RU42484U1 - DEVICE FOR ELECTRIC SUPPLY OF NON-TRAFFIC CONSUMERS ON ELECTRIFIED SECTIONS OF RAILWAYS OF AC - Google Patents

Abstract

The utility model relates to the field of power supply to non-traction railway consumers in electrified AC sections. The device contains two wires connected to the buses of 27.5 kV traction substation AC and a third additional wire connected to the suction of the traction substation. All three wires of the device have the same electrical parameters and are located on the field side of the contact network supports from the field side. The input of complete transformer substations, previously connected to the rails using the DPR line, is switched to an additional wire. The utility model allows improving the DPR lines, eliminating the electromagnetic influence of the contact network and improving the quality of electricity among non-traction rail consumers.

Description

The utility model relates to the field of power supply to non-traction railway consumers in electrified AC sections.

It is known that electrification of railways with alternating current allows to comprehensively solve the problem of power supply of a large number of non-traction consumers located along the railway line. To solve this problem, high-voltage lines of longitudinal power supply of 6-35 kV with insulated neutral are used, connected to the third winding of the traction transformer. Due to the low level of isolation and electromagnetic influence of the contact network, longitudinal power supply lines are run on separate supports at a distance from the railway track, which significantly increases the cost of building such lines.

The closest analogue of the proposed device for the combination of essential features is a three-phase line of 27.5 kV adopted as a prototype, made according to the two-wire-rail (DPR) system. Low costs for the construction of DPR lines in comparison with the longitudinal power supply lines of 6-35 kV determined their wide distribution for power supply to non-traction consumers on electrified sections of AC railways. Two wires of the DPR line connected to 27.5 kV busbars of traction substations are suspended from the field side of the contact network supports, and running rails are used as the third phase. The main power supply circuit of the DPR line

is a one-way power scheme from one of the traction substations. Two inputs of complete transformer substations (KTP) of non-traction consumers are connected to two phases of the DPR, and the third to the rails. Transformers KTP DPR have a star-star winding connection scheme with zero output and allow consumers to receive electricity at a voltage of 0.4-0.23 kV.

The main disadvantage of the DPR system is its susceptibility to electromagnetic influence of a closely located contact network, an asymmetric single-phase line with a high level of electric power transmission. Due to the magnetic influence of the traction current in two wire-to-ground circuits of the DPR line, additional emfs are induced, which, at high traction loads, reach significant values. In this case, the linear voltage triangle at the receiving end of the DPR line is distorted and its neutral is shifted with respect to the neutral of the linear voltage triangle at the traction substation. The presence of rectifiers on the electromotive composition of alternating current causes the appearance of harmonics in the voltage and current curves of the contact network, which are induced in the DPR line and appear in consumers. Therefore, the quality of electricity from consumers receiving electricity from traction substations of alternating current through the DPR line does not meet the indicators GOST 13109-97 "Norms of quality of electric energy in general power supply systems."

The technical result, which the proposed utility model is aimed at, is to improve the quality of electric energy in three-phase lines with a voltage of 27.5 kV located on the poles of the contact network, while supplying non-traction railway consumers with electricity on electrified AC sections.

This goal is achieved by improving the DPR system - using as a third phase, instead of the rails, an additional wire suspended on the supports of the contact network on one suspended

insulator and traction substations connected to the suction. An additional wire is selected with electrical parameters similar to those of the wires of the other two phases. Input KTP DPR, previously connected to the rails, is switched to an additional wire.

The essence of the utility model is illustrated by the drawing, which shows in figure 1 - connection diagram of a device for power supply of non-traction consumers to the tires of the traction substation,

At the traction substation, to the 27.5 kV 2 buses connected to the traction transformer 1, in addition to the contact network 4, two wires of the device 7.8 are connected. An additional wire 6 of the device is connected to the suction 3 of the traction substation. Input 9 KTP non-traction consumers 10, previously connected to the rails 5 is switched to an additional wire 6.

The utility model is a high-voltage line with a voltage of 27.5 kV for power supply to non-traction consumers of railways with the same own and mutual (relative to the contact network) parameters of wires with a grounded phase and works as follows. Under the influence of the contact network 4, additional emfs are induced in each of the three wires of the device 6, 7, 8 both first and higher harmonics. Moreover, due to the placement of all three wires of the device at almost the same distance from the influencing contact network, these emfs in each wire will match in magnitude and phase. As a result, in the line voltages to which the transformers of the transformer substation of consumers 10 are connected, the induced emfs both the fundamental and higher harmonics will be absent. The neutral of the transformer transformer substation is isolated, so no additional currents arise. The connection of the secondary winding of 0.4 kV KTP to a star with a zero output eliminates the emf induced by the contact network both in linear and in phase voltages at consumers.

The voltage of the auxiliary wire at the point of connection of the transformer substation of consumers with respect to the earth is equal to the induced voltage

fundamental and higher harmonics, as well as voltage drop from load currents. The magnitude of this voltage in normal mode does not exceed 1-2 kV. Therefore, an additional wire can be suspended on one suspension insulator at an operating voltage of U _slave = 18 kV.

When connecting KTP transformers to this line, no difficulties arise, since all three inputs of the 27.5 kV winding have the same insulation level with respect to the ground.

The practical use of the proposed device allows, on the basis of a large number of active DPR lines, to exclude the electromagnetic influence of the contact network, reduce voltage losses in the line and improve the quality of electricity among non-traction rail consumers.

Claims (1)

A device for powering non-traction consumers on electrified sections of AC railways, made in the form of a three-phase line containing two wires connected to 27.5 kV busbars of traction substations and suspended on the supports of the contact network, characterized in that a third additional wire with electrical parameters similar to those of the wires of the other two phases, suspended on the supports of the contact network and connected to the suction of the traction substation, and the third phase of the high-voltage winding consumer transformers are disconnected from the rails and connected to an additional wire.