Comparison of technological losses of 6 (10) kV and 20 kV electrical network.
Authors:   State Institution of Higher Education «Donetsk National Technical University», A. SHEINA , S. SKRYPNYK 
Published: December 2019

In the electricity networks of Ukraine the share of technological losses of electric networks with the three-stage 110-35-6 system (10) reaches up to 12-14%, the National Commission of Ukraine, which carries out regulation in the sphere of energy and utilities) tries to solve by means of the transition to the increased voltage of 20 kV and transition from three-stage system to two-stage. In the new economic environment, due to the limited energy resources in Ukraine and the privatization of certain energy facilities, electricity losses have become one of the levers of controlling the economic efficiency of energy companies. Among the facilities where there is excessive power and electricity losses, the distribution grids have not received much attention before. More important in them was the provision of the necessary level of reliability of electricity supply to consumers. In addition, the network data were not structurally adapted to optimal control, since they did not have any means of tele-information about the parameters of the current mode or the means of controlling the latter. The level of energy consumption, economical use of electricity is one of the determining factors in the economy of any country. Too many countries where there is an acute shortage of energy. The increased level of electricity losses during its transportation and distribution is caused by a number of reasons. Modern electrical networks in our country are characterized by: - high design current density of approximately 1 A / mm2 versus 0.4-0.6 A / mm2 in the developed countries of the West; - high level of heterogeneity, since this parameter was practically disregarded in the design standards; - a low level of reactive power compensation of approximately 0.3 kVA / kW of installed power against 0.8-1.0 kVA/ kW in the USA and Canada; - insufficient use of transformers with tap changers, so tap changers are practically not used in automatic mode, whereas the increase of transformer cost due to tap changers is 30-40%. The main technological losses of electricity in the grids are: 1) load losses in the wires of transmission lines (transmission lines) and windings of power transformers of substations; 2) loss of iron in transformer cores during idle; 3) losses on the crown of the power lines; 4) loss of own resources; 5) losses in compensation devices (capacitor batteries, synchronous compensators, static thyristor compensators, etc.); Measures to reduce network losses should be chosen on the basis of the principle of minimizing the above costs while fulfilling the conditions for reliability of electricity supply and quality of electricity. From the above, it is concluded that reducing the number of links in the grid will lead to a reduction in technological losses. After the calculations it is possible to notice that the total losses of the system of the 3-stage system will be equal to 37512 kWh, and for the 2-stage system 25560 kWh. Thus, the losses in the transformers of the 2-stage 110-20 kVelectric network are 32% less than the 3-stage 110-35-10 (6) kV, which confirms the economy and efficiency of the transition to the increased 20 kV disturbance in our country