RU110037U1 - DEVICE FOR DETERMINING THE DISTANCE FROM THE TRACTION SUBSTATION TO THE PLACE OF BREAKING OF SELF-CARRYING INSULATED WIRES OF LINES WITH A VOLTAGE OVER 1000 V WHEN LOCATED ON THE SUPPORTS OF THE AC CONTACT NETWORK - Google Patents

Abstract

 A device for determining the distance from the traction substation to the point of the breakdown of self-supporting insulated wires of lines with a voltage above 1000 V when they are located on the supports of the contact AC network, consisting of the traction substation grounding conductor, the power substation of the traction substation, the contact AC network and electric rolling stock, as well as disconnected and grounded self-supporting insulated wires of a line with a voltage above 1000 V, located on the supports of a contact AC network, from characterized in that to the grounding wires of the phase with the broken wire and the phase where there is no wire break, lines with a voltage higher than 1000 V made by self-supporting insulated wires, the input terminals of the current sensors are connected, the output terminals of which are connected to the input of the unit for comparing the current values of currents, from the output whose signal is fed to the input of the unit for determining and fixing the distance from the traction substation to the point of breakage of a self-supporting insulated wire line with a voltage above 1000 V.

Description

The utility model relates to electrical engineering, in particular to the electrification of railways, and can be used to determine the distance to the breakage point of self-supporting insulated wires (SIP) of three-phase overhead lines with voltages above 1000 V with insulated neutral (VL) when they are located on the supports of an alternating contact network current field side current system 25 kV electrified railways.

Known technical solutions for determining the distance to the breakage point of the overhead wires of a power line with a voltage above 1000 V [1], the principle of operation of which is based on the analysis of the input resistance "substation bus - ground", which is based on the results of experiments on the supply section of the substation.

However, due to the fact that the resistance to spreading of a self-supporting insulated wire that has fallen to the ground varies significantly, and in some cases tends to infinity, determining the distance from the input resistance is not possible.

The operation of the device for determining the distance to the breakdown point of SIP VL located on the supports of the contact AC network is based on the principle of the dependence of the bias currents in the disconnected and isolated lines on the length of their convergence in the zones of electromagnetic influence (voltage of the contact AC network) with an influence line [one].

A device for determining the distance to the point of wire breakage overhead lines [2, prototype]. However, in the prototype device, the principle of the conduction current flowing on a wire lying on the ground is laid. With regard to the breakage and subsequent fall of the SIP, the conduction current from an external source cannot flow. For this reason, the use of a prototype device to determine the distance from the traction substation to the point of the SIP VL breakdown cannot be used.

Figure 1 presents a schematic diagram of the power supply of non-traction consumers by SIP VL when it is located on the supports of the contact AC network.

In figure 1 is indicated:

1, 2, 3 - respectively the winding: primary, traction and district three-phase three-winding transformer of the traction substation;

3 - electric rolling stock;

5 - contact AC network voltage of 25 kV;

6 - supplying overhead lines through which power is supplied to non-traction consumers (voltage 10 kV or 35 kV);

7 - supplying non-traction consumers to SIP VL (voltage of 10 kV or 35 kV), located on the supports of the contact AC network;

8 - switching equipment (circuit breakers with voltage above 1000 V);

9, 10 - respectively, three-phase and single-phase transformers of the type TC or TM;

11 - place of cliff SIP VL.

Non-traction consumers are supplied with power from the district winding (3) of the traction transformer having three windings: primary (1), traction (2) and district (3). In this case, the electric rolling stock (4) is supplied from the traction winding (2) through the contact network (5). From the district winding (3) along the overhead line (6), power is supplied to the regional consumers. According to SIP VL (7), when the switches (8) are turned on, three-phase two-winding (9) and single-phase (10) power transformers are fed, to the secondary windings of which the load is connected.

In the event of a breakdown of the SIP VL, the corresponding distance protection [1] is triggered, which gives a signal to turn off the SIP VL and simultaneously fixes the damaged phase of the SIP VL.

Let U _KC = 25 kV be the voltage of the contact network, C ₁ and C _2, respectively, the capacity of 1 km of the contact network relative to SIP VL and the capacity of 1 km of SIP VL relative to the ground; l is the distance from the traction substation to the point of breakdown of self-supporting insulated lines; L is the length of the SIP VL.

According to [1], the potential relative to the earth disconnected from the power source (district winding of the traction transformer) of a self-supporting insulated wire is determined from the ratio:

When grounding a dangling wire for resistance (for example, to a contour ground electrode of a traction substation), the current in the wire connecting the SIP VL and the ground electrode can be calculated from the ratio:

where ω≈314 s ^-1 is the frequency of the alternating current.

Whence, at a known current value I _o determined by an experimental method, the desired distance from the traction substation to the point of breakdown of the self-supporting insulated overhead lines is calculated by the formula:

To more accurately determine the distance to the breakage point, it is advisable to compare the conduction currents (conduction currents are equal to the bias currents) in dangling (I _O ) and non-dangling (I _H ) wires. The current I _{H is} calculated according to the above expression for l = L.

Then, denoting by K = I _H / I _O , we write:

where from

at K≥1, or

Figure 2 presents a schematic diagram of a device that implements the principle of determining the distance from the traction substation to the point of breakdown of the self-supporting insulated overhead lines when they are located on the supports of the contact network.

The device consists of an electric energy source (1) - the traction winding of the transformer of the traction substation, from which the electric rolling stock receives power through the contact network (2), (3). self-supporting insulated overhead line wires (SIP VL) one of the phase wires of which is not damaged (4), and the second phase wire (5) has an open circuit, are grounded to the ground electrode (6). To the grounding wires (7) are connected the input terminals of the current sensors (8), the output terminals of which are connected to the input of the unit for comparing the current values of currents in the SIP VL (9), from the output of which the signal is sent to the unit for determining and fixing the distance from the traction, substation to the place breakage of a self-supporting insulated wire line voltage above 1000 V.

The device operates as follows. If one of the wires of the SIP VL located on the supports of the contact network is broken, the SIP of the VL is disconnected and its wires are earthed to the earthing switch (6) of the traction substation via grounding wires (7). Due to the electrical effect of the voltage of the contact network, conduction currents flow through the wires of the damaged and undamaged phases, grounded at one point. In this case, the magnetic effect of the currents of the electric rolling stock (3) on the grounded wires does not cause the flow of currents, because there is no circuit for their flow.

A signal about the flow of currents through the wires of the damaged and undamaged VL10kV phases (5 and 4) comes from the current sensors (8) to the input of the comparison unit (9) and then from the output terminals of the unit (9) it goes to the unit for determining and fixing (10) the distance from traction substation to the point of breakage (damage to the phase wire) of the wire.

The proposed device allows you to determine the distance from the traction substation to the point of breakdown of the self-supporting insulated overhead lines when they are located on the supports of the contact AC network.

Sources of information taken into account when compiling the description:

1. Kosarev A.B., Kosarev B.I. Fundamentals of electromagnetic safety of the railway power supply system. M .: Intext. - 2008 .-- 480 s.

2. Pupynin V.N., Nguyen V.Kh. Patent No. 2096795 for the invention “Device for determining the distance to the place of a single-phase earth fault in 6-35 kV networks of electrical systems with isolated or compensated neutral” (prototype).

Claims (1)

A device for determining the distance from the traction substation to the breakage point of self-supporting insulated wires of lines with a voltage above 1000 V when they are located on the supports of the contact AC network, consisting of the traction substation earthing switch, the power substation of the traction substation, the contact AC network and the electric rolling stock, as well as disconnected and grounded self-supporting insulated wires of a line with a voltage above 1000 V, located on the supports of a contact AC network, from characterized in that to the grounding wires of the phase with a broken wire and the phase where there is no wire breakage, lines with a voltage higher than 1000 V made by self-supporting insulated wires, the input terminals of current sensors are connected, the output terminals of which are connected to the input of the unit for comparing current values of currents, from the output whose signal is fed to the input of the unit for determining and fixing the distance from the traction substation to the point of breakage of the self-supporting insulated wire of a line with a voltage above 1000 V.