FUZZY ALGORITHM TO CONTROL REACTIVE POWER FLOW IN ELECTRIC NETWORK WITH NONLINEAR LOADS

One of the important problems of efficient function of electric networks containing load nodes of nonlinear character of power consumption is reactive power compensation and maintaining voltage quality in a grid. The commonly used methods for compensation of harmonic currents by filtering devices make it possible to solve the problem in a narrow band of variation of current of a nonlinear load. In the reality stochastic character of power consumption of nonlinear load reveals itself in appropriate changes in harmonic components of voltage and their share in total load current. This could considerably change the magnitude and direction of reactive power flow in a grid and impair the existing processes of reactive power control. The scheme and the algorithm of control of capacitor banks in networks with non-linear load that are based on the use of fuzzy logic software are presented in the article. The results of model experiments analysis of the modes of the harmonic of the power flows on behalf of the 14-nodal scheme recommended by IEEE as well as the schemes of a real grid with powerful traction substation are presented. The mentioned results demonstrate that when harmonic components of voltages exceed normative magnitudes, the use of the proposed algorithm eliminates additional loading on the capacitor banks with higher harmonic currents whereas the control procedure acquires quality, the number of commutations is being reduced, the capacitor battery functions longer and the probability of its malfunction decreases.

1. Rashtchizadeh A., Rahmanov N., Dursun K. (2009) Genetic Algorithm for ?ptimal Distributed Generation Sitting and Sizing for Losses and Voltage Improvement. International Journal for Knowledge, Science and Technology, 1 (1), 56–61.

2. Voronin K. A., Rakhmanova Yu. V., Volkova Yu. (2015) The Effectiveness of Reactive Power Compensation for Large Nonlinear Loads. Promyshlennfya Energetika [Industrial Power Engineering], (8), 54–58 (in Russian).

3. Wilkosz K. (2007) Harmonic Sources Localization: Comparison of Methods Utilizing the Voltage Rate or the Current Rate. 9thInternational Conference on Electrical Power Quali ty and Utilisation, EPQU. Barcelona, Spain, Article number 4424101. DOI: 10.1109/EPQU.2007.4424101/.

4. Oliveira L. C. O., Melo G. A., Souza J. B., Canesin C. A., Bonatto B. D., Belchior F. N., Oliveira M., Mertens E. A. (2007) Harmonic Propagation Analysis in Electric Energy Distribution Systems. 11th International Conference on Electrical Power Quality and Utilisation (EPQU 2007). Lisbon, Portugal, 577–583. DOI: 10.1109/EPQU.2011.6128827.

5. State Standard 32144–2013. Electric Power. Electromagnetic Compatibility of Technical Equipment. Quality Norms of Electric Power in Power Supply Systems of General Purpose. Moscow, Gosstandart, 2015. 18 (in Russian).

6. Gashimov A. M., Rahmanov N. R., Guliyev G. B. (2014) Improved Algorithm of Fuzzy Logic for Control of Reactive Capacity and Voltage in Distributive Networks. Energetika. Izvestiya Vysshikh Uchebnykh Zavedenii i Energeticheskikh Obedinenii SNG [Energetika. Proc. CIS Higher Educ. Inst. and Power Eng. Assoc.], (2), 29–39 (in Russian).

7. Guliyev H. B., Farkhadov Z. I., Mammadov J. F. (2015) System of Automatic Regulation of Reactive Power by Means of Fuzzy Logic. Reliability. Reliability: Theory & Applications,10 (2), 50–58.

8. Rahmanov N. P., Guliyev G. B., Farhadov Z. I. (2015) Structure Identification of a Fuzzy Controller of Reactive Power of the Induction Furnace. ELECTRO. Elektrotekhnika, Elektoenrgitika i Elektrotekhnicheskaya Promyshlennost. [ELECTRO. Electrical Engineering, Power Engineering, Electrical Industry], (4), 28–31 (in Russian).

9. Aliyev R. A., Arabskii A. K., Arno O. B., Gunkin S. I., Talybov E. G. (2014) ICS of GasOutput Facilities: Current State and Prospects of Development. ?oscow, Nedra. 462 (in Russian).

10. Shtovba S. D. (2007) The Design of Fuzzy Systems by Means ??tLab. ?oscow: Goryachaya Liniya – Telecom. 288 (in Russian).

11. Nayeripour M., Khorsand H., Roosta A. R., Niknam T. (2010) New Approach Based on Fuzzy Controller for Volt/Var Control in Distribution System. Australian Journal of Basic and Applied Sciences, 4 (3), 468–480.

12. Fuzzy Logic Toolbox. User’s Guide. Version 2. The MathWorks. Inc., 1999.