CN112350297A

CN112350297A - Subway contact net DC power supply integrated device

Info

Publication number: CN112350297A
Application number: CN202011149683.9A
Authority: CN
Inventors: 童翔; 张兴凯; 岳金; 彭刚; 杨卓; 张占仓; 王金龙; 张立军; 周鑫; 李现鹏; 李洁; 许伟; 温鑫; 张家涛; 杨少星; 包华; 屈文涛; 雷霆
Original assignee: WUHAN CHANGHAI ELECTRICAL TECHNOLOGY DEVELOPMENT CO LTD; Zhengzhou Metro Group Co ltd
Current assignee: WUHAN CHANGHAI ELECTRICAL TECHNOLOGY DEVELOPMENT CO LTD; Zhengzhou Metro Group Co ltd
Priority date: 2020-10-23
Filing date: 2020-10-23
Publication date: 2021-02-09

Abstract

The invention relates to a direct-current power supply integrated device for a subway overhead line system, which comprises a main body of the device, wherein a first switch module, a second switch module and a cross-zone load switch are arranged in the main body; the first switch module comprises a first isolating switch, and the second switch module comprises a second isolating switch; first isolator and second isolator are three station isolator, have three independent stations, include: closing, separating and grounding. The invention provides a direct-current power supply integrated device and a direct-current power supply integrated method for a subway contact network.A contact network isolating switch is remotely visible in closing position, separating position and grounding state, has an intelligent identification function of isolating fracture images, and can be loaded to switch a large double-side mode without influencing a travelling crane; no external interlocking exists, the internal interlocking is simple, and misoperation can be effectively prevented; the equipment is safe and reliable, and the cost is lower.

Description

Subway contact net DC power supply integrated device

Technical Field

The invention relates to the technical field of rail transit direct current power supply, in particular to a direct current power supply integrated device for a subway contact network.

Background

As shown in fig. 2, the existing subway overhead line system (rail) dc power supply equipment includes: networking combined switch and contact net earthing switch that is crossed, wherein: the combined internet access switch consists of two internet

access isolating switches

101 and 102 and a cross-over isolating switch 103.

The network

access isolating switches

101 and 102 are used as standard configurations of a subway direct-current power supply system to connect a substation feeder line and a contact network, and are used for switching the connection state and the isolation state of the contact network and the substation feeder line. The cross-area isolating switch 103 is used for connecting the left and right adjacent station contact network power sections and switching a large bilateral power supply mode, but because the cross-area isolating switch cannot be operated with load, a necessary operation interlocking function needs to be set, and three stations are powered off to carry out no-load switching operation, so that the temporary stop of the passenger car is caused, and the subway running is influenced.

In order to ensure the use, operation and maintenance safety of equipment, the feedback electrical signal states of the internet-access isolating switch and the grounding isolating switch are required to be consistent with the physical switch states, and a remote image (video) is required to be visible.

In summary, the deficiencies in the prior art are summarized as follows: 1) the cross-region isolating switch 103 cannot be operated with load, and needs to be stopped to influence the operation of the subway when a large bilateral mode is switched; 2) complicated electrical interlocking relation exists between the internet

access isolating switches

101 and 102 and the grounding isolating switch, and misoperation is easy to occur; 3) the

networking isolating switches

101 and 102 and the grounding isolating switch have functional overlapping, so that the construction cost is increased; 4) the physical states of the internet

access isolation switches

101 and 102 and the grounding switch cannot be all remotely visible and need to be manually judged.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides a direct-current power supply integrated device for a subway contact network.

The invention can be realized by the following technical scheme:

a direct-current power supply integrated device for a subway overhead line system comprises a main body of the device, wherein a first switch module, a second switch module and a cross-zone load switch are arranged in the main body;

the first switch module comprises a first isolating switch, and the second switch module comprises a second isolating switch;

first isolator and second isolator are three station isolator, have three independent station, include: closing, separating and grounding;

the static contact of the first isolating switch is connected with a corresponding feeder line of a direct current switch cabinet of an external substation, the moving contact of the first isolating switch is connected with an external contact network, and the grounding contact of the first isolating switch is connected with a subway steel rail; a fixed contact of the second isolating switch is connected with the other corresponding group of feeder lines of the direct current switch cabinet of the external substation, a moving contact of the second isolating switch is connected with an external contact network, and a grounding contact of the second isolating switch is connected with a subway steel rail; and the moving contact of the first isolating switch is connected with the moving contact of the cross-region load switch, and the moving contact of the second isolating switch is connected with the fixed contact of the cross-region load switch.

In some embodiments, the first switch module further includes a first camera and a first light supplement lamp installed beside the first isolating switch, and the second switch module further includes a second camera and a second light supplement lamp installed beside the second isolating switch.

In some embodiments, the intelligent image recognition and storage device further comprises a monitoring device, an intelligent image recognition and storage device and a network switch which are arranged in the main body;

the first switch module and the second switch module are electrically connected with the monitoring device, the first switch module and the second switch module are in network cable communication connection with the image intelligent identification and storage device, the image intelligent identification and storage device is in network cable communication connection with the monitoring device, and the image intelligent identification and storage device and the monitoring device are in network cable communication connection with the network switch.

In some embodiments, the first and second disconnectors are mirror images of each other and are mounted back to back at a lower portion in the main body, the moving contacts of the first and second disconnectors both hit the rear side of the device when the first and second disconnectors are in a closed position, the moving contacts of the first and second disconnectors both hit the front side of the device when the first and second disconnectors are in a closed position, and the cross-area load switch is mounted above the first disconnector.

In some embodiments, the main body further comprises a plurality of connecting devices arranged in the main body, wherein the plurality of connecting devices comprise two feeder line connecting interfaces, two contact net connecting interfaces, two handover switching copper bars, two internet surfing switching copper bars, two feeder line switching copper bars and two grounding switching copper bars;

the fixed contacts of the first isolating switch and the second isolating switch are respectively connected with the corresponding feeder line connecting interfaces through two feeder line switching copper bars;

moving contacts of the first isolating switch and the second isolating switch are respectively connected with corresponding contact net connecting interfaces through two internet switching copper bars;

the grounding contacts of the first isolating switch and the second isolating switch are respectively connected with an external subway steel rail through two grounding transfer copper bars;

and the moving contact and the fixed contact of the cross-area load switch are respectively connected with the two internet-surfing switching copper bars through the two cross-area switching copper bars.

In some embodiments, further comprising a bus high pressure chamber and a low pressure chamber disposed within the body; the bus high-pressure chamber is positioned in the middle of the inside of the main body, and the low-pressure chamber is positioned on one side of the inside of the main body;

the intelligent image identification and storage device is arranged at the lower part of the low-pressure chamber;

the monitoring device is arranged on the front surface of the inner side of the low-pressure chamber.

In some embodiments, the network switch further comprises an external terminal chamber arranged at the front side of the bottom in the main body, and the network switch is installed in the external terminal chamber.

In some embodiments, the residual pressure relief device comprises two sets of residual pressure relief devices, and the two sets of residual pressure relief devices are respectively installed on the left rear side and the right rear side of the bottom in the main body.

In some embodiments, the system further comprises a waterproof heat shield, a top seal assembly, a top mounting bracket, a top junction box, a base, a plurality of observation windows, two protective doors, and two maintenance steps;

the waterproof heat shield is fixedly connected with the shell of the main body;

the top sealing assembly, the top junction box and the top fixing support are mutually fixed and are all fixed at the top of the shell of the main body, and the top fixing support is fixed with a cable support of a cable entering and exiting the main body;

the base is fixed at the bottom end of the shell of the main body;

the two protective doors are respectively and symmetrically arranged on the left side and the right side of the main body;

the plurality of observation windows are arranged on the shell of the main body, the protective door and the top junction box;

and the two maintenance steps are respectively connected with the ground and the bottom end of the corresponding protective door.

Compared with the prior art, the invention has the advantages that at least: the invention provides a direct-current power supply integrated device and a direct-current power supply integrated method for a subway contact network, wherein the closed and separated grounding states of a contact network disconnecting switch are remotely visible, the device has the function of intelligently identifying an isolated fracture image, and large double-side mode switching can be carried out under load without influencing a travelling crane; no external interlocking exists, the internal interlocking is simple, and misoperation can be effectively prevented; the equipment is safe and reliable, and the cost is lower.

Drawings

Other objects and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings, and may assist in a comprehensive understanding of the invention.

Fig. 1 is a schematic view of a topological structure of a dc power supply integrated device for a subway overhead line system provided by the invention;

FIG. 2 is a schematic of a topology of a prior art solution;

fig. 3 is a schematic diagram of connection of internal modules of the dc power supply integrated device for the subway overhead line system provided by the invention;

fig. 4 is a front view of an internal structure of the dc power supply integrated device for the subway overhead line system provided by the invention;

FIG. 5 is a left side view and a right side view of FIG. 1;

fig. 6 is an appearance schematic diagram of the dc power supply integrated device for the subway overhead line system provided by the invention;

fig. 7 is a schematic view of the installation of the subway overhead line system direct current power supply integrated device provided by the invention on the side of a station in a tunnel.

Description of reference numerals:

1. a main body; 2. a waterproof heat shield; 3. a top seal assembly; 4. a base; 5. an observation window; 6. maintaining the step; 7. a protective door; 8. a top junction box; 9. a top fixed support; 101. 102, an internet access isolating switch; 103. a cross-region isolating switch; 11. a first isolation switch; 111. a first camera; 112. a first fill-in light; 12. a second isolation switch; 121. a second camera; 122. a second fill-in light; 13. a cross-area load switch; 14. the image intelligent identification and storage device; 15. a network switch; 150. for the outer terminal chamber; 16. a monitoring device; 161. an auxiliary control part; 171. a feeder line connection interface; 172. a contact network connecting interface; 173. the copper bar is switched over; 174. surfing the net to transfer the copper bar; 175; the feeder line is connected with the copper bar in a switching way; 176. a grounding switching copper bar; 181. a busbar high pressure chamber; 182. a low pressure chamber; 19. a residual pressure relief device; 20. a subway vehicle; 30. a catenary; 40. a station side wall; 50. and (4) a network cable.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention without any inventive step, are within the scope of protection of the invention.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs.

Referring to fig. 1, the invention provides a direct current power supply integrated device for a subway contact network, which comprises a main body 1 of the device, wherein a first switch module, a second switch module and a cross-zone load switch 13 are arranged in the main body 1; the first switch module comprises a first isolating switch 11, and the second switch module comprises a second isolating switch 12; first isolator 11 and second isolator 12 are three station isolator, have three independent stations, include: closing, separating and grounding; a fixed contact of the first isolating switch 11 is connected with a corresponding feeder line of a direct current switch cabinet of an external substation, a moving contact of the first isolating switch 11 is connected with an external contact network, and a grounding contact of the first isolating switch 11 is connected with a subway steel rail (a travelling rail); a fixed contact of the second isolating switch 12 is connected with another corresponding group of feeder lines of a direct current switch cabinet of an external substation, a moving contact of the second isolating switch 12 is connected with an external contact network, and a grounding contact of the second isolating switch 12 is connected with a subway steel rail (a travelling rail); and the moving contact of the first isolating switch 11 is connected with the moving contact of the load switch 13, and the moving contact of the second isolating switch 12 is connected with the fixed contact of the load switch 13.

It can be seen that, compared to the solution in the prior art shown in fig. 2, the solution of the present invention provides a brand new power supply topology for the overhead line system: the networking isolating switch and the grounding isolating switch in the contact network power supply topological structure are subjected to function fusion and are designed into a networking and grounding integrated three-station isolating switch, namely a first isolating switch 11 and a second isolating switch 12, so that external interlocking is changed into internal mechanical interlocking; the isolator of two three stations has closing, separating brake and three kinds of independent position states of ground connection, wherein: the closing position realizes the function of the feeder line surfing; the brake separating position realizes the function of isolating a contact net; the grounding position state realizes the function of maintaining and grounding the contact network; in addition, the over-zone isolating switch in the power supply topological structure of the overhead line system is designed as the over-zone load switch 13, so that the switching of a large bilateral mode of switching without power failure is realized under the condition of not influencing the operation, a certain station direct current traction power supply device can be automatically disconnected as required, the time for overhauling a skylight of the subway power supply device is prolonged, and the labor intensity is reduced.

Referring to fig. 3, the first switch module further includes a first camera 111 and a first light supplement lamp 112 installed beside the first isolating switch 11, and the second switch module further includes a second camera 121 and a second light supplement lamp 122 installed beside the second isolating switch 12. The first camera 111 and the second camera 121 may both be web cameras.

Preferably, the device also comprises a monitoring device 16, an intelligent image identification and storage device 14 and a network switch 15 which are arranged in the main body 1; the first switch module and the second switch module are electrically connected with the monitoring device 16, the first switch module and the second switch module are in network cable communication connection with the image intelligent identification and storage device 14, the image intelligent identification and storage device 14 is in network cable communication connection with the monitoring device 16, and the image intelligent identification and storage device 14 and the monitoring device 16 are in network cable communication connection with the network switch 15; the network switch 15 may be communicatively coupled to an external central office network.

When the remote monitoring device works, the first switch module and the second switch module transmit remote measuring and remote signaling signals to the monitoring device 16; the monitoring device 16 transmits remote control signals to the first switch module and the second switch module; the first camera 111 of the first switch module takes a picture and records a video in real time (the first light supplement lamp 112 automatically supplements light during taking a picture), the second camera 121 of the second switch module takes a picture and records a video in real time (the second light supplement lamp 122 automatically supplements light during taking a picture), and the images are respectively real-time image information to the image intelligent identification and storage device 14; the monitoring device 16 transmits the state signals of the two isolating switches to the image intelligent recognition and storage device 14, the image intelligent recognition and storage device 14 compares the image processing result at the moment with the image processing result to form a judgment result which is fed back to the monitoring device 16 for video linkage and abnormal alarm; the image intelligent recognition and storage device 14 stores the image data on site for external calling and viewing through the network switch 15.

With further reference to fig. 4 and 5, the first isolation switch 11 and the second isolation switch 12 are mirror images (mirror image plane in the seam perpendicular to the front) and are installed back to back at the lower part of the main body 1, when the first isolation switch and the second isolation switch are closed, the moving contacts are both on the rear side of the device, when the first isolation switch and the second isolation switch are connected, the moving contacts are both on the front side of the device, and the cross-area load switch 13 is installed above the first isolation switch 11.

Specifically, the device further comprises a plurality of connecting devices arranged in the main body 1, wherein the plurality of connecting devices comprise two feeder line connecting interfaces 171, two contact line connecting interfaces 172, two cross-area switching copper bars 173, two internet switching copper bars 174, two feeder line switching copper bars 175 and two grounding switching copper bars 176; the fixed contacts of the first isolating switch 11 and the second isolating switch 12 are respectively connected with the corresponding feeder line connecting interfaces 171 through two feeder line switching copper bars 175; the moving contacts of the first isolating switch 11 and the second isolating switch 12 are respectively connected with the corresponding contact network connecting interface 172 through two internet switching copper bars 174; the ground contacts of the first isolating switch 11 and the second isolating switch 12 are respectively connected with the external subway steel rail through two ground switching copper bars 176; the moving contact and the static contact of the load-crossing switch 13 are connected to two internet switching copper bars 174 through two load-crossing copper bars 173, respectively.

The device also comprises a bus high-pressure chamber 181 and a low-pressure chamber 182 which are arranged in the main body 1; the bus high-pressure chamber 181 is located at the middle part in the main body 1, and the low-pressure chamber 182 is located at one side in the main body 1; the image intelligent identification and storage device 14 is arranged at the lower part of the low-pressure chamber 182; the monitoring device 16 is mounted on the inside face of the low pressure chamber 182 to perform "three remote" (telecommand, telemetry and telecontrol) functions.

The device also comprises an external terminal chamber 150 arranged at the front side of the bottom in the main body 1, and the network switch 15 is arranged in the external terminal chamber 150; the external terminal chamber 150 may further contain an optical fiber terminal box and various external interface terminals for external communication and interaction.

Specifically, the two cameras are connected with the image intelligent recognition and storage device 14 through network cables, and can transmit image and video data to the image intelligent recognition and storage device 14 in real time for storage, analysis and processing; two light filling lamps all pass through the wire with monitoring device 16 and are connected, can realize that monitoring device 16 is to the control of light filling lamp: when the monitoring device 16 sends an operation instruction to the isolating switch, the light supplementing lamp is turned on in advance for 1s (before the isolating switch starts to act), and is turned off in a delayed manner for 1s (after the isolating switch acts), so that the video and the image in the action process of the isolating switch are clear. The monitoring device 14 is connected with the network cable and the image intelligent identification and storage device 14 through the network cable, the monitoring device 14 transmits a real-time state signal of the isolating switch to the image intelligent identification and storage device 14, the image intelligent identification and storage device 14 compares the real-time state signal with an image intelligent identification result, and finally the comparison result is fed back to the monitoring device 14. The monitoring device 14 and the image intelligent identification and storage device 14 are connected with the external terminal chamber 150 through network cable connection, so that the interaction of three remote signals of the device and the transmission of video image signals are realized.

The device also comprises two sets of residual pressure relief devices 19, wherein the two sets of residual pressure relief devices 19 are respectively arranged on the left rear side and the right rear side of the bottom in the main body 1. The residual voltage relief device 19 mainly comprises a bipolar contactor, a fuse, a voltage sensor and a discharge resistor, and all the parts are connected in series. In order to prevent the three-position isolating switch from being grounded with load, a residual voltage release device 19 is bridged between the moving contact and the grounding contact of the two three-position isolating switches to carry out residual voltage detection and release. The residual pressure relief device 19 is controlled by the monitoring device 16, and has the following specific functions: 1) the method comprises the steps that electricity testing is carried out before a three-station isolating switch is grounded, when the voltage of a contact net is larger than or equal to UL (settable, recommended value of 600V), the contact net is judged to be electrified, the isolating switch is forbidden to be grounded, and a discharging loop is forbidden to be put into; 2) when the voltage of the contact network is less than U0, the contact network is judged to have residual voltage and can be put into a discharge loop; 3) when UL is larger than or equal to the voltage of the contact network and is larger than or equal to U0, after the discharging loop is put into the preset time T (which can be set), the voltage of the contact network is smaller than U0, discharging is successful, the isolating switch can be operated to be grounded, if the detection voltage is larger than U0, a discharging fault is reported, and the isolating switch is locked to be operated to be grounded.

With further reference to fig. 6, the apparatus further comprises a waterproof heat shield 2, a top seal assembly 3, a top stationary support 9, a top junction box 8, a base 4, a plurality of observation windows 5, two guard doors 7, and two maintenance steps 6; the waterproof heat shield 2 is fixedly connected with the shell of the main body 1; the top sealing assembly 3, the top junction box 8 and the top fixing support 9 are mutually fixed and are all fixed at the top of the shell of the main body 1, and the top fixing support 9 is fixed with a cable support of a cable entering and exiting the main body 1; the base 4 is fixed at the bottom end of the shell of the main body 1; the two protective doors 7 are respectively and symmetrically arranged at the left side and the right side of the main body 1; the plurality of observation windows 5 are arranged on the shell of the main body 1, the protective door 7 and the top junction box 8; the two maintenance steps 6 are respectively connected with the ground and the bottom ends of the corresponding protective doors 7.

Specifically, maintain step 6 surface and adopt anti-skidding design, about two sets maintain step 6 respectively with base 4 through bolted connection, base 4 carries out the crab-bolt with the ground and is connected fixedly, for the sufficient space of inlet wire connecting cable turn reservation down, has reduced maintainer's operating height simultaneously. When the protective door 7 is closed, the shell of the main body 1 is of a fully closed structure, and the shell of the main body 1 is fixedly connected with the base 4 through foundation bolts. The observation window 5 is made of toughened glass and is installed on the totally-enclosed shell in a sealing and nesting mode, so that operation and maintenance personnel can conveniently observe the fracture condition of the isolating switch when patrolling at the station side. The protective doors 7 on the two sides are hermetically nested with the observation windows 5 made of toughened glass, so that operation and maintenance personnel can observe the internal operation condition of the device under the condition of not opening the doors; the left side guard gate is mirror symmetry structure with the right side guard gate, guarantees that the direction of opening the door all exceeds the platform side of standing, prevents that the cabinet door from opening by mistake invades the border. The waterproof heat shield 2 is fixedly connected with the totally-enclosed shell in a mode of external buckle sealing and internal bolt connection, so that all components in the device are rainproof, heat-insulating and dust-proof. Top junction box 8 adopts the outer sealed mode of adding inside bolted connection of knot to be connected fixedly with waterproof heat shield 2, for cable junction and copper bar in the junction box 8 of top provide abundant physics protection, and openly sealed nested observation window 5 of installing toughened glass and making at junction box 8 of top to the connection condition of top cable that the operation maintainer can be convenient when platform side patrols. Top seal assembly 3 passes through the ring flange and the sealing washer is fixed with 8 bolts of top junction box, and top seal assembly 3 body need be from taking cable crimping device, eliminates the physical clearance between cable and seal assembly to reach the waterproof dustproof requirement in top, protection level surpasss IP 54. The top fixing support 9 is welded on the top junction box 8, the top fixing support 9 is fixed with a cable support of a top incoming and outgoing cable, so that the top and the bottom of the integrated device are fixed simultaneously, and the working stability in the environment of random vibration in a tunnel and piston wind alternating pressure is further enhanced.

Referring to fig. 7, the invention designs a device structure convenient for installation at the station side in a tunnel: the integrated device is designed into an in-out mode of up-going and up-going (or down-going and up-going), and is connected with a contact network 30 through an internet cable 50 so as to meet the shortest requirement of the internet cable of the contact network; the integrated device is designed into a totally-enclosed structure, the cable sealing component is arranged at the top of the integrated device, so that water leakage or water seepage at the top is prevented, the requirement of the integral protection level IP54 is met, and a clean and proper operation environment is provided for each part in the integrated device (all main components in the integrated device cannot directly resist severe environments such as dripping water, salt mist and dust in a tunnel); the integrated device is designed into a mirror image structure with left and right double-sided maintenance, and a manual operating mechanism of the integrated device is designed to be close to a side wall 40 of the station, so that the requirement of equipment intrusion in the tunnel is met; the device has small design depth size and small corresponding wind section, and improves the structural stability of the equipment under the wind action of the tunnel piston; the integrated device is installed on the side of a platform in a tunnel, an operation maintenance surface is parallel to the section of the tunnel, the installation position considers the limit requirement under the condition that the device is completely opened, the distance from the wall of the tunnel platform is 800mm, and the distance from the outer contour of the railway vehicle 20 to the ground is more than 1500 mm.

In summary, in the existing scheme, the contact net is only grounded and visible, and the traveling is influenced by the large bilateral mode switching; the interlocking between the devices is complex; 6 sets of devices are needed for a single station (2 sets of networking cross-area devices and 4 sets of visual grounding devices); a station level network server needs to be added for independently storing and processing images and needs to be independently networked; the overall retrieval and operation and maintenance costs are relatively high. In the integrated device provided by the invention, the contact net isolating switch is closed, and the separated grounding is visible; the large double-side mode switching does not affect the traveling crane; no external interlocking is adopted, and the internal interlocking is simple; the equipment safety is high; only two sets of integrated devices are needed for a single station, and the number is small; the image storage and processing are finished in the device body by the aid of the non-station server; the overall retrieval and operation and maintenance costs are relatively low.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The direct-current power supply integrated device for the subway overhead line system is characterized by comprising a main body (1) of the device, wherein a first switch module, a second switch module and a cross-zone load switch (13) are arranged in the main body (1);

the first switch module comprises a first isolating switch (11), the second switch module comprises a second isolating switch (12);

first isolator (11) and second isolator (12) are three station isolator, have three independent stations, include: closing, separating and grounding;

a fixed contact of the first isolating switch (11) is connected with a corresponding feeder line of a direct current switch cabinet of an external substation, a moving contact of the first isolating switch (11) is connected with an external contact network, and a grounding contact of the first isolating switch (11) is connected with a subway steel rail; a fixed contact of the second isolating switch (12) is connected with another corresponding group of feeder lines of a direct current switch cabinet of an external substation, a moving contact of the second isolating switch (12) is connected with an external contact network, and a grounding contact of the second isolating switch (12) is connected with a subway steel rail; and the moving contact of the first isolating switch (11) is connected with the moving contact of the cross-area load switch (13), and the moving contact of the second isolating switch (12) is connected with the fixed contact of the cross-area load switch (13).

2. The subway overhead line system direct current power supply integrated device according to claim 1, wherein said first switch module further comprises a first camera (111) and a first light supplement lamp (112) installed beside said first isolating switch (11), and said second switch module further comprises a second camera (121) and a second light supplement lamp (122) installed beside said second isolating switch (12).

3. The subway overhead line system direct-current power supply integrated device as claimed in claim 2, further comprising a monitoring device (16), an intelligent image recognition and storage device (14) and a network switch (15) which are arranged in said main body (1);

the first switch module and the second switch module are electrically connected with the monitoring device (16), the first switch module and the second switch module are in network cable communication connection with the image intelligent identification and storage device (14), the image intelligent identification and storage device (14) is in network cable communication connection with the monitoring device (16), and the image intelligent identification and storage device (14) and the monitoring device (16) are in network cable communication connection with the network switch (15).

4. The subway overhead line system direct current power supply integrated device according to claim 1, wherein said first isolation switch (11) and said second isolation switch (12) are mirror image structures and are installed back to back in the lower part of said main body (1), and said over-area load switch (13) is installed above said first isolation switch (11).

5. The subway overhead line system direct-current power supply integrated device as claimed in claim 1, further comprising a plurality of connecting devices arranged in said main body (1), wherein said plurality of connecting devices comprise two feeder line connecting interfaces (171), two overhead line connecting interfaces (172), two handover switching copper bars (173), two internet access switching copper bars (174), two feeder line switching copper bars (175) and two grounding switching copper bars (176);

the fixed contacts of the first isolating switch (11) and the second isolating switch (12) are respectively connected with the corresponding feeder line connecting interfaces (171) through two feeder line switching copper bars (175);

moving contacts of the first isolating switch (11) and the second isolating switch (12) are respectively connected with corresponding contact net connecting interfaces (172) through two internet switching copper bars (174);

the grounding contacts of the first isolating switch (11) and the second isolating switch (12) are respectively connected with an external subway steel rail through two grounding transfer copper bars (176);

the moving contact and the static contact of the over-zone load switch (13) are respectively connected with two internet switching copper bars (174) through two over-zone switching copper bars (173).

6. The subway overhead line system direct current supply integrated device according to claim 3, further comprising a bus high-voltage chamber (181) and a low-voltage chamber (182) which are arranged in said main body (1); the bus high-pressure chamber (181) is positioned in the middle of the inside of the main body (1), and the low-pressure chamber (182) is positioned on one side of the inside of the main body (1);

the image intelligent identification and storage device (14) is installed at the lower part of the low-pressure chamber (182);

the monitoring device (16) is mounted on the inner front face of the low-pressure chamber (182).

7. The subway overhead line system direct current supply integrated device according to claim 3, further comprising an external terminal chamber (150) arranged at the front side of the bottom in the main body (1), wherein the network switch (15) is installed in the external terminal chamber (150).

8. The subway overhead line system direct current power supply integrated device according to claim 1, further comprising two sets of residual voltage relief devices (19), wherein the two sets of residual voltage relief devices (19) are respectively installed on the left rear side and the right rear side of the bottom in the main body (1).

9. The subway overhead line system direct current power supply integrated device according to claim 1, further comprising a waterproof heat shield (2), a top sealing assembly (3), a top fixing support (9), a top junction box (8), a base (4), a plurality of observation windows (5), two protective doors (7) and two maintenance steps (6);

the waterproof heat insulation cover (2) is fixedly connected with the shell of the main body (1);

the top sealing assembly (3), the top junction box (8) and the top fixing support (9) are fixed to each other and are fixed to the top of the shell of the main body (1), and the top fixing support (9) is fixed to a cable support of a cable which enters and exits the main body (1);

the base (4) is fixed at the bottom end of the shell of the main body (1);

the two protective doors (7) are respectively and symmetrically arranged at the left side and the right side of the main body (1);

the observation windows (5) are all arranged on the shell of the main body (1), the height of the observation window of the main body (1) is consistent with the height of moving contacts of the first isolating switch (11) and the second isolating switch (12), and the protective door (7) and the top junction box (8) are arranged on the protective door;

and the two maintenance steps (6) are respectively connected with the ground and the bottom ends of the corresponding protective doors (7).