1. Science
  2. Publications
  3. Systems of Arms and Military Equipment
  4. 2(58)'2019
  5. Increasing the efficiency of electricity supply by improving the operation of power system substations power transformers

Increasing the efficiency of electricity supply by improving the operation of power system substations power transformers

A. Panchenko, A.Ministerskiy, Ye.Zaricniak, V.Kalachova, M. Dolyna
Annotations languages:


Description: The switching equipment of power substations is made on electromechanical drives (sometimes manual), the duration of the signal passing from the moment of signal supply and the direct response of contacts can take several periods, due to the inertia of mechanical processes. It is impossible to obtain identical electromechanical systems for each phase. Therefore, the moment of switching on, both in relation to the voltage sinusoid, and in relation to the phases is random, which provokes significant current surges, which in a number of cases are perceived as a short circuit and equipment malfunction. Using modern transistor assemblies I J B T makes it possible to create switching equipment for a fixed time,, now the term control commutation is used. Transient processes when triggering switches occur as they are switched on and off. Switching overvoltages can be minimized by using soft switching methods. The periodic component when switched on can be substantially weakened if the circuit of the supply circuits occurs near the maximum voltage, or eliminated altogether, at several times turning on the same load (memory element used). When unlocking a consumer with a low power factor there is a risk of repeated breakdowns of the contacts, in order to eliminate the contact of the contacts should occur far enough from the zero value of the current and until the moment of transition through zero and the arcing of the arc, the distance between the contacts should be sufficient and corre-spond to a significant strength of the gap between the contacts. In some cases, with the arbitrary switching of an unloaded trans-former, there are current jets comparable to short-circuit currents, which provokes a false alarm of relay protection. To elimi-nate this phenomenon, “memory” is used for phase values of currents and the calculation of residual magnetism in them at the transformer's center, which allows it to choose a time moment that minimizes the transitional aperiodic process when re-switching. In the article the method of determination in automatic mode of the switching moment is offered depending on the size of the load, its nature and the history of the switching off of the transformer. Together, these parameters allow you to find the instant of each phase's activation without initiating the transient process.


Keywords: load parameters, transformer, short circuit, harmonious signal.

References

1.Kononov, B.T., Lagutin, G.I., Kotov, O.B. and Nechaus, A.O. (2015), “Elektrychni mashyny” [Electricalmachines], HUPS, Kharkiv, 320 p.
2.Kononov, B.T., Samojlenko, B.F. and Kononov, V.B. (2007), “Relejnyj zahyst ta avtomatyka v systemah elektro-postachannja vijskovyh ob’ektiv” [Relay protection and automation in the systems of electrical supply of military facilities], HUPS, Kharkiv, 405 p.
3.Kovach, K. (1936), “Perehodnue procesu v mashinah peremennogo toka” [Transients in ac machines], Gosenergoіzdat,Leningrad, 743 p.
4.State Standard of Ukraine (2003), 30830-2003 (MEK 60076-1-93) “Transformatory sylovi. Chastyna 1. Zagalni poloz-hennja” [Transformator power. Part 1. First position], 46 p.
5.Kidyba, V.P. (2015), “Relejnyj zahyst elektroenergetychnyh system” [Relay Zahist elektroenergeticheskih systems],Vyd-vo Lviv. politechniky, Lviv, 380 p.
6.Gilfillan, E.S. and Kaplan, E.L. (1941), “Perehidni mometu v asinhronnuh dvugynax z korotkozamknytum rotorom”[Transient Torques in Squirrelcage Induction Motors, with Spesial Reference to Plugging. Trans], AIEE, Trani, 1200 p.
7.Park, R.H., (1933), “Teoriy dvoh reakcii sinhronuh mashin” [Two – Reaction Theory of Synchronous Machines], AJEE,Trans, 680 p.
8.Karlashyk, V.I. (1999), “Electronna laboratoriy na IBM PC” [Electronic laboratory ІВМ РС], SOLON, Moscow, 506 p.
9.Gorev, A.A. (1950), “Perehidni procesu sunhronnoii maishinu” [Transient processes of the synchronous machine],Gosenergoizdat, Moscow, 730 p.
10.Konstantinov, B.A. (2005), “Kompensaciy reaktivnoi potugnosti” [Reactive power compensation], Energy, Leningrad, 101 p.
11.Gotman, V.I., (2011), “Korotkie zamukaniy і nesemitricheskie regimu v elektroenergeticheskih sistemah” [Shortcircuits and asymmetric modes in electric power systems], Tomsk Polytechnic institute, Tomsk, 240 p.
12.Kruchkov, I.P. (2009), “Perehodnue procesu v elektroenergeticheskih sistemah vtoroe izdanie” [Transients in electricpower systems 2nd edition], Publishing House MEI, Moscow, 416 p.

Reference:
 Panchenko, A.M., Ministerskyi, A.V., Zarichniak, Ye.M., Kalachova, V.V. and Dolyna, M.P. (2019), “Pidvyshchennia efektyvnosti postachannia elektroenerhii shliakhom udoskonalennia roboty sylovykh transformatoriv pidstantsii enerhosystemy” [Increasing the efficiency of electricity supply by improving the operation of power system substations power transformers], Systems of Arms and Military Equipment, No. 2(58), pp. 92-101. https://doi.org/10.30748/soivt.2019.58.12.