OPTIMAL LOSSES IN POWER DISTRIBUTION NETWORKS

The distributed power network 0,38–10 kV is investigated and the conditions for providing optimal load of network and technically reasonable (minimal) values of electricity consumption are determined. It is shown that the optimum (minimum) value of all technical losses of electricity in power network 0,38–10 kV is being achieved at the equality of semi-constant and variable (load) losses in network  and in denominated units for the period T and is characterized by twice value of variable losses. Optimum work load of transformers is determined by their technical data and is equal to (approximately) 40 % and corresponds to relatively low value of minimum losses – 1,73 %. In the whole, in network 0,38–10 kV there is optimal load factor for non-changeable equipment set, to a great extent, which depends on configuration and type of equipment. The more branching of network the less will be effective line’s resistance and so the value of optimal load factor will be more significant.

Networks 0,38 kV mainly influence on formation and value of total electricity losses in network 0,38–10 kV as losses in 0,38 kV networks under the equal conditions are higher than in 10 kV networks in times (or ten times). Losses in 0,38 kV network to a great extend decreases the value of generalized coefficient of network load and increases optimal value of relative loss in network 0,38–10 kV. And optimal total losses in denominated units are not changed. 

The developed structural algorithm of technical losses of electricity in network 0,38–10 kV allows evaluating actual and optimal network loading, to determine minimum and reserves of losses enhancement, but it can be realize only when loading of lines and transformers is low. That is why minimum technical losses are not finale criteria of optimal state of network which should be (in reality) determined from economical reasons, for example, from minimum cost of electrical energy transmission.

1. Kobez, B. B., Volkova N. O. (2010) Innovation Development of Electric Power Engineering on the Base of Convention VART GRID. Moscow, Energija. 207 p. (in Russian).

2. Bernd, M. B. (2010) Innovation Equipment for Intellectual Electrical Networks Smart Grids. Elektrika [Electrics], 11, 9–15 (in Russian).

3. Fadeeva, G. A., Fedin, V. T. (2009) Design of Power Distribution Networks: Educational Materials. Minsk, Higher School. 365 p. (in Russian).

4. . Zhelesko, Yu. S. (2009) Losses of Electrical Energy. Reactive Power. Quality of Electrical Energy. Instructions for Practical Calculations. Moscow, ENAS. 456 p. (in Russian).

5. Zhelesko, Yu. S. (1989) Choice of Actions for Loses Decreasing of Power. Instructions for Practical Calculations. Mocsow, Energoatomizdat. 176 p. (in Russian).

6. Fursanov, M. I., Fedin, V. T. (2010) Fundamentals of Power Systems Design: in 2 parts. Minsk: BNTU, Part 2. 203 p. (in Russian).

7. Fursanov, M. I. (2005) Determination and Analysis of Power Losses in Electric Power Networks of Power Systems. Minsk, Unitary Enterprise “Belenergosberezhenie”. 207 p. (in Russian).

8. . Fursanov, M. I., Petrashevich, N. S. (2012) Determination of Optimal Loading of Transformers of Power Distribution Networks in Operation. Izvestiia Vysshikh Uchebnykh Zavedenii i Energeticheskikh Ob’Edinenii – Energetika [Proceedings of the Higher Education Institutions and Power Engineering Associations – Power Engineering], 4, 9–18 (in Russian).

9. . Fursanov, M. I., Radkevich, V. N. (2008) About Optimal Regimes of Power Transformers Operation. Izvestiia Vysshikh Uchebnykh Zavedenii i Energeticheskikh Ob’edinenii – Energetika [Proceedings of the Higher Education Institutions and Power Engineering Associations – Power Engineering], 2, 32–38 p. (in Russian).

10. Power Transformers. Reference Book of the Minsk Electrotechnical Plant Named After V. N. Kozlov. Minsk, 2007. 76 p. (in Russian).

11. Instructions Dealing with Calculation and Standards of Power Consumption for its Transmission by Electrical Networks. Ministry of Power Engineering of the Republic of Belarus 16.12.2013, ? 48 (in Russian).

12. . Standard SPS ”Belenergo”. STP 09110.09.455–11. Calculation Methods and Standards of Power Consumption for its Transmission by Electrical Networks. Minsk, 2009. 50 p. (in Russian).