Transition method of overhead line system in non-stop state of existing metro vehicle depot

Abstract

The invention relates to the technical field of catenary transition, in particular to a catenary transition method in a non-stop state of an existing metro depot, which comprises the following steps of: acquiring point clouds of the existing catenary, a substation and a tunnel structure by using a millimeter-level precision laser scanner, constructing a four-dimensional BIM model, setting the tension of a wire to be 10-15kN, and setting the tension of the wire to be 10-15kN; the coordinate error of the suspension point is controlled to be + / -5mm, and the amplitude of the overhead line system is less than or equal to 50mm when According to the method, conflict points are pre-judged through high-precision three-dimensional laser scanning and four-dimensional BI M modeling, rigid-flexible suspension space interference in a low clearance area is solved in combination with a U-shaped insulating cross arm, parallel seamless switching of a new power supply system and an old power supply system is achieved through a pre-lifting busbar and a partition insulator, and operation interference is greatly reduced; according to the night skylight period hydraulic synchronous control, the rigid network is reduced section by section with millimeter-level precision, and the elastic coefficient is dynamically optimized with the assistance of an AI-driven LSTM neural network, so that the service life of equipment is prolonged, the use amount of temporary struts is reduced, and the annual maintenance cost is saved.

Description

Technical Field

[0001] This invention relates to the field of overhead contact line transition technology, specifically a transition method for overhead contact lines in the absence of interruption of operation in existing subway depots. Background Technology

[0002] The subway track contact network is a dedicated power supply line erected above the rails. It transmits electrical energy from the traction substation to the train drive system via a pantograph that slides into contact with a sliding plate on the train's roof, providing continuous power for subway operation. Its structural forms are mainly divided into two categories: overhead and contact rail. The overhead flexible contact network uses a chain-like suspension design of the catenary and contact wire, suitable for elevated and ground-level sections. The overhead rigid contact network uses busbars to fix the contact wire and is mainly used in tunnel sections. The contact rail collects current through contact between the trackside conductive rail and the current collector shoe. All three must ensure power supply stability and safety to meet the high-density, high-capacity operational needs of urban rail transit.

[0003] However, traditional overhead contact line transition construction typically requires a complete shutdown of the entire line to create a work window. It adopts a linear process of segmented dismantling and reconstruction, first cutting off the existing power supply system and then erecting new equipment. The process relies on manual measurement and positioning and mechanical hoisting, which not only interrupts train operation but also takes several weeks to months. Its rigid design is difficult to adapt to tunnel settlement or temperature deformation, which can easily lead to contact wire tension imbalance and increased local wear. Especially in the anchor section joints and turnout areas, it can easily cause pantograph-catenary arcing or wire breakage. Furthermore, the switching between the old and new systems requires multiple switching operations and lacks real-time monitoring methods. Current transfer errors may exceed the limits and cause power supply disturbances. At the same time, the maintenance costs are high and significantly affect the normal operation of the urban transportation network.

[0004] In summary, a transition method for the overhead contact system without interrupting operation of existing subway depots is needed to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a transition method for the overhead contact system in an existing subway depot without interrupting operation, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention proposes a transition method for the overhead contact system while maintaining operation in an existing subway depot, characterized by the following steps:

[0008] S1. Use a millimeter-precision laser scanner to collect point clouds of existing overhead contact lines, substations and tunnel structures, and build a four-dimensional BIM model. Set the conductor tension to 10-15kN, control the suspension point coordinate error to ±5mm, and simulate the overhead contact line amplitude ≤50mm when the train is running.

[0009] S2. Identify the spatial conflict points between the newly added rigid suspension and the existing flexible suspension, and install fiberglass U-shaped insulated cross braces in sections with a clearance of <5m. The U-shaped opening width is 200mm, the depth is 150mm, the length of the suspension channel steel is 600mm, the bolt length is ≤80mm, and the insulation strength is ≥100kV.

[0010] S3. Pre-install a rigid busbar above the flexible contact wire, with a pre-lift height of 100mm. Install a wire-laying pulley every 16m and install a 120mm high pulley. 2 Temporary electrical connection cable, pull-out value ≤ 250mm, cold sliding test height difference 100±10mm;

[0011] S4. In straight sections or superelevation ≤50mm sections, a slotted joint transition section is installed with a transition length of 12-15m. The rigid contact wire is 30-50mm higher than the flexible wire, and the pantograph is raised 2-5mm at the entry / exit point.

[0012] S5. During the nighttime skylight period, the busbar is lowered segment by segment at a rate of ≤10mm / minute. Non-insulated joint anchor sections are constructed simultaneously, and the flexible line is raised by 100mm to exit operation. The anchor section height difference is calibrated to ±1mm, and the dynamic envelope of the insulation gap is ≥150mm.

[0013] S6. The depot and main line power supply are separated by partition insulators. The length of the power supply partition is ≤1.5km. The parallel operation time of new and old equipment is ≤30 minutes and the current transfer error is ≤5%. The automatic switching system achieves link switching in <15 minutes.

[0014] S7. The inspection vehicle runs at a speed of 5-15 km / h, with a static lifting force of 70N±10N for the pantograph, and detects contact wire hard points ≤50g, conductor height deviation ±5mm, and pull-out value ±10mm.

[0015] S8. Based on the contact pressure and offline rate data with a sampling rate of 1kHz, the suspension point elastic coefficient is optimized to 15-20kN / mm using an LSTM neural network to compensate for the lifting amount, ensuring that the standard deviation of the contact pressure is ≤20N and the offline rate is <5%.

[0016] Preferably, the implementation steps of step S1 are as follows:

[0017] S1.1. On-site scanning preparation: Using a Leica P40 3D laser scanner, scanning stations were set up during the nighttime shutdown period, with one station every 30m, covering the contact wire, substation equipment and tunnel structure, and simultaneously collecting the existing contact wire tension parameters and the initial coordinates of the suspension points;

[0018] S1.2. Point cloud data processing: Denoise and stitch the point cloud using Cyclone software to generate a 3D model of the tunnel structure, label equipment attributes, and calibrate the coordinate error of the suspension point to within ±5mm;

[0019] S1.3. Construction of 4D BIM model: Integrate point cloud model into Revit platform, add time dimension to simulate catenary vibration when train passes, and verify pantograph-catenary dynamic envelope space conflict;

[0020] S1.4. Collision Pre-simulation Analysis: Navisworks is used to detect the collision points between the newly added rigid suspension and the existing pipeline, and a conflict report is output.

[0021] Preferably, the implementation steps of step S2 are as follows:

[0022] S2.1. Conflict point identification and location: Based on the BIM model, tunnel sections with a clearance of <5m are screened, and the minimum spacing point between the existing flexible suspension and rigid busbar is marked;

[0023] S2.2. Customized cross bracing structure: Design fiberglass U-shaped cross bracing: opening width 200mm, depth 150mm, suspension channel steel length 600mm, bolt length ≤80mm;

[0024] S2.3. Installation and Insulation Test: Drill holes at the point of impact to install the cross brace. The bolt torque is controlled at 100 N·m. After installation, use a 2500V megohmmeter to test the insulation strength of the cross brace. The test result is ≥100kV.

[0025] Preferably, the implementation steps of step S3 are as follows:

[0026] S3.1. Pre-lifting and positioning: A rigid busbar is installed 100mm above the flexible contact line and temporarily fixed with adjustable hangers, with a safety margin of ≥60mm;

[0027] S3.2. Temporary electrical connection installation: Install a cable-laying pulley block every 16m, and install 120mm wires simultaneously. 2 Copper cable electrical connector, resistance value ≤0.01Ω;

[0028] S3.3. Pull-out value control: Adjust the busbar pull-out value to ≤250mm to avoid crossing with the flexible line, and use a total station to verify the positioning;

[0029] S3.4. Cold sliding pre-verification: The test vehicle runs at 10km / h to verify the height difference of 100±10mm, and laser correction is performed on the points with excessive deviation.

[0030] Preferably, the implementation steps of step S4 are as follows:

[0031] S4.1. Optimal location of transition section: Select a section with superelevation ≤50mm for straight or curved lines, with a transition length of 12-15m;

[0032] S4.2. Slotted busbar installation: Start installing the slotted element from the rigid-flexible transition end, with a pull-out value of ≤100mm throughout the entire length, and the end raised by 30-50mm;

[0033] S4.3. Control of conductor height and lifting amount: The conductor height of the rigid contact line is 30-50mm higher than that of the adjacent flexible line, and the pantograph is raised by 2-5mm at the entry / exit point;

[0034] S4.4. Transition smoothness verification: The pantograph passes at 40km / h and the offline rate is less than 5%; otherwise, adjust the grooving angle.

[0035] Preferably, the implementation steps of step S5 are as follows:

[0036] S5.1. Construction organization during the skylight period: The single operation time is ≤3 hours, divided into sections according to the direction of travel, and the temporary power connection is removed before descent;

[0037] S5.2. Rate Synchronization Control: The hydraulic descent device speed is ≤10mm / min, monitored in real time by the laser rangefinder, and automatically paused when the deviation is >3mm;

[0038] S5.3. Flexible line withdrawal: After lowering, raise the existing flexible line by 100mm, anchor it to the non-working support, and withdraw it from the current receiving area;

[0039] S5.4. Anchor section fine adjustment: calibrate joint height difference ±1mm, insulation gap ≥150mm under dynamic envelope.

[0040] Preferably, the implementation steps of step S6 are as follows:

[0041] S6.1. Power supply zone division: Zone insulators shall be installed between the depot and the main line, and the length of the power supply zone shall be ≤1.5km;

[0042] S6.2. Parallel switching of old and new equipment: Parallel operation for ≤30 minutes before switching, current transfer error ≤5%;

[0043] S6.3. Automated switching operation: Program-controlled isolating switch, link switching time <15 minutes, power supply disturbance voltage <10%.

[0044] Preferably, the implementation steps of step S7 are as follows:

[0045] S7.1. Inspection vehicle calibration: pantograph static lifting force 70N±10N, speed range 5 / 10 / 15km / h;

[0046] S7.2. Key parameter detection: hard spot detection, guide height deviation ±5mm, pull-out value ±10mm;

[0047] S7.3. Real-time data feedback: A 3D location map of the defect point is generated and correction is completed within 2 hours.

[0048] Preferably, the implementation steps of step S8 are as follows:

[0049] S8.1. Multi-source data acquisition: fiber optic sensor plus vehicle-mounted monitoring device, sampling rate 1kHz;

[0050] S8.2.LSTM Model Training: Input historical data, output optimized elasticity coefficient values;

[0051] S8.3. Lifting compensation execution: Automatically adjusts the suspension bolts to compensate for uneven flow sections;

[0052] S8.4. Closed-loop verification: Retest the pantograph-catenary dynamics index within 72 hours after optimization. If the index is not met, initiate a second optimization.

[0053] Compared with existing technologies, the beneficial effects of this invention are as follows: The method of this invention uses high-precision three-dimensional laser scanning and four-dimensional BIM modeling to predict conflict points, combined with U-shaped insulating cross bracing to solve the spatial interference of rigid and flexible suspension in low clearance areas, and uses pre-lifted busbars and zone insulators to achieve seamless parallel switching of old and new power supply systems, greatly reducing operational interference; during nighttime skylight periods, hydraulic synchronous control lowers the rigid net segment by segment with millimeter-level precision, supplemented by AI-driven LSTM neural network to dynamically optimize the elastic coefficient, ensuring that the standard deviation of contact pressure is ≤20N, and finally forming a closed-loop optimization system, which not only compresses single-segment construction to within 3 hours and eliminates pantograph-catenary accidents, extending equipment life, but also reduces the amount of temporary supports and saves annual maintenance costs. Attached Figure Description

[0054] Figure 1 The flowchart of the method for transitioning the overhead contact system under the condition of not stopping operation in an existing subway depot is shown. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] Example 1, please refer to Figure 1 This invention proposes a transition method for the overhead contact system while maintaining operation in an existing subway depot, comprising the following steps:

[0057] S1. Use a millimeter-precision laser scanner to collect point clouds of existing overhead contact lines, substations and tunnel structures, and build a four-dimensional BIM model. Set the conductor tension to 10-15kN, control the suspension point coordinate error to ±5mm, and simulate the overhead contact line amplitude ≤50mm when the train is running.

[0058] S2. Identify the spatial conflict points between the newly added rigid suspension and the existing flexible suspension, and install fiberglass U-shaped insulated cross braces in sections with a clearance of <5m. The U-shaped opening width is 200mm, the depth is 150mm, the length of the suspension channel steel is 600mm, the bolt length is ≤80mm, and the insulation strength is ≥100kV.

[0059] S3. Pre-install a rigid busbar above the flexible contact wire, with a pre-lift height of 100mm. Install a wire-laying pulley every 16m and install a 120mm high pulley. 2 Temporary electrical connection cable, pull-out value ≤ 250mm, cold sliding test height difference 100±10mm;

[0060] S4. In straight sections or superelevation ≤50mm sections, a slotted joint transition section is installed with a transition length of 12-15m. The rigid contact wire is 30-50mm higher than the flexible wire, and the pantograph is raised 2-5mm at the entry / exit point.

[0061] S5. During the nighttime skylight period, the busbar is lowered segment by segment at a rate of ≤10mm / minute. Non-insulated joint anchor sections are constructed simultaneously, and the flexible line is raised by 100mm to exit operation. The anchor section height difference is calibrated to ±1mm, and the dynamic envelope of the insulation gap is ≥150mm.

[0062] S6. The depot and main line power supply are separated by partition insulators. The length of the power supply partition is ≤1.5km. The parallel operation time of new and old equipment is ≤30 minutes and the current transfer error is ≤5%. The automatic switching system achieves link switching in <15 minutes.

[0063] S7. The inspection vehicle runs at a speed of 5-15 km / h, with a static lifting force of 70N±10N for the pantograph, and detects contact wire hard points ≤50g, conductor height deviation ±5mm, and pull-out value ±10mm.

[0064] S8. Based on the contact pressure and offline rate data with a sampling rate of 1kHz, the suspension point elastic coefficient is optimized to 15-20kN / mm using an LSTM neural network to compensate for the lifting amount, ensuring that the standard deviation of the contact pressure is ≤20N and the offline rate is <5%.

[0065] It should also be noted that the implementation steps of step S1 are as follows:

[0066] S1.1. On-site scanning preparation: Using a Leica P40 3D laser scanner, scanning stations were set up during the nighttime shutdown period, with one station every 30m, covering the contact wire, substation equipment and tunnel structure, and simultaneously collecting the existing contact wire tension parameters and the initial coordinates of the suspension points;

[0067] S1.2. Point cloud data processing: Denoise and stitch the point cloud using Cyclone software to generate a 3D model of the tunnel structure, label equipment attributes, and calibrate the coordinate error of the suspension point to within ±5mm;

[0068] S1.3. Construction of 4D BIM model: Integrate point cloud model into Revit platform, add time dimension to simulate catenary vibration when train passes, and verify pantograph-catenary dynamic envelope space conflict;

[0069] S1.4. Collision Pre-simulation Analysis: Navisworks is used to detect the collision points between the newly added rigid suspension and the existing pipeline, and a conflict report is output.

[0070] It should also be noted that the implementation steps of step S2 are as follows:

[0071] S2.1. Conflict point identification and location: Based on the BIM model, tunnel sections with a clearance of <5m are screened, and the minimum spacing point between the existing flexible suspension and rigid busbar is marked;

[0072] S2.2. Customized cross bracing structure: Design fiberglass U-shaped cross bracing: opening width 200mm, depth 150mm, suspension channel steel length 600mm, bolt length ≤80mm;

[0073] S2.3. Installation and Insulation Test: Drill holes at the point of impact to install the cross brace. The bolt torque is controlled at 100 N·m. After installation, use a 2500V megohmmeter to test the insulation strength of the cross brace. The test result is ≥100kV.

[0074] It should also be noted that the implementation steps of step S3 are as follows:

[0075] S3.1. Pre-lifting and positioning: A rigid busbar is installed 100mm above the flexible contact line and temporarily fixed with adjustable hangers, with a safety margin of ≥60mm;

[0076] S3.2. Temporary electrical connection installation: Install a cable-laying pulley block every 16m, and install 120mm wires simultaneously. 2 Copper cable electrical connector, resistance value ≤0.01Ω;

[0077] S3.3. Pull-out value control: Adjust the busbar pull-out value to ≤250mm to avoid crossing with the flexible line, and use a total station to verify the positioning;

[0078] S3.4. Cold sliding pre-verification: The test vehicle runs at 10km / h to verify the height difference of 100±10mm, and laser correction is performed on the points with excessive deviation.

[0079] It should also be noted that the implementation steps of step S4 are as follows:

[0080] S4.1. Optimal location of transition section: Select a section with superelevation ≤50mm for straight or curved lines, with a transition length of 12-15m;

[0081] S4.2. Slotted busbar installation: Start installing the slotted element from the rigid-flexible transition end, with a pull-out value of ≤100mm throughout the entire length, and the end raised by 30-50mm;

[0082] S4.3. Control of conductor height and lifting amount: The conductor height of the rigid contact line is 30-50mm higher than that of the adjacent flexible line, and the pantograph is raised by 2-5mm at the entry / exit point;

[0083] S4.4. Transition smoothness verification: The pantograph passes at 40km / h and the offline rate is less than 5%; otherwise, adjust the grooving angle.

[0084] It should also be noted that the implementation steps of step S5 are as follows:

[0085] S5.1. Construction organization during the skylight period: The single operation time is ≤3 hours, divided into sections according to the direction of travel, and the temporary power connection is removed before descent;

[0086] S5.2. Rate Synchronization Control: The hydraulic descent device speed is ≤10mm / min, monitored in real time by the laser rangefinder, and automatically paused when the deviation is >3mm;

[0087] S5.3. Flexible line withdrawal: After lowering, raise the existing flexible line by 100mm, anchor it to the non-working support, and withdraw it from the current receiving area;

[0088] S5.4. Anchor section fine adjustment: calibrate joint height difference ±1mm, insulation gap ≥150mm under dynamic envelope.

[0089] It should also be noted that the implementation steps of step S6 are as follows:

[0090] S6.1. Power supply zone division: Zone insulators shall be installed between the depot and the main line, and the length of the power supply zone shall be ≤1.5km;

[0091] S6.2. Parallel switching of old and new equipment: Parallel operation for ≤30 minutes before switching, current transfer error ≤5%;

[0092] S6.3. Automated switching operation: Program-controlled isolating switch, link switching time <15 minutes, power supply disturbance voltage <10%.

[0093] It should also be noted that the implementation steps of step S7 are as follows:

[0094] S7.1. Inspection vehicle calibration: pantograph static lifting force 70N±10N, speed range 5 / 10 / 15km / h;

[0095] S7.2. Key parameter detection: hard spot detection, guide height deviation ±5mm, pull-out value ±10mm;

[0096] S7.3. Real-time data feedback: A 3D location map of the defect point is generated and correction is completed within 2 hours.

[0097] It should also be noted that the implementation steps of step S8 are as follows:

[0098] S8.1. Multi-source data acquisition: fiber optic sensor plus vehicle-mounted monitoring device, sampling rate 1kHz;

[0099] S8.2.LSTM Model Training: Input historical data, output optimized elasticity coefficient values;

[0100] S8.3. Lifting compensation execution: Automatically adjusts the suspension bolts to compensate for uneven flow sections;

[0101] S8.4. Closed-loop verification: Retest the pantograph-catenary dynamics index within 72 hours after optimization. If the index is not met, initiate a second optimization.

[0102] Example 2, please refer to Figure 1 In practical applications, this invention proposes a transition method for the overhead contact system while maintaining operation in an existing subway depot. Specifically, it includes the following steps:

[0103] Step 1. Use a millimeter-precision laser scanner to collect point clouds of existing overhead contact lines, substations and tunnel structures, and build a four-dimensional BIM model. Set the conductor tension to 10-15kN, control the suspension point coordinate error to ±5mm, and simulate the overhead contact line amplitude ≤50mm when the train is running.

[0104] Specifically, the implementation steps are as follows:

[0105] Step 1.1. On-site scanning preparation: Using a Leica P40 3D laser scanner, set up scanning stations during the nighttime shutdown period, with one station every 30m, covering the contact wire, substation equipment and tunnel structure, and simultaneously collect the existing contact wire tension parameters and the initial coordinates of the suspension points;

[0106] Step 1.2. Point cloud data processing: Denoise and stitch the point cloud using Cyclone software to generate a 3D model of the tunnel structure, label equipment attributes, and calibrate the coordinate error of the suspension points to within ±5mm;

[0107] Step 1.3. Four-dimensional BIM model construction: Integrate the point cloud model into the Revit platform, add the time dimension to simulate the vibration of the catenary when a train passes, and verify the dynamic envelope space conflict of the pantograph and catenary.

[0108] Step 1.4. Collision Pre-analysis: Navisworks is used to detect the collision points between the newly added rigid suspension and the existing pipeline, and a conflict report is output. The process parameters for 3D laser scanning modeling are shown in Table 1.

[0109] Table 1. Parameters of 3D Laser Scanning Modeling Process

[0110]

[0111]

[0112] S2. Identify the spatial conflict points between the newly added rigid suspension and the existing flexible suspension. Install fiberglass U-shaped insulated cross braces in sections with a clearance of <5m. The U-shaped opening width is 200mm, the depth is 150mm, the length of the suspension channel steel is 600mm, the bolt length is ≤80mm, and the insulation strength is ≥100kV.

[0113] Specifically, the implementation steps are as follows:

[0114] Step 2.1. Conflict point identification and location: Based on the BIM model, screen tunnel sections with a clearance of <5m and mark the minimum spacing point between the existing flexible suspension and rigid busbar;

[0115] Step 2.2. Customization of cross bracing structure: Design fiberglass U-shaped cross bracing: opening width 200mm, depth 150mm, suspension channel steel length 600mm, bolt length ≤80mm;

[0116] Step 2.3. Installation and Insulation Test: Drill holes at the point of conflict to install the cross brace. The bolt torque is controlled at 100 N·m. After installation, use a 2500V megohmmeter to test the insulation strength of the cross brace. It should be ≥100kV. The custom installation process parameters for the U-shaped cross brace are shown in Table 2.

[0117] Table 2. Custom Installation Process Parameters for U-Shaped Cross Braces

[0118] operate Control parameters Materials / Process Customized cross bracing for low headroom areas Bolt length ≤ 80mm Glass fiber reinforced resin Factory prefabrication and insulation testing Withstand voltage ≥100kV 2500V megohmmeter

[0119] S3. Pre-install a rigid busbar above the flexible contact wire, with a pre-lift height of 100mm. Install a wire-laying pulley every 16m and install a 120mm high pulley. 2 Temporary electrical connection cable, pull-out value ≤ 250mm, cold sliding test height difference 100±10mm;

[0120] Specifically, the implementation steps are as follows:

[0121] Step 3.1. Pre-lifting and positioning: Install a rigid busbar 100mm above the flexible contact line and temporarily fix it with adjustable hangers, with a safety margin of ≥60mm;

[0122] Step 3.2. Temporary electrical connection installation: Install a line-laying pulley block every 16m, and install 120mm pulleys simultaneously. 2 Copper cable electrical connector, resistance value ≤0.01Ω;

[0123] Step 3.3. Pull-out value control: Adjust the busbar pull-out value to ≤250mm to avoid crossing with the flexible line, and use a total station to verify the positioning;

[0124] Step 3.4. Cold-slip pre-verification: The test vehicle runs at 10km / h to verify the height difference of 100±10mm, laser correction of the out-of-tolerance points, and pre-set process parameters for rigid suspension;

[0125] Table 3 Rigid Suspension Pre-installation Process Parameters

[0126] operate Control parameters Tools / Verification Methods Pre-lift of the suspension cable Height difference 100±10mm Adjustable dropper device Temporary electrical connection installation Resistance ≤ 0.01Ω Multimeter testing

[0127] S4. In straight sections or superelevation ≤50mm sections, a slotted joint transition section is installed with a transition length of 12-15m. The rigid contact wire is 30-50mm higher than the flexible wire, and the pantograph is raised 2-5mm at the entry / exit point.

[0128] Specifically, the implementation steps are as follows:

[0129] Step 4.1. Optimal location of the transition section: Select a section with a superelevation of ≤50mm for straight lines or curves, and a transition length of 12-15m;

[0130] Step 4.2. Slotted busbar installation: Start installing the slotted element from the rigid-flexible transition end, with a pull-out value of ≤100mm throughout the entire length, and raise the end by 30-50mm;

[0131] Step 4.3. Control of conductor height and lifting amount: The conductor height of the rigid contact line is 30-50mm higher than that of the adjacent flexible line, and the pantograph is raised by 2-5mm at the entry / exit point;

[0132] Step 4.4. Transition smoothness verification: The pantograph passes at 40km / h, and the offline rate is detected to be <5%; otherwise, the grooving angle is adjusted.

[0133] Step 5. During the nighttime skylight period, lower the busbar segment by segment at a rate ≤10mm / minute, simultaneously construct non-insulated joint anchor segments, raise the flexible line by 100mm to exit operation, calibrate the anchor segment height difference ±1mm, and ensure the dynamic envelope of the insulation gap is ≥150mm.

[0134] Specifically, the implementation steps are as follows:

[0135] Step 5.1. Construction organization during the skylight period: The single operation time is ≤3 hours, divided into sections according to the direction of travel, and the temporary electrical connection is removed before descent;

[0136] Step 5.2. Rate Synchronization Control: The rate of the hydraulic descent device is ≤10mm / min, monitored in real time by the laser rangefinder, and automatically paused when the deviation is >3mm;

[0137] Step 5.3. Flexible line withdrawal: After lowering, raise the existing flexible line by 100mm, anchor it to the non-working support, and withdraw it from the current receiving area;

[0138] Step 5.4. Anchor section fine adjustment: Calibrate joint height difference ±1mm, insulation gap ≥150mm under dynamic envelope;

[0139] Step 6. Use partition insulators to separate the depot from the main line power supply. The length of the power supply partition is ≤1.5km. The parallel operation time of the new and old equipment is ≤30 minutes and the current transfer error is ≤5%. The automatic switching system achieves link switching in <15 minutes.

[0140] Specifically, the implementation steps are as follows:

[0141] Step 6.1. Power supply zone division: Zone insulators shall be installed between the depot and the main line, and the length of the power supply zone shall be ≤1.5km;

[0142] Step 6.2. Parallel switching of old and new equipment: Parallel operation for ≤30 minutes before switching, current transfer error ≤5%;

[0143] Step 6.3. Automated switching operation: The program controls the isolating switch, the link switching time is <15 minutes, the power supply disturbance voltage is <10%, and the process parameters for the cross-zone power supply separation are shown in Table 4;

[0144] Table 4. Process Parameters for Cross-Regional Power Supply Separation

[0145] operate Control parameters System / Device Parallel switching of old and new equipment Current error ≤5% intelligent relay Switching program control Switching time < 15 minutes Automated switching system

[0146] S7. The inspection vehicle runs at a speed of 5-15 km / h, with a static lifting force of 70N±10N for the pantograph, and detects contact wire hard points ≤50g, conductor height deviation ±5mm, and pull-out value ±10mm.

[0147] Specifically, the implementation steps are as follows:

[0148] Step 7.1. Test vehicle calibration: pantograph static lifting force 70N±10N, speed in gears 5 / 10 / 15km / h;

[0149] Step 7.2. Key parameter detection: hard spot detection, guide height deviation ±5mm, pull-out value ±10mm;

[0150] Step 7.3. Real-time data feedback: A 3D location map of the defect point is generated, and correction is completed within 2 hours;

[0151] Step 8. Based on the contact pressure and offline rate data with a sampling rate of 1kHz, optimize the elastic coefficient of the suspension point to 15-20kN / mm using an LSTM neural network to compensate for the lifting amount and ensure that the standard deviation of the contact pressure is ≤20N and the offline rate is <5%.

[0152] Specifically, the implementation steps are as follows:

[0153] Step 8.1. Multi-source data acquisition: Fiber optic sensor plus vehicle-mounted monitoring device, sampling rate 1kHz;

[0154] Step 8.2. LSTM Model Training: Input historical data, output optimized elasticity coefficient values;

[0155] Step 8.3. Lifting compensation execution: Automatically adjust the hanger bolts to compensate for uneven flow sections;

[0156] Step 8.4. Closed-loop verification: Retest the pantograph-catenary dynamics index within 72 hours after optimization. If the index is not met, initiate a second optimization.

[0157] Through the above steps, the method of this invention uses high-precision three-dimensional laser scanning and four-dimensional BIM modeling to predict conflict points, combined with U-shaped insulating cross bracing to solve the spatial interference of rigid and flexible suspension in low clearance areas, and uses pre-lifted busbars and zone insulators to achieve seamless parallel switching of old and new power supply systems, greatly reducing operational interference; during nighttime skylight periods, hydraulic synchronous control lowers the rigid net segment by segment with millimeter-level precision, supplemented by AI-driven LSTM neural network to dynamically optimize the elastic coefficient, ensuring that the standard deviation of contact pressure is ≤20N, and finally forming a closed-loop optimization system. This not only compresses single-segment construction to within 3 hours and eliminates pantograph-catenary accidents, extending equipment life, but also reduces the amount of temporary supports and saves annual maintenance costs.

[0158] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A transition method for the overhead contact system while maintaining continuous operation in an existing subway depot, characterized in that, Includes the following steps: S1. Use a millimeter-precision laser scanner to collect point clouds of existing overhead contact lines, substations and tunnel structures, and build a four-dimensional BIM model. Set the conductor tension to 10-15kN, control the suspension point coordinate error to ±5mm, and simulate the overhead contact line amplitude ≤50mm when the train is running. S2. Identify the spatial conflict points between the newly added rigid suspension and the existing flexible suspension, and install fiberglass U-shaped insulated cross braces in sections with a clearance of <5m. The U-shaped opening width is 200mm, the depth is 150mm, the length of the suspension channel steel is 600mm, the bolt length is ≤80mm, and the insulation strength is ≥100kV. S3. Pre-install a rigid busbar above the flexible contact wire, with a pre-lift height of 100mm. Install a wire-laying pulley every 16m and install a 120mm high pulley. 2 Temporary electrical connection cable, pull-out value ≤ 250mm, cold sliding test height difference 100±10mm; S4. In straight sections or superelevation ≤50mm sections, a slotted joint transition section is installed with a transition length of 12-15m. The rigid contact wire is 30-50mm higher than the flexible wire, and the pantograph is raised 2-5mm at the entry / exit point. S5. During the nighttime skylight period, the busbar is lowered segment by segment at a rate of ≤10mm / minute. Non-insulated joint anchor sections are constructed simultaneously, and the flexible line is raised by 100mm to exit operation. The anchor section height difference is calibrated to ±1mm, and the dynamic envelope of the insulation gap is ≥150mm. S6. The depot and main line power supply are separated by partition insulators. The length of the power supply partition is ≤1.5km. The parallel operation time of new and old equipment is ≤30 minutes and the current transfer error is ≤5%. The automatic switching system achieves link switching in <15 minutes. S7. The inspection vehicle runs at a speed of 5-15 km / h, with a static lifting force of 70N±10N for the pantograph, and detects contact wire hard points ≤50g, conductor height deviation ±5mm, and pull-out value ±10mm. S8. Based on the contact pressure and offline rate data with a sampling rate of 1kHz, the suspension point elastic coefficient is optimized to 15-20kN / mm using an LSTM neural network to compensate for the lifting amount, ensuring that the standard deviation of the contact pressure is ≤20N and the offline rate is <5%.

2. The transition method for the overhead contact system under the condition of non-stop operation in an existing subway depot, as described in claim 1, is characterized in that... The implementation steps of step S1 are as follows: S1.

1. On-site scanning preparation: Using a Leica P40 3D laser scanner, scanning stations were set up during the nighttime shutdown period, with one station every 30m, covering the contact wire, substation equipment and tunnel structure, and simultaneously collecting the existing contact wire tension parameters and the initial coordinates of the suspension points; S1.

2. Point cloud data processing: Denoise and stitch the point cloud using Cyclone software to generate a 3D model of the tunnel structure, label equipment attributes, and calibrate the coordinate error of the suspension point to within ±5mm; S1.

3. Construction of 4D BIM model: Integrate point cloud model into Revit platform, add time dimension to simulate catenary vibration when train passes, and verify pantograph-catenary dynamic envelope space conflict; S1.

4. Collision Pre-simulation Analysis: Navisworks is used to detect the collision points between the newly added rigid suspension and the existing pipeline, and a conflict report is output.

3. The transition method for the overhead contact system under the condition of non-stop operation in an existing subway depot, as described in claim 2, is characterized in that... The implementation steps of step S2 are as follows: S2.

1. Conflict point identification and location: Based on the BIM model, tunnel sections with a clearance of <5m are screened, and the minimum spacing point between the existing flexible suspension and rigid busbar is marked; S2.

2. Customized cross bracing structure: Design fiberglass U-shaped cross bracing: opening width 200mm, depth 150mm, suspension channel steel length 600mm, bolt length ≤80mm; S2.

3. Installation and Insulation Test: Drill holes at the point of impact to install the cross brace. The bolt torque is controlled at 100 N·m. After installation, use a 2500V megohmmeter to test the insulation strength of the cross brace. The test result is ≥100kV.

4. The transition method for the overhead contact system under the condition of non-stop operation in an existing subway depot, as described in claim 3, is characterized in that... The implementation steps of step S3 are as follows: S3.

1. Pre-lifting and positioning: A rigid busbar is installed 100mm above the flexible contact line and temporarily fixed with adjustable hangers, with a safety margin of ≥60mm; S3.

2. Temporary electrical connection installation: Install a cable-laying pulley block every 16m, and install 120mm wires simultaneously. 2 Copper cable electrical connector, resistance value ≤0.01Ω; S3.

3. Pull-out value control: Adjust the busbar pull-out value to ≤250mm to avoid crossing with the flexible line, and use a total station to verify the positioning; S3.

4. Cold sliding pre-verification: The test vehicle runs at 10km / h to verify the height difference of 100±10mm, and laser correction is performed on the points with excessive deviation.

5. The transition method for the overhead contact system under the condition of non-stop operation in an existing subway depot, as described in claim 4, is characterized in that... The implementation steps of step S4 are as follows: S4.

1. Optimal location of transition section: Select a section with superelevation ≤50mm for straight or curved lines, with a transition length of 12-15m; S4.

2. Slotted busbar installation: Start installing the slotted element from the rigid-flexible transition end, with a pull-out value of ≤100mm throughout the entire length, and the end raised by 30-50mm; S4.

3. Control of conductor height and lifting amount: The conductor height of the rigid contact line is 30-50mm higher than that of the adjacent flexible line, and the pantograph is raised by 2-5mm at the entry / exit point; S4.

4. Transition smoothness verification: The pantograph passes at 40km / h and the offline rate is less than 5%; otherwise, adjust the grooving angle.

6. The transition method for the overhead contact system under the condition of non-stop operation in an existing subway depot, as described in claim 5, is characterized in that... The implementation steps of step S5 are as follows: S5.

1. Construction organization during the skylight period: The single operation time is ≤3 hours, divided into sections according to the direction of travel, and the temporary power connection is removed before descent; S5.

2. Rate Synchronization Control: The hydraulic descent device speed is ≤10mm / min, monitored in real time by the laser rangefinder, and automatically paused when the deviation is >3mm; S5.

3. Flexible line withdrawal: After lowering, raise the existing flexible line by 100mm, anchor it to the non-working support, and withdraw it from the current receiving area; S5.

4. Anchor section fine adjustment: calibrate joint height difference ±1mm, insulation gap ≥150mm under dynamic envelope.

7. The method for transitioning the overhead contact line under the condition of non-stop operation in an existing subway depot, as described in claim 6, is characterized in that... The implementation steps of step S6 are as follows: S6.

1. Power supply zone division: Zone insulators shall be installed between the depot and the main line, and the length of the power supply zone shall be ≤1.5km; S6.

2. Parallel switching of old and new equipment: Parallel operation for ≤30 minutes before switching, current transfer error ≤5%; S6.

3. Automated switching operation: Program-controlled isolating switch, link switching time <15 minutes, power supply disturbance voltage <10%.

8. The transition method for the overhead contact system under the condition of non-stop operation in an existing subway depot, as described in claim 7, is characterized in that... The implementation steps of step S7 are as follows: S7.

1. Inspection vehicle calibration: pantograph static lifting force 70N±10N, speed range 5 / 10 / 15km / h; S7.

2. Key parameter detection: hard spot detection, guide height deviation ±5mm, pull-out value ±10mm; S7.

3. Real-time data feedback: A 3D location map of the defect point is generated and correction is completed within 2 hours.

9. A method for transitioning the overhead contact line under the condition of non-stop operation in an existing subway depot, as described in claim 8, is characterized in that... The implementation steps of step S8 are as follows: S8.

1. Multi-source data acquisition: fiber optic sensor plus vehicle-mounted monitoring device, sampling rate 1kHz; S8.2.LSTM Model Training: Input historical data, output optimized elasticity coefficient values; S8.

3. Lifting compensation execution: Automatically adjusts the suspension bolts to compensate for uneven flow sections; S8.

4. Closed-loop verification: Retest the pantograph-catenary dynamics index within 72 hours after optimization. If the index is not met, initiate a second optimization.

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