Real-time online measurement method and system for impedance of mechanical insulation joint of track circuit

Abstract

The invention discloses a track circuit mechanical insulation joint impedance real-time online measurement method and system. The method is suitable for a ZPW-2000 series in-station track circuit section, and the impedance value of the insulation joint can be monitored in real time so as to evaluate the insulation performance of the insulation joint. Track circuit equipment, a steel rail line and an insulation joint are abstracted into an integral mathematical model, and a quantitative relation between an insulation joint impedance value and an adjacent frequency current on a steel rail lead wire of transmitting and receiving end equipment is established, so that the method can be suitable for a scene that two ends of the insulation joint are communicated or not communicated. Four-end network modeling and a'source-load 'transmission loop are utilized, the adjacent-frequency current of adjacent sections is calculated, an'adjacent-frequency current-insulation resistance' table is established, and the current resistance value of the insulation joint is determined by quickly looking up the table. According to the real-time online measurement technology, the measurement efficiency is remarkably improved, the requirement for manual detection is reduced, the maintenance cost is reduced, and meanwhile the safety and reliability of a railway signal system are enhanced.

Description

Technical Field

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

[0002] In the railway signaling field, track circuit sections are separated by insulating sections to prevent leakage of electrical signals between adjacent track circuit sections.

[0003] The insulation joints used on site are mainly divided into mechanical insulation joints and electrical insulation joints. The insulation joints are exposed to the outdoor environment, wind, sun, rain, especially the mechanical insulation joints, which are squeezed and worn by the train wheels for a long time, and are prone to damage. The causes of damage are complicated and difficult to find, which puts great pressure on signal professional maintainers.

[0004] In order to understand the insulation performance of the insulation joint, signal professional maintenance personnel need to measure the impedance of the insulation joint to quantify the insulation performance of the insulation joint. At present, the measurement method of the insulation joint mainly adopts instruments, such as multimeter, insulation megger and special insulation joint impedance measuring instrument. The multimeter can make a qualitative judgment on the performance of the insulation joint, and the insulation megger cannot measure online. The special insulation joint measuring instrument is widely used because of its high accuracy and online measurement.

[0005] However, the current measurement cycle of insulation joints is as short as one day and as long as two weeks, which is far from meeting the requirement of real-time grasp of the insulation joint performance; at the same time, the number of insulation joints at the station is large (all stations are mechanical insulation joints) and their locations are scattered. It takes a team of two people about 5 hours to complete the measurement of all insulation joints. Summary of the invention

[0006] Based on this, an embodiment of the present application provides a real-time online measurement method and system for the impedance of a mechanical insulation node of a track circuit, which can solve the problems existing in the prior art.

[0007] In a first aspect, a real-time online measurement method for the impedance of a mechanical insulation node of a track circuit is provided, the method comprising:

[0008] A mathematical model is established based on the acquired parameters of the track circuit equipment, rail line and insulation joint body at both ends of the insulation joint; wherein the mathematical model specifically includes the quantitative relationship between the insulation joint impedance value and the adjacent frequency current on the rail lead wire of the power transmission and receiving end equipment;

[0009] The insulation node and the choke transformers at both ends are modeled by using a four-terminal network, and a quantitative relationship is established between the impedance value after insulation damage and the four-terminal network.

[0010] In the mathematical model, the power transmission equipment in this section is equivalent to a load impedance, whose value is equal to the internal resistance of the power supply after the power transmission equipment is equivalent to a voltage source; at the same time, the power transmission equipment in the adjacent section is equivalent to a voltage source to establish a "source-load" transmission loop;

[0011] Calculate the adjacent frequency currents of the rail lead wires of the power supply and receiving equipment in two adjacent sections respectively, and establish an "adjacent frequency current-insulation impedance" table based on the calculation results;

[0012] By using the on-site measuring equipment, the adjacent frequency current of the rail lead wires at the power transmission and receiving ends is measured online in real time. Then, according to the "adjacent frequency current-insulation impedance" table, the current impedance value of the insulation joint can be obtained by looking up the table, thereby realizing the real-time online measurement of the insulation joint impedance of the track circuit section within the station.

[0013] Optionally, the method specifically implements real-time online measurement of insulation node impedance of track circuit sections within ZPW-2000 series stations.

[0014] Optionally, a mathematical model is established based on the acquired parameters of the track circuit equipment, rail line and insulating joint body at both ends of the insulating joint, and the mathematical model is applicable to both scenarios where the two ends of the insulating joint are connected and not connected.

[0015] Optionally, a mathematical model is established based on the acquired parameters of the track circuit equipment at both ends of the insulating joint, the rail line and the insulating joint body, specifically including:

[0016] The voltage source and internal resistance of each track circuit device, the resistance, inductance, rail capacitance of the rail line, and the impedance value of the insulation joint are used as acquisition parameters to establish a mathematical model.

[0017] Optionally, a four-terminal network is used to model the insulation node and the choke transformers at both ends. For a rail line without compensation capacitor, the mathematical model of the track four-terminal network is shown in the formula:

[0018]

[0019] 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.

[0020] Optionally, γ and Z c The relationship with rail resistance, rail inductance, rail capacitance and ballast resistance includes:

[0021]

[0022] Among them, f is the frequency of the current track circuit section, specifically one of the four frequencies of 1700Hz, 2000Hz, 2300Hz, and 2600Hz.

[0023] Optionally, in the case of modeling the insulating node and the choke transformers at both ends thereof by means of a four-terminal network, for a rail line with a compensation capacitor, the track four-terminal network is a cascade of a segmented rail line and a compensation capacitor, and the impedance of the compensation capacitor is composed of the compensation capacitor and its rail lead wire. The four-terminal network calculation method formula specifically includes:

[0024]

[0025] 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.

[0026] Optionally, a "source-load" transmission loop is established, specifically including:

[0027] First, the power transmission equipment in this section is equivalent to a load impedance; wherein the value of the load impedance is the internal resistance of the power supply after the power transmission equipment is regarded as a voltage source;

[0028] Next, the power transmission equipment of the adjacent section is equivalent to a voltage source, that is, a simplified circuit model is constructed, which includes the power transmission equipment of the adjacent section and the power transmission equipment of the current section;

[0029] The “source-load” transmission loop is used to simulate and calculate the transmission behavior of signals in track circuits, especially the propagation and detection of adjacent frequency signals in track circuits when the insulation joint is damaged.

[0030] Optionally, the adjacent frequency currents of the rail lead wires of the power supply and receiving end equipment in two adjacent sections are calculated respectively, and an "adjacent frequency current-insulation impedance" table is established based on the calculation results, specifically including:

[0031] By using the established "source-load" transmission loop, the adjacent frequency currents on the rail lead wires of the power supply and receiving equipment in two adjacent sections are calculated respectively;

[0032] According to the calculated adjacent frequency current, an "adjacent frequency current-insulation impedance" table is established; wherein, the "adjacent frequency current-insulation impedance" table is a lookup table that maps the adjacent frequency current corresponding to different insulation impedance values. Specifically, by measuring the adjacent frequency current on site, the impedance value of the insulation joint can be quickly determined by looking up the table.

[0033] In a second aspect, a real-time online measurement system for the mechanical insulation impedance of a track circuit is provided, the system comprising:

[0034] A model building module is used to build a mathematical model based on the acquired parameters of the track circuit equipment at both ends of the insulating joint, the rail line and the insulating joint body; wherein the mathematical model specifically includes the quantitative relationship between the impedance value of the insulating joint and the adjacent frequency current on the rail lead wire of the power transmission and receiving end equipment;

[0035] A four-terminal network modeling module is used to model the insulation node and the choke transformers at both ends thereof by using a four-terminal network, and to establish a quantitative relationship between the impedance value after insulation damage and the four-terminal network;

[0036] The first processing module is used to, in the mathematical model, treat the power transmission end equipment of the current section as equivalent to a load impedance, whose value is equal to the internal resistance of the power supply after the power transmission end equipment is equivalent to a voltage source; at the same time, treat the power transmission end equipment of the adjacent section as equivalent to a voltage source, and establish a "source-load" transmission loop for calculating the adjacent frequency current;

[0037] The second processing module is used to calculate the adjacent frequency currents of the rail lead wires of the power supply and receiving end equipment in two adjacent sections respectively, and establish an "adjacent frequency current-insulation impedance" table according to the calculation results;

[0038] The online measurement module is used to measure the adjacent frequency current of the rail lead-in wires at the power supply and receiving ends in real time online using the on-site measurement equipment. Then, according to the "adjacent frequency current-insulation impedance" table, the current impedance value of the insulation joint can be obtained by looking up the table, thereby realizing real-time online measurement of the insulation joint impedance of the track circuit section within the station.

[0039] The beneficial effects brought by the technical solution provided by the embodiment of the present application include at least:

[0040] (1) It can realize real-time online measurement of the insulation joint impedance of the track circuit section in the ZPW-2000 series station, avoiding the tedious and time-consuming regular offline detection required in traditional measurement methods. Through real-time monitoring, potential problems of insulation joints can be quickly discovered and responded to, thereby significantly improving the measurement efficiency and the response speed of maintenance work.

[0041] (2) By real-time online monitoring of the impedance value of the insulation joint, the damage of the insulation joint can be discovered in time to prevent signal error transmission caused by the degradation of insulation performance, which is crucial to ensure the normal operation of the railway signal system and the safety of railway transportation. In addition, real-time monitoring also helps to reduce unexpected stops and delays caused by insulation joint problems, improving the overall reliability of railway transportation.

[0042] (3) Real-time online measurement reduces the frequency and workload of manual inspection, thereby reducing maintenance costs. At the same time, since problems can be discovered and repaired in a timely manner, potential maintenance costs and operational interruption losses caused by insulation joint problems are also reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] 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.

[0044] Figure 1 A real-time online measurement flow chart of the mechanical insulation joint impedance of a track circuit provided in an embodiment of the present application;

[0045] Figure 2 This is a schematic diagram of a track circuit in an embodiment of the present application;

[0046] Figure 3 This is a schematic diagram of an application scenario of an insulation joint in an embodiment of the present application;

[0047] Figure 4 This is a schematic diagram of the insulation joint damage in the embodiment of the present application;

[0048] Figure 5 This is a schematic diagram of a rail line (without compensation capacitor);

[0049] Figure 6 This is a schematic diagram of a rail line (with compensation capacitor);

[0050] Figure 7 It is a schematic diagram of the mathematical model of the rail line;

[0051] Figure 8 This is a schematic diagram of the track four-terminal network (with compensation capacitors);

[0052] Fig. 9 This is the equivalent circuit diagram of the insulation node being damaged (with a connected scenario);

[0053] Fig.10 Another equivalent circuit diagram for a damaged insulation joint (with a connected scenario);

[0054] Fig.11 This is the equivalent circuit diagram of the insulation node and the choke transformer (with a connected scenario);

[0055] Fig.12 This is a schematic diagram of a damaged insulation joint (no connectivity scenario);

[0056] Fig.13 This is the equivalent circuit diagram of the insulation node being damaged (no connectivity scenario);

[0057] Fig.14 This is the equivalent circuit diagram of the insulation node being damaged (no connectivity scenario). DETAILED DESCRIPTION

[0058] 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.

[0059] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two. The terms "first" and "second" in the specification and claims of the present invention and the above-mentioned drawings are intended to distinguish the objects referred to. For schemes with a sequential flow, this terminology does not have to be understood as describing a specific order or sequence. For schemes with device structures, this terminology does not distinguish between importance, positional relationships, etc.

[0060] In addition, the terms "comprises", "has" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that have been 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 that are added based on further optimization schemes conceived by the present invention.

[0061] Specifically, please refer to Figure 1 , which shows a flow chart of a real-time online measurement method for the mechanical insulation joint impedance of a track circuit provided by an embodiment of the present application. The method may include the following steps:

[0062] S1, a mathematical model is established based on the acquired parameters of the track circuit equipment at both ends of the insulating joint, the rail line and the insulating joint body.

[0063] The mathematical model specifically includes the quantitative relationship between the insulation joint impedance value and the adjacent frequency current on the rail lead wires of the power transmission and receiving end equipment.

[0064] S2, using a four-terminal network to model the insulation node and the choke transformers at both ends, and establish a quantitative relationship between the impedance value after insulation damage and the four-terminal network;

[0065] S3, in the mathematical model, the power transmission equipment in this section is equivalent to a load impedance, whose value is equal to the internal resistance of the power supply after the power transmission equipment is equivalent to a voltage source; at the same time, the power transmission equipment in the adjacent section is equivalent to a voltage source to establish a "source-load" transmission loop;

[0066] S4, respectively calculate the adjacent frequency currents of the rail lead wires of the power supply and receiving end equipment in two adjacent sections, and establish an "adjacent frequency current-insulation impedance" table based on the calculation results;

[0067] S5, using on-site measuring equipment, real-time online measurement of the adjacent frequency current of the rail lead-in wires at the power supply and receiving ends, and then, according to the "adjacent frequency current-insulation impedance" table, the current impedance value of the insulation joint can be obtained by looking up the table, thus realizing real-time online measurement of the insulation joint impedance of the track circuit section within the station.

[0068] The present application provides a real-time online measurement method for the mechanical insulation joint impedance of a track circuit, which can perform real-time online measurement of the insulation joint impedance of a track circuit section in a ZPW-2000 series station. It can be applied to two scenarios, namely, the two ends of the insulation joint are connected or not connected, and can meet all application scenarios on site.

[0069] Specifically, the track circuit equipment, rail lines and the insulating joint itself of the track circuit sections at both ends of the insulating joint are abstracted into an overall mathematical model, and then based on this model, a quantitative relationship between the impedance value of the insulating joint and the adjacent frequency current on the rail lead wires of the power sending and receiving end equipment is established.

[0070] The mathematical model uses a four-terminal network to model the insulation joint and the choke transformers at both ends, so as to establish a quantitative relationship between the impedance value after insulation damage and the four-terminal network. When calculating the adjacent frequency current of this section, the power transmission equipment of this section is equivalent to a load impedance, and the load impedance value is equal to the internal resistance of the power supply after the power transmission equipment is equivalent to a voltage source. At the same time, the power transmission equipment of the adjacent section is equivalent to a voltage source, so as to establish a "source-load" transmission loop. According to the different impedance values ​​of the insulation joint between the two adjacent sections, the adjacent frequency currents of the rail lead wires of the power transmission and receiving end equipment of the two adjacent sections are calculated respectively, so as to establish an "adjacent frequency current-insulation impedance" table. According to the adjacent frequency currents of the rail lead wires of the power transmission and receiving end measured online on site in real time, the current impedance value of the insulation joint can be obtained by looking up the table.

[0071] The following is a specific embodiment of the present application. The problem to be solved by the present invention is: efficient, real-time, and online measurement of the insulation impedance of a mechanical insulation joint. This embodiment is mainly divided into three parts, namely, the application scenario of the mechanical insulation joint and the online measurement modeling of the insulation joint impedance.

[0072] 1. Application scenarios of mechanical insulation joints

[0073] like Figure 2 The track circuit schematic diagram shown in the figure shows that BE is a choke transformer, power transmission refers to the track circuit sending equipment, power receiving refers to the track circuit receiving equipment, and three sets of insulating nodes (small black vertical lines) divide the track circuit sections into two sections. BE, power transmission, and power receiving are all connected to the rails through rail lead wires, forming a track circuit signal transmission loop of power transmission → double rail line → power receiving. The function of BE is to provide a path for traction return current.

[0074] like Figure 3The following is a schematic diagram of the insulation joint application scenario. In field applications, the equipment on both sides of the insulation joint is divided into the following three types: Figure 3 .

[0075] (1) BEs are installed at both ends and connected by a central connecting plate;

[0076] (2) BEs are set at both ends, but the BEs are not connected;

[0077] (3) BE is set at one end and not at the other end, or not at both ends.

[0078] When one of the insulation nodes in a group is damaged, the isolation performance of scenario (1) is more seriously degraded than that of scenarios (2) and (3). Therefore, this solution classifies the application scenarios of insulation nodes into two types: the two ends of the insulation nodes are connected and the two ends are not connected.

[0079] 2 Modeling of online measurement of insulation joint impedance

[0080] 2.1 Insulation joint impedance measurement principle

[0081] like Figure 4 The schematic diagram of insulation joint damage is shown in the figure. The top middle half-circle line indicates that the insulation joint between AG and BG is damaged. Since the signal frequencies of AG and BG are different, the BG frequency signal will appear on the AG power transmission and power receiving rail lead wires, and the AG frequency signal will also appear on the BG power transmission and power receiving rail lead wires. The number of adjacent section frequency signals (referred to as "adjacent frequency signals") on the power transmission and power receiving rail lead wires of this section reflects the degree of insulation joint damage. The larger the adjacent frequency signal, the more serious the insulation joint damage and the smaller the insulation joint impedance.

[0082] 2.2 Rail line modeling

[0083] When the rail line is longer than a certain length, a compensation capacitor will be connected in parallel to offset the inductive load of the rail and extend the transmission length of the track circuit. Figure 5 Schematic diagram of rail line (without compensation capacitor), Figure 6 Schematic diagram of rail line (with compensation capacitor).

[0084] 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 7 Schematic diagram of the mathematical model of the rail line.

[0085] Figure 7 In the equation, R is the rail resistance, in Ω / km; L is the rail inductance, in mH / km; C is the rail capacitance, in μF / km; G is the rail conductance, which is equal to the reciprocal of the ballast resistance, in Ω·km. Δx is the unit length of the rail line, in m.

[0086] The mathematical model of the track four-terminal network is shown in formula (1).

[0087]

[0088] 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.

[0089] γ and Z c The relationship with rail resistance, rail inductance, rail capacitance and ballast resistance is shown in formula (2) and formula (3).

[0090]

[0091] Among them, for the ZPW-2000 series station track circuits, f is the frequency of the current track circuit section, that is, one of the four frequencies of 1700Hz, 2000Hz, 2300Hz, and 2600Hz.

[0092] For rail lines without compensation capacitors (shown Figure 5 ), and the calculation method of the track four-terminal network is shown in formula (1).

[0093] For rail lines with compensation capacitors (shown in Figure 6 ), the track four-terminal network is a cascade of segmented rail lines and compensation capacitors, as shown in the figure. Figure 8 The cascade calculation of the first track four-terminal network on the left (length is △ / 2), the first capacitor, and the second track four-terminal network (length is △) is shown in formula (4), and the others are similar.

[0094]

[0095] 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 (5).

[0096]

[0097] 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.

[0098] 2.3 Insulation impedance modeling for scenarios where both ends of an insulation node are connected

[0099] Insulation damage indication when both ends of the insulation joint are connected Figure 4 When the insulation joint is intact, its impedance is not less than 1MΩ, and it is considered as 1MΩ in the modeling. Figure 4 The equivalent circuit of the damage scenario shown can be equivalent to Fig. 9 .

[0100] Fig. 9 In the figure, the rail lines of AG and BG are equivalent to the track four-terminal network, the impedance of the damaged insulation node is Rps, and the impedance of the undamaged insulation node is Rok.

[0101] Since the powered device is a passive network, it can be directly equivalent to a load. Its impedance value is the visible impedance from the rail line to the indoor direction. The visible impedance of the AG and BG powered devices is recorded as Rsag and Rsbg respectively.

[0102] Since the power transmission equipment is an active network with an independent power supply, according to the Thevenin theorem, it can be equivalent to a series connection of a voltage source and a resistor, and the series resistor is the internal resistance of the power supply.

[0103] When calculating the current leaking from BG to AG due to insulation damage, Fig. 9 In the equivalent circuit, there can be only one power source, namely, the BG power transmission device, and the AG power transmission device can be regarded as a load, that is, its equivalent voltage source is zero, and the load impedance is its equivalent internal resistance. Therefore, Fig. 9 The circuit shown can be further equivalent to Fig.10 The circuit shown. Fig.10 The equivalent circuit diagram of the insulation joint damage (connection scenario) is given.

[0104] Fig.10 In the figure, Zag and Zas are the equivalent impedances of the AG power transmitting end and the power receiving end; the dotted box is the equivalent circuit of the insulation node and the choke transformer, and Z is the impedance of half the coil of the choke transformer; R is the internal resistance of the AG power transmitting end equivalent to the power supply, and AC is the power supply voltage; Zbs is the equivalent impedance of the BG power receiving end; and Zel is the equivalent impedance of the entire coil of the choke transformer.

[0105] According to formula (1) or formula (4), the four-terminal network of AG and BG can be calculated respectively, and the equivalent circuit of the insulation node and the choke transformer can also be expressed by the four-terminal network. Fig.11 The equivalent circuit diagram of the insulation node and choke transformer (with connection scenario) is shown in the figure.

[0106] Fig.11 The four-terminal network can be expressed by formula (6), where A11, A12, A21, and A22 are the quantities to be determined.

[0107]

[0108] When U2 = 0, that is, the left side of the four-terminal network is short-circuited, formula (7) can be obtained from formula (6), Z 10 The impedance of the four-terminal network when the left side is short-circuited and viewed from the right side.

[0109]

[0110] When I2 = 0, that is, the left side of the four-terminal network is open, formula (8) can be obtained from formula (6), Z 1∞ The impedance of the four-terminal network when the left side is open and viewed from the right side.

[0111]

[0112] From formula (6), the reverse transmission network of the four-terminal network (i.e., the current flows in from the left and flows out from the right) can be derived, see formula (9).

[0113]

[0114] When U1 = 0, that is, the right side of the four-terminal network is short-circuited, formula (10) can be obtained from formula (9), Z 20 The impedance of the four-terminal network when the right side is short-circuited and viewed from the left side.

[0115]

[0116] When I1 = 0, that is, the right side of the four-terminal network is open, formula (11) can be obtained from formula (9), Z 2∞ The impedance of the four-terminal network when the right side is open and viewed from the left side.

[0117]

[0118] According to the series and parallel principle of impedance, it is easy to express Z with Rps 10 , Z 1∞ , Z 20 , Z 2∞ , substituting into formulas (7), (8), (10), and (11), we can calculate A 11 , A 12 , A 21 , A 22 , thus obtaining the four-terminal network model of the equivalent circuit of the insulation node and the choke transformer.

[0119] When insulation is damaged, the calculation method of the current leakage from BG to AG is shown in formula (12).

[0120]

[0121] The right side of the equal sign in the formula is a four-terminal network from left to right, which includes the internal resistance of the power supply, the equivalent circuit of the insulation node and choke transformer, the equivalent impedance of the AG receiving end, the rail line of the AG, and the equivalent impedance of the AG sending end. U1 and I1 are the power supply side, and U2 and I2 are the load side.

[0122] In formula (12), the equivalent impedance of the AG power transmission end is also regarded as a four-terminal network, which is equivalent to an open circuit at the load end, that is, I2 = 0. Since the voltage U1 of the voltage source AC is a known condition, the current I1 can be calculated by substituting the condition I2 = 0 into formula (12).

[0123] According to the matrix calculation principle, formula (12) can be expressed by formula (13), with the superscript -1 as the matrix solution. Then, according to the left side of the equal sign of formula (13), the current leaking from BG to the AG power transmission end equipment and the power transmission end choke transformer can be calculated. According to the left side of the equal sign of formula (14), the current leaking from BG to the AG power transmission end choke transformer can be calculated. The current calculated by formula (13) minus the current calculated by formula (14) is the current on the rail lead wire of the power transmission end equipment.

[0124]

[0125] Similarly, the current calculated on the left side of the equal sign of formula (15) minus the current calculated on the left side of the equal sign of formula (16) is the current leaking from BG to the rail lead wire at the AG receiving end.

[0126]

[0127] In this way, the resistance R after the insulation is damaged ps A quantitative relationship is established between the adjacent frequency (BG frequency) current on the rail lead-in wire at the AG power transmission end and the adjacent frequency (BG frequency) current on the rail lead-in wire at the AG power receiving end.

[0128] Similarly, the above method can also be used to calculate the resistance R after insulation damage. ps A quantitative relationship is established between the adjacent frequency (AG frequency) current of the BG sending and receiving end rail lead wires.

[0129] According to the different insulation impedance values ​​of the insulation joint between AG and BG, the adjacent frequency currents of the rail lead wires at the power supply and receiving ends of AG and BG are calculated respectively, so as to establish an "adjacent frequency current-insulation impedance" table. According to the adjacent frequency currents of the rail lead wires at the power supply and receiving ends of AG and BG measured online in real time on site, the current impedance value of the insulation joint can be obtained by looking up the table.

[0130] 2.4 Insulation impedance modeling for scenarios where both ends of the insulation node are not connected

[0131] Insulation damage indication when both ends of the insulation joint are not connected Fig.12 , the equivalent circuit is shown in Fig.13 .

[0132] The difference between the non-connected scenario and the connected scenario lies mainly in the equivalent circuit of the insulation node and the choke transformer. The further equivalent circuit is shown in Fig.14 .

[0133] According to formulas (6) to (11), the four-terminal network of the equivalent circuit of the insulation node and the choke transformer can be calculated. Substituting it into formula (12), the "adjacent frequency current-insulation impedance" table of the non-connected scenario can be calculated according to the same steps as the connected scenario.

[0134] An embodiment of the present application also provides a real-time online measurement system for the impedance of mechanical insulation nodes of a track circuit.

[0135] The system includes:

[0136] A model building module is used to build a mathematical model based on the acquired parameters of the track circuit equipment at both ends of the insulating joint, the rail line and the insulating joint body; wherein the mathematical model specifically includes the quantitative relationship between the impedance value of the insulating joint and the adjacent frequency current on the rail lead wire of the power transmission and receiving end equipment;

[0137] A four-terminal network modeling module is used to model the insulation node and the choke transformers at both ends thereof by using a four-terminal network, and to establish a quantitative relationship between the impedance value after insulation damage and the four-terminal network;

[0138] The first processing module is used to, in the mathematical model, treat the power transmission end equipment of the current section as equivalent to a load impedance, whose value is equal to the internal resistance of the power supply after the power transmission end equipment is equivalent to a voltage source; at the same time, treat the power transmission end equipment of the adjacent section as equivalent to a voltage source, and establish a "source-load" transmission loop for calculating the adjacent frequency current;

[0139] The second processing module is used to calculate the adjacent frequency currents of the rail lead wires of the power supply and receiving end equipment in two adjacent sections respectively, and establish an "adjacent frequency current-insulation impedance" table according to the calculation results;

[0140] The online measurement module is used to measure the adjacent frequency current of the rail lead-in wires at the power supply and receiving ends in real time online using the on-site measurement equipment. Then, according to the "adjacent frequency current-insulation impedance" table, the current impedance value of the insulation joint can be obtained by looking up the table, thereby realizing real-time online measurement of the insulation joint impedance of the track circuit section within the station.

[0141] The real-time online measurement system for the mechanical insulation joint impedance of a track circuit provided in the embodiment of the present application is used to implement the above-mentioned real-time online measurement method for the mechanical insulation joint impedance of a track circuit. For the specific definition of the real-time online measurement system for the mechanical insulation joint impedance of a track circuit, please refer to the definition of the real-time online measurement method for the mechanical insulation joint impedance of a track circuit in the above text, which will not be repeated here. Each part of the above-mentioned real-time online measurement system for the mechanical insulation joint impedance of a track circuit can be fully or partially implemented by software, hardware and a combination thereof. 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.

[0142] 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.

[0143] 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 measurement method for the impedance of a mechanical insulation node of a track circuit, characterized in that: The method comprises: A mathematical model is established based on the acquired parameters of the track circuit equipment, rail line and insulation joint body at both ends of the insulation joint; wherein the mathematical model specifically includes the quantitative relationship between the insulation joint impedance value and the adjacent frequency current on the rail lead wire of the power transmission and receiving end equipment; The insulation node and the choke transformers at both ends are modeled by using a four-terminal network, and a quantitative relationship is established between the impedance value after insulation damage and the four-terminal network. In the mathematical model, the power transmission equipment in this section is equivalent to a load impedance, whose value is equal to the internal resistance of the power supply after the power transmission equipment is equivalent to a voltage source; at the same time, the power transmission equipment in the adjacent section is equivalent to a voltage source to establish a "source-load" transmission loop; Calculate the adjacent frequency currents of the rail lead wires of the power supply and receiving equipment in two adjacent sections respectively, and establish an "adjacent frequency current-insulation impedance" table based on the calculation results; By using the on-site measuring equipment, the adjacent frequency current of the rail lead wires at the power transmission and receiving ends is measured online in real time. Then, according to the "adjacent frequency current-insulation impedance" table, the current impedance value of the insulation joint can be obtained by looking up the table, thus realizing the real-time online measurement of the insulation joint impedance of the track circuit section within the station.

2. The real-time online measurement method for the mechanical insulation impedance of a track circuit according to claim 1 is characterized in that: The method specifically implements real-time online measurement of insulation node impedance of track circuit sections within ZPW-2000 series stations.

3. The real-time online measurement method of track circuit mechanical insulation joint impedance according to claim 1 is characterized in that: A mathematical model is established based on the acquired parameters of the track circuit equipment, rail line and insulating joint body at both ends of the insulating joint. The mathematical model is applicable to two scenarios: the two ends of the insulating joint are connected and the two ends are not connected.

4. The real-time online measurement method of track circuit mechanical insulation joint impedance according to claim 1 is characterized in that: A mathematical model is established based on the acquired parameters of the track circuit equipment at both ends of the insulating joint, the rail line and the insulating joint body, including: The voltage source and internal resistance of each track circuit device, the resistance, inductance, rail capacitance of the rail line, and the impedance value of the insulation joint are used as acquisition parameters to establish a mathematical model.

5. The real-time online measurement method for track circuit mechanical insulation joint impedance according to claim 1 is characterized in that: In the modeling of the insulation node and the choke transformers at both ends using a four-terminal network, for rail lines without compensation capacitors, the mathematical model of the track 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.

6. The real-time online measurement method of track circuit mechanical insulation joint impedance according to claim 5 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 four frequencies of 1700Hz, 2000Hz, 2300Hz, and 2600Hz.

7. The real-time online measurement method for track circuit mechanical insulation joint impedance according to claim 1 is characterized in that: In the modeling of the insulation node and the choke transformers at both ends using a four-terminal network, for a rail line with compensation capacitors, the track four-terminal network is a cascade of segmented rail lines and compensation capacitors. The impedance of the compensation capacitor is composed of the compensation capacitor and its rail lead wire. The four-terminal network calculation method formula specifically includes: 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.

8. The real-time online measurement method for track circuit mechanical insulation joint impedance according to claim 1 is characterized in that: Establish a "source-load" transmission loop, including: First, the power transmission equipment in this section is equivalent to a load impedance; wherein the value of the load impedance is the internal resistance of the power supply after the power transmission equipment is regarded as a voltage source; Next, the power transmission equipment of the adjacent section is equivalent to a voltage source, that is, a simplified circuit model is constructed, which includes the power transmission equipment of the adjacent section and the power transmission equipment of the current section; The "source-load" transmission loop is used to simulate and calculate the transmission behavior of signals in the track circuit, especially the propagation and detection of adjacent frequency signals in the track circuit when the insulation joint is damaged.

9. The real-time online measurement method for the mechanical insulation joint impedance of a track circuit according to claim 1 is characterized in that: Calculate the adjacent frequency currents of the rail lead wires of the power supply and receiving equipment in two adjacent sections respectively, and establish an "adjacent frequency current-insulation impedance" table based on the calculation results, including: By using the established "source-load" transmission loop, the adjacent frequency currents on the rail lead wires of the power supply and receiving equipment in two adjacent sections are calculated respectively; According to the calculated adjacent frequency current, an "adjacent frequency current-insulation impedance" table is established; wherein, the "adjacent frequency current-insulation impedance" table is a lookup table that maps the adjacent frequency current corresponding to different insulation impedance values. Specifically, by measuring the adjacent frequency current on site, the impedance value of the insulation joint can be quickly determined by looking up the table.

10. A real-time online measurement system for mechanical insulation impedance of a track circuit, characterized in that: The system comprises: A model building module is used to build a mathematical model based on the acquired parameters of the track circuit equipment at both ends of the insulating joint, the rail line and the insulating joint body; wherein the mathematical model specifically includes the quantitative relationship between the impedance value of the insulating joint and the adjacent frequency current on the rail lead wire of the power transmission and receiving end equipment; A four-terminal network modeling module is used to model the insulation node and the choke transformers at both ends thereof by using a four-terminal network, and to establish a quantitative relationship between the impedance value after insulation damage and the four-terminal network; The first processing module is used to treat the power transmission end equipment of the current section as equivalent to a load impedance in the mathematical model, and its value is equal to the internal resistance of the power supply after the power transmission end equipment is equivalent to a voltage source; at the same time, the power transmission end equipment of the adjacent section is equivalent to a voltage source to establish a "source-load" transmission loop for calculating the adjacent frequency current; The second processing module is used to calculate the adjacent frequency currents of the rail lead wires of the power supply and receiving end equipment in two adjacent sections respectively, and establish an "adjacent frequency current-insulation impedance" table according to the calculation results; The online measurement module is used to measure the adjacent frequency current of the rail lead wires at the power supply and receiving ends in real time online using the on-site measurement equipment. Then, according to the "adjacent frequency current-insulation impedance" table, the current impedance value of the insulation joint can be obtained by looking up the table, thereby realizing real-time online measurement of the insulation joint impedance of the track circuit section within the station.

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