Rail transit multi-source cooperative energy supply system and construction method thereof

Abstract

The invention relates to the technical field of rail transit construction, and discloses a rail transit multi-source cooperative energy supply system and a construction method thereof. Comprising a 27.5 kV box-type switching station, a 400 kVA box-type transformer substation and a cable branch box, and in the cable branch box, a 3 # transformer inlet cabinet is connected with a 10 kV bus of a 110 kV transformer substation through a cable; in the 27.5 kV box-type switching station, a first switch cabinet is connected with one section of a 1.5 kV direct current bus through a 4 # transformer and a first railway energy dispatching device; the second switch cabinet is connected with the 1.5 kV direct current bus second section through the 5 # transformer and the second energy dispatching device; the 1.5 kV direct current bus section I and the 1.5 kV direct current bus section II are connected with a second photovoltaic power supply module and an energy storage power supply module; the 1.5 kV direct current bus second section is also connected with a first feeder cabinet in the 400 kVA box through a 10 kV intercommunication converter and a 6 # transformer; and a 27.5 kV bus of the 27.5 kV box type switching station is connected with a 27.5 kV bus of the 110kV transformer substation through a cable. The photovoltaic and energy storage device is connected to the 27.5 KV traction power supply system through integrated equipment, and the construction efficiency is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of rail transit construction, and particularly relates to a multi-source collaborative energy supply system for rail transit and a construction method thereof. Background Art

[0002] With the acceleration of the urbanization process and the rapid development of rail transit, the problem of energy consumption in rail transit has become increasingly prominent, and higher requirements are also put forward for the reliability, efficiency, and environmental protection of energy supply. In remote areas lacking high-voltage power grids, rich natural resources such as solar energy and wind energy along the railway can be developed locally and directly connected to the railway for use. This can not only reduce the operating cost of the railway but also reduce the dependence on traditional high-voltage power grids and improve the reliability of railway power supply. At present, China has carried out a pilot project on the Xinzhun Railway, which can not only be used as supplementary energy supply but also completely replace the substation for independent power supply. This exploration will be the first in the world.

[0003] Therefore, how to organically combine the power grid, renewable energy, energy storage devices, and the power supply system of rail transit vehicles to achieve efficient utilization and sustainable supply of energy has become a new direction for the sustainable development of rail transit. Summary of the Invention

[0004] In order to solve the above technical problems and realize the effective construction of a multi-source collaborative energy supply system, the present invention proposes a multi-source collaborative energy supply system for rail transit and a construction method thereof.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a multi-source collaborative energy supply system for rail transit, including: a 27.5 kV box-type switch station, a 400 kVA box transformer, a cable branch box, a first railway energy dispatching device, a second energy dispatching device, a first photovoltaic power module, a second photovoltaic power module, an energy storage power module, a 4# transformer, and a 5# transformer.

[0006] The cable branch box includes a distribution feeder cabinet, a 3# transformer incoming line cabinet, a photovoltaic incoming line cabinet, and a first metering cabinet sharing a 10 kV bus. The 3# transformer incoming line cabinet is connected to the 10 kV bus of an 110 kV substation through a cable; the photovoltaic incoming line cabinet is connected to the 400 kVA box transformer through the first metering cabinet.

[0007] The 400 kVA box-type substation includes a first feeder cabinet, a second feeder cabinet, a PT cabinet, a second metering cabinet, an incoming line cabinet, a No. 7 transformer, a low-voltage main incoming breaker, a converter low-voltage main disconnect switch, a photovoltaic low-voltage main disconnect switch, and a reverse power protection action switch that share a 10 kV busbar; the 10 kV busbar of the PT cabinet is connected to the 10 kV busbar of the incoming line cabinet through the second metering cabinet, and the incoming line cabinet is connected to the first metering cabinet in the cable distribution box through a cable; the second feeder cabinet is connected to the primary side of the No. 7 transformer; the secondary side of the No. 7 transformer is connected to the 0.4 kV AC busbar through the low-voltage main incoming breaker, and the 0.4 kV AC busbar is connected to multiple converter control switches through the converter low-voltage main disconnect switch, and each converter control switch is respectively connected to a low-voltage feeder; the first photovoltaic power module is connected to the 0.4 kV AC busbar through the reverse power protection action switch and the photovoltaic low-voltage main disconnect switch;

[0008] The 27.5 kV box-type switchgear station includes a first switchgear cabinet and a second switchgear cabinet that share a 27.5 kV busbar. The first switchgear cabinet is connected to one section of the 1.5 kV DC busbar through a No. 4 transformer and a first railway energy dispatching device; the second switchgear cabinet is connected to the second section of the 1.5 kV DC busbar through a No. 5 transformer and a second energy dispatching device; a second photovoltaic power module and an energy storage power module are respectively connected to the 1.5 kV DC busbar section and the 1.5 kV DC busbar second section; the second section of the 1.5 kV DC busbar is also connected to the first feeder cabinet in the 400 kVA box through a 10 kV interconnection converter and a No. 6 transformer;

[0009] The 27.5 kV busbar of the 27.5 kV box-type switchgear station is connected to the 27.5 kV busbar of the 110 kV substation through a cable.

[0010] The first photovoltaic power module is a photovoltaic power source with a power of 0.38 MW, and the second photovoltaic power module is a photovoltaic power source with a power greater than 2 MW.

[0011] The first railway energy dispatching device and the second railway energy dispatching device are AC / DC conversion modules.

[0012] The described rail transit multi-source collaborative energy supply system further includes a grid connection cabinet and a third metering cabinet. The 27.5 kV busbar of the 27.5 kV box-type switchgear station is connected to the 27.5 kV busbar of the 110 kV substation through a cable, a grid connection cabinet, and a third metering cabinet.

[0013] A disconnect switch 91031, a breaker 9103, and a grounding knife switch 618 are arranged in the second feeder cabinet. The second feeder cabinet is connected to the primary side of the No. 7 transformer through the disconnect switch 91031 and the breaker 9103;

[0014] Inside the first feeder cabinet, there are isolator 91021, circuit breaker 9102, and grounding switch 617. The first feeder cabinet is connected to the 6# transformer through isolator 91021 and circuit breaker 9102;

[0015] Inside the incoming line cabinet, there are isolator 91011 and circuit breaker 9101. The 10kV busbar of the incoming line cabinet is connected to the first metering cabinet in the cable distribution box through isolator 91011, circuit breaker 9101, and a cable;

[0016] Inside the incoming line cabinet of the 3# transformer, there are isolator 9031 and circuit breaker 903. The 10kV busbar of the incoming line cabinet of the 3# transformer is connected to the 3# transformer of the 110kV substation through isolator 9031, circuit breaker 903, and a cable;

[0017] Inside the photovoltaic incoming line cabinet, there are isolator 91041 and circuit breaker 9104. The 10kV busbar of the photovoltaic incoming line cabinet is connected to the first metering cabinet through isolator 91041 and circuit breaker 9104;

[0018] Inside the first switch cabinet and the second switch cabinet, there are circuit breaker 2204 and circuit breaker 2205 respectively. The 27.5kV busbar of the first switch cabinet is connected to the 4# transformer through circuit breaker 2204, and the 27.5kV busbar of the second switch cabinet is connected to the 5# transformer through circuit breaker 2205.

[0019] The described rail transit multi-source collaborative power supply system further includes a 1.5kV DC busbar first-section photovoltaic incoming line cabinet, a 1.5kV DC busbar first-section energy storage incoming line cabinet, a 1.5kV DC busbar second-section photovoltaic incoming line cabinet, a 1.5kV DC busbar second-section energy storage incoming line cabinet, a first-section single-phase converter incoming line cabinet, and a second-section single-phase converter incoming line cabinet;

[0020] The 1.5kV DC busbar first section and the 1.5kV DC busbar second section are respectively connected to a second photovoltaic power module through the 1.5kV DC busbar first-section photovoltaic incoming line cabinet and the 1.5kV DC busbar second-section photovoltaic incoming line cabinet. The 1.5kV DC busbar first section and the 1.5kV DC busbar second section are respectively connected to an energy storage power module through the 1.5kV DC busbar first-section energy storage incoming line cabinet and the 1.5kV DC busbar second-section energy storage incoming line cabinet;

[0021] The energy storage power module is installed outdoors in a box and includes multiple battery clusters and supporting equipment. Each battery cluster includes 15 battery modules, each battery module includes 16 energy storage battery cells, and each battery cluster is led out to the DC / DC converter room of the multifunctional integrated device through a DC cable and connected to the incoming line circuit breaker at the upper end of each DC / DC converter.

[0022] The construction method of the described multi-source collaborative power supply system for rail transit includes civil engineering construction and installation engineering construction. The civil engineering construction includes the following steps:

[0023] Step 1.1: Carry out site leveling;

[0024] Step 1.2: Then fabricate equipment foundations and cable trenches;

[0025] Step 1.3: Install screw piles;

[0026] The installation engineering construction includes the following steps:

[0027] Step 2.1: Install photovoltaic brackets and components;

[0028] Step 2.2: Install the grounding system;

[0029] Step 2.3: Lay cables in the cable trench;

[0030] Step 2.4: Install busbar boxes and power transformation and distribution equipment;

[0031] Step 2.5: Connect cables to each device;

[0032] Step 2.6: Conduct experiments and commissioning on the devices;

[0033] Step 2.7: Conduct grid connection commissioning on the devices.

[0034] The installation of the screw piles includes the following steps:

[0035] Step 1.3.1: Carry out surveying and setting out according to the general construction layout plan, and control the setting out accuracy within 7 mm;

[0036] Step 1.3.2: Based on the setting out results of the screw pile design drawings, determine the position of each pile to be driven and make marks; The surveyors use total stations and RTKs to set out the position of each screw pile according to the construction control network, and make good markings. The surveyors review the axis pile positions to ensure that the position of each pile meets the design requirements and the pile positions are correct;

[0037] Step 1.3.3: The pile driver reaches the pile position through its own walking function and mast luffing mechanism;

[0038] Step 1.3.4: Install the screw pile on the pile driver, and then use a magnetic level to correct the levelness and verticality of the pile driver. After meeting the requirements, start drilling the pile;

[0039] Step 1.3.5: When drilling the pile, first center it. When drilling to 1 / 3 of the depth, observe whether there is any deviation in the screw pile; If there is deviation, adjust it and then observe when drilling to 1 / 2. After ensuring no error, drill to the design depth.

[0040] Step 1.3.6: The pile driver operates according to the pile positions determined by the survey and setting out. Before driving piles with a crawler pile driver, select a relatively flat and stable place for positioning. If the ground slope is steep, use a winch to tow the pile driver. First, adjust the drill head in all directions. After preliminary adjustment, use a spirit level or a plumb bob to check the verticality. After confirmation, proceed to the next construction step. The requirement is that the pile position deviation < 7 mm and the verticality is 90 ± 1 0 .

[0041] The specific steps of Step 2.1 are as follows:

[0042] Step 2.1.1: Install the column. Before installing the bracket, determine the horizontal line of the column. Install the column on top of the screw pile and tighten the fastening nut until the column can be stabilized. Subsequently, install the diagonal beam, purlin, bracing, and tie bars. When installing the purlin, place the purlin on the diagonal beam, first put on the bolts and nuts, use a triangular scale to correct the component installation holes of the upper and lower purlins on the same component installation surface to be at a right angle, then tighten the bolts. Finally, check the tightening degree of all bolts. After checking each bolt one by one, make marks at the junctions of the bolts and nuts one by one to ensure that the surface of the PV array bracket is flat and the steel surface for fixing the solar panels is adjusted to be on the same plane. The component installation holes should be aligned and in a straight line, and the upper and lower installation holes should be at a right angle. The inclination angle meets the design requirements. Add lock washers to the connecting bolts of the components and tighten them. The straightness error of the entire array length is within ±5 mm;

[0043] Step 2.1.2: Install the PV modules. Before installing the PV modules, install the modules with the same technical parameters on the same module string. When installing the solar PV modules, handle them gently to prevent the surface glass from being scratched or impacted by hard objects. The installation position of the modules on the base frame and the arrangement of the junction boxes should comply with the construction regulations. When the fixing of the modules does not fit the surface of the base frame, use galvanized washers to level it and then tighten the connecting screws. After the installation of the PV modules is completed, it is necessary to check the tightening degree of all bolts. After checking each bolt one by one, make marks at the junctions of the bolts and nuts one by one. Finally, connect the series wiring of the PV modules and fix the cables to the PV brackets with metal straps. After the series wiring of the PV modules is completed, test whether the string voltage is normal and make a record;

[0044] The specific steps of Step 2.2 are as follows:

[0045] Step 2.2.1: Determine the base path of the node body points;

[0046] Step 2.2.2: Install the vertical grounding electrode;

[0047] Step 2.2.3: Excavate the trench for the horizontal grounding electrode;

[0048] Step 2.2.4: Lay the horizontal grounding electrode and perform welding;

[0049] Step 2.2.5: Connect the horizontal grounding electrode and the vertical grounding electrode;

[0050] Step 2.2.6: Backfill the grounding electrode trench and conduct a grounding resistance test.

[0051] The present invention has the following beneficial effects compared with the prior art:

[0052] 1. The present invention proposes a multi-source collaborative power supply system and construction method for rail transit, connecting a distributed photovoltaic power generation system and an energy storage device to the 27.5KV traction power supply system, organically combining the power grid, renewable energy, energy storage equipment and the power supply system of rail transit vehicles, leading or supplementing the public power grid to supply energy to electric locomotives, realizing multi-source collaborative power supply for rail transit, changing the power supply mode of traditional electrified railways that simply rely on the public power grid, and forming a new pattern of collaborative power supply of new energy, energy storage and the public power grid.

[0053] 2. The present invention optimizes the capacity and configuration of the energy storage system according to the load characteristics of rail transit and the power generation law of renewable energy, improving the energy utilization efficiency.

[0054] 3. The present invention solves problems such as the inability to arrange a large number of independent devices in a limited site, the large amount of construction tasks for equipment foundation production, cable laying and wiring construction at the construction site, and the complexity of operation and maintenance after completion through prefabricated integration technology, greatly improving the construction efficiency and reducing the operation cost.

[0055] 4. Through the optimization of the photovoltaic support foundation, the present invention selects steel spiral ground piles, optimizing the construction processes such as drilling, hole cleaning, pouring, and curing of the photovoltaic support foundation; at the same time, it provides conditions for multi-point pipeline operation, ensuring seamless connection between the installation of the photovoltaic support foundation and the support, simplifying the construction process and shortening the construction period. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 is a schematic circuit diagram of a multi-source collaborative power supply system for rail transit provided in Embodiment 1 of the present invention;

[0057] Figure 2 is a schematic flow diagram of a construction method of a multi-source collaborative power supply system for rail transit provided in Embodiment 2 of the present invention;

[0058] Figure 3 is a process flow diagram of the installation of spiral piles;

[0059] Figure 4 is a structural schematic diagram of a photovoltaic support;

[0060] Figure 5 is for Figure 4 the right view of;

[0061] Figure 6It is a process flow chart for the installation of a photovoltaic support.

[0062] Figure 7 It is a process flow chart for the installation of photovoltaic modules.

[0063] Figure 8 It is an installation flow chart for the grounding system.

[0064] In the figure, 1 is a screw pile, 2 is a column, 3 is a diagonal brace, 4 is a diagonal beam, 5 is a tie bar, 6 is a purlin, and 7 is a photovoltaic module. Specific implementation mode

[0065] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0066] Embodiment 1

[0067] As Figure 1 shown, Embodiment 1 of the present invention provides a multi-source collaborative power supply system for rail transit, including: a 27.5 kV box-type switch station, a 400 kVA box transformer, a cable branch box, a first railway energy dispatching device, a second energy dispatching device, a first photovoltaic power supply module, a second photovoltaic power supply module, a energy storage power supply module, a 4# transformer, and a 5# transformer;

[0068] The cable branch box includes a distribution feeder cabinet, a 3# transformer incoming line cabinet, a photovoltaic incoming line cabinet, and a first metering cabinet sharing a 10 kV bus. The 3# transformer incoming line cabinet is connected to the 10 kV bus of an 110 kV substation through a cable; the photovoltaic incoming line cabinet is connected to the 400 kVA box transformer through the first metering cabinet. Among them, the 10 kV bus of the 110 kV substation is connected to the 3# transformer.

[0069] The 400kVA box-type substation includes a first feeder cabinet, a second feeder cabinet, a PT cabinet, a second metering cabinet, an incoming line cabinet, a No. 7 transformer, a low-voltage main incoming breaker, a converter low-voltage main disconnect, a photovoltaic low-voltage main disconnect, and a reverse power protection action switch sharing a 10kV busbar; the 10kV busbar of the PT cabinet is connected to the 10kV busbar of the incoming line cabinet through the second metering cabinet, and the incoming line cabinet is connected to the first metering cabinet in the cable distribution box through a cable; the second feeder cabinet is connected to the primary side of the No. 7 transformer; the secondary side of the No. 7 transformer is connected to the 0.4kV AC busbar through the low-voltage main incoming breaker, and the 0.4kV AC busbar is connected to a plurality of converter control switches through the converter low-voltage main disconnect, and each converter control switch is respectively connected to a low-voltage feeder; the first photovoltaic power module is connected to the 0.4kV AC busbar through the reverse power protection action switch and the photovoltaic low-voltage main disconnect;

[0070] The 27.5kV box-type switch station includes a first switch cabinet and a second switch cabinet sharing a 27.5kV busbar. The first switch cabinet is connected to one section of the 1.5kV DC busbar through a No. 4 transformer and a first railway energy dispatching device; the second switch cabinet is connected to the second section of the 1.5kV DC busbar through a No. 5 transformer and a second energy dispatching device; a second photovoltaic power module and a energy storage power module are respectively connected to the 1.5kV DC busbar section one and the 1.5kV DC busbar section two; the second section of the 1.5kV DC busbar is also connected to the first feeder cabinet in the 400kVA box through a 10kV interconnection converter and a No. 6 transformer.

[0071] The 27.5kV busbar of the 27.5kV box-type switch station is connected to the 27.5kV busbar of the 110kV substation through a cable.

[0072] Specifically, in this embodiment, the first photovoltaic power module is a photovoltaic power source with a power of 0.38MW, and the second photovoltaic power module is a photovoltaic power source with a power greater than 2MW. Specifically, an island protector is provided on the instrument room cabinet door of the low-voltage chamber safety automatic protection cabinet of the 400kVA box-type substation. When there is voltage on the 0.4kV AC busbar, the reverse power protection action switch conducts, connecting the first photovoltaic power module to the 0.4kV AC busbar. Otherwise, when there is no voltage on the 0.4kV AC busbar, the reverse power protection action switch disconnects to prevent the 400kVA box-type substation from being energized for equipment maintenance.

[0073] Specifically, in this embodiment, the first railway energy dispatching device and the second railway energy dispatching device are AC / DC conversion modules.

[0074] Specifically, a multi-source collaborative power supply system for rail transit in this embodiment further includes a grid connection cabinet and a third metering cabinet. The 27.5 kV busbar of the 27.5 kV box-type switch station is connected to the 27.5 kV busbar of the 110 kV substation through a cable, the grid connection cabinet, and the third metering cabinet.

[0075] Specifically, in this embodiment, a disconnector 91031, a circuit breaker 9103, and a grounding switch 618 are arranged in the second feeder cabinet. The second feeder cabinet is connected to the primary side of the 7# transformer through the disconnector 91031 and the circuit breaker 9103;

[0076] A disconnector 91021, a circuit breaker 9102, and a grounding switch 617 are arranged in the first feeder cabinet. The first feeder cabinet is connected to the 6# transformer through the disconnector 91021 and the circuit breaker 9102;

[0077] A disconnector 91011 and a circuit breaker 9101 are arranged in the incoming line cabinet. The 10 kV busbar of the incoming line cabinet is connected to the first metering cabinet in the cable branch box through the disconnector 91011, the circuit breaker 9101, and a cable;

[0078] A disconnector 9031 and a circuit breaker 903 are arranged in the incoming line cabinet of the 3# transformer. The 10 kV busbar of the incoming line cabinet of the 3# transformer is connected to the 3# transformer of the 110 kV substation through the disconnector 9031, the circuit breaker 903, and a cable;

[0079] A disconnector 91041 and a circuit breaker 9104 are arranged in the photovoltaic incoming line cabinet. The 10 kV busbar of the photovoltaic incoming line cabinet is connected to the first metering cabinet through the disconnector 91041 and the circuit breaker 9104;

[0080] A circuit breaker 2204 and a circuit breaker 2205 are respectively arranged in the first switch cabinet and the second switch cabinet. The 27.5 kV busbar of the first switch cabinet is connected to the 4# transformer through the circuit breaker 2204, and the 27.5 kV busbar of the second switch cabinet is connected to the 5# transformer through the circuit breaker 2205.

[0081] Specifically, a multi-source collaborative power supply system for rail transit in this embodiment further includes a photovoltaic incoming line cabinet for the 1.5 kV DC busbar section 1, a storage incoming line cabinet for the 1.5 kV DC busbar section 1, a photovoltaic incoming line cabinet for the 1.5 kV DC busbar section 2, a storage incoming line cabinet for the 1.5 kV DC busbar section 2, a single-phase converter incoming line cabinet for section 1, and a single-phase converter incoming line cabinet for section 2;

[0082] The first section of the 1.5 kV DC busbar and the second section of the 1.5 kV DC busbar are respectively connected to a second photovoltaic power module through the 1.5 kV DC busbar first-section photovoltaic incoming line cabinet and the 1.5 kV DC busbar second-section photovoltaic incoming line cabinet, and the first section of the 1.5 kV DC busbar and the second section of the 1.5 kV DC busbar are respectively connected to an energy storage power module through the 1.5 kV DC busbar first-section energy storage incoming line cabinet and the 1.5 kV DC busbar second-section energy storage incoming line cabinet;

[0083] The energy storage power module is installed outdoors in a box type and includes a plurality of battery clusters and supporting equipment. Each battery cluster includes 15 battery modules, each battery module includes 16 energy storage battery cells, and each battery cluster is led out to the DC / DC converter room of the multi-functional integrated device through a DC cable and is connected to the incoming line breaker at the upper end of each DC / DC converter.

[0084] In this embodiment, the nominal voltage of each battery cluster is 768 V. The two energy storage power modules include 24 battery clusters, the nominal capacity is 5.16 MWh, and the nominal voltage of each battery cluster is 768 V.

[0085] Embodiment Two

[0086] As Figure 2 shown, Embodiment Two of the present invention provides a construction method for a multi-source collaborative power supply system for rail transit, including civil engineering construction and installation engineering construction.

[0087] Specifically, the civil engineering construction includes the following steps:

[0088] Step 1.1: Level the site.

[0089] Specifically, the site location, positioning control lines (piles), standard level piles and the site along the ash line should be determined according to the construction drawings. Obvious signs should be set in dangerous areas, and the excavation sequence should be reasonably arranged to prevent wrong excavation or over-excavation. Manual work should be equipped for parts where mechanical construction cannot operate and for trimming the slope gradient, etc. Before backfilling, the caves on the foundation soil or sundries such as tree roots and garbage on the surface of the foundation layer should be all processed and cleaned up.

[0090] Its technological process includes:

[0091] (1) Earth excavation: Determine the excavation sequence → Excavate in segments and layers according to the drawing elevation → Trim the edge and clean the bottom;

[0092] (2) Backfilling: Clean up on the floor → Transport the soil and lay it in layers → Compact it in layers → Trim and level.

[0093] Specifically, before construction, the control piles and level points should be checked and verified without errors, and the surveying and setting-out work should be completed. The on-site grid should be laid out; and according to the earthwork volume of excavation and filling calculated from the drawings, an earthwork balance and allocation plan should be formulated. For the positioning standard piles, standard level points, etc., leave some margin during earth excavation and transportation and do not collide with them. After the excavation earthwork volume is accepted, then level it. The plane position, level elevation and slope should be frequently measured and checked to see if they meet the design requirements. The positioning standard piles should also be re-measured and checked for correctness. If there is a large error between the on-site ground elevation and the design elevation of the drawing, it is necessary to promptly report to the construction management personnel of the general contractor to handle on-site. Construction personnel must abide by the mechanical operation procedures of their respective positions and the safety operation specifications of earth and stone construction machinery and transportation.

[0094] Step 1.2: Then construct the equipment foundation and cable trench.

[0095] Specifically, during the construction of the equipment foundation, the excavation should be carried out according to the following requirements:

[0096] 1) The position of the foundation pit shall be based on the center pile of the foundation pit in construction survey;

[0097] 2) For soft soil and filled areas, appropriately increase the pit opening and set protective measures;

[0098] 3) In areas with hard soil, it is advisable not to set external formwork and dig the pit according to the external dimensions of the foundation;

[0099] 4) For the overall solid rock area that meets the design requirements after detection, it is advisable to dig according to the cup size of the cup-shaped foundation or increase the outer diameter of the column by 150 - 300 mm;

[0100] 5) When excavating a foundation pit without setting external formwork, its shape, size and relative position should meet the design requirements.

[0101] 6) When the foundation is located on an unsettled soil layer, the bottom of the foundation pit should be dug 0.5 m below the original soil surface, then compacted and the cushion should be built to the design elevation of the foundation bottom.

[0102] 7) After the foundation pit excavation is completed, a soil bearing capacity test should be carried out on the bottom surface of the excavated foundation pit. If the geological conditions do not match the design, contact the design unit in time to solve.

[0103] 8) When blasting operations are required for foundation pit excavation, it should comply with the relevant regulations of the "Safety Regulations for Blasting" GB6722. When using blasting operations near the installed structure supports, buildings and electrical equipment, loose blasting or controlled blasting techniques should be used.

[0104] In addition, the foundation formwork should be firmly supported, able to withstand the lateral pressure of concrete and construction loads, the joints should be tight and leak-free, and release agents and measures to prevent concavities and convexities around the foundation should be taken on the outer side of the inner formwork and the inner side of the outer formwork. The support of the outer formwork should extend 100 - 150 mm below the ground.

[0105] In addition, foundation pouring should be carried out according to the following requirements:

[0106] 1) Pre-buried pipe fittings should be processed and manufactured in advance according to the construction design drawings and the actual situation of the equipment, and they should be re-measured and buried and fixed in time during the formwork support or foundation concrete pouring process;

[0107] 2) Before foundation concrete construction, written data on the pH value of the local soil water quality should be obtained from the survey and design unit in order to correctly select cement and concrete mix ratio;

[0108] 3) Foundation pouring shall comply with the provisions of the "Quality Acceptance Standards for Railway Concrete Engineering Construction";

[0109] 4) For foundation pouring, it is advisable to use commercial concrete or commercial concrete provided by the mixing station of the offline construction unit.

[0110] 5) Concrete should be poured continuously, and it is advisable to use electric vibrators to vibrate in layers. The thickness of the layered vibrating should not exceed 300mm, and the second layer of concrete should be poured before the previous layer of concrete solidifies. The foundation that is subject to dynamic forces should be poured continuously at one time;

[0111] 6) For concrete foundation construction where the average day and night temperature is below +5°C and the minimum temperature is below -3°C, the water, sand and gravel used to mix the concrete should be kept at a positive temperature and should be preheated if necessary; cement should not be heated and should be moved indoors 3 to 4 days before use; the maximum allowable temperature of concrete and its materials is shown in the table below.

[0112] Table 1 Maximum allowable temperature of concrete and its materials

[0113]

[0114] After the foundation is poured, the exposed part of the foundation should be kept warm. For example, steam heating and insulation materials should be used to cover the exposed part to keep the internal temperature at a positive temperature. When the backfill method is used, the thickness should exceed the thickness of the local frozen soil layer. Additives should be added to the concrete to make the concrete early strong, quick setting and frost resistant, but the mix ratio test of the concrete with additives should be carried out.

[0115] In addition, concrete should be maintained according to the following requirements:

[0116] (1) Within 12 hours after the concrete foundation is poured, its outer surface should be covered and watered for curing. In hot and windy weather, the foundation surface should be watered for curing within 2 to 3 hours after pouring;

[0117] (2) Watering and curing time: for ordinary Portland cement, it shall not be less than 7 days; for concrete with slow-setting admixtures or with anti-seepage requirements, it shall not be less than 14 days;

[0118] (3) The number of waterings should be based on keeping the concrete surface constantly moist;

[0119] (4) Water curing is not allowed when the temperature is below 5°C.

[0120] In addition, the concrete foundation test blocks should be carried out according to the following requirements:

[0121] (1) The test blocks should be cubes with a side length of 150 mm, and there should be 3 blocks in each group;

[0122] (2) Special molds should be used for production, and the ramming should be dense and the surface should be flat;

[0123] (3) The test blocks and the foundation should be cured under the same conditions for 28 d;

[0124] (4) Take 1 group of test blocks for each of the traction transformer and circuit breaker foundations; for other foundations, there should be no less than 1 group of test blocks for each working shift.

[0125] After the formwork of the foundation is removed, the dimensions of the foundation anchor bolts, embedded steel plates, pipe holes, etc. should be checked and verified in a timely manner. When the strength of the concrete foundation reaches more than 70% of the design strength, the installation of electrical equipment can be carried out.

[0126] Step 1.3: Install the screw piles.

[0127] As Figure 3 shown, the installation of the screw piles includes the following steps:

[0128] Step 1.3.1: Carry out surveying and setting out according to the general construction layout plan, and control the setting out accuracy within 7 mm;

[0129] Step 1.3.2: According to the setting out results of the screw pile design drawings, determine the position of each pile to be driven and make marks; the surveyors use total stations and RTKs to set out the position of each screw pile according to the construction control network, and make good marks. The surveyor checks and verifies the axis pile positions to ensure that the position of each pile meets the design requirements and the pile positions are correct;

[0130] Step 1.3.3: The pile driver reaches the pile position through its own walking function and mast luffing mechanism;

[0131] Step 1.3.4: Install the screw pile on the pile driver, and then use a magnetic level to correct the levelness and verticality of the pile driver. After meeting the requirements, start drilling the pile;

[0132] Step 1.3.5: When drilling the pile, first center it. When drilling to 1 / 3 of the depth, observe whether there is any deviation of the screw pile; if there is deviation, adjust it and then drill to 1 / 2 and observe again. After being correct, drill to the design depth.

[0133] Step 1.3.6: The pile driver operates according to the pile positions determined by the survey and setting out. Before driving piles with a crawler pile driver, select a relatively flat and stable place for positioning. If the ground slope is steep, use a winch to tow the pile driver; first, adjust the drill head in all directions. After preliminary adjustment, use a spirit level or a plumb bob to check the verticality. After confirmation, proceed to the next construction step. The requirement is that the pile position deviation < 7 mm and the verticality is 90 ± 1 0 .

[0134] Specifically, in this embodiment, the installation project construction includes the following steps:

[0135] Step 2.1: Install the photovoltaic support and components.

[0136] The specific steps of Step 2.1 include the following:

[0137] Step 2.1.1: Install the photovoltaic support.

[0138] As Figures 4 - 5 shown, it is a structural schematic diagram of the photovoltaic support, which includes columns 2, diagonal braces 3, diagonal beams 4, tie bars 5, and purlins 6. The tops of the front and rear columns are connected by the diagonal beam 4. The diagonal braces 3 are arranged between the columns and the diagonal beam for reinforcement. The purlins are arranged on the diagonal beam 4. Tie bars 5 are arranged between adjacent front columns to stabilize the structure of the photovoltaic support. As Figure 6 shown, it is a process flow chart of the installation of the photovoltaic support. Before installing the support, determine the horizontal line of the columns, install the columns on the screw piles, and screw on the fastening nuts until the columns can be stabilized. Subsequently, install the diagonal beams, purlins, diagonal braces, and tie bars; when installing the purlins, place the purlins on the diagonal beams, first put on the bolts and nuts, use a triangular scale to correct the component installation holes of the upper and lower purlins on the same component installation surface to be at a right angle, then tighten the bolts. Finally, check the tightening degree of all bolts. After checking each bolt one by one, make marks at the joints of the bolts and nuts one by one to ensure that the surface of the photovoltaic array support is flat and the steel surface for fixing the solar panels is adjusted to be on the same plane; the component installation holes of each component should be aligned and form a straight line, and the upper and lower installation holes should be at a right angle; the inclination angle meets the design requirements; anti-loosening washers are added to the bolts for component connection and tightened; the straightness error of the entire length of the array is within ±5 mm.

[0139] Step 2.1.2: Install the photovoltaic components.

[0140] As Figure 7As shown in the figure, it is the process flow chart of installing photovoltaic modules. Before installing the photovoltaic modules, install the modules with the same technical parameters on the same module string. When installing the solar photovoltaic modules, handle them with care to prevent the surface glass from being scratched or impacted by hard objects; the installation position of the modules on the base frame and the arrangement method of the junction boxes shall comply with the construction regulations; when the modules are not properly fitted to the surface of the base frame, use galvanized washers to level them and then tighten the connecting screws; after the installation of the photovoltaic modules is completed, it is necessary to check the tightening degree of all bolts. After checking each bolt one by one, make marks at the junctions of each bolt and nut; finally, connect the series wiring of the photovoltaic modules and fix the cables to the photovoltaic support with metal straps; after the connection of the series wiring of the photovoltaic modules is completed, test whether the series voltage is normal and make records.

[0141] Step 2.2: Install the grounding system.

[0142] As Figure 8 shown in the figure, it is the installation flow chart of the grounding system, which specifically includes the following steps:

[0143] Step 2.2.1: Determine the node body point base path;

[0144] Step 2.2.2: Install the vertical grounding electrode;

[0145] Step 2.2.3: Excavate the horizontal grounding electrode trench;

[0146] Step 2.2.4: Lay the horizontal grounding electrode and carry out welding;

[0147] Step 2.2.5: Connect the horizontal grounding electrode and the vertical grounding electrode;

[0148] Step 2.2.6: Backfill the grounding electrode trench and carry out the grounding resistance test.

[0149] When installing the grounding system, drive the grounding electrodes 2.5 meters deep into the ground. The distance between the grounding electrodes is 5 meters. Then, use a 40×4 hot-dip galvanized flat steel to connect the grounding network and the array support by welding. The number of connection points between the grounding network and the support for each array is not less than 2.

[0150] At each corner of the grounding network, it should be made into an arc shape. The best way to place the flat iron is to weld it vertically. The grounding electrode network and the grounding electrodes should be reliably welded. The welding length is not less than 80 mm. The welded parts should be treated with anti-corrosion. The grounding resistance should not be greater than 4 Ω. Each array has an independent grounding network. The nearby solar panel array supports, transformers, etc. need to be grounded. The connection between the horizontal grounding electrodes and between the horizontal grounding electrode and the vertical grounding electrode shall be carried out in accordance with the construction drawings.

[0151] Step 2.3: Lay the cables in the cable trench.

[0152] Specifically, insulation testing should be carried out before cable laying. It can be used only after passing the test, and the cable ends should be sealed.

[0153] Before cable laying, visual inspection must be carried out. There should be no defects on the cable surface such as twisting, armoring flattening, sheath fracture, and severe surface scratches; check whether the cable specifications, models, and lengths meet the requirements. The cable reel must be fixed securely on the transport vehicle to prevent strong vibration, rolling, mutual collision, or even overturning of the cable reel. It is not allowed to transport the cable reel flat, and overloading is strictly prohibited. For shorter cables, when ensuring that the cables will not be damaged, coil them into circles or "8" shapes according to the allowable bending radius of the cables, and tie them tightly at four places before transportation.

[0154] When constructing in places where non-construction personnel often pass by, appropriate safety warning signs should be set up. When the construction point is on the road, warning signs should be set up at a certain distance from the construction point, and traffic guidance should be arranged by personnel if necessary. When laying cables, be sure to pay attention not to scratch the cables, and the line names and phase sequences must be checked and marked clearly. When cables are laid through pipes, the pipe orifices should be polished with a steel file first to prevent burrs from scratching the cables.

[0155] Cables should be protected by pipes in the following locations: when cables are laid along walls and introduced or led out of buildings; when cables pass through roads, railways, ditches, and culverts; and other places where cables may be mechanically damaged. The inner diameter of the cable protection pipe should be ≥ 1.5 times the outer diameter of the cable.

[0156] Cable marker posts should be buried as required at cable bends, joints, crossings of rails, roads, and bridges, etc. One marker post should be buried every 50 m in the straight section.

[0157] When backfilling the cable trench, a layer of fine sand or soft soil not less than 100 mm thick should be laid above and below the cables, and the covering layer should be covered with bricks, with a width exceeding 50 mm on each side of the cables. Then the original soil should be backfilled on top of the bricks, and a settlement prevention layer not less than 300 mm thick should be left.

[0158] When cables are laid in cable troughs, a serpentine laying method is preferably adopted. They should be fully relaxed at bridge piers and expansion joints. When two or more high-voltage cables are laid in the same cable trough, the cables should not be intertwined with each other, and appropriate gaps should be left between the cables. The erection location and laying sequence of the cable reels should be reasonably planned according to the on-site situation to facilitate reducing the construction difficulty. When cables pass through steel pipes when going up and down bridges and culverts, the steel pipes should be fixed firmly, and the joints should be protected by concrete encapsulation.

[0159] When excavating and fabricating a new part of the cable trench, before construction outside the traction substation, a cable detector should be used for detection first. If necessary, a cable exploration trench should be dug. Construction can be carried out only if the detection results meet the construction conditions. If the conditions are not met, construction should be stopped and the path should be changed; the same applies to the construction of a new cable trench inside the traction substation.

[0160] Step 2.4: Install the busbar trunking and power transformation and distribution equipment.

[0161] Specifically, in this embodiment, the installation method of the power transformation and distribution equipment includes:

[0162] a. Construction preparation.

[0163] Carry out measurement and positioning work according to the drawings. Before measurement, jointly check and determine the plane coordinate position and the foundation elevation level point with the equipment management department, and then strictly in accordance with the requirements of the drawings, accurately measure the positions of the foundations of each newly built power transformation and distribution equipment.

[0164] b. Foundation and embedded part construction.

[0165] Determine the specific construction locations and foundation elevations of each newly built power transformation and distribution equipment according to the construction foundation drawings provided by the design drawings, set out and excavate, support the formwork with special steel formwork, and use a level to conduct recheck and leveling; pour the foundation with concrete of the designed grade, and fully consider the embedding work of cable embedded pipes and fixtures, and reserve the grounding lead-out terminals for the equipment; when pouring the foundation, pour in layers and make it flat. The foundation should be 200 mm higher than the ground to prevent the foundation from collapsing.

[0166] c. Earthing grid construction.

[0167] Carry out the system earthing construction of each newly built power transformation and distribution equipment while constructing the foundation. Around the substation and the newly built equipment, lay the earthing grid around the equipment foundation according to the geological conditions, use the earthing materials required by the design, connect according to the requirements of the drawings and specifications, and conduct earthing resistance testing after the earthing grid construction is completed. The earthing resistance is required to be less than 4 Ω.

[0168] d. Inspection before installation.

[0169] Before installing the newly built equipment, the following appearance inspections should be carried out: whether the nameplate data of the product is consistent with the order contract; whether the factory documents and materials are complete; whether the accessories in the packing box are consistent with the packing list; whether there is any damage to the product during transportation, and whether the product parts are damaged and displaced; whether the wiring is loose or broken, whether the insulation is damaged, and whether there is any dirt and foreign matter, etc. The box body has a normal shape, no leakage phenomenon, all connecting bolts at each part are complete and tightly fastened.

[0170] e. Equipment installation.

[0171] For the transportation and handling of the newly built power transformation and distribution equipment, use trucks and cranes. For the positioning of the newly built equipment, use a crane. Lift the newly built equipment to directly above the installation foundation, lower the hook vertically to the foundation, and make the box body and the cabinet body be positioned on the foundation according to the design and specification requirements. When the box body and the cabinet body are positioned on the foundation, pay attention to the placement direction of the box body and the cabinet body, and at the same time pay attention that the reserved positions of the cable holes for the lower entry and exit of the equipment must be consistent with the equipment; fix the connecting parts and remove the relevant auxiliary equipment.

[0172] Before and after the installation of newly built equipment, the following requirements shall be met: After construction, the site shall be cleaned up; the concrete foundation and supports, etc. shall reach the strength allowing installation, and the quality of welded components shall meet the requirements; the embedded parts and reserved holes shall meet the design requirements, and the embedded parts shall be firm; for the fasteners used in equipment installation, except for anchor bolts, galvanized products shall be adopted; for the anti-corrosion of grounding welds and equipment fixing points, two coats of antirust paint and one coat of magnetic powder paint shall be applied.

[0173] f. Equipment wiring.

[0174] After the equipment is installed, wiring shall be carried out. The cables shall be introduced into the incoming and outgoing switch cabinets respectively, and wiring shall be carried out as required. After wiring is completed, a comprehensive inspection of the wiring shall be carried out according to the developed diagram given by the design or the equipment instruction manual, and its insulation resistance shall be measured. At the same time, the following requirements shall be met: The cables entering and leaving the equipment shall be arranged neatly, configured vertically or horizontally regularly, with good insulation, no damage, and appropriate margins left for spare core wires; the connections of electrical circuits shall be firm and reliable, and the terminal boards connected by the cables shall not be subject to mechanical stress; the ends of the cable core wires and the wires to be configured shall be marked with their circuit numbers, and the numbers shall be correct, the handwriting shall be clear, and it shall not be easy to fade.

[0175] g. Equipment testing.

[0176] After installation is completed, the following items shall be inspected according to relevant regulations: There shall be no defects in the main body, cooling device and all accessories; the paint on the box body and cabinet shall be complete and the phase color marks shall be correct; there shall be no sundries left on the top cover; the grounding downlead and its connection with the main grounding grid shall be reliable and meet the design requirements; the protection devices on the high and low voltage sides shall be in good condition, the setting values shall meet the regulations, and the operation and interlock tests shall be correct and reliable.

[0177] h. Installation of grounding main line.

[0178] ① Embedding of protection sleeve: When the grounding main line passes through the wall, protection pipes shall be embedded in cooperation with the civil engineering or reserved holes shall be left.

[0179] ② Fixing of supports: The grounding wire laid openly on the indoor wall shall be laid in sections. First, draw the positioning line on the wall and drill holes to install and fix the S-shaped clips. The grounding wire shall be laid horizontally or vertically. The height of the grounding main line from the ground shall be 300 mm. The distance between supports shall be 0.5 - 1.5 m in the horizontal straight part, preferably 1.5 m - 3 m in the vertical part, and preferably 0.3 m - 0.5 m in the turning part.

[0180] ③ Laying of grounding main line: After the grounding main line is straightened, drilled and bent, the grounding main line shall be lifted along the wall. Fix the grounding main line at one end of the support, and the gap between the grounding wire and the wall surface shall be 10 - 15 mm.

[0181] ④Connection between the grounding main trunk and the grounding grid outlet terminal: Connect the grounding main trunk to the grounding grid outlet terminal, and perform anti-corrosion treatment on the welded part. The working neutral line of the transformer and the grounding grid outlet terminal should be bolted with terminals.

[0182] ⑤Measuring the grounding resistance: Straighten the test line in the opposite direction of the grounding electrode, insert all the probes into the ground, and connect the ground wire and test line of the grounding resistance tester. Place the tester flat, rotate the handle with the right hand at about 120 revolutions per minute, adjust the magnification from large to small, rotate the dial with the left hand from large value to small value until the pointer of the tester is centered, and read the reading.

[0183] Specifically, in this embodiment, the bus coupler box and the inverter are installed in a hanging manner.

[0184] Step 2.5: Connect the cables to each device.

[0185] Step 2.6: Conduct experiments and debugging on the devices.

[0186] Step 2.7: Conduct grid connection debugging on the devices.

[0187] Specifically, before system debugging, conduct a system check. Measure the grounding resistance value with a grounding resistance tester, and the grounding resistance value shall not be greater than 10 Ω. Use an insulation resistance tester to detect the insulation of the line, and the insulation resistance shall not be less than 1 MΩ.

[0188] The main contents of single-device debugging include:

[0189] 1. Inspection: According to the design drawings, check whether the connection wires inside the cabinet and between cabinets are correct.

[0190] 2. No-load operation: Conduct according to the technical requirements of each product. The main circuit is not powered on, only the control circuit is connected, check whether each control circuit is normal, and operate each power switch without load to check for any damage.

[0191] The output is disconnected, power is applied to the input of each device, and check whether the internal working conditions are normal and whether the output parameters are normal.

[0192] In this embodiment, the debugging of the subsystem is the debugging of the subsystems of single-phase transformers, single-phase converters, 27.5 KV switchgear containers, energy storage containers, and box-type converters. When debugging on-site equipment, a temporary power supply is used. The debugging of the subsystem includes:

[0193] 1. Light-load debugging: All outgoing switches are disconnected, the incoming switch is supplied with temporary power, and debugging is carried out according to the requirements of the design drawings. Power on step by step, conduct tests and inspections level by level, and the debugging of the lower-level equipment can only be carried out when the upper-level equipment is normal.

[0194] 2. Joint commissioning: Power on the entire subsystem and check whether the performance parameters at the interfaces of each device meet the technical requirements. If not, stop the machine immediately for inspection and only proceed to the next step after troubleshooting.

[0195] 3. Simulation test: According to the relevant design requirements, simulate various protection actions of the device respectively and check whether the protection actions are normal.

[0196] After all the commissioning work is completed, remove the temporary power supply and reset the power supply wires that have been removed.

[0197] After the single-device commissioning of each device is completed and passes the acceptance, the overall commissioning can only be carried out after reporting the single-device commissioning report to the relevant department for approval. The system commissioning is based on the passing of the commissioning of each subsystem, and can only be carried out after the relevant devices and their interfaces meet the requirements.

[0198] In summary, the present invention provides a multi-source collaborative power supply system for rail transit and its construction method, which can promote the deep integration of rail transit and new energy, connect renewable energy to the railway traction and power supply systems nearby, and avoid the power transmission loss caused by grid connection through the public power grid. Optimize the matching between electrified railways and the power grid, effectively suppress the fluctuation of railway traction load, reduce the harmonics injected into the power grid, improve the power quality on the grid side, and achieve a win-win situation for the power grid and the railway. The present invention has been applied in a certain railway project, and the average annual power generation during the operation period of the project is 6.5841 million kWh; it can save about 2027.91 tons of standard coal, reduce emissions of about 3.569 tons of SO2, about 0.856 tons of soot, about 5369.711 tons of CO2, and about 1.956 tons of NO2 per year, with significant environmental benefits. In addition, through the photovoltaic and energy storage systems, the present invention preferentially consumes new energy, reduces the electricity consumption from the power grid, can achieve peak shaving and valley filling of the traction load, and reduce the demand charge. The energy storage system absorbs the regenerative braking energy generated by the train and releases electric energy during traction, thereby reducing the electricity obtained from the power grid. New energy can be used as a backup power source for the railway traction power supply system, and can provide emergency power for traction and power loads when the power grid fails, avoiding major accidents caused by the failure of the incoming line of the substation.

[0199] Finally, it should be noted that: The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: They can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A rail transit multi-source coordinated energy supply system, characterized in that: include: 27.5kV box-type switch station, 400kVA box-type transformer, cable branch box, first railway energy dispatching device, second energy dispatching device, first photovoltaic power module, second photovoltaic power module, energy storage power module, 4# transformer, 5# transformer, The cable branch box includes a distribution feeder cabinet, a 3# transformer incoming line cabinet, a photovoltaic incoming line cabinet and a first metering cabinet that share a 10kV busbar. The 3# transformer incoming line cabinet is connected to the 10kV busbar of the 110kV substation through a cable; the photovoltaic incoming line cabinet is connected to the 400kVA box transformer through the first metering cabinet; The 400kVA box transformer includes a first feeder cabinet, a second feeder cabinet, a PT cabinet, a second metering cabinet, an incoming line cabinet, a 7# transformer, a low-voltage main incoming line circuit breaker, a converter low-voltage main disconnection, a photovoltaic low-voltage main disconnection, and a reverse power protection action switch that share a 10kV busbar; the 10kV busbar of the PT cabinet is connected to the 10kV busbar of the incoming line cabinet through the second metering cabinet, and the incoming line cabinet is connected to the first metering cabinet in the cable branch box through a cable; the second feeder cabinet is connected to the primary end of the 7# transformer; the secondary end of the 7# transformer is connected to the 0.4kV AC busbar through the low-voltage main incoming line circuit breaker, and the 0.4kV AC busbar is connected to multiple converter control switches through the converter low-voltage main disconnection, and each converter control switch is connected to a low-voltage feeder; the first photovoltaic power module is connected to the 0.4kV AC busbar through the reverse power protection action switch and the photovoltaic low-voltage main disconnection; The 27.5kV box-type switch station includes a first switch cabinet and a second switch cabinet that share a 27.5kV busbar. The first switch cabinet is connected to the first section of the 1.5kV DC busbar through a 4# transformer and a first railway energy dispatching device; the second switch cabinet is connected to the second section of the 1.5kV DC busbar through a 5# transformer and a second energy dispatching device; a second photovoltaic power module and an energy storage power module are connected to the first section of the 1.5kV DC busbar and the second section of the 1.5kV DC busbar, respectively; the second section of the 1.5kV DC busbar is also connected to the first feeder cabinet in the 400kVA box through a 10kV intercommunication converter and a 6# transformer; The 27.5kV busbar of the 27.5kV box-type switch station is connected to the 27.5kV busbar of the 110kV substation via a cable.

2. A rail transit multi-source coordinated energy supply system according to claim 1, characterized in that: The first photovoltaic power module is a photovoltaic power module with a power of 0.38 MW, and the second photovoltaic power module is a photovoltaic power module with a power greater than 2 MW.

3. A rail transit multi-source coordinated energy supply system according to claim 1, characterized in that: The first railway energy dispatching device and the second railway energy dispatching device are AC / DC conversion modules.

4. A rail transit multi-source coordinated energy supply system according to claim 1, characterized in that: It also includes a grid-connected cabinet and a third metering cabinet. The 27.5kV busbar of the 27.5kV box-type switch station is connected to the 27.5kV busbar of the 110kV substation through cables, the grid-connected cabinet and the third metering cabinet.

5. The rail transit multi-source coordinated energy supply system according to claim 1 is characterized in that: The second feeder cabinet is provided with a partition 91031, a circuit breaker 9103, and a grounding switch 618, and the second feeder cabinet is connected to the primary end of the 7# transformer through the partition 91031 and the circuit breaker 9103; The first feeder cabinet is provided with a partition 91021, a circuit breaker 9102, and a grounding switch 617, and the first feeder cabinet is connected to the 6# transformer through the partition 91021 and the circuit breaker 9102; The incoming line cabinet is provided with a partition 91011 and a circuit breaker 9101, and the 10kV busbar of the incoming line cabinet is connected to the first metering cabinet in the cable branch box through the partition 91011, the circuit breaker 9101, and the cable; The 3# transformer incoming line cabinet is provided with a partition 9031 and a circuit breaker 903. The 10kV busbar of the 3# transformer incoming line cabinet is connected to the 3# transformer of the 110kV substation through the partition 9031, the circuit breaker 903, and the cable; The photovoltaic incoming line cabinet is provided with a partition 91041 and a circuit breaker 9104, and the 10kV busbar of the photovoltaic incoming line cabinet is connected to the first metering cabinet through the partition 91041 and the circuit breaker 9104; The first switch cabinet and the second switch cabinet are respectively provided with circuit breakers 2204 and 2205. The 27.5kV busbar of the first switch cabinet is connected to the 4# transformer through the circuit breaker 2204. The 27.5kV busbar of the second switch cabinet is connected to the 5# transformer through the circuit breaker 2205.

6. A rail transit multi-source coordinated energy supply system according to claim 1, characterized in that: It also includes 1.5kV DC bus section 1 photovoltaic incoming line cabinet, 1.5kV DC bus section 1 energy storage incoming line cabinet, 1.5kV DC bus section 2 photovoltaic incoming line cabinet, 1.5kV DC bus section 2 energy storage incoming line cabinet, one section single-phase converter incoming line cabinet, two sections single-phase converter incoming line cabinet, The first section of the 1.5kV DC bus and the second section of the 1.5kV DC bus are connected to a second photovoltaic power module through the first section of the 1.5kV DC bus photovoltaic incoming cabinet and the second section of the 1.5kV DC bus photovoltaic incoming cabinet, respectively; the first section of the 1.5kV DC bus and the second section of the 1.5kV DC bus are connected to an energy storage power module through the first section of the 1.5kV DC bus energy storage incoming cabinet and the second section of the 1.5kV DC bus energy storage incoming cabinet, respectively; The energy storage power module box-type outdoor installation includes multiple battery clusters and supporting equipment, each battery cluster includes 15 battery modules, each battery module includes 16 energy storage cells, each battery cluster is led out to the DC / DC converter room of the multifunctional integrated device through a DC cable, and is connected to the incoming line circuit breaker at the upper end of each DC / DC converter.

7. The construction method of a rail transit multi-source coordinated energy supply system according to claim 1, characterized in that: It includes civil engineering construction and installation engineering construction, and the civil engineering construction includes the following steps: Step 1.1: Level the site; Step 1.2: Then make the equipment foundation and cable trench; Step 1.3: Install screw piles; The installation project construction includes the following steps: Step 2.1: Install photovoltaic brackets and components; Step 2.2: Install the grounding system; Step 2.3: Lay cables in the cable trench; Step 2.4: Install combiner box and power distribution equipment; Step 2.5: Connect cables to each device; Step 2.6: Experiment and debug the equipment; Step 2.7: Connect the device to the grid for debugging.

8. The construction method of a rail transit multi-source coordinated energy supply system according to claim 7 is characterized in that: The installation of the screw pile comprises the following steps: Step 1.3.1: Measure and lay out the lines according to the general construction plan, and control the accuracy of the lines within 7MM; Step 1.3.2: According to the layout results of the spiral pile design drawings, determine each location where piles need to be driven and mark them; the surveyor uses a total station and RTK to measure the location of each spiral pile according to the construction control network and mark them. The surveyor reviews the axis pile position to ensure that the position of each pile meets the design requirements and is correct; Step 1.3.3: The pile driver reaches the pile position through its own travel function and mast luffing mechanism; Step 1.3.4: Install the screw pile on the pile driver, and then use a magnetic level to calibrate the horizontality and verticality of the pile driver. When the horizontality and verticality meet the requirements, start drilling the pile. Step 1.3.5: When drilling piles, first align the center, and when drilling to 1 / 3 of the depth, observe whether the spiral pile has any deviation; if there is any deviation, make adjustments and drill to 1 / 2 and observe again. After confirming that there is no error, drill to the designed depth. Step 1.3.6: The pile driver is operated according to the measured pile position. Before the crawler pile driver is driven, a relatively flat and stable place is selected. If the ground slope is steep, the pile driver is towed by a winch. First, adjust the drill head forward, backward, left and right. After the preliminary adjustment, use a level ruler or plumb line to hang the verticality. After confirmation, proceed to the next step of construction. The pile position deviation is required to be less than 7mm and the verticality is 90±1 0 .

9. The construction method of a rail transit multi-source coordinated energy supply system according to claim 7, characterized in that: The step 2.1 specifically includes the following steps: Step 2.1.1: Install the column. Before installing the bracket, set the horizontal line of the column, install the column on the spiral pile, tighten the fastening nut until the column can be stabilized, and then install the diagonal brace, diagonal beam, tie rod and purlin; when installing the purlin, place the purlin on the diagonal beam, put on the bolts and nuts first, use a triangular ruler to calibrate the component installation holes of the upper and lower purlins on the same component installation surface to a right angle, and then tighten the bolts. Finally, check the tightness of all bolts. After checking each bolt, mark the intersection of the bolt and nut one by one to ensure that the surface of the photovoltaic array bracket is flat and the steel surface fixing the solar panel is adjusted to the same plane; the installation holes of each component should be neat and in a straight line, and the upper and lower installation holes should be at right angles; the inclination angle meets the design requirements; the component connection bolts are equipped with anti-loosening gaskets and tightened; the squareness error of the entire length of the array is within plus or minus 5mm; Step 2.1.2: Install the photovoltaic modules. Before installing the photovoltaic modules, install the modules with the same technical parameters on the same module string. When installing the solar photovoltaic modules, handle them with care to prevent hard objects from scratching and hitting the surface glass. The installation position of the modules on the base frame and the arrangement of the junction boxes should comply with the construction regulations. When the module fixing does not match the surface of the base frame, use galvanized gaskets to level it and then tighten the connecting screws. After the photovoltaic modules are installed, the tightness of all bolts must be checked. After checking each bolt, mark the intersection of the bolt and the nut one by one. Finally, connect the series wires of the photovoltaic modules and fix the cables to the photovoltaic bracket with metal straps. After the series wires of the photovoltaic modules are connected, test whether the string voltage is normal and make records.

10. The construction method of a rail transit multi-source coordinated energy supply system according to claim 7, characterized in that: The step 2.2 specifically includes the following steps: Step 2.2.1: Determine the node body point location basis path; Step 2.2.2: Install vertical grounding electrodes; Step 2.2.3: Dig a horizontal grounding trench; Step 2.2.4: Lay the horizontal grounding electrode and weld it; Step 2.2.5: Connect the horizontal grounding electrode and the vertical grounding electrode; Step 2.2.6: Backfill the grounding trench and conduct a grounding resistance test.

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