RU1832092C - Method of inspection of railway line clear condition - Google Patents

Abstract

The invention relates to railway automation, and in particular to methods for monitoring a rail line for sections of railways with variable and low insulation resistance. SUMMARY OF THE INVENTION: signals of two frequencies — lower and higher — are fed into a rail line at the same time, these signals are compared with each other, and when the signal of a lower frequency is exceeded, the free part of the rail line from the transmitting end is judged. 5 ill.

Description

The invention relates to railway automation, in particular, to methods for monitoring a rail line for sections of railways with variable and low insulation resistance with autonomous or electric traction.

The purpose of the invention is to increase reliability.

Figure 1 shows the functional diagram of the rail circuit (RC). reflecting those techniques and operations at the first (feeding) and second (receiving) ends of the rail line that comprise the essence of this method; figure 2 shows the dependences on the coordinate of the application of the shunt p relative (to the EMF values) voltages of both frequencies, higher Kn2 and lower DHI at the first end of the rail line in the shunt mode (SH); Fig. 3 shows the dependences of the same voltages in normal mode (HP) on the conductivity of the insulation di, the magnitude of the inverse insulation resistance RU, i.e. di 1 / Ru: figure 4 shows the dependence of the difference between the fixed voltage Ui proportional to the lower frequency UHL and the fixed voltage U2 proportional to the voltage higher

frequencies 1) n2, at the first end of the coordinate of the imposition of the shunt p in SR; Fig. 5 shows the dependence of the same difference in HP on the conductivity of the insulation.

A device that implements this method (Fig. 1) contains a rail line 1 to which sources 2 and 3 of a higher f2 and lower fi frequency are connected at one end, blocks 4 and 5 of fixing voltage levels of signals of both frequencies at the first end of the rail line the outputs of which are connected to the input of the comparison unit 6, the output of which is connected to the first input of the And 7. unit. To the second end of the rail line 1, the receiving end equipment unit 8 is connected, the output of which is connected to the second input of the And 7 block.

The functional circuit of the RC (Fig. 1) provides for the following techniques and operations with the blocks included in it. The rail line 1 (supply end) serves the signals of two frequencies fi and. A signal of a higher frequency f2 is generated from source 2 with a constant voltage level, such a source is close to the EMF source E2 (its internal resistance is much less than the input load resistance).

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A signal of a lower frequency fi is generated from a source 3, which is usual for P C, and consists of an emf source and a limiting resistance. At the first (supply) end of the rail line 1, the voltage levels of the signals of both frequencies are extracted and fixed from the two-frequency signal Urn + UH2: at the output of block 4, the voltage Ut is proportional to the voltage of the lower frequency Urn, and at the output bTkzha 5, the voltage Ua proportional to the voltage of the higher frequency IJH2. The fixed voltages Ui and LJ2 are compared with each other in the comparison unit 6, and if the signal (voltage) of the lower frequency Ui exceeds the signal (voltage) of the higher frequency U2, the free part of the rail line from the side of its first end is judged (output block 6).

At the second (receiving) end of the rail line in the apparatus unit 8, the voltage levels of signals of both frequencies are also recorded, compared with reference signals and, if the voltage levels of each signal are exceeded above the corresponding reference signal, the part of the rail line is free from the side of its second end (block 8 output).

You indicate that there is a coincidence in time of the condition for the freedom of parts of the rail line 1 at both ends, i.e. the presence of simultaneously free commands from blocks 6 and 8 to the logical circuit And 7, in which case the freedom of the entire rail line is judged (output of the And 7 circuit).

The formation of a higher frequency signal with a constant voltage level (without limiting resistance) can significantly facilitate the conditions at the second end of the rail line:

-. in comparison with a RC having a limiting resistance, the voltage level of a higher frequency increases with a decrease in the insulation resistance due to a small decrease in voltage at the first (supply end), therefore, the condition that the signal voltage level is higher than the reference voltage at the second end of the rail line is satisfied to a lower insulation resistance values RU;

- it is possible to equalize the character of voltage reduction of higher and lower frequencies at the second (receiving) end while decreasing the insulation resistance RU. because for the most part, the attenuation in the line is large, but the voltage drop at the first (supply) end is small, and at the lower frequency the attenuation in the line is less, but we have a greater decrease in voltage at the first end, as a result, the ratio of both voltages at the second end is small Ru

remains stable enough, therefore, the excess of the voltage level of a higher frequency at the second end of the free rail line over the voltage of a lower frequency, which plays the role of a reference, is observed to very small RU values. However, these advantages of generating a higher frequency signal with a constant voltage level can be realized

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They are only available if there is a shunt control from the side of the first (supply) end of the rail line, because the application of a shunt near the first end will not result in the required reduction of the voltage level of a higher frequency at the second end for the shunt mode due to the constancy of the voltage level at the first end. There is a critical coordinate of the imposition of the shunt PK relative to which the SR is determined

equipment of the second end only at r pH (closer to the second end).

The shunt control near the first (supply) end of the rail line uses

,. a greater dependence of the voltage of a lower frequency UHI at its first end on the input resistance of the rail line than the voltage of a higher frequency Un2. because the level of the latter is constant (within real possibilities), and the level of the former is variable. Moreover, the difference in the levels of these stresses in the SR when the shunt is located in the region of the first (supply) end is sharper than in HP with a decrease

, insulation resistance RU (increasing the conductivity of the insulation di). This effect, which is used in this method of controlling the freedom of the rail line to distinguish SR and HP at the first end, is illustrated

according to the dependences Um (/) UH2 (p) in SR (Fig. 2) and Um (gu), UH2 (gu) in HP (Fig. 3).

The proportionality coefficient Kn between UH2 and UHI is determined by the limiting value of dimax in HP, to which

5 .in2 (Fig. 3).

In Fig. 2 and Fig. 3, the dashed lines show the curves of Kn.1) H2, showing that the condition UHI Kn.in in HP is met to dimax, and the condition Dm m Kn.in2 in SR is observed

 higher / He (closer to the first end) is the critical coordinate of the shunt, and the SR is determined by the apparatus of the first end at.

To ensure that SR is respected throughout

(- of the rail line, it is necessary to configure the RC so as to have a pH range, i.e. with a zone of overlap of the section of the rail line, where the SR is determined from both ends of the rail line. For example, if the condition for OH is not observed, then it is necessary

reduce dimax (Fig.Z), i.e. increase KN (curve Kn. Una in Fig.Z will be located above). Also located above is the Kn.in curve of Fig. 2, which will lead to a decrease in p, i.e. rapprochement / He and / Ek.

Figures 2 and 3 are supplemented by Figures 4 and 5 in HP and SR, where Ui is the fixed voltage level of a signal of a lower frequency (proportional to UHI), UH2 is the fixed voltage level of a signal of a lower frequency (proportional to 1) n2 taking into account Kn.) ; The curves of Figs. 4 and 5 show the possibility of implementing the method with first-end equipment that does not respond to a controlled quantity (level), but to its sign, which is always more reliable and with fewer errors. For AU, Ui - U2 0 has HP, and for Д1) 0 - SR.

So, one of the conditions for the freedom of the rail line (from the side of its first end) is the excess of the fixed voltage level of the signal of lower frequency at the first end over the fixed voltage level of the signal of higher frequency at the first end. This technique is new. The second condition of freedom (from the side of the second end) is the excess of the signal level of a higher frequency at the second end over the reference. (The voltage level of a lower frequency at the second end must also exceed its reference in order to ensure a safe failure in the event of a breakdown of a channel of a lower frequency in apparatus 8 (Fig. 1)) This technique is known.

To determine the freedom of the entire rail line, both conditions must coincide in time; revealing such a coincidence is a must. Its implementation is possible using the communication channel from the first end of the rail line to the second, where the logical operation is carried out (block 7 in Fig. 1). The latter can be realized by a serial connection of the contacts of the output relays included in blocks 6 and 8 (Fig. 1).

Additional advantages of the method include the weakening of the influence of such negative factors that reduce the working limits of known RCs, such as voltage fluctuations in the network, changes in the resistance of the rail loop, because they have almost the same effect on the fixed voltage levels of both frequencies, without changing their ratio, i.e. difference sign Au.

The implementation of this method does not cause technical difficulties. But some very obvious conditions should be observed. Sources 2 and 3 (Fig. 1) must be protected by obstruction filters from the flow of current from another source through them. The source of higher frequency 2 (FIG. 1) must be protected against short circuit (train at the supply end), because there is no limiting resistance in this source. The implementation of protection can be carried out by known methods. For example, in the form of using a generator with a breakdown, or in the blocking filter of this source, use saturable elements, which will lead to a malfunction of the filter during a short circuit. This is equivalent to introducing

5 of the limiting resistance, after which the magnitude of the voltage of a higher frequency at the receiving end decreases, i.e. a situation arises when the reference signal exceeds the signal level of a higher frequency, corresponding to SR.

In the equipment of the first end of the rail line in block 5 (Fig. 1), there must be a control of the presence of the voltage of the signal of a higher frequency in case of a break in the channel of this voltage

ALSN can be performed at any frequency, but better at a higher frequency, because a signal of this frequency is supplied without decreasing the voltage at the supply end, i.e. he is more

0 powerful.

The implementation of the condition U i Ui- must be carried out using a limiter amplifier (which are semiconductor or magnetic) and a relay.

5 The range of variation of the voltage difference is wide, therefore limitation is necessary. The limit value does not matter, because the amplifier of the track receiver does not respond to the magnitude of the signal, but to its sign.

0 The proposed method for controlling the freedom of the rail line is more complicated than the prototype, but expanding the range of operability of the rail circuit in terms of insulation resistance (almost twice) when it is

A 5 downgrade justifies this complexity.

Expanding the range of operability of the rail circuit in terms of insulation resistance gives a number of economic advantages:

0 - increase in the overhaul period for cleaning ballast and sleepers;

-exclusion of the need to shorten the length p.,, OBOi lines and install additional equipment for broadcasting

5 signals in the middle of the block;

-improving the working conditions of staff in connection with the exclusion of seasonal adjustments due to the lower likelihood of employment signals at RUMHH and reducing downtime for this reason.

Claims (1)

The claims A method for monitoring the free ™ of a rail line, namely, that two frequency signals are fed to the rail line at its first end, one of which having a high frequency is formed with a constant voltage level, and signal voltage levels are fixed at the second end of the line of both frequencies, compare them with the reference signals and if the voltage levels of each of the signals are exceeded above the corresponding reference court, the part of the rail line is free from the side its second end, characterized in that, in order to increase reliability, the voltage levels of the signals of both frequencies are fixed at the first end of the rail line, they are compared with each other and, when the signal of a lower frequency is exceeded, the freedom and span of the part of the rail line from the side of its first end, you find that there is a coincidence in time of exceeding the voltage levels of the signals above the reference at the second end of the rail line with the excess of the voltage of the second signal ned voltage of the first at its first end and it determines the freedom of the entire rail oh line. Oh Oh line free 1 & M FIG. 4 Fig 5