Real-time online test method and system for track circuit ballast bed resistance

Abstract

The invention discloses a track circuit ballast bed resistance real-time online test method and system. According to the method, a track four-end network mathematical model is adopted, track surface current attenuation ratio is calculated by adjusting track bed resistance parameters in the model, and an ''attenuation ratio-track bed resistance'' table is established. By means of the meter, the rail surface current attenuation ratio measured on site can be directly converted into the ballast bed resistance value, and rapid and accurate on-line testing is achieved. The method is suitable for various track circuit types. By simplifying the test process, reducing the operation complexity and improving the real-time performance and accuracy of the test, the invention provides an efficient, simple, convenient and reliable test means for the maintenance and operation of the railway signal system.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical variable measurement, and in particular to a real-time online testing method and system for track circuit ballast resistance. Background Art

[0002] In railway signaling, the resistance of the ballast bed is the leakage resistance from one rail to another rail through the ballast bed. The ballast bed is composed of a large number of sleepers, fastener systems, rubber pads, ballast or concrete blocks. The insulation performance between the rail and the ballast bed determines the size of the ballast bed resistance. The worse the insulation performance, the smaller the ballast bed resistance.

[0003] The lower the resistance of the track bed, the faster the attenuation speed of the track circuit signal during transmission from the power transmission end to the power receiving end, which seriously restricts the transmission distance of the track circuit, that is, the length of the track circuit, and is not conducive to the use and maintenance of the track circuit. Therefore, during the use of the track circuit, it is necessary to perform periodic tests on the track bed resistance.

[0004] At present, the main types of track circuits used in railways include 25Hz phase-sensitive track circuits, ZPW-2000 series non-insulated track circuits, and ZPW-2000 series in-station track circuits.

[0005] The main methods for testing the resistance of the ballast bed include the open circuit short circuit method, the secondary short circuit method, and the double short circuit method. By inputting an AC signal into the rail line, the open circuit impedance or short circuit impedance of a section of the line is tested, and finally the resistance value of the ballast bed is calculated based on the uniform transmission line theory. During the test of the resistance of the ballast bed, all the equipment connected to the rail line within the test range needs to be removed. The test efficiency is low, time-consuming and labor-intensive, and the test is not online, and the test results are delayed. Summary of the invention

[0006] Based on this, an embodiment of the present application provides a real-time online testing method and system for track circuit ballast resistance, which is suitable for different track circuit types and can solve the problems existing in the existing ballast resistance testing methods.

[0007] In a first aspect, a real-time online testing method for track circuit ballast resistance is provided, the method comprising:

[0008] Identify the type of track circuit to be tested, and further classify the track circuit section according to the identified type; wherein the types of track circuit to be tested include 25Hz phase-sensitive track circuit and ZPW-2000 series station track circuit;

[0009] The rail line is mathematically modeled using the track four-terminal network mathematical model. By adjusting the ballast resistance value parameters in the model, the corresponding rail surface current attenuation ratio is calculated and the "attenuation ratio-ballast resistance" table is established.

[0010] The rail surface currents at the power supply and receiving ends measured on site are obtained, the rail surface current attenuation ratio is calculated, and the current ballast resistance value of the track circuit section is obtained by looking up the table.

[0011] Optionally, the identified type is further classified into track circuit sections, including:

[0012] When identified as a 25Hz phase-sensitive track circuit, the track circuit sections are further classified into one sending and one receiving section, one sending and two receiving section, and one sending and three receiving section, and it can handle possible non-powered branches with choke transformers in parallel at the end of the branch and non-powered branches without choke transformers at the end of the branch.

[0013] Optionally, the identified type is further classified into track circuit sections, including:

[0014] When identified as a ZPW-2000 series station track circuit, it is further classified into a one-sending and one-receiving section without a power receiving branch section, a one-sending and one-receiving section with a choke transformer in parallel at the end of the branch and a no power receiving branch section without a choke transformer at the end of the branch.

[0015] Optionally, for a non-powered branch with a choke transformer connected in parallel at the branch end, the impedance of the choke transformer is determined by measuring the rail surface voltage and rail surface current at the branch end;

[0016] The choke transformer is modeled using a four-terminal network model of parallel impedance, and the four-terminal network of the non-powered branch is cascaded with the four-terminal network of the choke transformer to achieve accurate modeling of the branch end.

[0017] Optionally, when processing a one-transmitting-multiple-receiving section, only the receiving end farthest from the transmitting end is regarded as the main receiving end, and the other receiving ends are regarded as non-receiving branches with a choke transformer connected in parallel at the branch end.

[0018] Optionally, the track section with compensation capacitors is modeled by cascading a segmented rail line four-terminal network and a compensation capacitor four-terminal network.

[0019] Optionally, when dealing with a non-powered branch, an equivalent model of the rail resistance, rail inductance, and rail capacitance of the parallel section based on the length of the non-powered branch and the parallel length of the main rail line rails is proposed; when a choke transformer is connected in parallel to the end of the non-powered branch, the choke transformer adopts a four-terminal network model of parallel impedance and is connected to the end of the parallel section.

[0020] Optionally, a track four-terminal network mathematical model is used to mathematically model the rail line. The mathematical model of the track four-terminal network is shown in the formula:

[0021]

[0022] Among them, γ is the propagation constant of the rail line, Z c is the characteristic impedance of the rail line, x is the length of the rail line; U2 and I2 are the input voltage and current of the track four-terminal network, and U1 and I1 are the load voltage and current of the track four-terminal network.

[0023] Optionally, γ and Z c The relationship with rail resistance, rail inductance, rail capacitance and ballast resistance includes:

[0024]

[0025] Among them, f is the frequency of the current track circuit section, specifically one of the five frequencies of 25Hz, 1700Hz, 2000Hz, 2300Hz, and 2600Hz.

[0026] In a second aspect, a real-time online testing system for track circuit ballast resistance is provided, the system comprising:

[0027] An identification module is used to identify the type of track circuit to be tested, and further classify the track circuit section according to the identified type; wherein the types of track circuit to be tested include 25Hz phase-sensitive track circuit and ZPW-2000 series station track circuit;

[0028] Modeling module, used to use the track four-terminal network mathematical model to mathematically model the rail line, and by adjusting the ballast resistance value parameters in the model, calculate the corresponding rail surface current attenuation ratio and establish the "attenuation ratio-ballast resistance" table;

[0029] The test module is used to obtain the rail surface current at the power supply and receiving ends measured on site, calculate the rail surface current attenuation ratio, and obtain the current ballast resistance value of the track circuit section by looking up the table.

[0030] (1) The method can be used to conduct real-time online testing without interrupting the normal operation of the track circuit, which greatly improves the efficiency of the test. At the same time, since the track bed resistance can be monitored in real time, problems that may affect the performance of the track circuit can be discovered and handled in a timely manner, thereby improving the reliability and safety of the railway signal system.

[0031] (2) By establishing a "loss ratio-ballast resistance" table, the test process is simplified. On-site staff only need to measure the rail surface current at the power supply and receiving ends, and then look up the table based on the measurement results to obtain the ballast resistance value without complicated calculations. This simplified operation process reduces the technical requirements for testers and makes the test process more convenient and quick.

[0032] (3) The track four-terminal network mathematical model is used for precise mathematical modeling. Combined with the actual on-site measurement data, the track bed resistance value can be calculated more accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0034] Figure 1 A real-time online test flow chart of track circuit ballast resistance provided in an embodiment of the present application;

[0035] Figure 2 This is a schematic diagram of one power transmission, one power receiving and one power non-receiving branch in the embodiment of the present application;

[0036] Figure 3 This is a schematic diagram of one power transmission, two receiving bands and one non-power receiving branch in an embodiment of the present application;

[0037] Figure 4 This is a schematic diagram of one sending and three receiving in the embodiment of the present application;

[0038] Figure 5 This is a schematic diagram of one sending and one receiving without a power receiving branch in an embodiment of the present application;

[0039] Figure 6 This is a schematic diagram of the parallel connection without power receiving branches in the embodiment of the present application;

[0040] Figure 7 A schematic diagram of a mathematical model of a rail line in an embodiment of the present application;

[0041] Figure 8 This is a schematic diagram of a track four-terminal network in an embodiment of the present application;

[0042] Fig. 9 This is a schematic diagram of a four-terminal network without a choke transformer in the power receiving branch in the embodiment of the present application;

[0043] Fig.10 This is a schematic diagram of a four-terminal network with one transmission, one receiving and one non-receiving branch (with a choke transformer) in an embodiment of the present application;

[0044] Fig.11 This is a schematic diagram of a track four-terminal network (with compensation capacitors) in an embodiment of the present application;

[0045] Fig.12 This is a schematic diagram of a track four-terminal network in an embodiment of the present application. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0047] In the description of the present invention, the terms "comprises", "has" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may also include other steps or units that are not explicitly listed but are inherent to these processes, methods, products or apparatuses, or steps or units added based on further optimization schemes conceived by the present invention.

[0048] Specifically, please refer to Figure 1 , which shows a flow chart of a real-time online test method for track circuit ballast resistance provided by an embodiment of the present application. The method may include the following steps:

[0049] S1, identifying the type of track circuit to be tested, and further classifying the track circuit sections according to the identified type.

[0050] Among them, the types of track circuits to be tested include 25Hz phase-sensitive track circuits and ZPW-2000 series in-station track circuits.

[0051] S2, using the track four-terminal network mathematical model to mathematically model the rail line, by adjusting the ballast resistance value parameters in the model, calculate the corresponding rail surface current attenuation ratio, and establish a "attenuation ratio-ballast resistance" table;

[0052] S3, obtain the rail surface current at the power supply and receiving ends measured on site, calculate the rail surface current attenuation ratio, and obtain the current track bed resistance value of the track circuit section by looking up the table.

[0053] The invention discloses a simple and easy real-time online test method for track bed resistance applicable to different track circuit types.

[0054] A real-time online test method for the resistance of the track bed of a track circuit can perform real-time online testing on the resistance of the track bed of a 25Hz phase-sensitive track circuit and a ZPW-2000 series station track circuit section. It can be applied to the one-send-one-receive section, one-send-two-receive section, and one-send-three-receive section of a 25Hz phase-sensitive track circuit, and can process the possible non-receiving branch with a choke transformer in parallel at the end of the branch, and the non-receiving branch without a choke transformer at the end of the branch. At the same time, it can be applied to the one-send-one-receive section of the ZPW-2000 series station track circuit without a non-receiving branch, the one-send-one-receive section with a choke transformer in parallel at the end of the branch, and the non-receiving branch section with a choke transformer at the end of the branch.

[0055] This application specifically adopts the mathematical model of the four-terminal network of the track, and only mathematically models the rail line of the track circuit section. By adjusting the ballast resistance value parameters in the model, the corresponding rail surface current attenuation ratio (the rail surface current at the receiving end divided by the rail surface current at the sending end) is calculated, and a "attenuation ratio-ballast resistance" table is established. Based on the rail surface currents at the sending and receiving ends measured on site, the rail surface current attenuation ratio is calculated, and the current ballast resistance value of the track circuit section can be obtained by looking up the table.

[0056] When processing a non-powered branch with a choke transformer in parallel at the end of the branch, the impedance of the choke transformer is obtained by dividing the rail surface voltage at the end of the branch by the rail surface current, and the choke transformer is modeled using a four-terminal network model of parallel impedance. The four-terminal network modeling of the non-powered branch with a choke transformer in parallel at the end of the branch is achieved by cascading the four-terminal network of the non-powered branch rail line and the four-terminal network of the choke transformer. The four-terminal network model is converted into a four-terminal network model with an impedance in parallel to the main rail in an open-circuit mode at the load end of the model to complete the branch processing.

[0057] When processing a one-transmitting-multiple-receiving section, only the receiving end that is the longest away from the transmitting end is treated as the receiving end, and the remaining receiving ends are treated as non-receiving branches with a choke transformer connected in parallel at the end of the branch.

[0058] The track section with compensation capacitor is modeled by cascading the segmented rail line four-terminal network and the compensation capacitor four-terminal network.

[0059] When dealing with non-powered branches, an equivalent model of rail resistance, rail inductance, and rail capacitance of the parallel section based on the length of the non-powered branch and the parallel length of the main rail line rails is proposed. When a choke transformer is connected in parallel at the end of the non-powered branch, the choke transformer adopts a four-terminal network model of parallel impedance and is connected at the end of the parallel section.

[0060] The technical solution adopted by the present invention is: a simple and easy real-time online test method for the resistance of the track bed applicable to different track circuit types. The present invention provides the following technical solutions:

[0061] The problem to be solved by the patent of this invention is: simple and easy, applicable to different track circuit types, and real-time online testing of track bed resistance.

[0062] This technical solution is mainly divided into three parts, namely the topological structure of the track circuit rail line, the selection of test data, and the mathematical modeling of the ballast resistance test.

[0063] 1. Topological structure of track circuit rail line

[0064] 1.1 25Hz phase-sensitive track circuit

[0065] For 25Hz phase-sensitive track circuits, the topological structure of the rail line is divided into one sending and one receiving, one sending and two receiving, and one sending and three receiving. Each type can also have a non-receiving branch (the end of the branch does not transmit signals to the room), as shown in the schematic diagram. Figure 2 Schematic diagram of one sending, one receiving and one non-receiving branch, Figure 3 Schematic diagram of one sending, two receiving and one receiving branch. Figure 4 Diagram of one send and three receive.

[0066] 1.2ZPW-2000 Series Non-insulated Track Circuit

[0067] For the ZPW-2000 series non-insulated track circuit, the rail line topology is one-sending and one-receiving, and there is no non-receiving branch. Figure 5 Schematic diagram of one sending and one receiving without receiving branch.

[0068] For the ZPW-2000 series station track circuit, the rail line topology structure is one sending and one receiving. It is possible that there is a receiving branch. Figure 2 Different from the 25Hz phase-sensitive track circuit, the ZPW-2000 series station track circuit connects the rail line without power receiving branch with the main rail line with wire rope intervals and connects the opinions Figure 6 Schematic diagram of parallel connection without receiving branches.

[0069] 2. Test data selection

[0070] Since the resistance of the ballast bed is only affected by the ballast bed conditions (ballasted, ballastless, contaminated, etc.), the insulation performance between the rails and the ballast bed (including the insulation performance between the rails and the ballast bed or sleepers, the insulation performance of the fastener system, etc.), and the climate conditions (rainy days, sunny days), it has nothing to do with the power transmission and receiving equipment of the track circuit. Therefore, the present invention uses the rail surface current at the power transmission and receiving ends (i.e., the rail lead wire current) as the basic data for the ballast bed resistance test, and the mathematical model of the test only considers the rail line, and does not include the power transmission and receiving end equipment of the track circuit. The input of the test mathematical model is the rail surface current attenuation ratio, that is, the rail surface current at the power receiving end divided by the rail surface current at the power transmission end, and the output is the ballast bed resistance value of the track circuit section.

[0071] 3. Mathematical modeling of track bed resistance test

[0072] 3.1 Mathematical model of the track four-terminal network

[0073] The theoretical basis of rail line modeling is the uniform transmission line theory, so the mathematical model of the rail line can be described by the track four-terminal network. Figure 7Schematic diagram of the mathematical model of the rail line. In the figure, R is the rail resistance, unit Ω / km; L is the rail inductance, unit mH / km; C is the rail capacitance, unit μF / km; G is the rail conductance, which is equal to the reciprocal of the ballast resistance, unit Ω·km. Δx is the unit length of the rail line, unit m.

[0074] The mathematical model of the track four-terminal network is shown in formula (1).

[0075]

[0076] In the formula, γ is the propagation constant of the rail line, Z c is the characteristic impedance of the rail line, x is the length of the rail line, U2 and I2 are the input voltage and current of the track four-terminal network, and U1 and I1 are the load voltage and current of the track four-terminal network.

[0077] γ and Z c The relationship with rail resistance, rail inductance, rail capacitance and ballast resistance is shown in formula (2) and formula (3).

[0078]

[0079] Where ω=2πf, f is the track circuit frequency. For 25Hz phase-sensitive track circuit, f=25Hz; for ZPW-2000 series station track circuit, f is the frequency of the current track circuit section, that is, one of the four frequencies of 25Hz, 1700Hz, 2000Hz, 2300Hz, and 2600Hz.

[0080] 3.2 Mathematical model of ballast resistance test

[0081] For a track circuit section with one transmission and one reception and no non-receiving branch, the four-terminal network of the track shall indicate the following: Figure 8 Its mathematical model is shown in formula (1), where U1 and I1 are the rail surface voltage and rail surface current at the receiving end, and U2 and I2 are the rail surface voltage and rail surface current at the transmitting end.

[0082] The railway industry standard specifies the typical values ​​of rail resistance and rail inductance; the frequency of the 25Hz phase-sensitive track circuit is low, and the rail capacitance can be ignored; the frequency of the ZPW-2000 series station track circuit is high, and the rail capacitance takes its typical value at different frequencies. Therefore, it can be considered that the rail resistance, rail inductance, and rail capacitance are all known quantities.

[0083] From formula (1), it can be seen that if the rail resistance, rail inductance, rail capacitance, ballast resistance, track circuit section length, and track circuit frequency are known, the track four-terminal network can be calculated; the receiving end rail surface voltage and rail surface current can be obtained through on-site measurement, and the power transmission end rail surface voltage and rail surface current can be calculated. By dividing the receiving end rail surface current by the power transmission end rail surface current, the rail surface current attenuation ratio can be calculated.

[0084] According to different ballast resistance values, the corresponding rail current attenuation ratio is calculated respectively, so as to establish a "attenuation ratio-ballast resistance" table. According to the rail current at the power supply and receiving ends measured on site, the rail current attenuation ratio is calculated, and the current ballast resistance value of the track circuit section can be obtained by looking up the table, which is simple and easy.

[0085] 3.3 25Hz phase-sensitive track circuit

[0086] 3.3.1 Dealing with the situation where there is no receiving branch

[0087] The non-receiving branch is divided into the non-receiving branch with choke transformer and the non-receiving branch without choke transformer. For the non-receiving branch with choke transformer, the four-terminal network shows the following: Fig. 9 Schematic diagram of a four-terminal network without a choke transformer in the receiving branch.

[0088] In the figure, Z el is the impedance of the choke transformer, which is obtained by dividing the rail voltage at the choke transformer by the rail current measured on site. The four-terminal network is shown in formula (4).

[0089]

[0090] The four-terminal network without receiving branch and choke transformer is equivalent to the cascade of the four-terminal network without receiving branch and the four-terminal network with choke transformer. w is the length of the non-powered branch, see formula (5).

[0091]

[0092] Since the load end of the four-terminal network without a receiving branch choke transformer is open, that is, the current is 0, formula (6) can be derived from formulas (4) and (5).

[0093]

[0094] Substituting the condition I1=0 and performing matrix operations, we obtain formula (7).

[0095] U2=(ch(γL w )+Z c sh(γL w ) / Z el )U1 (7)

[0096] I2=(sh(γL w ) / Z c +ch(γL w ) / Z el )U1 (8)

[0097] From formulas (7) and (8), the impedance Z of the transformer without choke in the receiving branch can be derived: wsd+el , see formula (9).

[0098]

[0099] Here we use one transmission, one receiving and one non-receiving branch as an example to illustrate the opinions Figure 2 , there is no power receiving device in the figure, which is a choke transformer, then the four-terminal network shows the opinion Fig.10 Schematic diagram of a four-terminal network with one transmission, one receiving and one non-receiving branch (with choke transformer).

[0100]

[0101] In the formula, L z is the length of the rail line on the left side of the parallel point, L y It is the length of the rail line on the right side of the paralleling point.

[0102] The difference between a branch without a choke transformer and a branch with a choke transformer is whether there is a choke transformer four-terminal network in formula (6), and the rest of the calculations are the same.

[0103] 3.3.2 Dealing with the Situation of One Delivery and Multiple Receivers

[0104] One transmission and multiple receiving are divided into one transmission and two receiving and one transmission and three receiving. Only the receiving end that is the longest distance from the transmission end is treated as the receiving end, and the other receiving ends are treated as the receiving end without a receiving branch with a choke transformer. For the specific calculation method, refer to 3.1.1.

[0105] 3.4ZPW-2000 series station track circuit

[0106] 3.4.1 Rail-end four-terminal network with compensation capacitor

[0107] The rail line of the ZPW-2000 series station track circuit will be connected in parallel with a compensation capacitor when it exceeds a certain length, thereby offsetting the inductive load of the rail and extending the transmission length of the track circuit. For the rail line with compensation capacitor, the track four-terminal network is a cascade of the segmented rail line and the compensation capacitor. The cascade calculation method refers to formula (6), as shown in the figure. Fig.11 Schematic diagram of the track four-terminal network (with compensation capacitors).

[0108] The impedance of the compensation capacitor is composed of the compensation capacitor and its rail lead wire. The four-terminal network calculation method is shown in formula (11).

[0109]

[0110] Among them, Z yjx is the lead line impedance; C bc is the capacitance of the compensation capacitor; ω=2πf, f is the track circuit frequency.

[0111] 3.4.2 No power receiving branch processing

[0112] The non-powered branches of the ZPW-2000 series station track circuits are also divided into non-powered branches with choke transformers and non-powered branches without choke transformers.

[0113] The non-powered branch processing of the ZPW-2000 series station track circuit is different from the 25Hz phase-sensitive track circuit. The non-powered branch part is connected to the main track line in sections using wire ropes. Figure 6 .

[0114] The non-powered branch and the main rail are connected in parallel in sections, which is equivalent to the non-powered branch rail and the main rail in parallel. Then the rail resistance and rail inductance conform to the law of parallel resistance. The calculation method is shown in formulas (12) and (13).

[0115] R b =RL fz ×RL zg RL fz +RL zg (12)

[0116] L b =LL fz ×LL zg LL fz +LL zg (13)

[0117] L fz L is the length of the branch without power supply, zg is the length of the parallel section of the main rail line with the non-powered branch. From formulas (12) and (13), it can be seen that the parallel coefficient of rail inductance and rail resistance is shown in formula (14).

[0118] K b =L fz ×L zg L fz +L zg (14)

[0119] The rail resistance and rail inductance of the section where there is no power receiving branch and the main rail line in parallel are shown in formulas (15) and (16).

[0120] R b =RK b (15)

[0121] L b =LK b (16)

[0122] Since the rail capacitance is connected in parallel between the two rails, and there is no power receiving branch and the main rail in parallel, the rail capacitance is equivalent to being connected in parallel with the capacitor, that is, the rail capacitance is added. Since there is a situation where the parallel branch is larger than the main rail section being connected in parallel, the parallel capacitor needs to be connected in parallel in the main rail section. The calculation method is shown in formula (17).

[0123]

[0124] Taking a track section with 4 compensation capacitors, a non-powered branch, and a choke transformer at the end of the branch as an example, the track four-terminal network model is analyzed and the opinions are given. Fig.12 Schematic diagram of the four-terminal track network.

[0125] In the figure, the parallel section is from the second compensation capacitor to the fourth compensation capacitor; Zel is the impedance of the choke transformer connected in parallel at the end of the branch; when calculating the four-terminal network of the track with the words "parallel network", the rail resistance, rail inductance and rail capacitance must be calculated according to formulas (15), (16) and (17).

[0126] For branches without choke transformers, the cascade calculation is not calculated. Fig.12 Z el Track sections with multiple branches are calculated as multiple parallel sections cascaded one by one.

[0127] The track circuits in ZPW-2000 series stations are all one-sending and one-receiving sections, and there is no one-sending and multiple-receiving situation.

[0128] The present application also provides a real-time online test system for track circuit ballast resistance. The system includes:

[0129] An identification module is used to identify the type of track circuit to be tested, and further classify the track circuit section according to the identified type; wherein the types of track circuit to be tested include 25Hz phase-sensitive track circuit and ZPW-2000 series station track circuit;

[0130] Modeling module, used to use the track four-terminal network mathematical model to mathematically model the rail line, and by adjusting the ballast resistance value parameters in the model, calculate the corresponding rail surface current attenuation ratio and establish the "attenuation ratio-ballast resistance" table;

[0131] The test module is used to obtain the rail surface current at the power supply and receiving ends measured on site, calculate the rail surface current attenuation ratio, and obtain the current ballast resistance value of the track circuit section by looking up the table.

[0132] The real-time online testing system for track circuit track bed resistance provided in the embodiment of the present application is used to implement the above-mentioned real-time online testing method for track circuit track bed resistance. For the specific definition of the real-time online testing system for track circuit track bed resistance, please refer to the definition of the real-time online testing method for track circuit track bed resistance in the above text, which will not be repeated here. The various parts of the above-mentioned real-time online testing system for track circuit track bed resistance can be fully or partially implemented by software, hardware and their combination. The above-mentioned modules can be embedded in or independent of the processor in the device in the form of hardware, or can be stored in the memory in the device in the form of software, so that the processor can call and execute the operations corresponding to the above-mentioned modules.

[0133] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0134] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A real-time online test method for track circuit ballast resistance, characterized in that: The method comprises: Identify the type of track circuit to be tested, and further classify the track circuit section according to the identified type; wherein the types of track circuit to be tested include 25Hz phase-sensitive track circuit and ZPW-2000 series station track circuit; The rail line is mathematically modeled using the track four-terminal network mathematical model. By adjusting the ballast resistance value parameters in the model, the corresponding rail surface current attenuation ratio is calculated and the "attenuation ratio-ballast resistance" table is established. The rail surface currents at the power supply and receiving ends measured on site are obtained, the rail surface current attenuation ratio is calculated, and the current ballast resistance value of the track circuit section is obtained by looking up the table.

2. The real-time online test method for track circuit ballast resistance according to claim 1 is characterized in that: The identified types are further classified into track circuit sections, including: When identified as a 25Hz phase-sensitive track circuit, the track circuit sections are further classified into one sending and one receiving section, one sending and two receiving section, and one sending and three receiving section, and it can handle possible non-powered branches with choke transformers in parallel at the end of the branch and non-powered branches without choke transformers at the end of the branch.

3. The real-time online testing method for track circuit ballast resistance according to claim 1 is characterized in that: The identified types are further classified into track circuit sections, including: When identified as a ZPW-2000 series station track circuit, it is further classified into a one-sending and one-receiving section without a power receiving branch section, a one-sending and one-receiving section with a choke transformer in parallel at the end of the branch and a no power receiving branch section without a choke transformer at the end of the branch.

4. The real-time online testing method for track circuit ballast resistance according to claim 2 is characterized in that: For a non-powered branch with a choke transformer connected in parallel at the branch end, the impedance of the choke transformer is determined by measuring the rail surface voltage and rail surface current at the branch end; The choke transformer is modeled using a four-terminal network model of parallel impedance, and the four-terminal network of the non-powered branch is cascaded with the four-terminal network of the choke transformer to achieve accurate modeling of the branch end.

5. The real-time online test method for track circuit ballast resistance according to claim 2 is characterized in that: When dealing with a one-transmitting-multiple-receiving section, only the receiving end farthest from the transmitting end is regarded as the main receiving end, while the other receiving ends are regarded as non-receiving branches with a choke transformer connected in parallel at the end of the branch.

6. The real-time online test method for track circuit ballast resistance according to claim 3 is characterized in that: The track section with compensation capacitor is modeled by cascading the segmented rail line four-terminal network and the compensation capacitor four-terminal network.

7. The real-time online test method for track circuit ballast resistance according to claim 3 is characterized in that: When dealing with a non-powered branch, an equivalent model of the rail resistance, rail inductance and rail capacitance of the parallel section based on the length of the non-powered branch and the parallel length of the main rail line is proposed; when a choke transformer is connected in parallel at the end of the non-powered branch, the choke transformer adopts a four-terminal network model of parallel impedance and is connected to the end of the parallel section.

8. The real-time online test method for track circuit ballast resistance according to claim 1 is characterized in that: When the mathematical model of the rail four-terminal network is used to mathematically model the rail line, the mathematical model of the rail four-terminal network is shown in the formula: Among them, γ is the propagation constant of the rail line, Z c is the characteristic impedance of the rail line, x is the length of the rail line; U2 and I2 are the input voltage and current of the track four-terminal network, and U1 and I1 are the load voltage and current of the track four-terminal network.

9. The real-time online test method for track circuit ballast resistance according to claim 8 is characterized in that: γ and Z c The relationship with rail resistance, rail inductance, rail capacitance and ballast resistance includes: Among them, f is the frequency of the current track circuit section, specifically one of the five frequencies of 25Hz, 1700Hz, 2000Hz, 2300Hz, and 2600Hz.

10. A real-time online test system for track circuit ballast resistance, characterized in that: The system comprises: An identification module is used to identify the type of track circuit to be tested, and further classify the track circuit section according to the identified type; wherein the types of track circuit to be tested include 25Hz phase-sensitive track circuit and ZPW-2000 series station track circuit; Modeling module, used to mathematically model the rail line using the track four-terminal network mathematical model, calculate the corresponding rail surface current attenuation ratio by adjusting the ballast resistance value parameters in the model, and establish the "attenuation ratio-ballast resistance" table; The test module is used to obtain the rail surface current at the power supply and receiving ends measured on site, calculate the rail surface current attenuation ratio, and obtain the current ballast resistance value of the track circuit section by looking up the table.

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