CN101196543A

CN101196543A - On-line measurement method for electric resistance of rail traffic road bed

Info

Publication number: CN101196543A
Application number: CNA2007103000728A
Authority: CN
Inventors: 张兴杰
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-12-13
Filing date: 2007-12-13
Publication date: 2008-06-11
Anticipated expiration: 2027-12-13
Also published as: CN100529774C

Abstract

The invention discloses an online method for measuring the resistance of rail transit road bed, which comprises the following steps: 1. make the distance between the bordering compensation capacitor C1 and C2 set along the rail as a section S, divide the section S into a plurality of equal subsections Delta S; 2. inflict an AC signal F in the middle point A on the ordering compensation capacitor C1 and C2; 3. set an isolation unit between AC signal F and track circuit, the isolation unit connects a syntonic circuit in series with LC; 4. test the voltage U of the AC signal F on point A inflicted by AC signal F; 5. calculate the road bed equivalent resistance Rz of a half section S; 6. calculate the road bed equivalent resistance Rz on subsection Delta S, and converse the result expressed in Km.Omega. The advantage of the invention is to realize online measurement of rail transit road bed resistance anytime without affecting the normal transportation of rail transit.

Description

The On-line Measuring Method of electric resistance of rail traffic road bed

Technical field

The present invention relates to track traffics such as railway, subway and light rail, especially relate to the On-line Measuring Method of electric resistance of rail traffic road bed.

Background technology

Present railway line, track traffic such as subway and light rail, the overwhelming majority all adopts ground signal that train operation is controlled, these ground signal systems are commonly referred to as track circuit, track-circuit signalling all is to transmit through rail, yet rail is laid on the railway roadbed (railway bed and bridge etc.), be difficult to accomplish desirable insulation between rail and the railway roadbed again, so railway roadbed is distributed on the railway line as many leak resistances concerning signal, railway roadbed is to the equivalent resistance of signal leakage in one kilometer range, in track circuit, be called railway roadbed resistance, represent with Km. Ω.After the limit of railway roadbed resistance less than the track circuit design objective, track circuit will break down, and the direct result of track circuit failure influences train operation exactly even causes security incident.

Existing method to the railway roadbed resistance detection has following two kinds: the one, in very necessary, to transportation dispatching department main points or at the skylight point, break away from the electric equipment that can influence measurement result, allow tested section become no track circuit and no electrified railway, directly measure track circuit resistance with multimeter, these equipment are installed after measuring again, and on busy rail transportation circuit, this detection method is difficult to implement.The 2nd, go into the scope whether voltage method differentiation railway roadbed resistance is requiring by measuring rail.Rail go into voltage be exactly when track circuit is adjusted to rail set one can operate as normal voltage, at this moment railway roadbed resistance is normal, so it is generally acknowledged, if variation has taken place railway roadbed resistance, rail is gone into voltage and also will be changed so.But in fact to go into the factor of change in voltage be many-sided to rail, and not merely depend on railway roadbed resistance, and therefore this method can not reflect really whether railway roadbed resistance meets the demands.

Summary of the invention

The object of the invention is to provide the On-line Measuring Method of the electric resistance of rail traffic road bed that a kind of measuring process is easy, measuring accuracy is high.

For achieving the above object, the present invention can take following technical proposals:

The On-line Measuring Method of electric resistance of rail traffic road bed of the present invention, it comprises following step:

The first step, will be arranged on distance between rail along the line last two adjacent building-out capacitor C1, the C2, it will be divided into a plurality of away minor segment Δ S as a section S;

Second the step, apply an AC signal F in the intermediate point A position of rail between described two adjacent building-out capacitor C1, C2, the two ends of described AC signal F are connected on respectively on two one steel rails, its frequency is greater than 2600Hz; Therefore, AC signal F application point: promptly constitute two symmetrical circuit between two adjacent building-out capacitor C1, the C2 between the adjacent building-out capacitor C1 of intermediate point A to two, the C2 of rail; Thereby the equivalent electrical circuit network when drawing at measurement;

The 3rd goes on foot, is provided with an isolated location between AC signal F and track circuit, described isolated location adopts the LC series resonant circuit, and the centre frequency of resonance is the frequency of AC signal F;

The voltage U of the AC signal F at the 4th step, A place, Measuring Alternating Current Signal F application point, and the electric current I of Measuring Alternating Current Signal F output;

The railway roadbed equivalent resistance Rz of the 5th step, half section S of calculating:

The electric current I of the output at the place, voltage U ÷ 0.5 AC signal F application point at place, railway roadbed equivalent resistance Rz=AC signal F application point;

Because the railway roadbed resistance R of away minor segment Δ S and the railway roadbed equivalent resistance Rz of half section S have unique corresponding relation, with this circuit network of simulation software emulation, can draw the railway roadbed resistance R of away minor segment Δ S and the railway roadbed equivalent resistance Rz graph of relation of half section S;

The 6th step,

Find the solution the railway roadbed resistance R of away minor segment Δ S at second circuit of step in resulting two symmetrical circuit, and it is converted into Km. Ω represents.

The railway roadbed resistance R method of finding the solution away minor segment Δ S in described the 6th step is hit-and-miss method, approximatioss or look-up table.

The invention has the advantages that does not influence under the track traffic normal transport prerequisite, is implemented in the on-line measurement of any time to electric resistance of rail traffic road bed, need not break away from the equipment on the rail in the measuring process, need not main points, and also need not the skylight point.The simple and easy to do degree of accuracy height of measuring process is for searching of track circuit failure provides scientific basis.

Description of drawings

Fig. 1 is the equivalent electrical circuit network chart described in second step of the present invention.

Fig. 2 is the equivalent network figure of half section S track circuit described in the 5th step of the present invention.

Fig. 3 is the railway roadbed resistance R of away minor segment Δ S described in the 5th step of the present invention and the railway roadbed equivalent resistance Rz graph of relation of half section S.

Fig. 4 is the away minor segment Δ S railway roadbed resistance R that obtains of approximatioss of the present invention and the railway roadbed equivalent resistance Rz graph of relation of half section S.

Embodiment

As shown in the figure, the On-line Measuring Method of electric resistance of rail traffic road bed of the present invention, it is undertaken by following step:

The first step,

In the actual motion of railway line, generally all be local railway roadbed resistance variation, rather than whole section variation, therefore can carry out areal survey to the railway roadbed resistance of whole section, thereby locate the position of railway roadbed resistance variation more accurately; Therefore, with being arranged on distance between rail along the line last two adjacent building-out capacitor C1, the C2, it is divided into a plurality of away minor segment Δ S as a section S; Away minor segment Δ S is the smaller the better in theory, and in actual applications, away minor segment Δ S be as long as can satisfy accuracy requirement near the distance between adjacent two sleepers, thus away minor segment Δ S can be between 0.5～1 meter value.

Second the step, apply an AC signal F in the intermediate point A position of rail between described two adjacent building-out capacitor C1, C2, the two ends of described AC signal F are connected on respectively on two one steel rails, its frequency greater than 2600Hz to avoid the frequency of track-circuit signalling; Therefore, AC signal F application point: promptly constitute two symmetrical circuit between two adjacent building-out capacitor C1, the C2 between the adjacent building-out capacitor C1 of intermediate point A to two, the C2 of rail; Thereby the equivalent electrical circuit network when drawing at measurement.

As shown in Figure 1; Among Fig. 1, C1, C2 are two adjacent building-out capacitors; L, R and Cx are respectively the distributed capacitance between rail inductance under the away minor segment Δ S length, railway roadbed distributed resistance, two one steel rails; Wherein, rail under certain-length and AC signal frequency one regularly its rail inductance, distributed capacitance are a constant; Railway roadbed distributed resistance and railway roadbed length are inversely proportional to, when away minor segment Δ S between 0.5～1 meter during value, railway roadbed distributed resistance R size is between hundreds of Ω to tens K Ω.

The 3rd goes on foot, is provided with an isolated location between AC signal F and track circuit, described isolated location adopts the LC series resonant circuit, and the centre frequency of resonance is the frequency of AC signal F.

AC signal F is as signal source, internal resistance generally is smaller, can produce absorption to track-circuit signalling, in order to guarantee the safety of track circuit, so between AC signal F and track circuit, need to increase an isolated location, the effect of isolated location is low-resistance exactly concerning AC signal F, be high resistant concerning track-circuit signalling.

Concerning the frequency of AC signal F, frequency is big more, the capacitive reactance of building-out capacitor C1, C2 is more little, then the AC signal F component that can be leaked to outside the S interval is more little, when the capacitive reactance of building-out capacitor C1, C2 was far smaller than the railway roadbed distributed resistance R under the away minor segment Δ S length even approaches zero, this frequency was an optimum frequency.

The voltage U of the AC signal F at the 4th step, A place, Measuring Alternating Current Signal F application point, and the electric current I of Measuring Alternating Current Signal F output.

The 5th step, in Fig. 1, the circuit of A both sides, AC signal F application point is a symmetric circuit, the railway roadbed equivalent resistance Rz that therefore only calculates half section S gets final product.

As shown in Figure 2, the electric current I of the output at the place, voltage U ÷ 0.5 AC signal F application point at place, railway roadbed equivalent resistance Rz=AC signal F application point;

Because the railway roadbed resistance R of away minor segment Δ S and the railway roadbed equivalent resistance Rz of half section S have unique corresponding relation, with simulation software analogous diagram 2 circuit networks, can draw the railway roadbed resistance R of away minor segment Δ S and railway roadbed equivalent resistance Rz relation curve Fig. 3 of half section S.

The 6th step,

Find the solution the railway roadbed resistance R of away minor segment Δ S at Fig. 2, and it is converted into Km. Ω represents.

Take approximatioss to find the solution the process signal of the railway roadbed resistance R of away minor segment Δ S, on the railway roadbed equivalent resistance Rz relation curve of the railway roadbed resistance R of away minor segment Δ S and half section S, represent to obtain Fig. 4.

Because Fig. 4 curve zero crossing, thus zero point as a particular point.Performing step is as follows:

As shown in Figure 4, step 1: suppose railway roadbed resistance R value x1 ≠ 0 a substitution circuit network earlier, calculate equivalent resistance r1 ≠ 0, if equaling 1, Rz/r1 (perhaps approximates 1, according to the precision decision that will calculate), x1 is exactly the R value of requirement so, otherwise carries out step 2;

Step 2: according to the proportionate relationship of Rz=U/I and r1, can extrapolate an x2, formula is as follows:

Rz/r1＝x2/x1

Because curve is dull increasing in interval, so the x2 that solves necessarily than the more approaching real R value of x1, the R value of x2 as supposition, reenters step 1.

Through circulation, the R value finally converges on the x point, and x is exactly the R value of requirement, the R value is converted into Km. Ω unit gets final product.

Claims

1. the On-line Measuring Method of an electric resistance of rail traffic road bed, it is characterized in that: it comprises following step:

The first step, will be arranged on distance between the rail last two adjacent building-out capacitors (C1, C2) along the line, it will be divided into a plurality of away minor segment (Δ S) as a section (S);

Second the step, apply an AC signal (F) in intermediate point (A) position that is positioned at rail between the described two adjacent building-out capacitors (C1, C2), the two ends of described AC signal (F) are connected on respectively on two one steel rails, its frequency is greater than 2600Hz; Therefore, AC signal (F) application point: promptly between the two adjacent building-out capacitors (C1, C2) intermediate point (A) of rail to constituting two symmetrical circuit between the two adjacent building-out capacitors (C1, C2); Thereby the equivalent electrical circuit network when drawing at measurement;

The 3rd goes on foot, is provided with an isolated location between AC signal (F) and track circuit, described isolated location adopts the LC series resonant circuit, and the centre frequency of resonance is the frequency of AC signal (F);

The voltage (U) of the AC signal (F) that the 4th step, Measuring Alternating Current Signal (F) application point (A) are located, and the electric current (I) of Measuring Alternating Current Signal (F) output;

The railway roadbed equivalent resistance (Rz) of the 5th step, half section of calculating (S):

The electric current (I) of the output at the place, voltage (U) ÷ 0.5 AC signal (F) application point at railway roadbed equivalent resistance (Rz)=place, AC signal (F) application point;

Because the railway roadbed resistance (R) of away minor segment (Δ S) has unique corresponding relation with the railway roadbed equivalent resistance (Rz) of half section (S), with this circuit network of simulation software emulation, can draw the railway roadbed resistance (R) of away minor segment (Δ S) and railway roadbed equivalent resistance (Rz) graph of relation of half section (S);

The 6th step,

Find the solution the railway roadbed resistance (R) of away minor segment (Δ S) at second circuit of step in resulting two symmetrical circuit, and it is converted into Km. Ω represents.

2. according to the On-line Measuring Method of the described electric resistance of rail traffic road bed of claim 1, it is characterized in that: railway roadbed resistance (R) method of finding the solution away minor segment (Δ S) in described the 6th step is hit-and-miss method, approximatioss or look-up table.