A rail return device and detection system for DC traction power supply system

Abstract

The invention discloses a rail return device and a detection system for a DC traction power supply system, comprising a T-type busbar, a first moving contact, a second moving contact, a first shunt, a second shunt and a rail insulation joint, wherein the rail insulation joint comprises an insulation sheet and a rail fishtail plate arranged at a rail seam, the T-type busbar comprises a first port, a second port and a third port, wherein the first port and the second port are both static contacts, the first port and the second port are respectively connected to a moving end of the first moving contact and a moving end of the second moving contact, the first moving contact is connected to one end of the rail insulation joint through a first shunt and a cable, the second moving contact is connected to the other end of the rail insulation joint through a second shunt and a cable, the connection or disconnection of the T-type busbar and the rail insulation joint is realized by moving the first moving contact and the second moving contact, and through the arrangement of each module and the connection relationship between them, the rail can be conveniently and quickly electrically segmented without changing the electrical connection of the entire main line rail, thereby preventing the generation of stray current to the maximum extent.

Description

Technical Field

[0001] The present invention belongs to the technical field of rail transportation, and more specifically, relates to a rail return device and a detection system for a DC traction power supply system. Background Art

[0002] The DC traction system of urban rail transit selects the running rail as the return rail to form the path of locomotive traction return. The rail is used as the path of locomotive traction return, and the rail is required to be installed insulated from the ground. Since the rail cannot be completely insulated from the ground, and there is a voltage drop in the return rail, a part of the load current leaks from the track to the sleeper, the ballast and the underground metal facilities. This part of the current is the stray current. The long-term action of stray current not only causes a large amount of metal loss, but more seriously, it may cause structural damage and damage to other systems. Due to the hidden and sudden nature of corrosion, once an accident occurs, it often has catastrophic consequences.

[0003] The insulation level of rails to the ground is the most important factor that directly affects the generation of stray currents. Usually, stray currents cannot be measured directly, and there is a lack of fast and effective detection methods for rail insulation. The rails of the entire rail transit main line are electrically connected, and a weak insulation point at a certain point will affect the insulation level of the entire line. The traditional method of measuring the insulation of rails is very time-consuming and labor-intensive, and requires a large number of measurement signals to be collected synchronously to ensure the correctness of the measured section. The rails of the traditional main line are long rails, and the rails of the line are electrically connected for dozens of kilometers. Any weak insulation link will directly destroy the insulation structure of the entire line, causing very serious stray current problems, and fault finding in the area where the insulation is damaged is a very wasteful task of manpower and material resources. A large amount of time and economic investment is only exchanged for a certain rail insulation test, and subsequent repeated tests will repeat the investment of manpower and material resources. Summary of the invention

[0004] In response to at least one defect or improvement need in the prior art, the present invention provides a rail return device and detection system for a DC traction power supply system, which, through the arrangement of various modules and the connection relationship between them, can conveniently and quickly perform electrical segmentation of the rails without changing the electrical continuity of the existing mainline rails, thereby preventing the generation of stray currents to the greatest extent.

[0005] To achieve the above object, according to one aspect of the present invention, a rail return device for a DC traction power supply system is provided, the device comprising a T-type busbar, a first moving contact, a second moving contact, a first shunt, a second shunt and a rail insulation joint.

[0006] The rail insulation joint includes an insulation sheet and a rail fishplate placed at the rail joint. The rail insulation joint is used to achieve electrical isolation function at both ends of the insulation joint.

[0007] The T-type busbar includes a first port, a second port and a third port, the first port and the second port are both static contacts, the first port is used to connect to the moving end of the first moving contact, the second port is used to connect to the moving end of the second moving contact, and the third port is used to connect to the negative pole cabinet of the DC traction power supply system through a cable;

[0008] The first moving contact is connected to one end of the rail insulation joint through the first shunt and the cable, and the second moving contact is connected to the other end of the rail insulation joint through the second shunt and the cable. The connection or disconnection of the T-type busbar and the rail insulation joint is achieved by moving the first moving contact and the second moving contact.

[0009] As a further improvement of the present invention, the first moving contact and the second moving contact are connected via an insulating linkage rod, the insulating linkage rod is connected to a motor, and the insulating linkage rod is operated by the motor to achieve synchronous operation of the position states of the two moving contacts.

[0010] As a further improvement of the present invention, the first moving contact is connected to the first motor, the second moving contact is connected to the second motor, and the first motor and the second motor respectively perform opening and closing operations on the first moving contact and the second moving contact.

[0011] As a further improvement of the present invention, the first moving contact and the second moving contact are connected by an insulating linkage rod, the insulating linkage rod is connected to a manual rocker, and the insulating linkage rod is operated by the manual rocker to achieve synchronous operation of the position states of the two moving contacts.

[0012] As a further improvement of the present invention, the T-type busbar is insulated and installed on the housing of the return device or the concrete side wall through supporting insulators.

[0013] As a further improvement of the present invention, the reflux device further includes a monitoring module, and the monitoring module includes a monitoring camera and a signal transmission medium.

[0014] As a further improvement of the present invention, the reflux device further includes an auxiliary switch, and the auxiliary switch includes a contact as a passive output node for outputting a moving contact state position to the outside.

[0015] To achieve the above-mentioned purpose, according to another aspect of the present invention, a detection system for the above-mentioned rail return device is provided, wherein the detection system includes a DC power supply, a high-precision voltage acquisition module, a microprocessor module and a display module, the two ends of the DC power supply are respectively connected to one end of the first shunt close to the rail insulation joint and one end of the second shunt close to the rail insulation joint, the high-precision voltage acquisition module is respectively connected to the two ends of the fixed-length rail in the rail insulation joint between the first shunt and the second shunt, and the high-precision voltage acquisition module is also respectively connected to the two ends of the fixed-length rail outside the rail insulation joint between the first shunt and the second shunt.

[0016] As a further improvement of the present invention, the detection method adopted by the detection system includes:

[0017] Calculation of rail insulation joint performance evaluation index F J :

[0018]

[0019] Among them: U 1，on , U 2，on It is the average voltage within 1 minute after the current is injected into the rail; U 1，off , U 2，off It is the average value of rail voltage noise within 1 minute when no current is injected.

[0020] When the insulation performance index F J When ≤95%, it indicates that there is electrical connection between the insulation nodes and a fault defect exists.

[0021] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0022] The present invention provides a rail return device and detection system for a DC traction power supply system. Through the arrangement of modules such as a T-type busbar, a first moving contact, a second moving contact, a first shunt, a second shunt, and a rail insulation joint and their mutual connection, the existing electrical continuity of the entire mainline rails can be maintained during rail transit operations, and the rails can be conveniently and quickly electrically segmented to prevent the generation of stray currents to the greatest extent. The electrical segmentation of the entire line of rails can be quickly achieved during power outages, maintenance, and troubleshooting. This is of great significance for quickly troubleshooting rail insulation faults, ensuring the insulation level of the rails, and curbing the generation of stray currents from the source. The characteristics are suitable for transportation fields such as subways, light rails, trams, and intercity railways that use running rails as locomotive traction return paths and have requirements for rail insulation and stray protection.

[0023] The present invention provides a rail return device and detection system for a DC traction power supply system. Two return devices are added to each traction station and rail partitioning and segmentation functions can be realized without affecting the normal traction current intake and return of trains during normal operation of the main line. The invention is suitable for all DC traction power supply systems that use running rails as return rails, and is suitable for new lines and reconstruction of existing lines. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is one of the structural schematic diagrams of a rail return device for a DC traction power supply system provided by an embodiment of the present invention;

[0025] Figure 2This is a second structural schematic diagram of a rail return device for a DC traction power supply system provided by an embodiment of the present invention;

[0026] Figure 3 This is a third structural schematic diagram of a rail return device for a DC traction power supply system provided by an embodiment of the present invention;

[0027] Figure 4 is a schematic diagram of a T-type busbar installation method provided in an embodiment of the present invention;

[0028] Figure 5 is a structural schematic diagram of a detection system for the rail return device provided by an embodiment of the present invention;

[0029] In all the drawings, the same reference numerals represent the same technical features, specifically:

[0030] 1- shunt, 2- motor, 3- T-type busbar, 4- static contact, 5- insulating linkage rod, 6- moving contact, 7- camera. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention 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 invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0032] The working principle of the urban rail transit self-healing power supply method and system provided by the present invention is described in detail below with reference to the embodiments and drawings.

[0033] A rail return device for a DC traction power supply system, the device comprising a T-type busbar, a first moving contact, a second moving contact, a first shunt, a second shunt and a rail insulation joint,

[0034] The rail insulation joint includes an insulation sheet and a rail fishplate placed at the rail joint. The rail insulation joint is used to achieve electrical isolation function at both ends of the insulation joint.

[0035] The T-type busbar includes a first port, a second port and a third port, the first port and the second port are both static contacts, the first port is used to connect to the moving end of the first moving contact, the second port is used to connect to the moving end of the second moving contact, and the third port is used to connect to the negative pole cabinet of the DC traction power supply system through a cable;

[0036] The first moving contact is connected to one end of the rail insulation joint through the first shunt and the cable, and the second moving contact is connected to the other end of the rail insulation joint through the second shunt and the cable. The connection or disconnection between the T-type busbar and the rail insulation joint is achieved by moving the first moving contact and the second moving contact, so as to control the reflux state of the negative cabinet of the DC traction power supply system according to the needs of testing or other operations. As an example, when the rail transit is operating normally, the moving contact and the static contact of the reflux device are in the closed position, that is, the electrical working condition. When the rail transit is in the skylight period, that is, there is no train on the line, the reflux device can be remotely opened to facilitate the relevant maintenance work on the rails after segmentation.

[0037] Figure 1 FIG. 1 is one of the structural schematic diagrams of a rail return device for a DC traction power supply system provided by an embodiment of the present invention. Figure 1 As shown, optionally, the first moving contact and the second moving contact are connected by an insulating connecting rod, and the insulating connecting rod is connected to the motor. By operating the insulating connecting rod by the motor, synchronous operation of the position status of the two moving contacts can be achieved. The two moving contacts are synchronously operated to achieve electrical conduction and electrical isolation with the corresponding static contacts, that is, the two moving contacts are in the open or closed state.

[0038] Figure 2 This is a second structural schematic diagram of a rail return device for a DC traction power supply system provided by an embodiment of the present invention. Figure 2 As shown, optionally, the first moving contact is connected to the first motor, and the second moving contact is connected to the second motor, and the two independent motors independently perform opening and closing operations on the moving contacts they are responsible for.

[0039] Figure 3 This is a third structural schematic diagram of a rail return device for a DC traction power supply system provided by an embodiment of the present invention. Figure 3 As shown, optionally, the first moving contact and the second moving contact are connected by an insulating linkage rod, and the insulating linkage rod is connected to a manual rocker. By operating the insulating linkage rod through the manual rocker, synchronous operation of the position status of the two moving contacts can be achieved. The synchronous operation of the two moving contacts can respectively achieve electrical conduction and electrical isolation with the corresponding static contacts, that is, the two moving contacts are both in the open or closed state.

[0040] Figure 4 Schematic diagram of the T-type busbar installation method provided by the embodiment of the present invention. Figure 4As shown, optionally, a T-type busbar (preferably made of copper) is insulated and installed on the housing of the return device or on the concrete side wall through a supporting insulator. The installation of the return device can be encapsulated inside a housing, and the T-type busbar, the moving contact, the static contact, and the metal conductor inside the device directly connected thereto are all insulated and installed with the housing of the return device through supporting insulators. Because the T-type busbar, the moving contact, the static contact, and the rails of the rail transit are connected through cables, and the rails of the rail transit are insulated and installed, the use of the return device will not change the electrical working conditions of the existing rail insulation installation. The return device can also be installed directly on the wall of the concrete structure without passing through the housing, and the return device composed of the copper busbar, the moving contact, the static contact, and the motor can be directly installed through supporting insulators, bolts, channel steel and other accessories. Similarly, the installation of the return device will not change the electrical working conditions of the existing rail insulation installation.

[0041] Optionally, the reflux device also includes a monitoring module, which includes a monitoring camera and a signal transmission medium. Preferably, the monitoring camera is installed inside the reflux device to realize the monitoring function of the status positions of the moving contact and the static contact, and upload the video information to the power monitoring system in real time through the signal transmission medium. At the same time, the power monitoring system can control the status positions of the moving and static contacts of the device through a remote control motor.

[0042] Optionally, the reflux device also includes an auxiliary switch, which includes a contact as a passive output node, and the contact is used to output the status position of the moving contact to the outside. By relying on the mechanical action of the moving contact to drive the change of the opening and closing position of the contacts (contacts) of the auxiliary switch, the contacts (contacts) inside the auxiliary switch can be used as a passive output node (secondary auxiliary contact) for outputting the status position of the moving contact to the outside, and can realize electrical locking function with equipment such as the DC circuit breaker switch cabinet of the substation.

[0043] Figure 5 Schematic diagram of a detection system for the rail return device provided by an embodiment of the present invention. Figure 5As shown, the detection system includes a DC power supply, a high-precision voltage acquisition module, a microprocessor module and a display module. The two ends of the DC power supply are respectively connected to one end of the first shunt near the rail insulation joint and one end of the second shunt near the rail insulation joint. The high-precision voltage acquisition module is respectively connected to the two ends of the fixed length (L) rail inside the rail insulation joint between the first shunt and the second shunt. The high-precision voltage acquisition module is also respectively connected to the two ends of the fixed length (L) rail outside the rail insulation joint between the first shunt and the second shunt. As an example, the length of L should not be less than 5m. The specific process of testing the performance of the insulation joint is as follows: the moving contact and the static contact of the return device are in a split position, that is, an electrically isolated state, and the measurement terminal inside the return device is connected through the DC power supply. At the same time, the input current of the DC power supply is I (I should not be less than 50A). The high-precision voltage acquisition device respectively collects the longitudinal voltage drops U1 and U2 of the rails of the same length L on the inside and outside of the rail insulation joint (the length of L should not be less than 5m). MCPU uses the calculation method of the following formula to calculate the collected voltage signal to achieve result input, and the output result is directly output through the digital display LED screen to output the test result;

[0044] The calculation method is as follows:

[0045] Rail insulation joint performance evaluation index F J for:

[0046]

[0047] Among them: U 1，on , U 2，on It is the average voltage within 1 minute after the current is injected into the rail; U 1，off , U 2，off It is the average value of rail voltage noise within 1 minute when no current is injected.

[0048] When the insulation performance index F J When ≤95%, it indicates that there is electrical connection between the insulation nodes and a fault defect exists.

[0049] The DC traction power supply system is generally powered by a DC750V or DC1500V overhead contact network or contact rail. The positive pole of the rectifier is connected to the DC positive busbar through the incoming DC cabinet, and the feeder DC cabinet connects the DC positive busbar to the DC traction network through the online disconnector. The locomotive takes power from the positive traction network through a pantograph or a collector shoe, and the return current flows through the running rail (rail) to the negative busbar and then returns to the negative pole of the rectifier, thereby forming a complete electrical circuit. Conventional rail transit generally has 4 DC feeders, which are divided into the traction network for the upward left line, right line and the downward left line, right line to provide electrical energy. The rail return device of the present invention is provided with two rail insulation joints on the upward and downward rails near the traction station, respectively, to achieve electrical isolation of the left and right lines of the upward rail and the left and right lines of the downward rail. The device of the present invention is installed in parallel at both ends of the two rail insulation joints of the upward and downward rails, and then connected to the negative busbar of the traction substation through a cable. Under normal operating conditions, the moving contact inside the return device near the traction station is in a closed condition, and the equivalent rail insulation section is "short-circuited". When the locomotive draws current between the two traction substations, the "double-sided power supply" condition can still be guaranteed. When a traction station is decoupled and out of operation, the moving contact of the return device in the traction station is still in a closed condition, which is equivalent to the rail insulation section there being "short-circuited". Closing the online cross-zone disconnector of the traction station can still ensure that the locomotive draws power from the two nearby traction stations, and the "large double-sided power supply" condition can be guaranteed. When it is in the skylight period and the rails need to be segmented, the return device near the traction station can be controlled remotely or locally to be in a segmented state, so as to achieve electrical isolation of the left and right lines of the upward rails and the left and right lines of the downward rails.

[0050] It will be easily understood by those skilled in the art that 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 rail return device for a DC traction power supply system, characterized in that: The device comprises a T-type busbar, a first moving contact, a second moving contact, a first shunt, a second shunt and a rail insulation joint. The rail insulation joint comprises an insulation sheet and a rail fishtail plate placed at the rail seam, and the rail insulation joint is used to realize the electrical isolation function at both ends of the insulation joint; The T-type busbar comprises a first port, a second port and a third port, the first port and the second port are both static contacts, the first port is used to connect to the moving end of the first moving contact, the second port is used to connect to the moving end of the second moving contact, and the third port is used to connect to the negative pole cabinet of the DC traction power supply system through a cable; The first moving contact is connected to one end of the rail insulation joint through a first shunt and a cable, and the second moving contact is connected to the other end of the rail insulation joint through a second shunt and a cable. The connection or disconnection of the T-type busbar and the rail insulation joint is achieved by moving the first moving contact and the second moving contact.

2. A rail return device for a DC traction power supply system according to claim 1, wherein: The first moving contact and the second moving contact are connected via an insulating linkage rod, and the insulating linkage rod is connected to a motor. The insulating linkage rod is operated by the motor to achieve synchronous operation of the position states of the two moving contacts.

3. A rail return device for a DC traction power supply system according to claim 1, wherein: The first moving contact is connected to the first motor, the second moving contact is connected to the second motor, and the first motor and the second motor respectively perform opening and closing operations on the first moving contact and the second moving contact.

4. A rail return device for a DC traction power supply system according to claim 1, wherein: The first moving contact and the second moving contact are connected via an insulating linkage rod, and the insulating linkage rod is connected to a manual rocker. The insulating linkage rod is operated by the manual rocker to achieve synchronous operation of the position states of the two moving contacts.

5. A rail return device for a DC traction power supply system according to any one of claims 1 to 4, wherein: The T-type busbar is insulated and installed on the housing of the return device or the concrete side wall through supporting insulators.

6. A rail return device for a DC traction power supply system according to any one of claims 1 to 4, wherein: The reflux device further includes a monitoring module, which includes a monitoring camera and a signal transmission medium.

7. A rail return device for a DC traction power supply system according to any one of claims 1 to 4, wherein: The reflux device further comprises an auxiliary switch, wherein the auxiliary switch comprises a contact as a passive output node for outputting a moving contact state position to the outside.

8. A detection system for the rail return device according to any one of claims 1 to 7, wherein: The detection system includes a DC power supply, a high-precision voltage acquisition module, a microprocessor module and a display module. The two ends of the DC power supply are respectively connected to one end of the first shunt close to the rail insulation joint and one end of the second shunt close to the rail insulation joint. The high-precision voltage acquisition module is respectively connected to the two ends of the fixed-length rail in the rail insulation joint between the first shunt and the second shunt. The high-precision voltage acquisition module is also respectively connected to the two ends of the fixed-length rail outside the rail insulation joint between the first shunt and the second shunt.

9. The detection system according to claim 8, wherein: The detection method adopted by the detection system includes: Calculation of rail insulation joint performance evaluation index : in: , It is the average voltage within 1 minute after the current is injected into the rail; , is the average value of rail voltage noise within 1 minute when no current is injected; When the insulation performance index F J When ≤95%, it indicates that there is electrical connection between the insulation nodes and a fault defect exists.

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