Compatibility setting method of grounding system at the junction of railway station and section

Abstract

The present invention relates to the technical field of railway integrated grounding, in particular to a method for setting compatibility of grounding systems at the junction of railway stations and sections, comprising the following steps: when the track circuit of the station approaching section is a ZPW‑2000 track circuit, a short-circuit line directly connected to the rails 23m outside the track circuit is used as an equipotential connection point; when the track circuit of the station approaching section is a 25Hz track circuit, at the choke transformer set at the end of the station approaching section, equipotential connection is achieved by setting a completely horizontal connecting line. The present invention is based on an integrated grounding system in which rails are used in sections instead of through-ground wires, and an integrated grounding system in which through-ground wires are laid separately at stations, and proposes an equipotential connection method between integrated grounding systems at the junction of railway stations and sections.

Description

Technical Field

[0001] The invention relates to the technical field of railway integrated grounding, in particular to a method for setting compatibility of a grounding system at a junction of a railway station and a section. Background Art

[0002] The current standard high-speed railway integrated grounding system is developed based on the ZPW-2000 track circuit in the section. By setting up a single through ground wire as a common ground wire, the equipotential connection between the electrical equipment and facilities along the railway and the integrated grounding system is achieved. The through ground wire is the core carrier of the integrated grounding system. The rails, return wires, through ground wires and the earth serve as the return channels for traction return current, of which the through ground wire bears 15-20% of the traction return current. In view of the difficulties faced in construction and operation and maintenance of high-speed railways in difficult mountainous areas with many equipment points and long lines, as well as the construction goals of the new CTCS-4 level train control system and the characteristics of CBTC railways under the AC traction power supply system, their common feature is that there is no track circuit in the section. Since one of the key technologies of the integrated grounding set under the existing specifications is to solve the problem of electromagnetic interference between the ZPW-2000 track circuit equipment and the traction return current by setting up a single through ground wire, the compatibility of the signal track circuit and the traction return current system is achieved. If there is no ZPW-2000 track circuit equipment in the section, the best existing return conductor, steel rail, can be used instead of the through ground wire as a common ground wire. The advantage of this solution is that there is no need to lay a separate through ground wire along the railway, which can significantly improve the construction and operation and maintenance effects, reduce maintenance difficulties and other problems, and adapt to the harsh natural geographical environment and the high-speed railway in the harsh operating environment to the greatest extent. If a separate through ground wire is set according to the integrated grounding system of the section and station, the equipotential connection between the section and the station is directly achieved through a continuous and uninterrupted through ground wire. Since the section uses steel rails instead of through ground wires, the equipotential connection scheme between the integrated grounding system of the section and the station also needs to be adaptively optimized and improved.

[0003] The integrated grounding system of the station adopts the method of laying a through ground wire separately, and the section adopts the method of replacing the through ground wire with a steel rail. According to the overall principle of the integrated grounding system, in order to avoid the dangerous potential difference between the two at the junction, damage to the trackside equipment along the line and the safety of the operation and maintenance personnel, it is necessary to achieve equipotential connection at the junction of the station and the section. The equipotential connection plan should be combined with the track circuit system and equipment layout, and try to use the existing equipment as much as possible without adding any additional equipment. Summary of the invention

[0004] The present invention is based on a comprehensive grounding system in which rails replace through-ground wires in sections and a comprehensive grounding system in which through-ground wires are separately laid in stations, and proposes a method for setting compatibility of grounding systems at the junction of railway stations and sections.

[0005] In order to achieve the above objectives, the following technical solutions are proposed:

[0006] The method for setting compatibility of the grounding system at the junction of a railway station and a section includes the following steps:

[0007] Setting up steel rails as common ground wires;

[0008] When the track circuit in the station approach section is a ZPW-2000 track circuit, a short-circuit line is set at a preset distance from the suction line position outside the tuning and matching receiving and sending units of the track circuit along the rail to directly connect to the rail to achieve equipotential connection;

[0009] When the track circuit of the station approach section is a 25Hz track circuit, a complete transverse connecting line is installed at the choke transformer installed at the end of the station approach section to achieve equipotential connection.

[0010] Preferably, the preset distance is 23m.

[0011] Preferably, the complete transverse connection of the station approach section includes a station entrance having a complete transverse connection and a station entrance not having a complete transverse connection.

[0012] Preferably, when complete transverse connecting lines are set to achieve equipotential connection, the spacing of the complete transverse connecting lines is determined according to the ballast bed resistance: when the ballast bed resistance is not less than 2Ω·km, the distance between adjacent complete transverse connecting lines is greater than or equal to 1200m; when the ballast bed resistance is less than 2Ω·km, the distance between adjacent complete transverse connections is greater than or equal to 1500m.

[0013] Compared with the prior art, the present invention has the following beneficial effects: the present invention is based on a comprehensive grounding system in which rails replace through-ground wires in sections, and a comprehensive grounding system in which through-ground wires are separately laid in stations. A method for setting the grounding system compatibility at the junction of railway stations and sections is proposed, which not only does not require additional equipment and saves investment, but also meets the requirement that the track circuit can work normally. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of equipotential connection of the ZPW-2000 track circuit station approach section junction in Example 1;

[0015] Figure 2 It is a schematic diagram showing that the distance between two adjacent fully horizontal connections in Example 1 should not be less than 1500m;

[0016] Figure 3 This is a schematic diagram of equipotential connection at the junction of the 25Hz track circuit station approaching section in Example 1;

[0017] Figure 4 This is an equipotential connection diagram of the junction where a complete horizontal connection is not provided at the station entrance in Example 1;

[0018] Figure 5 This is the equipotential connection diagram of the junction with complete horizontal connection at the station entrance in Example 1. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with test examples and specific implementation methods. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0020] Example 1

[0021] The boundary between the station and the section is the entry signal JX and JXN. According to the specification, the entry signal must be equipped with a circuit close to the section track to realize the train occupancy check. The entry signal is the boundary between the station and the section, that is, Figure 1 In the middle, X and XN. According to the interlocking logic requirements, each station entry signal must be set with an approach section for train occupancy inspection and interlocking with the signal. This function is realized by the track circuit outside the signal. There are currently two types of track circuits, namely ZPW-2000 and 25Hz track circuits. Therefore, the following mainly describes the equipotential connection scheme of the grounding system under the two track circuit systems.

[0022] 1) Use ZPW-2000 track circuit. Since there is only one tuned matching receiving and transmitting unit BA at the end of the approaching section, there is no electrical insulation node, that is, it is impossible to short-circuit and transmit the track circuit information from the approaching signal JX / JXN through the rail. In order to ensure the normal operation of the track circuit in the approaching section and prevent the track circuit from sending information to the approaching signal JX / JXN through other loops, and causing the train locomotive signal to operate in advance by crossing BA, according to the technical conditions of the ZPW-2000 track circuit, generally along the track direction, about 23m away from the tuned matching receiving and transmitting unit BA, a short-circuit line directly connected to the rail is set. The function of this short-circuit line is to short-circuit the track circuit information that should not pass through BA. Therefore, the joint is first considered to be connected at the same potential here, and no additional choke transformer is required. Try to be in the same position as the complete horizontal connection line set in the section without track circuit, and no additional equipment is required. At the same time, changes in the external environment and rails will also affect the transmission characteristics of the track circuit, making the information transmission distance across the BA uncertain, causing the locomotive signal receiving position to be unstable, causing the driver to misjudge and possibly stop.

[0023] The schematic diagram of equipotential connection of the ZPW-2000 track circuit station approach section is as follows Figure 1As shown in the figure, there is usually a traction substation in the station. In order to reduce the imbalance of traction return and meet the requirements of electromagnetic interference on equipment and facilities along the line due to the rapid return of traction return, according to the experience of railway engineering construction, a complete transverse connection line is generally set at the entrance far away from the traction substation. Since the complete transverse connection line is set near the end of the section (23m in the figure) and the entrance (X and XN), the track circuit may form a "third rail" in addition to the two rails, that is, rail-transverse connection line-rail-transverse connection line-rail, rail-suction line-return line-suction line-rail or rail-transverse connection grounding line-through grounding line-transverse connection grounding line-rail, resulting in the failure of the normal circuit of the track circuit to be disconnected. The hidden danger of failure not leading to the safety side, while the normal track circuit path is the track circuit sending equipment BA at JX-rail-receiving equipment BA near the end of the section. Therefore, the minimum connection spacing between the adjacent two transverse connection lines at the entrance and near the end of the section should be able to ensure the normal operation of the track circuit without forming a "third rail". Furthermore, the suction line is the equipotential connection line between the rail and the overhead return line. Its function is to reduce the traction return on the rail to reduce the rail potential and protect the safety of personnel and equipment. The position of the suction line requires the same "sky-ground" position, that is, the suction line is connected to the return line in the sky and to the four rails and the through ground wire (if any) on the ground. Therefore, the position of the suction line is the same as the equipotential connection line and short-circuit wire of the rail to avoid excessive drilling of the rail.

[0024] The above-mentioned full transverse connection spacing is determined according to the resistance of the ballast bed. When the ballast bed resistance is not less than 2Ω·km, the distance between two adjacent full transverse connections should not be less than 1200m; when the ballast bed resistance is less than 2Ω·km, the distance between two adjacent full transverse connections should not be less than 1500m. If the approach section is calculated based on the maximum allowable speed of 160km / h, the length of the station approach section is at least 2800m, which is greater than the full transverse connection spacing under the most unfavorable ballast bed resistance of the line. It can be concluded that it is feasible to implement the grounding system connection plan of the joint according to this requirement. The schematic diagram of the distance between two adjacent full transverse connections should not be less than 1500m is as follows Figure 2 shown.

[0025] 2) Use 25Hz track circuit. Figure 3As shown, a choke transformer has been installed near the end of the section of the station, and priority is given to achieving equipotential connection of the joint by setting a complete transverse connection line at this location. As mentioned above in the "third rail" of the ZPW-2000 track circuit, for stations with 25Hz track circuits, since the track section in the throat area of ​​the station is generally short, and the two adjacent 25 Hz track circuit sections use phase cross protection, if the distance between the two complete transverse connection lines is too short, the "third rail" of the track circuit will be formed, which is not conducive to the fault safety protection of the track circuit, that is, when a track circuit fails, the current of other track circuit sections with the same phase may cause the track relay of this section to malfunction.

[0026] Taking the above factors into consideration, the spacing between adjacent fully horizontal connecting lines should meet the requirements for the normal operation of the 25Hz track circuit. According to the experience of railway engineering construction, if the length of the "third rail" of the 25Hz track circuit is greater than 3km, that is, after exceeding 3km, the track circuit signal will be significantly attenuated and insufficient to move the track circuit equipment, which can meet the normal operation of the track circuit. Figure 3 L 轨道 As mentioned above for the ZPW-2000 track circuit, the installation of full transverse connection lines at the end of the approach section and the entrance to the station does not meet the normal operation of the 25Hz track circuit. There are two situations in which the full transverse connection is set up at the station approach section. One is that the entrance is equipped with a full transverse connection, and the other is that the joint part of the entrance is not equipped with a full transverse connection. Figure 4 As shown in the figure, the second is that there is no complete horizontal connection. The equipotential connection diagram of the joint with complete horizontal connection at the entrance is as follows Figure 5 As shown, however, the prerequisite is that the connection of the joint grounding system is achieved close to the end of the section.

[0027] As mentioned above, the length of the approach section is generally 2.8 km, which is less than the safety limit of the 25Hz track circuit "third rail". Figure 4 If there is no full lateral connection at the entrance, a full lateral connection can be set up near the end of the section, and another full lateral connection can be set up at a location greater than 3 km. Figure 5 If the entrance is equipped with a complete transverse connection, then a complete transverse connection can be provided outside the approaching section greater than 3 km from the entrance, increasing the construction workload such as rail drilling. Figure 5 Although the distance between the entrance and the fully lateral connection line outside the approach section meets the requirements for the use of a 25Hz track circuit, the track circuit information will still form a circuitous loop through the rail - choke transformer midpoint grounding wire - through ground wire - choke transformer midpoint grounding wire - rail, and the track circuit will lose fault safety protection, regardless of whether a fully lateral connection is set up near the end.

[0028] Therefore, the first method is recommended for equipotential connection of the joint grounding system, that is, to set a complete transverse connection near the end. In short, the principle of equipotential connection of the joint is to achieve it by setting a complete transverse connection line, but it must be ensured that the spacing between two adjacent complete transverse connection lines should meet the normal operation of track circuits of different standards and cannot lead to the dangerous side.

[0029] In summary, the equipotential connection of the ZPW-2000 track circuit station approach section junction is realized at the end of the approach section using existing equipment, but the spacing between the complete horizontal connection line and the station entrance must be greater than 1500m. The equipotential connection of the 25Hz track circuit station approach section junction is also realized at the end of the approach section using existing equipment, but the spacing between the complete horizontal connection line and the station entrance must be greater than L 轨道 Greater than 3000m.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for setting compatibility of grounding systems at the junction of railway stations and sections, characterized in that: The following steps are involved: Setting up steel rails as common ground wires; When the track circuit of the station approach section is a ZPW-2000 track circuit, a short-circuit line is set at a preset distance from the suction line position outside the tuning and matching receiving and sending units of the track circuit along the rail to directly connect to the rail to achieve equipotential connection; including: full transverse connecting lines are set at the end of the approach section and the entrance, and the minimum connection spacing between the two adjacent transverse connecting lines at the entrance and the end of the approach section should be able to ensure the normal operation of the track circuit without forming a "third rail"; when full transverse connecting lines are set to achieve equipotential connection, the spacing of full transverse connecting lines is determined according to the resistance of the ballast bed: when the ballast bed resistance is not less than 2 Ω·km, the distance between adjacent full transverse connecting lines is greater than or equal to 1200m; when the ballast bed resistance is less than 2 Ω·km, the distance between adjacent full transverse connecting lines is greater than or equal to 1500m; When the track circuit of the station approach section is a 25Hz track circuit, a complete transverse connecting line is set at the choke transformer set at the end of the station approach section to achieve equipotential connection; including: the equipotential connection of the joint is achieved by setting a complete transverse connecting line, ensuring that the spacing between two adjacent complete transverse connecting lines should meet the normal operation of track circuits of different standards and cannot lead to the dangerous side; the equipotential connection of the joint of the 25Hz track circuit station approach section is also achieved at the end of the approach section using existing equipment, but it must be ensured that the spacing L track of the complete transverse connecting line with the entrance is greater than 3000m.

2. The method for setting compatibility of grounding system at the junction of railway station and section as claimed in claim 1, characterized in that: The preset distance is 23m.

3. The method for setting compatibility of grounding system at the junction of railway station and section as claimed in claim 1, characterized in that: The full lateral connection of the station approach section includes the station entrance with a full lateral connection and the station entrance without a full lateral connection.

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