Abstract
The article is devoted to the problem of reduction of electric energy losses of traction power supply system of alternating current (AC). The Strategic Development Programs of Russian Railways (RZD) provide for introduction of information technology. Information technology requires new approaches to estimation methods of traction power supply system operation. The formulas are offered to calculate power and electric energy losses within the traction power supply system, which make use of digital technology to ensure its proper operation. Proceeding from the methods of theoretical fundamentals of electrical engineering and theory of power supply of 25 kV AC traction loads new calculation formulas to determine power losses of transformers are obtained. Iron power losses are determined taking into account asymmetry of winding voltage. Coil power losses of power transformers of traction substations are determined taking into account asymmetry of current of transformer windings. Current asymmetry is represented by phase currents of windings. As initial data the research group takes discrete values of expected instantaneous current values of traction loads at a certain time interval as well as load values, the capacity of the given district traction power supply system is able to cope with. Expected instantaneous current values of traction loads are determined by the results of monitoring and statistical analysis. Calculation of power losses in power transformers of traction substations is performed both for one and two transformers in operation respectively. Electric energy losses are to be calculated considering power losses caused by occurrence of instantaneous current values of traction loads. The number of the transformers in operation is to be chosen for the minimum electric energy losses.
Keywords
Power transformer, traction substation, alternating current, power loss, loss of electrical energy.
1. Energeticheskaya strategia kholdinga “Rossiiskie zheleznye dorogi”na period do 2015 g. i na perspektivu do 2030 goda: utv. rasporyazheniem OAO “RZD” № 2718 r ot 15 dekabrya 2011 g. [Energy Strategy of the holding company “Russian Railways” for the time period of up to 2015 and for successive period of up to 2030: appr. by the order of JSC ”RZD”], no. 2718, December 15, 2011. (In Russian)
2. Grigoryev N.P., Krikun A.A. Sistema elektrosnabzheniya elektrifitsirovannykh zheleznykh dorog peremennogo toka [Power supply system of alternating current electrified railways]. Patent RF, no. 2478049, 2011. (In Russian)
3. Vlasenko S.A., Grigoryev N.P., Parfianovich A.P. Increasing power efficiency of 25 kV AC electrified railways by means of normal feed circuits of traction loads. Elektrifikatsiya, razvitie elektroenergeticheskoi infrastruktury i elektricheskogo podvizhnogo sostava skorostnogo i vysoko-skorostnogo zheleznodorozhnogo transporta. Materialy VII mezhdunar. symp. [Electrification, development of power engineering infrastructure and electric rolling stock for express and high-speed railway transport. Proceedings of the VIIth International Symposium “Eltrans-2015”]. St. Petersburg: St. Petersburg State Transport University, 2012, pp. 88–92. (In Russian)
4. Li V.N., Protasov F.A., Tryapkin E. Yu., Gulyaev A.V., Keino M.Yu. Automated monitoring system for traction substations. Avtomatizatsiya v promyshlennosti [Automation in industry], 2013, no. 11, pp. 22–25. (In Russian)
5. Grigoryev N.P., Klykov M.C., Parfianovich A.P., Shestukhina V.I. Increasing power efficiency of 25 kV AC traction power supply. Elektrotekhnika [Electrical engineering], 2016, no.2, pp. 58–60. (In Russian)
6. Idelchik V.I. Elektricheskie sistemy i seti [Electric systems and networks]. Moscow: Energoatomizdat, 1989. 592 p. (In Russian)
7. GOST 3484.1-88 (ST SEV1070-78). Power transformers. Methods of electromagnetic tests (with Modification 1). Date of introduction 01.01.1900. (In Russian)
8. Tikhomirov P.M. Raschet transformatorov [Calculation of transformers]. Moscow: Energoatomizdat, 1986. 528 p. (In Russian)
9. Prikaz Ministerstva RF ot 30 dekabrya 2008 g. N 326 "Ob organizatsii v Ministerstve energetiki Rossiiskoi Federatsii raboty po utverzhdeniyu normativov tekhnologicheskikh poter elektroenergii pri eyo peredache po elektricheskim setyam” [Order of Energy Ministry of the Russian Federation of December 30, 2008, no. 326 “On setting and approving the standards for technological losses of electric power during its transmission through electric networks”]. (In Russian)
10. Markvardt K.G. Elektrosnabzhenie elektrifitsirovannykh zheleznykh dorog [Power supply of electrified railways]. Moscow: Transport, 1982. 528 p. (In Russian)