Anti-interference system for axle counting suitable for 27.5kv system line
By optimizing the installation position of the axle counting sensor on the 27.5KV standard line of the urban railway and adopting grounding wire and current equalization wire technology, the problem of harmonic current interference on the axle counting equipment was solved, and the stable operation of the equipment and the safe and efficient operation of rail transit were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- TAIZHOU CHANGXING RAIL TRANSIT OPERATION MANAGEMENT CO LTD
- Filing Date
- 2025-08-21
- Publication Date
- 2026-05-29
AI Technical Summary
The axle counting equipment on the 27.5KV standard line of the urban rail transit is susceptible to harmonic current interference, which leads to frequent failures and affects the safety and efficiency of rail transit.
By optimizing the installation position of the axle counting sensor along the track, using electromagnetic shielding and distance attenuation principles, and combining grounding wire and current-equalizing line technology, the influence of external interference on the axle counting sensor is reduced, and anti-interference measures suitable for different track bed types are designed.
It effectively suppresses interference from axle counting equipment, reduces the failure rate, decreases maintenance costs and operational interruptions, and improves the safety and efficiency of train operation.
Smart Images
Figure CN224297183U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of rail transit technology, specifically to an axle counting anti-interference system suitable for 27.5KV railway lines. Background Technology
[0002] Axle counting equipment is a type of railway signaling device used to detect whether a track section is occupied by a train or is vacant. It mainly consists of two parts: outdoor equipment and indoor equipment. The outdoor equipment includes axle counting sensors (magnetic heads) installed on or under the track, and the main axle counting cabinet installed in a trackside machine room. When a train passes, the axle counting sensors detect wheel signals (electromagnetic induction) and convert them into electrical signals, which are then transmitted to the main axle counting cabinet. The main cabinet analyzes and calculates the number of axles passed by each wheel to determine the train's position and direction of travel, ensuring safe train operation. Therefore, ensuring the stable and reliable operation of the axle counting equipment is crucial. A malfunction in the axle counting equipment can lead to train delays, operational chaos, and a series of other problems, seriously affecting the operational safety and efficiency of rail transit.
[0003] Currently, urban railways generally use a 27.5KV AC overhead contact system for power supply; that is, power is supplied to the train via substation—overhead contact system—pantograph—roller equipment—rails—return to traction substation. However, due to the large axle load of the locomotive and the high target speed of the train, the instantaneous change in traction current is large at the moment of power supply or acceleration. This generates a large amount of harmonic current components in the traction power supply system. These harmonic currents are released onto the rails and then return through the rails, interfering with the axle counting sensors installed on the rails, thus causing malfunctions in the axle counting equipment (see [link to details]). Figure 1 ). Utility Model Content
[0004] To overcome the aforementioned problems in existing technologies, this utility model provides an axle counting anti-interference system suitable for 27.5KV railway lines. By optimizing the installation position of the axle counting sensor along the track and utilizing electromagnetic shielding and distance attenuation principles, it avoids placing the sensor near strong electromagnetic interference sources, reduces the impact of external interference on the axle counting sensor, lowers the axle counting failure rate, and ensures the safe and efficient operation of rail transit. Specifically, differentiated anti-interference measures are adopted according to different track bed types: For the mainline integral track bed, a separate grounding technology is used at both ends of the axle counting point. Utilizing the low resistance characteristics of the grounding grid, the interference current generated by the rail return flow is introduced into the ground, reducing the traction current flowing through the axle counting sensor and ensuring the stable operation of the axle counting equipment; For the crushed stone track bed in the depot, a current equalization technology is used to evenly distribute the rail return flow before and after the axle counting point to the surrounding tracks, effectively weakening the interference of large currents on the rails on the axle counting sensor and ensuring the normal operation of the axle counting equipment in the complex environment of the depot.
[0005] The technical solution of this application is as follows: an axle counting anti-interference system applicable to 27.5KV standard lines, including a track, axle counting sensors, and an axle counting main cabinet; a set of axle counting points are distributed at intervals on the track; the axle counting sensors are installed at the axle counting points to collect wheelset information when a train passes the track; the axle counting main cabinet is installed in a machine room next to the track to process the information collected by the axle counting sensors to determine the track occupancy or vacancy status; when the track is a mainline track and uses an integral ballast bed, a grounding wire is provided at both ends of the axle counting sensor on the rail of the track; the other end of the grounding wire is connected to the grounding grid; when the track is a depot track and uses a crushed stone ballast bed, a flow equalization line is provided at both ends of the axle counting sensor on the rail of the track; the other end of the flow equalization line is connected to the rail of the surrounding track, so that the rails of the parking track area, turnout area, and depot entry / exit throat area of the depot track are connected in series.
[0006] Compared with existing technologies, the axle counting anti-interference system of this application for 27.5KV lines optimizes the installation position of the axle counting equipment along the track and utilizes electromagnetic shielding and distance attenuation principles to avoid placing the equipment near strong electromagnetic interference sources. This effectively suppresses axle counting interference, reduces the axle counting failure rate, thereby lowering maintenance costs and indirect losses caused by operational interruptions, improving economic efficiency, and reducing train delays and operational disorder, ensuring the safe and efficient operation of rail transit. The axle counting anti-interference system of this application is developed from multiple dimensions, including layout and grounding, based on different interference sources and levels. It integrates two different anti-interference strategies: For the mainline track bed, grounding wires are used to individually ground both ends of the axle counting point, forming an independent grounding system. This utilizes the low resistance characteristics of the grounding grid to conduct electromagnetic interference generated by rail return current into the ground before it enters the axle counting sensor. This pre-return current method effectively reduces the traction current flowing through the axle counting sensor, reduces the impact of interference on the axle counting equipment, and thus improves the operational stability of the axle counting equipment. For the ballast track bed in the depot, a flow equalization line is used to connect the rails before and after the axle counting point with the rails of the surrounding tracks. This connects the rails in the parking track area, turnout area, and throat area of the depot track in series. Based on the principles of electromagnetic induction and current distribution, the return current of the rails before and after the axle counting point can be evenly distributed to the surrounding tracks. This method of equalizing the return current can effectively reduce the interference of large currents on the rails on the axle counting sensor, ensuring the normal operation of the axle counting equipment in the complex environment of the depot.
[0007] As an optimization, in the aforementioned axle counting anti-interference system applicable to 27.5KV lines, one end of the grounding wire is equipped with a grounding hook; the grounding hook is fixedly fastened to the rail. This grounding hook installation method is easy to assemble, has low implementation difficulty, and allows for easy replacement and relocation, offering high flexibility. Furthermore, connecting pieces are welded to both ends of the grounding wire; these connecting pieces are bolted to the lead-out end of the grounding grid and the grounding hook. This results in a simple, easy-to-implement connection structure with high connection strength. Furthermore, the track bed of the main line is equipped with wire clamps for limiting the grounding wire. These clamps allow for the organization of the grounding wire, reducing space occupation, and prevent maintenance personnel from tripping over tangled lines during later maintenance.
[0008] As an optimization, in the aforementioned axle counting anti-interference system applicable to 27.5KV lines, grounding hooks are installed at both ends of the current averaging line; the grounding hooks are fixedly connected to the rail. This grounding hook installation method allows for easy replacement and relocation, offering high flexibility. Furthermore, connecting pieces are welded to both ends of the current averaging line; these connecting pieces are fixed to the grounding hooks with bolts. This results in a simple, easy-to-implement connection structure with high connection strength. Furthermore, wire clamps are installed on the sleepers of the depot tracks to limit the movement of the current averaging line. This allows for the organization of the grounding wires using the wire clamps, reducing space occupation and preventing maintenance personnel from tripping over messy lines during later maintenance.
[0009] As an optimization, in the aforementioned axle counting anti-interference system applicable to 27.5kV lines, the grounding wire and current-equalizing wire can be 70mm². 2 Copper cable. 70mm 2 Copper cables have advantages such as high current carrying capacity, high transmission efficiency, good corrosion resistance, and high mechanical strength. They are not easily broken during installation, have high reliability, are suitable for harsh environments such as humidity and high temperature, and have a long service life. Attached Figure Description
[0010] Figure 1 This is a schematic diagram of the disturbance of the shaft counting equipment in the existing technology;
[0011] Figure 2 This is a schematic diagram (main track) of the axle counting anti-interference system applicable to 27.5KV standard lines according to this application.
[0012] Figure 3 This is a schematic diagram of the axle counting anti-interference system adopted by Wenling Chengnan Station in Taizhou City in the implementation case of this application (a is the main line track, b is the depot track). Detailed Implementation
[0013] The present application will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the scope of the application. Contents not described in detail in the following embodiments are all common knowledge in the art or can be implemented using conventional techniques in the art.
[0014] To address the common problem of interference in existing 27.5KV axle counting systems for urban railways, the company's research team constructed an axle counting system model based on massive amounts of data collected and in-depth analysis. Through repeated simulations and optimizations of this model, they independently developed an axle counting anti-interference system suitable for 27.5KV lines. This system innovatively integrates two anti-interference measures, enabling effective suppression of axle counting interference based on different interference sources and levels.
[0015] The data collection and analysis process is as follows.
[0016] (i) Operational scenario data collection: Using monitoring equipment and data collection systems, comprehensive information on operational scenarios is collected under different time periods (such as peak, off-peak, and low-peak periods) and different train operation states (acceleration, constant speed, deceleration, and stopping), including real-time position of train operation, speed changes, signal transmission status, etc., so as to facilitate subsequent analysis of the axle counting system's operation status under various working conditions.
[0017] (II) In-depth analysis of failure cases: A systematic review of axle counting failure cases was conducted, and detailed records were made of various parameters of the axle counting equipment at the time of each failure, including the installation height, sensing height, working voltage and current of the axle counting sensor; at the same time, environmental conditions at the time of failure were recorded, such as weather conditions (temperature, humidity, lightning, etc.), electrical characteristics of the track, and vehicle operation; through in-depth analysis of these data, the potential patterns and influencing factors of failure were identified.
[0018] (III) Interference Waveform Characteristic Analysis: Using oscilloscope testing equipment, a comprehensive and in-depth analysis of the axle interference waveform is conducted; from the frequency dimension, the frequency range of the interference signal is accurately measured to determine whether it overlaps or interferes with the operating frequencies of other communication equipment, power equipment, etc.; from the amplitude perspective, the intensity variation law of the interference signal is explored in detail, and its correlation with the train operation status and changes in the surrounding environment is analyzed, providing solid data support for the subsequent formulation of targeted anti-interference measures.
[0019] By comprehensively collecting operational scenario information under different time periods and train operating conditions, and recording in detail the equipment parameters and environmental conditions in axle counter failure cases, and by using an oscilloscope to deeply analyze the waveform characteristics of axle counter interference, the interference patterns were analyzed from multiple dimensions such as frequency and amplitude. This provided a solid data foundation for subsequent technology research and development and the formulation of measures, enabling the anti-interference measures of this application to be highly consistent with the actual interference situation.
[0020] The specific anti-interference measures are as follows.
[0021] (I) Anti-interference measures for the main line: Considering the characteristics of the main line track using an integral track bed and the track beds being connected by a ground grid loop, anti-interference measures for connecting to the ground grid were designed (see...). Figure 2 At the axle counting outdoor equipment (axle counting sensor), at 3 meters for both the small and large mileage intervals (if site conditions are limited, this can be extended appropriately within a reasonable range), use a dedicated grounding hook to install a 70mm grounding hook. 2 A high-quality grounding wire is used and connected to the grounding grid connection point. Utilizing the low resistance characteristics of the grounding grid, the interference current generated by the rail return flow is quickly diverted to the ground, effectively reducing the impact of interference on the axle counting equipment and ensuring its stable operation.
[0022] Adding a rail grounding wire to a single axle counting point will change the potential of that point, making it the point with the lowest potential in the vicinity. As a result, current will preferentially flow to that axle counting point. In this case, the interference intensity flowing from behind the axle counting sensor will increase, affecting other axle counting points. Therefore, in actual operation, the method of adding grounding wires to all points is adopted.
[0023] (II) Anti-interference measures for the depot: Considering that the depot has a crushed stone track bed and lacks grounding conditions such as grounding and continuous grounding wires near the axle counting points, current sharing technology is adopted as an anti-interference measure. A 70mm... 2 Copper cables are attached to the rails before and after the axle counter using dedicated grounding hooks. Following a carefully designed flow-equalizing layout, the rails in key locations such as the parking track area, turnout area, and throat area of the depot access lines are connected in series. This method evenly distributes the current back to the surrounding rails, effectively reducing the interference of high current on the rails on the axle counter sensor and ensuring the normal operation of the axle counter system in the complex environment of the depot.
[0024] Implementation Case:
[0025] In this case, the two anti-interference measures mentioned above were applied to the main line track and the depot track of Wenling Chengnan Station in Taizhou City.
[0026] See Figure 3 The axle counting anti-interference system applicable to 27.5KV line in this case includes a track, axle counting sensors, and an axle counting main cabinet; a set of axle counting points are distributed at intervals on the track; the axle counting sensors are installed at the axle counting points to collect wheelset information when the train passes the track; the axle counting main cabinet is installed in a machine room next to the track to process the information collected by the axle counting sensors to determine the track occupancy or vacancy status;
[0027] When the track is a mainline track using an integral track bed, a grounding wire is installed on each end of the axle counter sensor on the rail. The other end of each grounding wire is connected to a grounding grid. Connecting pieces are welded to both ends of each grounding wire. One connecting piece is bolted to the lead-out end of the grounding grid, and the other connecting piece is bolted to a grounding hook, which is then secured to the rail. A wire clamp is installed on the track bed to limit the movement of the grounding wire. The grounding wire is 70mm long. 2 Copper cable;
[0028] When the track is a depot track with a ballast bed, a flow equalization line is installed at both ends of the axle counting sensor on the rails. The other end of the flow equalization line is connected to the rails of the surrounding tracks, thus connecting the rails in the parking track area, turnout area, and throat area of the depot access track in series. Connecting pieces are welded to both ends of the flow equalization line. The connecting pieces are bolted to grounding hooks. The grounding hooks are clamped to the rails. The sleepers of the depot track are equipped with wire clamps to limit the movement of the flow equalization lines. The flow equalization lines are all 70mm in diameter. 2 Copper cables.
[0029] The axle counting anti-interference system described in this application effectively solves the common interference problem of 27.5KV axle counting systems in urban railways, reduces the axle counting failure rate, lowers maintenance costs and indirect losses caused by operational interruptions, and reduces train delays and operational disorder, ensuring the safe and efficient operation of rail transit and enhancing the passenger travel experience. Furthermore, the axle counting anti-interference system of this application employs differentiated anti-interference measures for different track bed types, enabling the system to adapt to various complex environments. This provides new ideas and methods for the field of axle counting anti-interference, and also offers valuable experience for other similar lines. It has good scalability and is conducive to promoting the further development of the entire rail transit industry.
[0030] The foregoing general description of the utility model and its specific embodiments should not be construed as limiting the technical solution of the utility model. Those skilled in the art, based on the disclosure of this application, can add, reduce, or combine the disclosed technical features in the foregoing general description and / or specific embodiments (including examples) without departing from the constituent elements of the utility model, to form other technical solutions within the protection scope of this application.
Claims
1. An axle counting anti-interference system suitable for 27.5KV power lines, comprising a track, axle counting sensors, and an axle counting main unit cabinet; a set of axle counting points are distributed at intervals on the track; the axle counting sensors are installed at the axle counting points to collect wheelset information when a train passes the track; the axle counting main unit cabinet is installed in a machine room next to the track to process the information collected by the axle counting sensors to determine the track occupancy or vacancy status; characterized in that: When the track is a mainline track with an integral ballast bed, a grounding wire is installed at both ends of the axle counter sensor on the rails of the track; the other end of the grounding wire is connected to the grounding grid. When the track is a depot track with a crushed stone ballast bed, a flow equalization line is installed at both ends of the axle counter sensor on the rails of the track; the other end of the flow equalization line is connected to the rails of the surrounding tracks, so that the rails of the parking track area, turnout area, and depot entry / exit throat area of the depot track are connected in series.
2. The axle counting anti-interference system for 27.5KV transmission lines according to claim 1, characterized in that: One end of the grounding wire is equipped with a grounding hook; the grounding hook is clamped and fixed to the rail.
3. The axle counting anti-interference system for 27.5KV transmission lines according to claim 2, characterized in that: The grounding wire has connecting pieces welded to both ends; the connecting pieces are fixed to the lead-out end of the grounding grid and the grounding hook by bolts.
4. The axle counting anti-interference system for 27.5KV transmission lines according to claim 3, characterized in that: The track bed of the main line is equipped with a wire clamp for limiting the grounding wire.
5. The axle counting anti-interference system for 27.5KV transmission lines according to claim 1, characterized in that: The two ends of the flow equalization line are respectively equipped with grounding hooks; the grounding hooks are clamped and fixed to the rail.
6. The axle counting anti-interference system for 27.5KV transmission lines according to claim 5, characterized in that: The two ends of the flow equalization line are respectively welded with connecting pieces; the connecting pieces are fixed to the grounding hook by bolts.
7. The axle counting anti-interference system for 27.5KV transmission lines according to claim 6, characterized in that: The sleepers of the depot track are equipped with wire clips to limit the flow lines.
8. The axle counting anti-interference system for 27.5KV transmission lines according to claim 1, characterized in that: Both the grounding wire and the current-equalizing wire are 70mm. 2 Copper cables.