Economy. 2020;5:10–18. (In Russ.) https://doi.org/10.18635/2071-2219-2020-5-10-18

3. Semenov AS, Egorov AN, Kharitonov YaS, Bebikhov YuV, Yakushev IA, Fedorov AV. Analysis of the operation of variable-frequency electric drive systems under the influence of high harmonics. In: Elektrotekhnicheskie sistemy i kompleksy: sbornik nauchnyh trudov Mezhdunarodnoj nauchno-prakticheskoj konferencii = Electrotechnical systems and complexes: collected scientific works of the International scientific and practical conference. 22–25 October 2019, Ufa. Ufa: Ufa State Aviation Technical University; 2019, vol. 1, p. 178–184. (In Russ.) 4. Egorov AN, Semenov AS, Fedorov OV. The practical experience of the application of the frequency converter power flex 7000 in the mining industry. Trudy Nizhegorodskogo gosudarstvennogo tekhnicheskogo universiteta imeni R.E. Alekseeva. 2017;4:86–93. (In Russ.)

4. Klunduk GA. Influence of a frequency converter on the power saving of a pump unit and electromagnetic compatibility of equipment. In: Nauka i obrazovanie. Opyt, problemy, perspektivy razvitiya: sbornik nauchnyh trudov Mezhdunarodnoj nauchno-prakticheskoj konferencii = Science and Education. Experience, problems, development prospects: Collected scientific works of the International scientific and practical conference. 21–23 April 2020, Krasnoyarsk. Krasnoyarsk: Krasnoyarsk State Agrarian University; 2020, vol. 1, p. 153–157. (In Russ.)

5. Bebikhov YuV, Egorov AN, Matul GA, Semenov AS, Kharitonov YaS. 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.)

6. Shevyrev YV, Shevyreva NY. 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

7. Ashraf N, Abbas G, Abbassi R, Jerbi H. Power quality analysis of the output voltage of AC voltage and frequency controllers realized with various voltage control techniques. Applied Sciences (Switzerland). 2021;11(2). https://doi.org/10.3390/app11020538

8. Dutta N, Kaliannan P, Subramaniam U. Experimental analysis of PQ parameter estimation of VFD drives. In: Materials Science and Engineering: IOP Conference Series. 2020;937(2):012042. https://doi.org/10.1088/1757-899X/937/1/012042

9. Jyothi R, Sumitgupta, Rao KU, Jayapal R. IoT application for real-time condition monitoring of voltage source inverter driven induction motor. In: Innovative Data Communication Technologies and Application. 2021, vol. 59, p. 97–105. https://doi.org/10.1007/978-981-15-9651-3_8

10. Skakunov DA. Influence of power electronics on electric power quality and methods of higher harmonics filtering. In: Trudy vserossiiskoi nauchno-tekhnicheskoi konferentsii = Proceedings of All-Russian Scientific and Technical Conference. 2004, Novokuznetsk. Novokuznetsk; 2004, vol. 1, p. 253–257. (In Russ.)

11. Akagi H Active harmonic filters. Proceedings of the IEEE. 2005;93(12):2128 – 2141.

12. Kuz'min SV 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.)

13. Kuzmin RS, Kuzmin IS, Menshikov VA, Kuzmin SV, Kulikovskii VS. Method of assessment and prediction of overvoltage caused by single-phase arc ground short circuits in the 6–10 kV mains as a way of increasing the electrical safety level in mining facilities. Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal. 2020;5:116–132. (In Russ.) https://doi.org/10.21440/0536-1028-2020-5-116-132

14. Kuzmin SV, Mainagashev RA, Gavrilova EV, Nemkov SV. The experience of operating the protection means against the commutation overvoltage in the systems of supplying mining companies with 6 kV electric power. Gornoe oborudovanie i elektromehanika = Mining equipment and electromechanics. 2011;4:53–54. (In Russ.)

15. Kuzmin SV, Umetskaia EV, Zavalov AA. Influence of power quality on value of switching overvoltages in networks 6–10 kV. In: International Multi-Conference on Industrial Engineering and Modern Technologies. 2020. https://doi.org/10.1109/FarEastCon50210.2020.9271527

16. Sowa P, Macha D. Electromagnetic switching transients in transmission line cooperating with the local subsystem. International Journal of GEOMATE. 2020;19(72):180–189. https://doi.org/10.21660/2020.72.5781

17. Guo Yaxun, Jiang Xiaofeng, Chen Yun, Zheng Ming, Liu Gang, Li Xiaohua, Tang Wenhu. Reignition overvoltages induced by vacuum circuit breakers and its suppression in offshore wind farms. International Journal of Electrical Power & Energy Systems. 2020;122:106227. https://doi.org/10.1016/j.ijepes.2020.106227

18. Fritz N. Engelmann G, De Doncker RW. RC snubber design procedure for enhanced oscillation damping in wide-bandgap switching cells. In: 21st European Conference on Power Electronics and Applications. 2019. https://doi.org/10.23919/EPE.2019.8915541

19. De Paula dos Santos D, Sartori CAF. Impact of mismatch cables impedances on active motor terminal overvoltage mitigation using parallel voltage source inverters. In: IEEE 3rd Global Electromagnetic Compatibility Conference. 2017. https://doi.org/10.1109/GEMCCON.2017.8400662

20. Kuzmin SV, Gavrilova EV, Baryshnikov DV. The influence of the arc extinction process in high-voltage switches on the communication overvoltage value appearing in the 6–10 kV circuits of mining enterprises. Gornoe oborudovanie i elektromehanika = Mining equipment and electromechanics. 2009;2:41–44. (In Russ.)