SU1283129A1 - Device for power supply of alternating current traction power system - Google Patents

Abstract

A device for the power supply of the AC mains is related to electrified railways and can be used to supply electricity to electric railways while simultaneously supplying adjacent regional and agricultural consumers. The aim of the invention is to reduce energy losses and equipment installed by balancing the loads of the transformer. The device for power supply of the AC mains contains a three-phase three-winding transformer 1, the primary winding 2 of which is connected in a star and connected to the supply network 3, and the first and second secondary windings 5 and 6 are connected respectively in a star and a triangle, one phase of which is connected to the contact network 7 and the rail 8 of the first feeder zone 9, and the block 10 of redistributing the load current, the inputs of which are connected to phases 11 and 12, whose directions do not coincide with the voltage of phase 6 of the second secondary winding 5, and block 10 is made in the form of an autotransformer, the outputs of which are connected to the contact network 13 and the rail 14 of the second feeder zone 15. 2 Cp. f-ly 2 ill. w c

Description

sixteen

Fig., Z

The invention relates to electrified railways and can be used to supply electric railways while simultaneously supplying adjacent regional and agricultural consumers.

The aim of the invention is to reduce the energy loss and installed power of the equipment by balancing the loads of the transom.

FIG. Figure 1 shows the electrical circuit of the device with a unit for redistributing the load current, which is an autotransformer; in fig. 2 is the same with a load current redistribution unit, in which part of the phases of the first secondary transformer are used.

The device for power supply of the AC mains contains a three-phase three-winding transformer 1, the primary winding 2 of which is connected in a star and connected to the supply network 3, and the first and second secondary windings 4 and 5 are connected respectively in a star and a triangle, one phase 6 of which is connected to contact network 7 and the rail 8 of the first feeder zone 9, and the block 10 of redistributing the load current, the inputs of which are connected to phases 11 and 12, the voltages of which do not coincide with the voltage of phase 6 of the second secondary winding 5, and block 10 in FIG. 1 is designed as an autotransformer, the outputs of which are connected to the contact network 13 and the rail 14 of the second feeder zone 15, and FIG. 2, said unit 10 is made of parts of phases 11 and 12 of the first secondary winding 4 of the transformer, which, in turn, is connected to buses 16 supplying regional and agricultural loads.

The device works as follows.

With the receipt (Figs. 1 and 2) of the positive direction of the currents Ij and the feeder zones 9 and 15 and the absence of a symmetric regional load, the currents of phases A, B, C of the primary winding 2 of transformer 1 are reduced to the voltage of the traction network:

iA 2ig / 3; Ie Is / 3-f Ic I, / 3-bs.

Since the currents Ig and I j5 are shifted by 90 °, since the voltage of the feeder arms of the supply zones of these zones 9 and 15 is shifted to this angle by the symmetrical load of the primary winding 2 of transformer 1, and therefore the symmetrical load of the phases of the supply network 3. As a result, a symmetrical voltage in the network 3. If the winding 4 is positioned so that its inductive resistance is minimal, we will have

five

Symmetrical voltage and on tires 16 district load.

In the real range of variation of the load ratio of the supply arms of the feeder zones 9 and 15, the asymmetry of the currents in the primary winding 2 of transformer 1 and in the supply network 3, and consequently, the asymmetry of the voltages on the buses 16 of three-phase consumers fed from the network 3 and regional buses 16 of the transformer 1 decreases several times.

It is possible to further increase the efficiency of the proposed device by eliminating the consumption of active materials on an additional autotransformer, as shown in FIG. 2

Unloading the primary windings 2 of the transformer 1 and the supply network 3 from negative sequence currents reduces the loss of electrical energy in the supply network 3, the primary winding 2 of transformer I, and the current network by eliminating losses from proteins of reverse sequence currents and components surge current due to the occurrence of lagging and advanced phases; reduce voltage imbalance on tires 16 of three-phase consumers powered from the first secondary winding 4 of the device and from the network 3 of the primary power supply; to increase the available power of transformers 1 of substations and the transmission capacity of the network 3 of the primary power supply. For the practical implementation of the proposed device, commercially available three-phase three-winding transformers and switching equipment are suitable. It is necessary to make only

5 additional autotransformers or to ensure the modernization of existing transformers by making the appropriate conclusions from the district winding.

Claims (3)

Invention Formula 0 1. A device for power supply of the AC mains, containing a three-phase three-winding transformer, the primary winding of which is connected in a star and connected to the mains supply, and one and the other secondary windings are connected in star and delta, respectively, with one phase last connected to the contact network and the rail of the first feeder zone, characterized in that, in order to reduce energy losses and installed equipment power by balancing the transformer loads, it is equipped with definiteness load current, whose inputs are connected to the phases of a three-phase secondary windings of a three-winding transformer, not falling sov- 5 with the phase voltage of the first feeder band, and outputs - to the contact rail network and another feeder zone. five 2. The apparatus of claim 1, wherein the load current redistribution unit is in the form of an autotransformer. 3. The device according to claim 1, characterized in that the load current redistribution unit is made of parts of the phases of the first secondary winding. (rig.1