Abstract
Improvement of the technological process of steelmaking and higher requirements to reduce production costs in the competitive market conditions require the use of more economical and flexible systems of power supply for powerful motors. That is why large synchronous motors are not supplied directly from the network of the three-phase alternating current, but through frequency converters, which leads to a change in not only energy, but also to sustainability of electrical load as a whole. Such a transition, on the one hand, increases the energy efficiency of production at the expense of reducing electricity consumption. On the other hand, synchronous motors are no longer reactive power sources that can at the big electrical distance reduce resistance of motors operating in parallel with the grid. This article deals with analysis of static stability of synchronous motors in the load node containing large synchronous motors powered both through frequency converters, and directly from the power grid, as well as distributed generation sources of relatively small power using the developed software complex. Some recommendations are given aimed at improving of static stability of synchronous motors. The research group investigated variation of energy consumption of blowers as major consumers of electric energy at the oxygen converter shop when inverters designed for start-up are replaced with fully adjustable frequency converter and simultaneous rebuilding of the technological scheme of their operation using power-supply system of the OJSC “Magnitogorsk Iron and Steel Works” as an example. On the basis of the experimental data, the authors carried out analyses of changes in parameters of the blowers when inverters designed for start-up were replaced with frequency converters for permanent operation. The selected cyclograms of the drive and pantograph operation were studied. The authors developed activities to increase the energy efficiency of new actuators in terms of frequency and time intervals of acceleration-braking. The obtained data can serve as a basis for further improving the energy efficiency of powerful synchronous motors with fan moment on the shaft resistance in different production cycles.
Keywords
Synchronous generator, synchronous motor, static stability, industrial enterprise, load software, power supply system, energy efficiency, energy consumption, supercharger, frequency converter.
1. Nikiforov G.V., Oleynikov V.K., Zaslavets B.I., Shemetov A.N. Upravlenie energopotrebleniem i energosberezhenie: monografiya [Energy Management and Energy Saving: a monograph]. Magnitogorsk, Publishing center of Nosov Magnitogorsk State Technical University, 2013. 422 p.
2. Meshcheryakov V.N., Turkin M.A. Energy Saving at Rational Operation of Synchronous Motor with Frequency Regulation. Sistemy uprav-leniya i informatsionnye tekhnologii [Control systems and information technology], 2007, vol. 27, no. 1.1, pp. 180-183. (In Russian)
3. Lisitsyn A.S., Ernst A.V. Prospects of Control and Frequency Control of Synchronous Electric Motors. Dinamika sistem, mekhanizmov i mashin [Dynamics of systems, mechanisms and machines], 2014, no.1, pp.302-303. (In Russian)
4. Kothari D.P., Nagrath I.J. Power System Engineering. Second Edition. New Delhi, Tata McGraw-Hill Publishing Company Limited, 2008.
5. Kimbark E. Sinkhronnye mashiny i ustoychivost elektricheskikh system [Synchronous machines and stability of electrical systems]. Мosxow-Leningrad, Gosenergoizdat Publ., 1960. 392 p.
6. Xiufeng S., Shiguang M. Research on Measures to Improve Stability of the Power System. Applied Mechanics and Materials, Vol. 742, 2015, pp. 648-652.
7. Hazarika D. New method for monitoring voltage stability condition of a bus of an interconnected power system using measurements of the bus variables. IET Generation, Transmission & Distribution. Oct 2012, Vol. 6, Issue 10, pp. 977-985.
8. Malafeev A.V., Bulanova O.V., Rotanova Yu.N. Research of Dynamic Stability of Industrial Power Systems with Internal Power Stations at Separation from Electric System as a Result of Short-circuit Failure. Vestnik Yuzhno-Ural'skogo gosudarstvennogo universiteta. Seriya: Komp'yuternye tekhnologii, upravlenie, radioelektronika [Bulletin of the South Ural State University. Series "Computer Technologies, Automatic Control & Radioelectronics"], 2008, no. 17 (117), pp. 72-74. (In Russian)
9. Malafeev A.V., Karandaeva O.I., Rotanova Yu.N., Bulanova O.V. Influence of High-Voltage Motors of own Needs on Reliability of System of Electrical Power Supply of Own Needs of CHPP JSC MMK. Elektrotekhnicheskie sistemy i kompleksy [Electrotechnical systems and complexes], 2009, no. 17, pp. 96-104. (In Russian)
10. Bulanova O.V., Igumenschev V.A., Malafeev A.V., Rotanova Yu.N. Investigation of Convergence of Method of Calculation of Set Modes of Systems of Electrical Power Supply Operating Separately from Power Supply System. Elektrotekhnicheskie sistemy i kompleksy [Electrotechnical systems and complexes], 2005, no. 10, pp. 129-134. (In Russian)
11. Gazizova O.V., Malafeev A.V., Tarasov V.M., Izvolsky M.A. Research of Overall Performance of Dividing Automatic Equipment in System of Electrical Power Supply of Industrial Enterprise of Ferrous Metallurgy. Promyshlennaya energetika [Industrial power engineering], 2012, no. 10, pp. 12-17. (In Russian)
12. Igumenschev V.A., Malafeev A.V., Bulanova O.V., Rotanova Yu.N. Calculation of Response Characteristics of Synchronous and Asynchronous Motors of Industrial Enterprises for Purpose of Analysis of Stability of Systems of Electrical Power Supply]. Vestnik Magnitogorskogo Gosudarstvennogo Tekhnicheskogo Universiteta im. G.I. Nosova [Vestnik of Nosov Magnitogorsk State Technical University], 2006, no. 2, pp. 71.-75. (In Russian)
13. Akagi H., Takahashi K., Kobayashi T., Sugihara H., Kai T. Analysis of an Adjustable Speed Rotary Condenser for Power System Stabilization. Electrical Engineering in Japan, Vol. 133, no. 1, 2000.
14. Xu Y., Dong Zh. Y., Zhao J., Xue Y., Hill D. J. Trajectory sensitivity analysis on the equivalent one-machine-infinite-bus of multi-machine systems for preventive transient stability control. The Institution of Engineering and Technology IET Gener. Transm. Distrib., 2015, Vol. 9, Iss. 3, pp. 276–286.
15. Satheesh A., Manigandan T. Maintaining Power System Stability with Facts Controller using Bees Algorithm and NN. Journal of Theoretical and Applied Information Technology. 10th March 2013. Vol. 49, Iss. 1, pp. 38-47.
16. Boudour M., Hellal A. Mohamed Power System Dynamic Security Mapping Using Synchronizing and Damping Torques Technique. The Arabian Journal for Science and Engineering, Vol. 30, no. 1B.
17. Harikrishna D., Srikanth N.V. Dynamic Stability Enhancement of Power Systems Using Neural-Network Controlled Static-Compensator. TELKOMNIKA. Vol.10, No.1, March 2012, pp. 9-16.
18. Sujatha Er.S., Anitha Dr.R ., Selvan Dr.P., Selvakumar Er.S. Transient Stability Enhancement of Tneb 400 kV Transmission Network with SVC. Journal of Theoretical and Applied Information Technology. 10th May 2014. Vol. 63, Iss. 1, pp. 85-91.
19. Welhazi Y., Guesmi T., Jaoued I. B., Abdallah H. H. Power System Stability Enhancement Using FACTS Controllers in Multimachine Power Systems. J. Electrical Systems, 2014, 10-3, pp. 276-291.
20. Malafeev A.V., Gazizova O.V., Kochkina A.V., Grinchak E.A. Analiz staticheskoy ustoychivosti generatorov [Analysis of Static Stability of Synchronous Generators. Glavnyy energetik [Chief Power Engineer], 2013, no. 7, pp. 17-25. (In Russian)
21. Kondrashova Yu.N., Gazizova O.V., Gladysheva M.M., Galliulin I.M. Research of Influence of Implementation of Perspective Overhead Line on Modes of Industrial Energetic Hub. Mezhdunarodnyy nauchno-issledovatel'skiy zhurnal [International research journal], 2014, no. 4-2 (23), pp. 35-37. (In Russian)
22. Malafeev A.V., Bulanova O.V., Panova E.A., Grigoryeva M.V. Analysis of Modes of Asymmetrical Short Circuits in Complex Systems of Electrical Power Supply with Auxiliary Power Stations. Promyshlennaya energetika [Industrial Power Engineering], 2010, no. 3, pp. 26-31. (In Russian)
23. Bulanova O.V., Malafeev A.V., Nikolayev N.A., Rotanova Yu.N., Panova E.A. Determination of Asynchronous Power of Synchronous Generators in Calculations of Electromechanical Transient Processes in case of Asymmetrical Modes. Elektrika [Electrician], 2010, no. 8, pp. 24-26. (In Russian)
24. Igumenschev V.A., Zaslavets B.I., N.A. Nikolayev, A.V. Malafeev, O.V. Bulanova, Yu.N. Kondrashova, E.A. Panova Otsenka effektivnosti releynoy zaschity v setyakh 110-220 kV slozhnykh sistem elektrosnabzheniya promyshlennykh predpriyatiy s sobstvennymi elektrostantsiyami [Evaluating the Effectiveness of Relaying Networks in Complex Systems of 110-220 kV Power Supply of Industrial Enterprises with Auxiliary Power Plants], Magnitogorsk, Nosov Magnitogorsk State Technical University Publ. House, 2011, p. 141.
25. Malafeev A.V., Khlamova A.V., Krasnov M.I. Optimization of Loading of Generators of Auxiliary Power Stations of JSC MMK Taking into Account Losses of Active Power on Distributive Network by Decomposition of General Task. Glavnyy energetik [Chief Power Engineer], 2011, no. 3, pp. 54-57. (In Russian)
26. Varganova A.V., Panova E.A., Kurilova N.A., Nasibullin A.T. Mathematical Modeling of Synchronous Generators in Out-of-balance Conditions in the Task of Electric Power Supply Systems Optimization. Collection of scientific papers: International Conference on Mechanical Engineering, Automation and Control Systems (MEACS). 2015.
27. Kornilov G.P., Panova E.A., Varganova A.V.Algorithm of Economically Advantageous Overhead Wires Cross Section Selection Using Corrected Transmission Lines Mathematical Models. Procedia Engineering, 2015, Vol. 129, pp. 951-955.
28. Khramshin V.R., Odintsov K.E., Gubajdullin A.R., Karandaeva O.I., Kondrashova Yu.N. Fault Rate Analysis of Variable-FREQUENCY Electric Drives in District Heating Stations under Power Supply Violations. Vestnik Yuzhno-Ural'skogo gosudarstvennogo universiteta. Seriya: Energetika [Bulletin of the South Ural State University. Series "Power Engineering"], 2014, Vol. 14, no. 2, – pp. 68-79. (In Russian)
29. Odintsov K., Rotanova Yu., Karandayeva O., Mostovoy S., Shilyaev P. Technique to Predict Electrical Equipment Operational Remaining Life. Izvestiya Tul'skogo gosudarstvennogo universiteta. Tekhnicheskie nauki [News of the Tula state university. Technical science], 2010, no. 3-1, pp. 192-198. (In Russian)
30. Kondrashova Yu.N., Gladysheva M.M., Nikolaev Art.A., Nikolaev A.A. Development of Technique of Failure Prediction of Complex Electrotechnical Systems Using Electrical Networks as an Example. Tekhnicheskie nauki: ot teorii k praktike [Technical science: from the theory to practice], 2014, no. 33, pp. 101-108. (In Russian)
31. Karandaev A.S., Khramshin V.R., Evdokimov S.A., Kondrashova Yu.N., Karandaeva O.I. Methodology of calculation of the reliability indexes and life time of the electric and mechanical systems. Collection of scientific papers: Proceedings of 2014 International Conference on Mechanical Engineering, Automation and Control Systems, MEACS 2014. pp. 1-6.
32. Polyakov V.N. Energoeffektinyje rezhimy reguliruemyh elektroprivodov peremennogo toka [Energy saving operating modes of controlled AC electric drives]. Under the editorship of R.T. Shreiner. Yekaterinburg, FSAEI HPE Russian State Vocational Pedagogical University, 2012. 220 p.
33. Emadi A. Energy-efficient Electric Motors, Third Edition, Revised and Expanded, (2005), New York, Marsel Dekker Inc., 400 p.
34. Osipov O.I. Chastotno-reguliruemyi asinkhronnyi elektroprivod [Variable-frequency induction motor drive]. Moiscow, MPEI Publ., 2004.80 p.