Published on 09 November 2018
Goal. In this paper a study of power transmission lines operating in the "Two wires-to-ground" (DWS) mode, as well as four-phase lines (CHLEP) was made which were first mentioned in the 50s of the last century. These lines have greater bandwidth and reliability. To confirm the above results comparison with three-phase systems was carried out and the dependence on power losses on the lines regimes was determined. Methods. The research was carried out with the help of mathematical modeling. The algorithm and complex of the software solution with the help of the Mathcad system are compiled. Basis of constructing a mathematical model – is the canonical form of the method of nodal stresses, all elements of the network are decomposed into symmetric components. This algorithm is universal and can serve to calculate the parameters of a three-phase network with the number of nodes up to 400 in different modes of operation. Results and its discussion. It is shown that the DPZ lines have lower than other losses, the greater the transmitted power and the length of the lines. Thus, the efficiency of the system directly depends on the length of the air line. The modes of operation of four-phase power lines including fivewire lines are considered. Conclusions. The use of two-wire-to-ground transmission lines under current conditions is economically feasible due to significant losses in them as compared to three-wire lines at a voltage of 6-35 kV. The current reduction in the earth is possible with the use of four-phase power transmission lines consisting of two DPZ, in which the voltages on the same phases are opposite in direction. With the same loads, both circuits in the ground are absent, therefore, there is No power loss in the grounded phases. The introduction of an additional wire improves the reliability of a four-phase line to the reliability of a two-circuit three-phase line. By reducing the number of line wires in the proposed electrical system in comparison with two-chain three-phase line the electric energy and voltage losses are reduced, decreasing the cost due to the lower expenditures on line construction(five wires instead of six).
Tags: параметры электрических систем, линии электропередачи, метод узловых напряжений, линии электропередачи «два провода – земля» (ДПЗ), четырехфазные линии электропередачи, снижение потерь электроэнергии
ISSN 1998-4502 (Print) ISSN 2499-975Х (Online)