National Mineral Resources University (Russia):

Ustinov D. A., Associated Professor, Ph. D. in Technical Sciences, bescheiden@rambler.ru 

National Research Irkutsk State Technical University (Russia):

Konovalov Yu. V., Associated Professor, Ph. D. in Technical Sciences, yrvaskon@mail.ru

Interruptions in continuous production processes power supply result in significant economic damage. Electrical-and-mechanical systems with highpower synchronous motor drives are widely used at mining-and-processing complexes. Starting of ore-grinding mills' drives may significantly affect electrical equipment operating regime. By way of example, the statistical data of voltage depressions at OAO Karelian Okatysh crushing-and-concentrating plant and Oskolsky electrometallurgical works are presented. Different alternatives are analyzed with regard to synchronous motor start, and a combination alternative is proposed, providing for starting current minimization, pull-in torque increase and synchronous motor heating-up limitation, leading to successful synchronization even with reduced power voltage. The problems, related to frequency converter output voltage matching with supply voltage at synchronous motor switching-over from frequency converter to supply mains and back, are considered.

1. Nikulov I. A., Zhukov V. A., Pupin V. M. Novosti elektrotekhniki — The news of electrical engineering, 2012, No. 4 (76), pp. 34– 36.
2. Syromyatnikov I. A. Rezhimy raboty asinkhronnykh i synkhronnykh dvigateley (Operating modes of asynchronous and synchronous motors). Moscow, Energoatomizdat, 1984, 240 p.
3. Abramovich B. N., Kruglyy A. A., Ustinov D. A. Elektromekhanicheskiye kompleksy s sinkhronnymi dvigatelyami. Vozbuzhdeniye, regulirovaniye, ustoychivost (Electromechanical complexes with synchronous motors. Excitation, regulation, stability). Palmarium Academic Publishing. Lambert Academic Publishing GmbH & Co. KG, 2012, 370 p.
4. Ivanov G. M., Osipov O. I., Kuzin K. A. Problemy pereklyucheniya sinkhronnykh dvigateley nasosnykh stantsiy ot preobrazovatelya chastoty na pitayushchuyu set (Problems of switching of synchronous motors of pump stations from the frequency converter to a power line). VII Mezhdunarodnaya (XVIII Vserossiyskaya) konferentsiya po avtomatizirovannomu elektroprivodu AEP—2012 (VII Intern. (XVIII AllRussian) conf. on automated electric drive AEP—2012), Moscow, 2012, pp. 577–579.
5. Pat. 2242080 Russian Federation.
6. Abramovich B. N., Kruglyy A. A. Vozbuzhdeniye, regulirovaniye i ustoychivost sinkhronnykh dvigateley (Excitation, regulation, and stability of synchronous motors). Leningrad, Energoatomizdat, Leningrad department, 1983, 128 p.
7. Vazhnov A. I. Osnovy teorii perekhodnykh protsessov sinkhronnoy mashiny (Bases of theory of synchronous machine transients). Moscow, GEI, 1960, 312 p.
8. Gamazin S. I., Stavtsev V. A., Tsyruk S. A. Perekhodnyye protsessy v sistemakh promyshlennogo elektrosnabzheniya, obuslovlennyye elektrodvigatelnoy nagruzkoy (Transients in systems of industrial power supply, caused by electric motor loading). Moscow, MEI, 1997, 424 p.