Русская версия English version

Improving of operation stability of frequency converters with active rectifiers in electric steel-making complex electrical equipment switching

A.A. Nikolaev, A.S. Denisevich, V.S. Ivekeev

Vestnik IGEU, 2019 issue 5, pp. 48—58

Download PDF

Abstract in English: 

Background. Frequency converters with active rectifiers (FC-AR) are now used in rolling mill electric drives. Modern control systems of ARs are not adapted to voltage sags in power supply systems, which leads to converter tripping. The known methods of ensuring AR operation stability, such as kinetic buffering, correction signals based on negative sequence voltage and others, do not eliminate these emergency trips. As an additional measure the paper proposes the method of voltage sag compensation by using static var compensators (SVC) of electric arc furnaces (EAF) for parallel operation of frequency converters with active rectifiers and electric arc furnaces. However, it remains unknown how disturbances (such as overvoltages of switching of SVC harmonic filters (HF) and voltage sags during furnace transformer switching) affect operation stability of frequency converters with active rectifiers. All this makes it necessary to study the effect of these processes on the operation conditions of FC-AR and to improve the active rectifier control system.

Materials and methods. The authors used experimental arrays of instantaneous values of voltages and currents of the real-life complex «EAF-SVC» («Electric Arc Furnace – Statistic VAR Compensator») in this study. They also applied mathematical models of FC-AR with different PWM algorithms realized in Matlab-Simulink software. The main assumption of the model consists in using equivalent current sources modelling the operation of autonomous voltage invertors.

Results. An improved control system of AR has been developed. The main feature that distinguishes it from the known systems is the fact that it ensures operation stability during SVC harmonic filter and EAF transformer switching by using a signal conditioning unit for setting the active rectifier reactive current component as a function of power supply and AR input voltage difference.

Conclusions. Implementation of the improved AR control system improves FC-AR stability during parallel operation with EAFs through reactive power consumption of the supply system. As a result, it reduces the amplitude of inrush current and voltage deviations in the DC-link of the FC-AR to the values lower than the setpoints of the AR protection system.

References in English: 
  1. Khramshin, T.R., Krubtsov, D.S., Kornilov, G.P. Matematicheskaya model' aktivnogo vypryamitelya v nesimmetrichnykh rezhimakh raboty [A mathematical model of the active rectifier under unbalanced voltage operating conditions]. Elektrotekhnika: setevoy elektronnyy nauchnyy zhurnal, 2014, vol. 1, no. 2, pp. 3–9,
  2. Khramshin, T.R., Krubtsov, D.S., Kornilov, G.P. Matematicheskaya model' silovoy skhemy glavnykh elektroprivodov prokatnykh stanov [A Mathematical Model of the Power Circuit of Main Electric Drives of Rolling Mills]. Elektrotekhnika: setevoy elektronnyy nauchnyy zhurnal, 2014, vol. 1, no. 1, pp. 3–7.
  3. Nikolaev, A.A., Kornilov, G.P., Khramshin, T.R., Akcay, I., Gok, Y. Application of Static Var Compensator of Ultra-High Power Electric Arc Furnace for Voltage Drops Compensation in Factory Power Supply Systems of Metallurgical Enterprise. Procedings of IEEE 2014 Electrical Power and Energy Conference. (EPEC 2014), 2014, pp. 235–241.
  4. Nikolaev, A.A., Denisevich, A.S., Bulanov, M.V. Issledovanie parallel'noy raboty avtomatizirovannykh elektroprivodov prokatnogo stana i dugovoy staleplavil'noy pechi [Investigation of parallel work of rolling mill automated electric drives and an electric arc furnace]. Vestnik IGEU, 2017, issue 3, pp. 59–69.
  5. Nikolaev, A.A., Kornilov, G.P., Ivekeev, V.S., Lozhkin, I.A., Kotyishev, V.E., Tukhvatullin, M.M. Ispol'zovanie staticheskogo tiristornogo kompensatora sverkhmoshchnoy dugovoy staleplavil'noy pechi dlya obespecheniya ustoychivosti elektroenergeticheskoy sistemy i povysheniya nadezhnosti vnutrizavodskogo elektrosnabzheniya [Using of the static var compensator of the ultra-high power electric arc furnace for ensuring stable operation of the power system and increasing reliability of the in-house power supply]. Mashinostroenie: setevoy elektronnyy nauchnyy zhurnal, 2014, no. 1, pp. 59–69.
  6. Nikolaev, A.A., Denisevich, A.S., Lozhkin, I.A., Tukhvatullin, M.M. Issledovanie vliyaniya provalov napryazheniya v sisteme elektrosnabzheniya zavoda MMK «Metalurji» na rabotu glavnykh elektroprivodov stana goryachey prokatki [Investigation of voltage sag effects in the power supply system of the «MMK Metalurji» on the operation of the main electric drives of the hot rolling mill]. Elektrotekhnicheskie sistemy i kompleksy, 2015, no. 3(28), pp. 8–14.
  7. Khramshin, T.R., Krubtsov, D.S., Kornilov, G.P. Metody shirotno-impul'snoy modulyatsii moshchnykh aktivnykh vypryamiteley pri nesimmetrii napryazheniya [Methods of PWM of large power active rectifiers under unbalanced voltage operating conditions]. Mashinostroenie: setevoy elektronnyy nauchnyy zhurnal, 2014, vol. 2, no. 4, pp. 7–13.
  8. Nikolaev, A.A., Kornilov, G.P., Denisevich, A.S. Razrabotka usovershenstvovannoy metodiki rascheta parametrov fil'tro-kompensiruyushchikh tsepey staticheskogo tiristornogo kompensatora elektrodugovoy pechi [Developing of an improved method for calculating parameters of harmonic filters of the arc furnace static var compensator]. Vestnik YuUrGU. Seriya «Energetika», 2018, vol. 18, no. 4, pp. 89–100.
  9. O'Brien, K., Teichmann, R., Bernet, S. Active rectifier for medium voltage drive systems. Applied Power Electronics Conference and Exposition, 2001. APEC 2001. Sixteenth Annual IEEE, 2001, pp. 557–562.
  10. Maklakov, A.S. Imitatsionnoe modelirovanie glavnogo elektroprivoda prokatnoy kleti tolstolistovogo stana 5000 [Simulation of the main electric drive of plate mill rolling stand 5000]. Mashinostroenie: setevoy elektronnyy nauchnyy zhurnal, 2014, no. 3, pp. 16–25.
  11. Nikolaev, A.A., Anokhin, V.V., Urmanova, F.F. Razrabotka sposoba snizheniya kommutatsionnykh perenapryazheniy pri nalichii fil'trov vysshikh garmonik staticheskogo tiristornogo kompensatora [Development of a new method of switching overvoltage reduction in harmonic filters of static var compensators]. Elektrotekhnika: setevoy elektronnyy nauchnyy zhurnal, 2015, vol. 2, no. 4, pp. 72–76.
  12. Maklakov, A.S., Gasiyarov, V.R., Belyy, А.V. Energosberegayushchiy elektroprivod na baze dvukhzvennogo preobrazovatelya chastoty s aktivnym vypryamitelem i avtonomnym invertorom napryazheniya [The energy-saving electric drive based on a back to back frequency converter and an autonomous voltage inverter]. Elektrotekhnika: setevoy elektronnyy nauchnyy zhurnal, 2014, vol. 1, no. 1, pp. 23–30.
  13. Blooming, T.M., Carnovale, D.J. Application of IEEE STD 519-1992 Harmonic Limits. Conference Record of 2006 Annual Pulp and Paper Industry Technical Conference, 2006, pp. 1–9.
  14. Khramshin, T.R., Abdulveleev, I.R., Kornilov, G.P. Matematicheskaya model' silovoy skhemy moshchnogo STATKOMa [A Mathematical Model of the Power Circuit of a Large Capacity STATCOM]. Elektrotekhnika: setevoy elektronnyy nauchnyy zhurnal, 2015, vol. 2, no. 1, pp. 38–46.
  15. Maklakov, A.S., Radionov, A.A. Vliyanie na set' trekhfaznogo mostovogo dvukhurovnevogo aktivnogo vypryamitelya napryazheniya pri razlichnykh vidakh ShIM [Influence of three-phase bridge two-stage active rectifier with different types of PWM on the power network]. Mashinostroenie: setevoy elektronnyy nauchnyy zhurnal, 2013, no. 2, pp. 40–47.
  16. Khramshin, T.R., Krubtsov, D.S., Kornilov, G.P. Otsenka metodov shirotno-impul'snoy modulyatsii napryazheniya aktivnykh vypryamiteley prokatnykh stanov [Evaluation of the methods of rolling mill active rectifier voltage PWM]. Mashinostroenie: setevoy elektronnyy nauchnyy zhurnal, 2013, no. 2, pp. 48–52.
  17. Maklakov, A.S., Radionov, A.A. Issledovanie vektornoy ShIM s razlichnymi tablitsami pereklyucheniya silovykh klyuchey trekhurovnevogo preobrazovatelya [A study of the three-level converter space-vector PWM with various vector selection tables]. Elektrotekhnika: setevoy elektronnyy nauchnyy zhurnal, 2015, vol. 2, no. 1, pp. 30–37.
  18. Maklakov, A.S. Analiz raboty aktivnogo vypryamitelya napryazheniya v rezhimakh kompensatsii reaktivnoy moshchnosti [Analysis of active rectifier operation in reactive power compensation modes]. Mashinostroenie: setevoy elektronnyy nauchnyy zhurnal, 2013, no. 1, pp. 43–50.
  19.  Luk'yanov, S.I., Shvidchenko, N.V., Pishnograev, R.S., Shvidchenko, D.V. Razrabotka matematicheskoy modeli elektroprivoda otvodyashchego rol'ganga shirokopolosnogo stana goryachey prokatki [Development of a mathematical model of the broad-strip hot mill outgoing table electric drive]. Matematicheskoe i programmnoe obespechenie sistem v promyshlennoy i sotsial'noy sferakh, 2011, no. 1–2, pp. 71–76.
Key words in Russian: 
преобразователь частоты, активный выпрямитель, дуговая сталеплавильная печь, статический тиристорный компенсатор, несимметрия напряжения, провал напряжения, перенапряжение, качество электрической энергии
Key words in English: 
frequency converter, active rectifier, electric arc furnace, static var compensator, voltage asymmetry, voltage sag, overvoltage, power quality
The DOI index: 
10.17588/2072-2672.2019.5.048-058
Downloads count: 
37