Rail transit traction power supply system, backflow circuit monitoring method and device and medium

Abstract

The invention relates to the technical field of rail transit, discloses a rail transit traction power supply system, a backflow circuit monitoring method and device and a medium, and is used for solving the problem that a maintainer cannot know the health state of a backflow circuit in time due to the lack of effective supervision on leaked current to ground and the backflow circuit. The rail transit traction power supply system comprises a backflow leakage monitoring device, the backflow leakage monitoring device comprises a comprehensive monitoring assembly and at least two one-way backflow detection circuits, the input end of each one-way backflow detection circuit is grounded, the output end of each one-way backflow detection circuit is electrically connected with a backflow rail, and the backflow leakage monitoring device is used for guiding leaked current to ground to the backflow rail; the output end of each one-way backflow detection circuit is electrically connected with the comprehensive monitoring assembly, and the comprehensive monitoring assembly judges whether earth current leakage exists or not according to the electrical signals of each one-way backflow detection circuit and determines the health state of each one-way backflow detection circuit according to the electrical signals of at least two one-way backflow detection circuits.

Description

Technical Field

[0001] The present application relates to the field of rail transit technology, and in particular to a rail transit traction power supply system, a return circuit monitoring method, a device and a medium. Background Art

[0002] At present, rail transit in some cities has the characteristics of long lines and cross-city transportation. Along the long-distance rail lines between these cities, many pipelines are laid underground, such as natural gas pipelines, cable and optical cable pipelines, etc. Such pipelines play an important role in livelihood projects. The traditional DC traction power supply method is that the pantograph of the locomotive receives power through the contact network or contact rail, and returns to the traction station through the running rail. Although the running rail is insulated, its insulation is limited, and it is inevitable that some current will leak into the ground, causing electrochemical reactions in the metal pipes laid underground, corroding the metal pipes.

[0003] Therefore, in this kind of long-distance rail transportation across the country, in order to avoid leakage current from corroding the pipelines along the way, a special return rail power supply method is adopted. Different from the traditional power supply method, the locomotive receives power from the contact network or contact rail through the pantograph. The locomotive is designed with a special return shoe in contact with a special return rail to return the current to the traction station, so the steel rail is no longer used for return. The special return rail is insulated from the ground, which minimizes the leakage of current to the ground.

[0004] However, the traditional rail transit traction power supply system that uses return rails lacks effective supervision of the leakage of ground current and the return circuit. Maintenance personnel cannot promptly learn the health status of the return circuit. Failure to maintain the return circuit in a timely manner will lead to leakage of ground current and damage to underground pipelines. Summary of the invention

[0005] The present application provides a rail transit traction power supply system, a return circuit monitoring method, a device and a medium. The rail transit traction power supply system that traditionally uses a return rail lacks effective supervision of the leakage ground current and the return circuit. Maintenance personnel cannot promptly learn the health status of the return circuit. If the return circuit is not maintained in time, it will cause the ground current to leak and damage the underground pipeline.

[0006] The first aspect of the present application provides a rail transit traction power supply system, characterized in that it includes: a traction substation, a contact network, a return rail, a rail, an isolation grounding device and a return leakage monitoring device;

[0007] The isolated grounding device is electrically connected to the traction substation, the contact network, the return rail and the rail respectively, and the isolated grounding device is used to control the power supply and grounding of the contact network;

[0008] The return leakage monitoring device comprises an integrated monitoring component and at least two unidirectional return detection circuits, the input end of each unidirectional return detection circuit is grounded, and the output end of each unidirectional return detection circuit is electrically connected to the return rail, for directing the leakage current to the ground to the return rail;

[0009] The output end of each unidirectional return detection circuit is electrically connected to the integrated monitoring component, and the integrated monitoring component determines whether there is current leakage to the ground based on the electrical signal of each unidirectional return detection circuit, and determines the health status of each unidirectional return detection circuit based on the electrical signal of the at least two unidirectional return detection circuits.

[0010] The second aspect of the present application provides a return circuit monitoring method, which is characterized in that, when applied to the above-mentioned rail transit traction power supply system, the return circuit monitoring method includes: obtaining an electrical signal corresponding to each unidirectional return detection circuit; judging whether there is a ground current leakage based on the electrical signal corresponding to each unidirectional return detection circuit; and determining the health status of each unidirectional return detection circuit in any two unidirectional return detection circuits based on the electrical signals of the unidirectional return detection circuits.

[0011] The third aspect of the present application provides a return circuit monitoring device including: an acquisition module, used to acquire the electrical signal corresponding to each unidirectional return detection circuit; a first judgment module, used to judge whether there is a ground current leakage according to the electrical signal corresponding to each unidirectional return detection circuit; a second judgment module, used to determine the health status of each unidirectional return detection circuit in any two unidirectional return detection circuits according to the electrical signals of the unidirectional return detection circuits.

[0012] A fourth aspect of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores instructions, which, when executed on a computer, enable the computer to execute the above-mentioned reflux circuit monitoring method.

[0013] In the technical solution provided in the present application, a rail transit traction power supply system is constructed by a traction substation, a contact network, a return rail, a rail, an isolation grounding device and a return leakage monitoring device. The power supply and grounding of the contact network are controlled by the isolation grounding device, and the ground current leakage caused by the return rail is avoided. The return current and monitoring of the ground current are achieved through the return leakage monitoring device. Further, the presence of ground current leakage is determined by electrical signals of at least two unidirectional return detection circuits, and the health status of each unidirectional return detection circuit is monitored. Maintenance personnel can promptly learn the health status of each unidirectional return detection circuit to achieve timely maintenance, maximize the return effect of the return rail, and ensure the safety of underground pipelines. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic diagram of an embodiment of a rail transit traction power supply system in this application;

[0015] Figure 2 A schematic diagram of an embodiment of a backflow leakage monitoring device in the present application;

[0016] Figure 3 It is a schematic diagram of another embodiment of the rail transit traction power supply system in this application;

[0017] Figure 4 A schematic diagram of an embodiment of a double-pole isolation grounding switch in the present application;

[0018] Figure 5 A schematic diagram of an embodiment of a reflux circuit monitoring method in the present application;

[0019] Figure 6 A schematic diagram of another embodiment of the reflux circuit monitoring method in the present application;

[0020] Figure 7 A schematic diagram of an embodiment of a reflux circuit monitoring device in the present application;

[0021] Figure 8 FIG. 4 is a schematic diagram of another embodiment of the reflux circuit monitoring device in the present application. DETAILED DESCRIPTION

[0022] The present application provides a rail transit traction power supply system, a return circuit monitoring method, a device and a medium. The rail transit traction power supply system that traditionally uses a return rail lacks effective supervision of the leakage ground current and the return circuit. Maintenance personnel cannot promptly learn the health status of the return circuit. If the return circuit is not maintained in time, it will cause the ground current to leak and damage the underground pipeline.

[0023] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" or "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0024] For ease of understanding, the system composition of this application is described below. Figure 1, an embodiment of the rail transit traction power supply system in the present application includes:

[0025] The traction substation 10 is electrically connected to the isolation component of the isolation grounding device 20, the isolation grounding device 20 is electrically connected to the contact network 30, the traction substation 10 performs a power outage operation on the contact network 30 through the isolation component of the isolation grounding device 20, the return rail 60 is electrically connected to the isolation grounding device 20, the return rail 60 performs a return operation through the isolation component of the isolation grounding device 20, the contact network 30 performs a grounding operation through the grounding component of the isolation grounding device 20, and the return rail 60 performs a grounding operation through the grounding component of the isolation grounding device 20.

[0026] Specifically, the isolation grounding device 20 is used to control the on-off control of the power supply circuit. When the locomotive is in normal operation, the power supply circuit provides current to the traction substation 10 through the positive pole (or feeder cabinet, i.e., the positive cabinet). The current is transmitted to the contact network 30 through the isolation component of the isolation grounding device 20. The contact network 30 supplies power to the locomotive 42 through the pantograph 41. The locomotive 42 runs on the rail 50, which is the running rail. The locomotive 42 contacts the return rail 60 through the electric shoe 43. The current flows from the return rail 60 through the isolation component of the isolation grounding device 20 to the negative pole of the traction substation 10, i.e., the negative cabinet.

[0027] Specifically, the isolation grounding device 20 is also used to control the on-off control of the grounding circuit. When on-site operations are required, such as when the rail transit traction power supply system needs to be grounded during maintenance, the grounding circuit is that the contact network 30 is electrically connected to the rail through the grounding component of the isolation grounding device 20, and the return rail 60 is electrically connected to the rail through the grounding component of the isolation grounding device 20 to achieve ground wire hanging.

[0028] In this embodiment, the isolation component and the grounding component of the isolation grounding device 20 are locked with each other to prevent the occurrence of "live grounding" or "grounding power supply". For example, only one of the isolation switch and the grounding switch is in the closed state, and the locking method can be any one or more combinations of mechanical locking, electrical locking and logical locking, which is not specifically limited in this embodiment.

[0029] Optionally, the isolation component may include two isolation switches, and the grounding component may include two grounding switches, the two isolation switches are respectively connected to the positive pole and the contact network of the traction substation, and the return rail and the negative pole of the traction substation to construct a power supply circuit; the two grounding switches are respectively connected to the contact network and the rail, and the return rail and the rail to construct a grounding circuit.

[0030] Optionally, the isolation grounding device 20 may also include two isolation grounding switches, each isolation grounding switch includes a static contact assembly, a moving contact assembly, a drive assembly and a locking structure, the moving contact assembly includes two moving contacts, the drive assembly includes two drive units, each drive unit is transmission-connected to the corresponding moving contact to drive the gate blade of the corresponding moving contact to contact or separate from the contact piece of the corresponding static contact in the static contact assembly, the locking structure can act on the two drive units respectively, when one of the drive units drives the corresponding moving contact to rotate, the locking structure can limit the other drive unit so that the other drive unit cannot drive the corresponding moving contact, wherein the gate blade contacts the contact piece to close the switch, and the gate blade separates from the contact piece to open the switch.

[0031] Specifically, the auxiliary switch contacts are used to determine the closing position and opening position of the moving contact; the state of the knife switch is transmitted to the power test locking controller through the auxiliary switch contacts for monitoring and locking control.

[0032] Specifically, the static contact assembly includes a feeder static contact (i.e., a static contact of a traction substation), a contact network static contact, and a grounding static contact. The two moving contacts are a knife-spacer moving contact and a grounding moving contact. The knife-spacer moving contact is provided with a knife-spacer hinged portion and a knife-spacer movable portion, the knife-spacer hinged portion is hinged with the contact network static contact, the grounding moving contact is provided with a grounding hinged portion and a grounding movable portion, and the grounding hinged portion is hinged with the grounding static contact.

[0033] The two driving units are a blade isolation driving unit and a grounding driving unit. The blade isolation driving unit is connected to the blade isolation moving contact to drive the blade isolation movable part to contact or separate from the contact piece of the feeder static contact. The grounding driving unit is connected to the grounding moving contact to drive the grounding movable part to contact or separate from the contact piece of the contact network static contact.

[0034] The rail transit traction power supply system also includes a backflow leakage monitoring device 70, which includes a comprehensive monitoring component 71 and at least two unidirectional backflow detection circuits 72. The backflow leakage monitoring device 70 is used to determine whether there is a ground current leakage, control the ground current to flow back to the return rail 60, and monitor the health status of each unidirectional backflow detection circuit.

[0035] The input end of each unidirectional return current detection circuit is grounded, and the output end of each unidirectional return current detection circuit is electrically connected to the return rail, so as to guide the leakage current to the ground to the return rail. In this embodiment, the current leaking to the ground is forwardly returned to the negative electrode of the traction substation 10 through the unidirectional return current detection circuit to protect the underground pipeline, and the unidirectional conductivity of the unidirectional return current detection circuit is used to prevent the normal return rail from leaking the current to the ground.

[0036] The above-mentioned backflow leakage monitoring device may include two or more parallel unidirectional backflow detection circuits, such as Figure 2The first unidirectional backflow detection circuit 72a, the second unidirectional backflow detection circuit 72b, ..., the Nth unidirectional backflow detection circuit 72n, where N is a positive integer greater than 1.

[0037] The output end of each unidirectional return detection circuit is electrically connected to the comprehensive monitoring component, which determines whether there is current leakage to the ground based on the electrical signal of each unidirectional return detection circuit, and determines the health status of each unidirectional return detection circuit based on the electrical signals of at least two unidirectional return detection circuits.

[0038] The above-mentioned isolation grounding device may also include a camera to monitor the status of the knife switch.

[0039] It can be understood that the above-mentioned electrical test locking controller, camera, comprehensive detection component and system background communicate through Ethernet and optical fiber, so that the staff can monitor the overall operating status and control of the system in real time on the host, such as controlling the opening and closing operations of the knife switch.

[0040] In this embodiment, a rail transit traction power supply system is constructed by a traction substation, an overhead contact network, a return rail, a rail, an isolation grounding device and a return leakage monitoring device. The power supply and grounding of the overhead contact network are controlled by the isolation grounding device. The return rail avoids the leakage of ground current caused by the return through the rail. The return leakage monitoring device realizes the return and monitoring of the ground current. Further, it is determined whether there is a ground current leakage according to the electrical signal of each unidirectional return detection circuit. When there is a ground current leakage, the ground current is guided to the return rail through the unidirectional return detection circuit to avoid damage to the underground pipeline. Moreover, through the redundant design of the unidirectional return detection circuit, when some unidirectional return detection circuits fail, the return and monitoring can be realized through the remaining unidirectional return detection circuits, thereby improving the reliability of the system. The comprehensive monitoring component further determines the health status of each unidirectional return detection circuit according to the electrical signals of the at least two unidirectional return detection circuits. The maintenance personnel can timely learn the health status of each unidirectional return detection circuit to realize timely maintenance, maximize the return function of the return rail, and ensure the safety of the underground pipeline.

[0041] In actual applications, due to other reasons, the positive pole of the power supply system such as the traction substation may be short-circuited to the ground, or the return rail may leak current to the ground, that is, there is current to the ground. It is necessary to further set up a return circuit dedicated to the return rail to realize the return of the current to the ground. When it is necessary to replace and maintain the components inside the return leakage monitoring device, the return leakage monitoring device needs to be disconnected from the return rail to ensure the safety of the maintenance personnel. Please refer to Figure 2-3 Another embodiment of the rail transit traction power supply system in the present application includes:

[0042] In this embodiment, the backflow leakage monitoring device also includes: a first isolation knife switch 73, which is used to control the on-off control of the backflow rail 60 and the backflow leakage monitoring device 70, one end of the first isolation knife switch 73 is electrically connected to the backflow rail 60, the other end of the first isolation knife switch 73 is electrically connected to the output end of the backflow leakage monitoring device 70, and the input end of the backflow leakage monitoring device 70 is grounded.

[0043] During maintenance, the first isolation switch 73 is controlled to be opened to achieve electrical isolation. During normal operation, the first isolation switch 73 is controlled to be closed to return the leaked current from the ground along the unidirectional diode through the return rail to the negative pole of the traction station.

[0044] Specifically, the unidirectional backflow detection circuit may include a unidirectional diode and an electrical parameter monitor, such as Figure 2 The first unidirectional diode 721a and the first current sensor 722a of the first unidirectional return current detection circuit, the input end of the unidirectional diode is grounded, and the ground current flows to the return rail 60 through the output end of the unidirectional diode. The electrical parameter monitor is used to monitor the electrical signal passing through the unidirectional diode and send it to the integrated monitoring component.

[0045] Optionally, the electrical parameter monitor is a current sensor, the output end of the unidirectional diode is electrically connected to the current sensor, and the current sensor is electrically connected to the first isolation switch 73 and the integrated monitoring component 71, respectively. The current sensor is used to monitor the current signal passing through the unidirectional diode and send it to the integrated monitoring component. Specifically, the ground current once passes through the unidirectional diode and the current sensor back to the return rail 60, and further back to the negative pole of the traction substation. This embodiment prevents the normal return rail from leaking current to the ground through the unidirectional conductivity of the unidirectional diode, and returns the ground current leaked to the ground in a positive direction to the negative pole of the traction substation 10 to protect the underground pipeline.

[0046] It is understandable that the electrical parameter monitor can also be a voltage sensor connected in parallel to the unidirectional diode to monitor the voltage signal passing through the unidirectional diode; the electrical parameter monitor of each unidirectional backflow detection circuit can include only a current sensor, or can include both a current sensor and a voltage sensor, and this embodiment does not impose any specific limitations.

[0047] For ease of understanding, refer to Figure 3 The description is made by taking the backflow leakage monitoring device including the first unidirectional backflow detection circuit 72a and the second unidirectional backflow detection circuit 72b as an example.

[0048] The first unidirectional backflow detection circuit is used to generate a first current signal, and the second unidirectional backflow detection circuit is used to generate a second current signal;

[0049] The comprehensive monitoring component determines that the health status of the first unidirectional return current detection circuit or the second unidirectional return current detection circuit is damaged when the current difference between the first current signal and the second current signal exceeds a preset current difference threshold, or the current directions of the first current signal and the second current signal are opposite.

[0050] Specifically, the first unidirectional backflow detection circuit includes a first unidirectional diode and a first current sensor connected in series, and the second unidirectional backflow detection circuit includes a second unidirectional diode and a second current sensor connected in series.

[0051] The input end of the first unidirectional diode and the input end of the second unidirectional diode are both grounded, the output end of the first unidirectional diode is electrically connected to one end of the first current sensor, and the other end of the first current sensor is electrically connected to the first isolation switch and the integrated monitoring component (not shown in the figure) respectively;

[0052] The output end of the second unidirectional diode is electrically connected to one end of the second current sensor; the other end of the second current sensor is electrically connected to the first isolation switch and the integrated monitoring component (not shown in the figure) respectively; the integrated monitoring component is used to determine that there is a ground current leakage when the first current signal or the second current signal meets the ground current leakage condition; the integrated monitoring component is also used to determine that the health state is damaged when the first current signal and the second current signal meet the circuit fault condition, or when the direction of the first current signal and / or the second current signal is reversed.

[0053] The above-mentioned ground current leakage condition is that the first current signal and / or the second current signal exceeds a preset current threshold; the above-mentioned circuit fault condition is that the current difference between the first current signal and the second current signal exceeds the current difference threshold, or the current directions of the first current signal and the second current signal are opposite, and the health status of the first unidirectional return current detection circuit or the second unidirectional return current detection circuit is determined to be damaged.

[0054] The first current signal is an electrical parameter collected by the first current sensor and passing through the first unidirectional diode, and the second current signal is an electrical parameter collected by the second current sensor and passing through the second unidirectional diode.

[0055] Optionally, the backflow leakage monitoring device further includes: a lightning arrester 74, one end of which is electrically connected to one end of the first isolation switch 73, and the other end of which is grounded. In this embodiment, the lightning arrester connected in parallel prevents the unidirectional diode from being broken down during lightning strikes, so as to improve the protection capability of the unidirectional diode.

[0056] The isolation grounding device of this embodiment can be a single-pole isolation grounding device, and the isolation grounding device includes: a second isolation switch and a third isolation switch, the second isolation switch is electrically connected to the positive pole of the traction substation and the contact network 30 respectively, and the second isolation switch is used to control the positive pole of the traction substation to perform a power outage operation to the contact network 30; the third isolation switch is electrically connected to the return rail 60 and the negative pole of the traction substation respectively, and the third isolation switch is used to control the return operation of the return rail.

[0057] The isolation grounding device further includes: a first grounding switch and a second grounding switch, wherein the first grounding switch is electrically connected to the contact network 30 and the rail 50 respectively, and is used to control the contact network 30 to perform a grounding operation; the second grounding switch is electrically connected to the return rail 60 and the rail 50 respectively, and is used to control the return rail 60 to perform a grounding operation. The two isolation switches are interlocked with the two grounding switches.

[0058] The isolating grounding device of this embodiment can also be a bipolar isolating grounding device, that is, a bipolar isolating grounding switch (refer to Figure 3 and Figure 4 ), which saves the installation space of the knife switch in the cabinet, reduces the number of knife switches in the equipment, saves the connecting copper bars between the knife switches, reduces the cost, simplifies the production and assembly, and reduces the workload of engineering commissioning and after-sales maintenance. The two isolation knife switches are driven by the first motor, and the two grounding knife switches are driven by the second motor to realize the opening and closing operations at the same time.

[0059] Reference Figure 3 The bipolar isolation grounding switch includes a bipolar isolation switch. The bipolar isolation switch and the bipolar grounding switch of this embodiment are interlocked with each other. The bipolar isolation switch is electrically connected to the traction substation, the contact network 30 and the return rail 60 respectively. The bipolar isolation switch is used to control the traction substation to perform power outage operations on the contact network 30 and return operations on the return rail 60.

[0060] If the target operation request is a maintenance operation request, the bipolar isolating knife switch is controlled to open, and when it is determined that the power-off condition is met, the bipolar earthing knife switch is controlled to close; when the maintenance operation is completed, the bipolar earthing knife switch is controlled to open, and when it is determined that the power supply condition is met, the bipolar isolating knife switch is controlled to close. If the target operation request is a power outage request, the bipolar isolating knife switch is controlled to open; if the target operation request is a power supply request, that is, the rail locomotive is operating normally, the bipolar earthing knife switch is controlled to open, and the bipolar isolating knife switch is controlled to close.

[0061] Specifically, the bipolar isolating knife switch includes a second isolating knife switch 21 and a third isolating knife switch 22, and the second isolating knife switch 21 and the third isolating knife switch 22 are driven by a first motor 25 to simultaneously perform opening and closing operations. When closing, the positive pole of the traction substation is powered by the second isolating knife switch 21 to the contact network 30, so that the return rail 60 is connected to the negative pole of the traction substation through the third isolating knife switch 22 to construct a power supply circuit; when opening, the second isolating knife switch 21 is disconnected from the contact network 30, and the third isolating knife switch 22 is disconnected from the return rail 60 to realize a power outage operation.

[0062] The bipolar isolation grounding switch also includes a bipolar grounding switch, which is electrically connected to the contact network 30, the rail 50 and the return rail 60 respectively, and is used to control the contact network 30 and the return rail 60 to perform a grounding operation.

[0063] Specifically, the bipolar grounding switch includes a first grounding switch 23 and a second grounding switch 24, which are driven by a second motor 26 to simultaneously perform opening and closing operations. When closing, the first grounding switch 23 is connected to the contact network 30, the contact network 30 is connected to the rail 50 through the first grounding switch 23, the second grounding switch 24 is connected to the return rail 60, and the return rail 60 is connected to the rail 50 through the second grounding switch 24, so as to replace manual ground wire hanging operations; when opening, the first grounding switch 23 is disconnected from the contact network 30, and the second grounding switch 24 is disconnected from the return rail 60, so as to replace manual ground wire removal operations.

[0064] Reference Figure 4 An example of a bipolar isolation grounding knife switch, the second isolation knife switch 21 includes a positive static contact 211 of a traction substation, a contact network static contact 212 and a first isolation moving contact 213, the positive static contact 211 of the traction substation is electrically connected to the positive pole of the traction substation, the third isolation knife switch 22 includes a negative static contact 221 of the traction substation, a return rail static contact 222 and a second isolation moving contact 223; the first motor 25 drives the first isolation moving contact 213 and the second isolation moving contact The heads 223 move simultaneously; when closing the circuit, the contact network static contact 212 and the first isolating moving contact 213 are in contact with each other to realize the passage between the contact network and the positive pole of the traction substation, and the return rail static contact 222 and the second isolating moving contact 223 are in contact with each other to realize the passage between the return rail and the negative pole of the traction substation; when opening the circuit, the contact network static contact 212 and the first isolating moving contact 213 are separated, and the return rail static contact 222 and the second isolating moving contact 223 are separated to realize the power outage operation.

[0065] The first grounding switch 23 includes a contact network grounding static contact 231 and a first grounding moving contact 232, and the second grounding switch 24 includes a return rail grounding static contact 241 and a second grounding moving contact 242. The contact network grounding static contact 231 and the return rail grounding static contact 241 are both electrically connected to the rail, and the second motor 26 drives the first grounding moving contact 232 and the second grounding moving contact 242 to move simultaneously; when closing the switch, the contact network static contact 212 and the first grounding moving contact 232 are in contact to achieve contact network grounding, and the return rail static contact 222 and the second grounding moving contact 242 are in contact to achieve return rail grounding; when opening the switch, the contact network static contact 212 and the first grounding moving contact 232 are separated, and the return rail static contact 222 and the second grounding moving contact 242 are separated to end grounding.

[0066] Optionally, the bipolar DC isolation grounding device and the return leakage monitoring device can be installed in an integrated cabinet, or installed in parallel in the switch cabinet room or beside the track. Since one end of the return leakage monitoring device is connected to the return rail, the integrated cabinet or parallel cabinet installation can shorten the connection copper bus (i.e., static contact) or cable, reduce the construction difficulty, save material costs, etc. At the same time, it is also convenient for equipment maintenance.

[0067] In this embodiment, a rail transit traction power supply system is constructed by a traction substation, an overhead contact network, a return rail, a rail, a bipolar isolation grounding device and a return leakage monitoring device. The power supply and grounding of the overhead contact network are controlled by the bipolar isolation grounding device, the number of switches in the equipment is reduced, the equipment cost is reduced, the production and assembly are simple, and the workload of engineering commissioning and after-sales maintenance is small. The return rail avoids the leakage of ground current caused by the return of the rail. The return and monitoring of the ground current are realized by the return leakage monitoring device. The unidirectional conductivity of the two unidirectional return detection circuits is used to prevent the normal return rail from leaking current to the ground and realize the return of the ground current. The electrical signals of the two unidirectional return detection circuits are used to monitor the ground current leakage and the health status of each unidirectional return detection circuit. The maintenance personnel can timely learn the health status of each unidirectional return detection circuit to realize timely maintenance, maximize the return function of the return rail, and ensure the safety of underground pipelines.

[0068] See also Figure 5 , an embodiment of the reflux circuit monitoring method in the present application includes:

[0069] 501. Obtain an electrical signal corresponding to each unidirectional backflow detection circuit.

[0070] It is understandable that the execution subject of the present application may be a reflux circuit monitoring device, or a rail transit traction power supply system, a terminal or a server, which is not limited here. This embodiment is described by taking the rail transit traction power supply system as the execution subject.

[0071] In this embodiment, the electrical signal is collected by the parameter monitor of each unidirectional return current detection circuit, and the input end of each unidirectional return current detection circuit is grounded. If the electrical signal meets the corresponding conditions, it can be determined that there is a current leakage to the ground. In order to ensure the safety of the underground pipeline, this embodiment guides the leaked current to the ground through the unidirectional diode and the first isolation switch to the return rail.

[0072] The electrical parameter monitor may be a current sensor for collecting the current signal of each unidirectional return detection circuit; the electrical parameter monitor may be a current sensor and a voltage sensor for collecting the current signal and the voltage signal of each unidirectional return detection circuit.

[0073] The integrated detection component of the rail transit traction power supply system obtains the current signal corresponding to each unidirectional return detection circuit to monitor the operation status and protect the system, or the integrated detection component obtains the current signal and voltage signal corresponding to each unidirectional return detection circuit to monitor the operation status and protect the system.

[0074] 502. Determine whether there is current leakage to ground according to the electrical signal corresponding to each unidirectional return current detection circuit.

[0075] The rail transit traction power supply system determines whether the electrical signal corresponding to each unidirectional return current detection circuit meets the ground current leakage condition through a comprehensive detection component. If the electrical signal of at least one unidirectional return current detection circuit meets the ground current leakage condition, it is determined that there is ground current leakage.

[0076] In this embodiment, the ground current leakage condition may be that the current signal of at least one unidirectional return current detection circuit exceeds a preset current threshold, or may be that the voltage signal of any unidirectional return current detection circuit exceeds a preset voltage threshold.

[0077] When there is a ground current leakage, the ground current is guided to the return rail through at least two unidirectional return current detection circuits.

[0078] Specifically, the rail transit traction power supply system of this embodiment controls the closing of the first isolation switch to achieve conduction of at least two unidirectional return current detection circuits and the return rail, and utilizes the unidirectional conductivity of the unidirectional diodes in at least two unidirectional return current detection circuits to forwardly return the ground current leaked to the ground to the return rail, and prevents the normal return rail from leaking current to the ground, so that the ground current is guided to the negative pole of the traction substation through the return rail and the second isolation switch.

[0079] 503. Determine the health status of each of the two unidirectional backflow detection circuits according to the electrical signals of the two unidirectional backflow detection circuits.

[0080] The rail transit traction power supply system uses a comprehensive detection component to determine whether the circuit fault condition is met based on the electrical signals of any two unidirectional return current detection circuits. If so, it is determined that there is a damaged unidirectional return current detection circuit. If not, the health status of any two unidirectional return current detection circuits is normal.

[0081] In this embodiment, the circuit fault condition may be that the current difference between any two unidirectional return current detection circuits is greater than a preset current difference threshold, or that the current directions of any two unidirectional return current detection circuits are opposite, or that the voltage directions of any two unidirectional return current detection circuits are opposite.

[0082] Take the backflow leakage monitoring device including the first unidirectional backflow detection circuit and the second unidirectional backflow detection circuit as an example:

[0083] Specifically, a first current difference is determined based on the first current signal and the second current signal, and / or the current direction of the first current signal and the current direction of the second current signal are determined; if the first current difference is greater than a preset current difference threshold, and / or the current directions are opposite, it is determined that there is damage in the first unidirectional return detection circuit and the second unidirectional return detection circuit.

[0084] Furthermore, when the electrical signals of any two unidirectional return current detection circuits meet the circuit fault conditions, in order to further determine the faulty unidirectional return current detection circuit, the electrical signal of each unidirectional return current detection circuit can be compared to see whether it is reverse, and the unidirectional return current detection circuit with a reverse electrical signal can be marked as a faulty circuit, so as to facilitate maintenance personnel to improve the location of equipment fault points and improve maintenance efficiency.

[0085] The forward direction of the above-mentioned electrical signal direction is the conduction direction of the unidirectional return current detection circuit in a normal state, such as the current direction flowing to the return rail is forward; the reverse direction of the electrical signal is used to indicate the current flow direction when a fault occurs in the unidirectional return current detection circuit, such as when the diode of the unidirectional return current detection circuit is broken down, the current of the return rail may flow to the ground. Specifically, the reverse direction of the electrical signal may be the reverse direction of the current signal or the reverse direction of the voltage signal.

[0086] In this embodiment, whether there is current leakage to the ground is determined by the electrical signal of each unidirectional return detection circuit, and the health status of each unidirectional return detection circuit is determined according to the electrical signals of at least two unidirectional return detection circuits, so that the staff can monitor the leakage current and the health status of the return circuit, so as to perform equipment maintenance in time when the return leakage monitoring device fails, avoid damage to underground pipelines caused by ground current, and improve the safety of the rail transit traction power supply system.

[0087] See also Figure 6 Another embodiment of the reflux circuit monitoring method in the present application includes:

[0088] 601. Obtain an electrical signal corresponding to each unidirectional backflow detection circuit.

[0089] Step 601 can be performed with reference to step 501 and will not be described in detail here.

[0090] 602. Determine whether the current signal corresponding to each unidirectional backflow detection circuit exceeds a preset current threshold.

[0091] The integrated monitoring component of the rail transit traction power supply system compares the current signal corresponding to each unidirectional return detection circuit with a preset current threshold value to determine whether the current signal corresponding to each unidirectional return detection circuit exceeds the preset current threshold value.

[0092] 603. If the current signal corresponding to each unidirectional backflow detection circuit does not exceed the preset current threshold, it is determined that there is no current leakage.

[0093] Specifically, when the first current signal and the second current signal do not exceed the preset current threshold, it is determined that there is no current leakage.

[0094] 604. When the ground current monitored by at least one unidirectional return current detection circuit exceeds a preset current threshold, determine whether the direction of the ground current is forward.

[0095] Specifically, when the first current signal and / or the second current signal exceeds a preset current threshold, it is determined that there is current leakage to ground, and it is further determined whether the current direction of the first current signal and / or the second current signal is forward.

[0096] In a feasible implementation, if the current signal corresponding to each unidirectional return detection circuit is less than the preset current threshold, it is determined that there is no current leakage to the ground, and a self-test circuit can be set in the return leakage monitoring device to achieve self-test of the health status of each unidirectional return detection circuit.

[0097] 605. If not, it is determined that at least one unidirectional backflow detection circuit is damaged.

[0098] Specifically, if the current direction of the first current signal is reverse, it is determined that the first unidirectional backflow detection circuit is damaged; if the current direction of the second current signal is reverse, it is determined that the second unidirectional backflow detection circuit is damaged.

[0099] 606. If yes, direct the ground current to the return rail through at least two unidirectional return detection circuits.

[0100] Specifically, if the current direction of the first current signal is forward, the health state of the first unidirectional backflow detection circuit is determined to be normal; if the current direction of the second current signal is reverse, the health state of the second unidirectional backflow detection circuit is determined to be normal.

[0101] 607. Determine a target current difference between any two unidirectional return current detection circuits and / or current directions between any two unidirectional return current detection circuits according to electrical signals of any two unidirectional return current detection circuits.

[0102] The backflow leakage monitoring device of this embodiment may include two or more unidirectional backflow detection circuits. Taking three unidirectional backflow detection circuits as an example, a first current difference is determined according to a first current signal of the first unidirectional backflow detection circuit and a second current signal of the second unidirectional backflow detection circuit; a second current difference is determined according to the first current signal of the first unidirectional backflow detection circuit and a third current signal of the third unidirectional backflow detection circuit; and a third current difference is determined according to the second current signal of the second unidirectional backflow detection circuit and the third current signal of the third unidirectional backflow detection circuit.

[0103] 608. If the target current difference is greater than the preset current difference threshold, and / or the current directions of any two unidirectional return detection circuits are opposite, it is determined that there is damage in any two unidirectional return detection circuits, otherwise it is determined that the health status of any two unidirectional return detection circuits is normal.

[0104] Optionally, if the target current difference is greater than a preset current difference threshold, and / or the current directions of any two unidirectional backflow detection circuits are opposite, the unidirectional backflow detection circuit with the reverse current direction is determined as a faulty circuit.

[0105] Further, if the current direction of the third unidirectional return flow detection circuit is forward, that is, it is determined that the health status of the third unidirectional return flow detection circuit is good, then when the second current signal exceeds the preset current difference threshold, it is determined that the first unidirectional return flow detection circuit is damaged; when the third current signal exceeds the preset current difference threshold, it is determined that the second unidirectional return flow detection circuit is damaged.

[0106] 609. When any one-way backflow detection circuit is damaged, an alarm message is generated.

[0107] When the comprehensive detection component of the rail transit traction power supply system determines that any one-way return current detection circuit is damaged, it generates an alarm message and sends it to the system background to remind the staff to maintain and replace the diode in time.

[0108] In this embodiment, whether there is ground current leakage is determined by the size of the current signal of each unidirectional return detection circuit, the health status of the single-line diode therein is determined according to the direction of the current signal of each unidirectional return detection circuit, and the health status of each unidirectional return detection circuit is determined by the electrical signals of any two unidirectional return detection circuits. This facilitates the staff to monitor the leakage current and the health status of the return circuit, so that equipment maintenance can be carried out in time when a return leakage monitoring device fails, avoiding damage to underground pipelines caused by ground current, and improving the safety of the rail transit traction power supply system.

[0109] The above describes the reflux circuit monitoring method in the present application. The following describes the reflux circuit monitoring device in the present application. Figure 7 , an embodiment of the reflux circuit monitoring device in the present application includes:

[0110] An acquisition module 701 is used to acquire an electrical signal corresponding to each unidirectional backflow detection circuit;

[0111] A first judgment module 702, configured to judge whether there is a ground current leakage according to the electrical signal corresponding to each unidirectional backflow detection circuit;

[0112] The second determination module 703 is used to determine the health status of each of the two unidirectional backflow detection circuits according to the electrical signals of the two unidirectional backflow detection circuits.

[0113] In this embodiment, whether there is current leakage to the ground is determined by the electrical signal of each unidirectional return detection circuit, and the health status of each unidirectional return detection circuit is determined according to the electrical signals of at least two unidirectional return detection circuits, so that the staff can monitor the leakage current and the health status of the return circuit, so as to perform equipment maintenance in time when the return leakage monitoring device fails, avoid damage to underground pipelines caused by ground current, and improve the safety of the rail transit traction power supply system.

[0114] See also Figure 8 , another embodiment of the reflux circuit monitoring device in the present application includes:

[0115] An acquisition module 701 is used to acquire an electrical signal corresponding to each unidirectional backflow detection circuit;

[0116] A first judgment module 702, configured to judge whether there is a ground current leakage according to the electrical signal corresponding to each unidirectional backflow detection circuit;

[0117] The second determination module 703 is used to determine the health status of each of the two unidirectional backflow detection circuits according to the electrical signals of the two unidirectional backflow detection circuits.

[0118] Optionally, the first judgment module 702 is specifically used to: judge whether the current signal corresponding to each unidirectional backflow detection circuit exceeds a preset current threshold;

[0119] If the current signal corresponding to each unidirectional backflow detection circuit does not exceed the preset current threshold, it is determined that there is no current leakage;

[0120] If the ground current detected by at least one unidirectional return current detection circuit exceeds a preset current threshold, determining whether the direction of the ground current is forward;

[0121] If not, determining that the at least one unidirectional backflow detection circuit is damaged;

[0122] If so, the ground current is directed to the return rail via at least two unidirectional return detection circuits.

[0123] Optionally, the second judgment module 703 is specifically used to: determine the target current difference between any two unidirectional backflow detection circuits and / or the current directions of any two unidirectional backflow detection circuits according to the electrical signals of any two unidirectional backflow detection circuits;

[0124] If the target current difference is greater than the preset current difference threshold, and / or the current directions of any two unidirectional return detection circuits are opposite, it is determined that there is damage in any two unidirectional return detection circuits, otherwise the health status of any two unidirectional return detection circuits is determined to be normal.

[0125] The reflux circuit monitoring device further includes: an alarm module 704, which is used to generate an alarm message when any one-way reflux detection circuit is damaged.

[0126] In this embodiment, whether there is ground current leakage is determined by the size of the current signal of each unidirectional return detection circuit, the health status of the single-line diode therein is determined according to the direction of the current signal of each unidirectional return detection circuit, and the health status of each unidirectional return detection circuit is determined by the electrical signals of any two unidirectional return detection circuits. This facilitates the staff to monitor the leakage current and the health status of the return circuit, so that equipment maintenance can be carried out in time when a return leakage monitoring device fails, avoiding damage to underground pipelines caused by ground current, and improving the safety of the rail transit traction power supply system.

[0127] The following is a detailed description of the reflux circuit monitoring device in the present application from the perspective of hardware processing.

[0128] The backflow circuit monitoring device includes a processor and a memory, wherein the memory stores machine executable instructions that can be executed by the processor, and the processor executes the machine executable instructions to implement the backflow leakage monitoring method.

[0129] Furthermore, the reflux circuit monitoring device also includes a bus and a communication interface, and the processor, the communication interface and the memory are connected via the bus.

[0130] The memory may include high-speed random access memory (RAM) and may also include non-volatile memory (non-volatile memory), for example, at least one disk storage. The communication connection between the system network element and at least one other network element is realized through at least one communication interface (which may be wired or wireless), and the Internet, wide area network, local area network, metropolitan area network, etc. may be used. The bus may be an ISA bus, a PCI bus, or an EISA bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc.

[0131] The processor may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in the processor or an instruction in the form of software. The above processor may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The disclosed methods, steps and logic block diagrams in the embodiments of the present disclosure may be implemented or executed. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the method disclosed in conjunction with the embodiments of the present disclosure may be directly embodied as being executed by a hardware decoding processor, or may be executed by a combination of hardware and software modules in a decoding processor. The software module may be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the method steps of the above-mentioned embodiment in combination with its hardware.

[0132] The present application also provides a computer-readable storage medium, which may be a non-volatile computer-readable storage medium or a volatile computer-readable storage medium. Instructions are stored in the computer-readable storage medium. When the instructions are executed on a computer, the computer executes the steps of the reflux circuit monitoring method.

[0133] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0134] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk and other media that can store program code.

[0135] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A rail transit traction power supply system, It is characterized in that include: Traction substation, overhead line, return rail, rail, isolation grounding device and return leakage monitoring device; The isolated grounding device is electrically connected to the traction substation, the contact network, the return rail and the rail respectively, and the isolated grounding device is used to control the power supply and grounding of the contact network; The return leakage monitoring device comprises an integrated monitoring component and at least two unidirectional return detection circuits, the input end of each unidirectional return detection circuit is grounded, and the output end of each unidirectional return detection circuit is electrically connected to the return rail, for directing the leakage current to the ground to the return rail; The output end of each unidirectional return detection circuit is electrically connected to the integrated monitoring component, and the integrated monitoring component determines whether there is current leakage to the ground based on the electrical signal of each unidirectional return detection circuit, and determines the health status of each unidirectional return detection circuit based on the electrical signal of the at least two unidirectional return detection circuits.

2. The rail transit traction power supply system according to claim 1, It is characterized in that Each unidirectional backflow detection circuit comprises: a unidirectional diode and a current sensor; The input end of the unidirectional diode is grounded, the output end of the unidirectional diode is electrically connected to the current sensor, the current sensor is electrically connected to the integrated monitoring component, and the electrical parameter monitor is used to monitor the electrical signal passing through the unidirectional diode and send it to the integrated monitoring component.

3. The rail transit traction power supply system according to claim 1 or 2, It is characterized in that The backflow leakage monitoring device comprises: a first unidirectional backflow detection circuit and a second unidirectional backflow detection circuit; The first unidirectional backflow detection circuit is used to generate a first current signal, and the second unidirectional backflow detection circuit is used to generate a second current signal; The comprehensive monitoring component determines that the health status of the first unidirectional return current detection circuit or the second unidirectional return current detection circuit is damaged when the current difference between the first current signal and the second current signal exceeds a preset current difference threshold, or the current directions of the first current signal and the second current signal are opposite.

4. The rail transit traction power supply system according to claim 1, It is characterized in that The backflow leakage monitoring device further comprises: a first isolation switch; The first isolation switch is used to control the connection and disconnection between the at least two unidirectional return current detection circuits and the return rail.

5. The rail transit traction power supply system according to claim 1, It is characterized in that The backflow leakage monitoring device also includes: a lightning arrester; One end of the lightning arrester is electrically connected to one end of the first isolating switch, and the other end of the lightning arrester is grounded.

6. The rail transit traction power supply system according to claim 1, It is characterized in that The isolation grounding device comprises: a bipolar isolation switch; The bipolar isolating knife switch is electrically connected to the traction substation, the contact network and the return rail respectively, and is used to control the traction substation to perform power outage operation on the contact network and return operation on the return rail.

7. The rail transit traction power supply system according to claim 1 or 6, It is characterized in that The isolation grounding device comprises: a double-pole grounding switch; The bipolar grounding switch is electrically connected to the contact network, the rail and the return rail respectively, and is used to control the contact network and the return rail to perform a grounding operation.

8. A reflux circuit monitoring method, It is characterized in that Applied to the rail transit traction power supply system described in any one of 1-7 above, the return circuit monitoring method includes: Obtaining an electrical signal corresponding to each unidirectional backflow detection circuit; Judging whether there is current leakage to the ground according to the electrical signal corresponding to each unidirectional return current detection circuit; The health status of each of the two unidirectional backflow detection circuits is determined according to the electrical signals of the two unidirectional backflow detection circuits.

9. The reflux circuit monitoring method according to claim 8, It is characterized in that Determining the health status of each of the two unidirectional backflow detection circuits according to the electrical signals of the two unidirectional backflow detection circuits comprises: Determining a target current difference between any two unidirectional return current detection circuits and / or current directions of any two unidirectional return current detection circuits according to electrical signals of the any two unidirectional return current detection circuits; If the target current difference is greater than the preset current difference threshold, and / or the current directions of any two unidirectional return detection circuits are opposite, it is determined that there is damage in any two unidirectional return detection circuits; otherwise, the health status of any two unidirectional return detection circuits is determined to be normal.

10. The reflux circuit monitoring method according to claim 8 or 9, It is characterized in that Each unidirectional backflow detection circuit includes a unidirectional diode and a current sensor, and judging whether there is a current leakage to the ground according to the electrical signal corresponding to each unidirectional backflow detection circuit includes: Determine whether the current signal corresponding to each unidirectional backflow detection circuit exceeds a preset current threshold; If the current signal corresponding to each unidirectional backflow detection circuit does not exceed the preset current threshold, it is determined that there is no current leakage; If the ground current detected by at least one unidirectional return current detection circuit exceeds a preset current threshold, determining whether the direction of the ground current is forward; If not, determining that the at least one unidirectional backflow detection circuit is damaged; If so, the ground current is directed to the return rail via at least two unidirectional return detection circuits.

11. A reflux circuit monitoring device, It is characterized in that The reflux circuit monitoring device comprises: An acquisition module, used for acquiring an electrical signal corresponding to each unidirectional backflow detection circuit; A first judgment module, used for judging whether there is a ground current leakage according to the electrical signal corresponding to each unidirectional backflow detection circuit; The second judgment module is used to determine the health status of each of the two unidirectional backflow detection circuits according to the electrical signals of the two unidirectional backflow detection circuits.

12. A computer-readable storage medium having stored thereon instructions, It is characterized in that When the instruction is read and executed, the reflux circuit monitoring method according to any one of claims 8 to 10 is executed.

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