UA54127C2 - Alternating current supply system of railroad - Google Patents

Abstract

Invention relates to the branch of electrification of railroads. The system of power supply of alternating current of railroad contains three-phase transformer connected by one outlet to the track circuit, and by two other outlets - to the sectional traction network connected by cross connections with the feeder cable. Neutral inserts are introduced along the overhead electric transport power line between each section; in this case each section alternately, like other outlets of three-phase transformer, is connected with current-conducting lead and sheath of coaxial cable. The realization of the proposed circuit of power supply contributes to reduction of the voltage ratio of power supply system.

Description

Description of the invention

The invention relates to the power supply of electrified alternating current railways. 2 A known alternating current railway power supply system contains a three-phase transformer, one phase of which is connected to the rail circuit and the other two to the catenary network. Markquarst K.G. Electrical supply of electrical railways. M.: Transport, 1982., p. 251

The disadvantage of such a power supply system is the appearance of significant asymmetry: currents in the transformer windings when several trains arrive on one of the feeder zones to the right or left of the substation.

The closest thing to the proposed object is the electric traction network of alternating current, which contains a sectioned contact network connected by jumpers to the supply cable. |(Authority certificate of the USSR Mo1425109. Bull.

Inventions..., 1988., Mo351

However, the disadvantage of operating such a traction network is the occurrence of significant asymmetry of currents in the windings of a three-phase transformer when there are several electric locomotives on the feeder zone to the right or left of the substation.

The basis of the invention is the task of improving the AC railway power supply system, in which, by changing the scheme, a more uniform redistribution between the phases of a three-phase transformer of any traction load is achieved, due to which the asymmetry of the currents in the transformer windings is reduced, which contributes to the reduction of the coefficient of asymmetry of the voltage of the three-phase power supply system.

The problem is solved by the fact that the alternating current railway power supply system, which contains a three-phase transformer, connected by one output to the rail chain, and by the other two outputs to the sectioned traction network, connected by jumpers to the supply cable, according to the invention, differs in that introduced along the contact line networks between each section, neutral inserts, while each section is alternately, like the other outputs of the three-phase transformer, "connected, respectively, to the current-carrying core and sheath of the coaxial cable with 22. Go)

Figure 1 shows the proposed alternating current railway power supply system, and figures 2 and 3 respectively show vector current diagrams of a three-phase transformer without using the invention and with the proposed alternating current railway power supply system.

The alternating current power supply system (Fig. 1) consists of a three-phase transformer 1 located at the traction substation 11, which is connected by the output of one of the phases (phase "c" 14) to the rail circuit 2, and by the other two phase outputs to the supply coaxial cable 3.

At the same time, the outputs of the second phases of the transformer (phase "a" 12 and M13) are connected, respectively, to the current-carrying core 4 and sheath 5 of the coaxial cable 3. Sectioned along the entire length of the railway with neutral inserts "I 7 of section 8 of the catenary network 10 alternately with" connected by jumpers b, respectively, to the current-carrying core 4 and sheath 5 of the coaxial cable 3. Electric locomotives 9 are connected to the catenary network 10 and the rail circuit 2. o

In the traditional supply system, when there are several trains on one of the feeder zones to the right or left of the substation, the traction load falls on one of the transformer windings, which causes a significant asymmetry of the currents of the three-phase power supply system. The proposed AC railway power supply system is implemented as follows. Several load trains are located to the right or to the left of the substation 11. Since the sectioned contact network 10 is alternately connected by sections 8 with jumpers to the current-carrying core 4 and sheath 5 of the supply coaxial cable 3, which connected with

with different windings of transformer 1, the electric locomotives 9 located on adjacent sections 8 of the catenary network 10 simultaneously receive electricity from different windings of transformer 1, which reduces the asymmetry of the currents in the phases of transformer 1. So, for example, when several electric locomotives 9 are simultaneously supplied with electricity ( see fig. 1) that are located on the site | from substation 11, the latter receive i-th electricity from different windings of transformer I. In fig. 2 shows a vector diagram of the currents of the phases "" of the transformer II a, yiv, ys depending on the currents of electric locomotives 9 (Ie114Che2), without using the device, from which it can be seen that the vectors Ia, yiv, Ys do not have any elements of three-phase symmetry at all. The use of the proposed alternating current railway power supply system allows symmetrization of the traction load of 9U electric locomotives between the phases of the transformer (see vectors Ia, Iv, Is in Fig. 3). The resulting system of vectors has all the signs of three-phase symmetry. The illustrations prove that the proposed device allows you to improve the energy characteristics of the three-phase supply network by reducing the asymmetry of the currents in the windings of transformer 1 for any variants of the traction load. The proposed alternating current railway power supply system due to sectioning of the catenary network 10 with neutral 29 inserts 7 on section 8 with alternate connection of the latter with the current-carrying core 4 and sheath 5

HF) of the coaxial cable Z allows the traction load, regardless of the number of trains located to the right or left of the substation 11, to be balanced by the phases of the transformer 1. o The proposed AC railway power supply system can be implemented using serial equipment. For example, for the power supply of a contact network, you can use the APVI-17350 coaxial cable, which passes a current of up to 500 A, which meets the necessary technical conditions for alternating current power supply systems.

Claims (1)

The formula of the invention b5 An alternating current railway power supply system containing a three-phase transformer connected at one output to the rail circuit and at the other two outputs to a sectional traction network connected by jumpers to the feeder cable, characterized by the fact that neutral inserts are inserted along the contact network between each section, at the same time, each section is connected in turn, like other outputs of the three-phase transformer, to the current-carrying core and sheath of the coaxial cable, respectively. se that o u se "- "I IS o) - and 1 t" - ko and ko bo b5