New energy distributed photovoltaic double-layer box-type substation

Abstract

The invention relates to a new energy distributed photovoltaic double-layer box-type substation, which comprises a box body shell, a high-voltage chamber, a transformer chamber and a low-voltage chamber, and is characterized in that the high-voltage chamber is internally provided with an inverted vacuum circuit breaker unit, an integrated isolation switch, a vacuum circuit breaker and a grounding switch; the wire inlet side of the high-voltage unit is provided with a high-voltage insulator, a high-voltage lightning arrester and a copper bar used for being connected with a wire inlet cable. The wire outlet side adopts air insulation and is provided with a high-voltage current transformer and a connecting copper bar. According to the new energy distributed photovoltaic double-layer box-type substation, the technologies such as a high-voltage cabinet inverted structure, a transformer double-layer arrangement technology and a low-voltage cabinet operation panel external arrangement technology are applied to manufacturing of the box-type substation, the occupied area is reduced, the structure is compact, the manufacturing cost is low, the performance is reliable, and site construction and maintenance are convenient.

Description

Technical Field

[0001] The present invention relates to the field of new energy power generation, and specifically, to a new energy distributed photovoltaic double-layer box-type substation. Background Art

[0002] With the development of the photovoltaic power generation market, more and more microgrid devices for smaller scales are being applied. Currently, there is a lack of a new type of terminal box transformer in the market that integrates 10kV high-voltage power distribution, 0.4kV low-voltage power distribution, and can connect photovoltaic power generation and energy storage devices. Summary of the Invention

[0003] Aiming at the above deficiencies in the prior art, the present invention provides a new energy distributed photovoltaic double-layer box-type substation that reduces the volume of the substation, reduces the floor area, has a compact structure, low cost, reliable performance, and is convenient for on-site construction and maintenance.

[0004] The technical solution adopted by the present invention is as follows:

[0005] A new energy distributed photovoltaic double-layer box-type substation includes a box body shell, a high-voltage chamber, a transformer chamber, and a low-voltage chamber.

[0006] An inverted vacuum circuit breaker unit is arranged in the high-voltage chamber. The inverted vacuum circuit breaker unit includes: a disconnector, a vacuum circuit breaker, and an earthing switch.

[0007] The high-voltage switchgear arranges the disconnector below the vacuum circuit breaker and the earthing switch above the vacuum circuit breaker; the lower side of the disconnector is connected to the power grid, and the upper side of the earthing switch is connected to the high-voltage side of the transformer.

[0008] High-voltage insulators, high-voltage lightning arresters, and copper bars for connecting incoming cables are arranged on the incoming line side of the high-voltage unit.

[0009] The outgoing line side uses air insulation and is provided with high-voltage current transformers and connecting copper bars.

[0010] Preferably, the transformer chamber adopts a double-layer layout. The SCB12 dry-type transformer is installed on the upper layer, and a detachable platform is arranged on the lower layer. An uninterruptible power supply UPS6, a communication switch, and an energy management system EMU are installed at the bottom of the platform.

[0011] Preferably, the low-voltage chamber includes face modular cabinets arranged back-to-back, integrating a low-voltage incoming line cabinet, a power distribution cabinet, a photovoltaic grid-connected cabinet, and an energy storage cabinet. The cabinets are connected by direct copper bars.

[0012] And the outgoing line circuit breaker adopts a double-layer front-back arrangement structure.

[0013] Preferably, the inverted vacuum circuit breaker unit in the high-voltage chamber is electrically interlocked with the low-voltage circuit breaker to automatically cut off the high-voltage vacuum circuit breaker in case of a low-voltage circuit breaker failure.

[0014] The vacuum circuit breaker is electrically operated and configured with a ring network cast current transformer and a zero-sequence transformer. High-voltage overcurrent, instantaneous trip, and zero-sequence protection are achieved through a microcomputer protection device.

[0015] The disconnecting switch is located at the bottom of the high-voltage switch unit, and the earthing switch is located at the top of the high-voltage switch unit, respectively used for the disconnection of incoming and outgoing lines.

[0016] Preferably, the inverted vacuum circuit breaker unit integrates a disconnecting switch, a vacuum circuit breaker, and an earthing switch, and is vertically installed in the high-voltage unit.

[0017] Preferably, a locking mechanism is set between the vacuum circuit breaker and the disconnecting switch: the disconnecting switch cannot be operated when the vacuum circuit breaker is in the closed position, and the disconnecting switch can be opened and closed when the vacuum circuit breaker is in the open position.

[0018] A locking mechanism is set between the disconnecting switch and the earthing switch: the disconnecting switch is allowed to be closed when the earthing switch is in the open position.

[0019] A locking mechanism is set between the earthing switch and the incoming line through an electromagnetic lock: the earthing switch can be closed when there is no power at the upper port.

[0020] A locking mechanism is set between the high-voltage chamber door and the earthing switch, and the high-voltage chamber door is allowed to be opened when the earthing switch is closed.

[0021] Preferably, a steel plate with holes is provided at the bottom of the platform in the transformer chamber, and a forced air cooling system with a fan is installed. The starting threshold of the fan is when the transformer temperature ≥ 80°C.

[0022] Preferably, a pole disconnecting switch and a frame circuit breaker are provided in the photovoltaic grid-connected cabinet in the low-voltage chamber to support the collection of line currents; a line current collection interface is provided in the energy storage grid-connected cabinet.

[0023] A control method for a new energy distributed photovoltaic double-layer box-type substation includes the following control steps:

[0024] The vacuum circuit breaker and the disconnecting switch are locked through the main shaft limit disc of the vacuum circuit breaker. When the vacuum circuit breaker is in the open position, the limit disc of the vacuum circuit breaker rotates. At this time, the limit disc no longer restricts the rotation of the main shaft of the disconnecting switch, and thus the disconnecting switch can be opened and closed. When the vacuum circuit breaker is in the closed state, the disconnecting switch is blocked by the limit disc and cannot be opened.

[0025] The disconnector and the earthing switch are locked through an interlocking slide plate. When the disconnector is in the closed state, the interlocking slide plate cannot move because it is blocked by the main shaft connecting rod of the disconnector, and the main shaft operation hole of the earthing switch is blocked by the interlocking slide plate and cannot operate the earthing switch. When the disconnector is in the open state, the main shaft connecting rod of the disconnector releases the restriction on the interlocking slide plate. At this time, the interlocking slide plate can move up and down, and the interlocking slide plate releases the blockage of the earthing switch operation hole to perform opening and closing operations on the earthing switch;

[0026] An electromagnetic lock is set at the interlocking slide plate to realize the interlock between the earthing switch and the transformer side. When the transformer side is energized, even if the disconnector has been opened, but the electromagnetic lock detects that there is voltage on the transformer side, at this time the electromagnetic lock is in the working state, and the lock tongue of the electromagnetic lock blocks the interlocking slide plate, making the interlocking slide plate unable to move, and thus unable to operate the earthing switch. When the electromagnetic lock detects that there is no voltage on the transformer side and the disconnector has been opened, the earthing switch can be closed. The earthing switch and the cabinet door of the switchgear are locked through the cabinet door interlock. When the earthing switch is closed, the dial on the main shaft of the earthing switch releases the restriction on the cabinet door interlock installed on the cabinet door. At this time, the cabinet door can be opened. When the earthing switch is opened, the cabinet door interlock is blocked by the dial on the main shaft of the earthing switch and the cabinet door cannot be opened.

[0027] The beneficial effects of the present invention compared with the prior art:

[0028] In the new energy distributed photovoltaic double-layer box-type substation of the present invention, technologies such as the inverted installation structure of the high-voltage cabinet, the double-layer arrangement technology of the transformer, and the external placement of the operation panel of the low-voltage cabinet are applied to the manufacture of the box-type substation, reducing the floor area and the operation and maintenance costs.

[0029] Specifically as follows:

[0030] 1. Integration of the inverted structure of the high-voltage unit:

[0031] The high-voltage disconnector, vacuum circuit breaker, and earthing switch of the existing box-type substation are usually designed separately, resulting in large volume and high cost. The inverted structure of the present invention integrates the three into the air-insulated unit, improves the safety through the five-prevention interlock function, and at the same time reduces the volume by 20%-30% (compared with the common sizes in the industry), reducing the floor area.

[0032] 2. Double-layer arrangement of the transformer and space optimization:

[0033] In the traditional box-type substation, the transformer and the high / low-voltage cabinets are arranged in a single layer, and the length of the copper busbar connection is long and the loss is high. The column support + double-layer arrangement of the present invention raises the transformer, shortens the length of the copper busbar (measured to be reduced by 40%), and integrates the UPS and communication equipment at the bottom, increasing the space utilization rate by more than 50%.

[0034] 3. Low-voltage modularization and maintenance-free design:

[0035] Existing low-voltage switchgear requires a reserved maintenance corridor (width ≥ 800 mm), while the back-to-back modular design of the present invention eliminates the corridor. Through out-of-door operation and direct-connected copper bars, the width of the cabinet is compressed to 60% of the industry average (e.g., from 2.5 m to 1.5 m), and it supports maintenance-free replacement, reducing operation and maintenance costs.

[0036] 4. Economic benefits:

[0037] The material cost is reduced by 15% (reduction in copper bar usage + simplified structure), and the transportation cost is reduced by 30% (reduced volume).

[0038] 5. Function integration:

[0039] For the first time, a photovoltaic grid-connected cabinet (6-way current collection), an energy storage cabinet (5-way current collection), and a power distribution cabinet are integrated in a single box substation, supporting flexible networking of microgrids.

[0040] 6. Intelligence level:

[0041] Remote monitoring (temperature, humidity, current) and remote control of circuit breakers are realized through the EMU system, filling the gap in the lack of intelligent interaction in traditional box substations. Description of the drawings

[0042] Figure 1 It is the front view structural schematic diagram of the new energy distributed photovoltaic double-layer box substation of the present invention;

[0043] Figure 2 It is the top view internal structural schematic diagram of the new energy distributed photovoltaic double-layer box substation of the present invention;

[0044] Figure 3 It is the front view internal structural schematic diagram of the new energy distributed photovoltaic double-layer box substation of the present invention;

[0045] Figure 4 It is the side view structural schematic diagram of the new energy distributed photovoltaic double-layer box substation of the present invention;

[0046] Figure 5 It is the structural schematic diagram of the inverted vacuum circuit breaker unit of the new energy distributed photovoltaic double-layer box substation of the present invention.

[0047] Description of the main component symbols in the drawings:

[0048] In the figure:

[0049] 1. High-voltage inverted switchgear cabinet 2. Low-voltage incoming line cabinet

[0050] 3. Transformer room 4. High-voltage lightning arrester

[0051] 5. Copper bar 6. Uninterruptible power supply UPS

[0052] 7. High-voltage sensor 8. Operation panel of high-voltage gas charging unit

[0053] 9. Current transformer 10. Fan

[0054] 11. Top cover of box-type transformer substation 12. High-voltage compartment

[0055] 13. Low-voltage compartment 14. Box body shell

[0056] 15. Isolating switch 16. Vacuum circuit breaker

[0057] 17. Earthing switch 18. Cabinet door interlock

[0058] 19. Interlocking slide plate Detailed implementation manners

[0059] The present invention will be described in detail with reference to the accompanying drawings and embodiments as follows:

[0060] The high-voltage sensor is horizontally installed at the power supply inlet end, and is used in combination with an electromagnetic lock to lock the high-voltage compartment door. When it detects that the power supply inlet end is electrified, the electromagnetic lock is in a locked state, so that the high-voltage compartment door cannot be opened.

[0061] Appendix Figures 1 - 5 It can be known that a new energy distributed photovoltaic double-layer box-type transformer substation includes a box body shell 14, a high-voltage compartment 12, a transformer compartment 3 and a low-voltage compartment 13.

[0062] An inverted vacuum circuit breaker unit 1 is arranged in the high-voltage compartment 12. The inverted vacuum circuit breaker unit 1 includes: an isolating switch (15), a vacuum circuit breaker (16) and an earthing switch (17);

[0063] The high-voltage cabinet arranges the isolating switch 15 below the vacuum circuit breaker 16 and the earthing switch 17 above the vacuum circuit breaker 16; the lower side of the isolating switch 15 is connected to the power grid, and the upper side of the earthing switch 17 is connected to the high-voltage side of the transformer; this layout is an inverted structure.

[0064] When overhauling the main transformer, the vacuum circuit breaker 16 is disconnected, the isolating switch 15 is further disconnected, and the earthing switch 17 is closed. Disconnecting the vacuum circuit breaker 16 ensures that the main circuit has been powered off. Disconnecting the isolating switch 15 cuts off the connection with the power grid side and forms an obvious break point. Closing the earthing switch 17 further ensures that the box-type transformer substation body side is in an earthed state, reducing potential safety hazards.

[0065] In the existing switchgear cabinet, the vacuum circuit breaker 16 is in the middle position, the disconnector 15 is on the upper side of the vacuum circuit breaker 16, and the earthing switch 17 is on the lower side of the vacuum circuit breaker 16. When maintenance of the main body is required, after disconnecting the vacuum circuit breaker 16 and then the disconnector 15, it is impossible to ensure an obvious break on the grid side. At the same time, when closing the earthing switch 17, it is necessary to ensure that there is no electricity on the grid side, otherwise the earthing switch 17 cannot be closed, and it is impossible to ensure that the main body of the box-type transformer is in the earthed state.

[0066] The inverted structure is applicable to the outgoing line cabinet of the step-up transformer and the incoming line cabinet of the step-down transformer, and the existing conventional structure is applicable to the outgoing line cabinet of the step-down transformer. It realizes that the earthing switch 17 is close to the power supply incoming end. During maintenance in the high-voltage chamber, the high-voltage incoming end can be grounded, ensuring electrical safety.

[0067] High-voltage insulators, high-voltage surge arresters 4 and copper bars 5 for connecting incoming line cables are arranged on the incoming line side of the high-voltage unit;

[0068] Air insulation is adopted on the outgoing line side, and high-voltage current transformers 9 and connecting copper bars are arranged.

[0069] The high-voltage chamber 12 is bounded by the transformer and is connected to the high-voltage side of the primary winding of the transformer; it contains components such as an inverted vacuum circuit breaker unit 1, high-voltage insulators, high-voltage surge arresters 4, high-voltage current transformers 9, high-voltage sensors 7, electromagnetic locks, microcomputer protection, busbars, etc.;

[0070] The low-voltage chamber 13 is bounded by the transformer and is connected to the low-voltage side of the secondary winding of the transformer; it contains components such as a frame circuit breaker, surge protection, measurement and control devices, busbars, etc.

[0071] Preferably, the transformer chamber 3 is arranged in a double layer. The SCB12 dry-type transformer is installed on the upper layer, and a detachable platform is arranged on the lower layer. An uninterruptible power supply UPS6, a communication switch and an energy management system EMU are installed at the bottom of the platform.

[0072] Preferably, the low-voltage chamber 13 includes 6 modular cabinets arranged back-to-back, integrating a low-voltage incoming line cabinet 2, a power distribution cabinet, a photovoltaic grid-connected cabinet and an energy storage cabinet. The cabinets are connected by direct-connected copper bars, and the outgoing line circuit breakers adopt a double-layer front-back arrangement structure.

[0073] Preferably, the inverted vacuum circuit breaker unit 1 in the high-voltage chamber 12 is electrically interlocked with the low-voltage circuit breaker, and the high-voltage vacuum circuit breaker is automatically cut off in case of a low-voltage circuit breaker failure;

[0074] The vacuum circuit breaker 16 is electrically operated, and is configured with a ring network cast current transformer 9 and a zero-sequence current transformer to achieve high-voltage overcurrent, instantaneous trip and zero-sequence protection through a microcomputer protection device;

[0075] The disconnector 15 is located at the bottom of the high-voltage switch unit, and the earthing switch 17 is located at the top of the high-voltage switch unit, respectively used for the disconnection of the incoming and outgoing lines.

[0076] Preferably, the inverted vacuum circuit breaker unit 1 integrates a disconnector 15, a vacuum circuit breaker 16, and an earthing switch 17, and is vertically installed in the high-voltage unit.

[0077] Preferably, the vacuum circuit breaker 16 and the disconnector 15 are provided with a locking mechanism: when the vacuum circuit breaker

[0078] is in the closed position, the disconnector 15 cannot be operated; when the vacuum circuit breaker 16 is in the open position, the disconnector 15 can be opened and closed;

[0079] The disconnector 15 and the earthing switch 17 are provided with a locking mechanism: when the earthing switch 17 is in the open position, the disconnector 15 can be closed;

[0080] The earthing switch 17 and the incoming line are provided with a locking mechanism through an electromagnetic lock: the earthing switch 17 can be closed when there is no power at the upper port;

[0081] The high-voltage chamber door and the earthing switch 17 are provided with a locking mechanism, and the high-voltage chamber door can be opened when the earthing switch is closed.

[0082] Preferably, the bottom of the platform in the transformer chamber 3 is provided with a perforated steel plate, and a forced air cooling system with a fan is installed. The starting threshold of the fan is that the transformer temperature ≥ 80°C.

[0083] Preferably, a 3-pole disconnector and a frame circuit breaker are provided in the photovoltaic grid-connected cabinet in the low-voltage chamber 13 to support the collection of 6-way currents; 5-way current collection interfaces are provided in the energy storage grid-connected cabinet.

[0084] The operation panel 8 of the high-voltage gas charging unit is located on the front of the box body.

[0085] A control method for a new energy distributed photovoltaic double-layer box-type substation includes the following control steps:

[0086] The vacuum circuit breaker 16 and the disconnector 17 are locked through the main shaft limit disc of the vacuum circuit breaker 16. When the vacuum circuit breaker 16 is in the open position, the limit disc of the vacuum circuit breaker 16 rotates. At this time, the limit disc does not restrict the rotation of the main shaft of the disconnector 15, and then the disconnector 15 can be opened and closed. When the vacuum circuit breaker 16 is in the closed state, the disconnector 15 is blocked by the limit disc and cannot be opened.

[0087] The isolating switch 15 and the grounding switch 17 are locked by an interlocking slide. When the isolating switch 15 is in a closed state, the locking slide cannot move because it is blocked by the main shaft connecting rod of the isolating switch 15. The main shaft operating hole of the grounding switch 17 is blocked by the interlocking slide and the grounding switch 17 cannot be operated. When the isolating switch 15 is in an open state, the main shaft connecting rod of the isolating switch 15 releases the restriction on the interlocking slide. At this time, the interlocking slide can move up and down, and the interlocking slide releases the blocking of the operating hole of the grounding switch 17, so that the grounding switch 17 can be opened and closed.

[0088] An electromagnetic lock is provided at the interlocking slide to realize the locking of the grounding switch 17 with the transformer side.

[0089] When the transformer side is energized, even if the isolating switch 15 has been opened, the electromagnetic lock detects that there is voltage on the transformer side. At this time, the electromagnetic lock is in working state, and the electromagnetic lock tongue blocks the interlocking slide, making the interlocking slide unable to move, and thus the grounding switch 17 cannot be operated. When the electromagnetic lock detects that there is no voltage on the transformer side and the isolating switch 15 has been opened, the grounding switch 173 can be closed. The grounding switch 17 and the switch cabinet door are locked through the door interlock setting. When the grounding switch 17 is closed, the paddle on the main shaft of the grounding switch 17 releases the door interlock restriction installed on the door. At this time, the door is opened. When the grounding switch 17 is opened, the door interlock is blocked by the paddle on the main shaft of the grounding switch 17, and the door cannot be opened.

[0090] The vacuum circuit breaker 16 and the isolating switch 15 are provided with a limit switch.

[0091] When opening, the operating hole of the isolating switch 15 can be opened to perform the opening and closing operations of the isolating switch 15;

[0092] The isolating switch 15 and the grounding switch 17 are provided with limit switches. When the grounding switch 17 is in the open position, the operating hole of the isolating switch 15 can be opened to perform the opening and closing operation of the isolating switch 15;

[0093] An electromagnetic lock is provided between the grounding switch 17 and the incoming line. When there is no power at the incoming line end, the electromagnetic lock is opened to operate the grounding switch 17.

[0094] A limit switch is provided between the high voltage chamber door and the grounding switch 17, and the high voltage chamber door is opened when the grounding switch 17 is closed.

[0095] The transformer column is assembled with 8# channel steel using assembly technology, and the digital platform is used to simulate the overall structural strength and modular design. The bottom uses ventilation partitions to improve ventilation strength and enhance the overall heat dissipation effect of the transformer room.

[0096] The new energy distributed photovoltaic double-layer box-type substation of the present invention applies technologies such as the inverted structure of high-voltage cabinets, the double-layer layout technology of transformers, and the external placement of the operation panel of low-voltage cabinets to the manufacturing of box-type substations, having great cost and performance advantages, specifically as follows:

[0097] 1. Integration of the inverted structure of the high-voltage unit:

[0098] The high-voltage disconnector, vacuum circuit breaker, and earthing switch of existing box-type substations are usually designed as separate units, resulting in large volume and high cost. The inverted structure of the present invention integrates the three into an air-insulated unit, improves safety through the five-prevention interlock function, and at the same time reduces the volume by 20%-30% (compared with common industry sizes), solving the pain point of large floor area of traditional box-type substations.

[0099] 2. Double-layer layout of the transformer and space optimization:

[0100] In traditional box-type substations, the transformer and high / low-voltage cabinets are arranged in a single layer, with long copper busbar connection length and high loss. The column support + double-layer layout of the present invention raises the transformer, shortens the copper busbar length (measured to be reduced by 40%), and integrates UPS and communication equipment at the bottom, increasing the space utilization rate by more than 50%.

[0101] 3. Low-voltage modularization and maintenance-free design:

[0102] Existing low-voltage cabinets need to reserve a maintenance corridor (width ≥ 800 mm), while the back-to-back modular design of the present invention cancels the corridor, compresses the box width to 60% of the industry average (such as from 2.5 m to 1.5 m) through out-of-door operation and direct-connected copper busbars, and supports maintenance-free replacement, reducing the operation and maintenance cost.

[0103] 4. Economic benefits:

[0104] The material cost is reduced by 15% (reduction in copper busbar usage + simplification of structure), and the transportation cost is reduced by 30% (reduction in volume).

[0105] 5. Function integration:

[0106] For the first time, a photovoltaic grid-connected cabinet (6-way current collection), an energy storage cabinet (5-way current collection), and a power distribution cabinet are integrated in a single box-type substation, supporting flexible networking of microgrids.

[0107] 6. Intelligent level:

[0108] Remote monitoring (temperature, humidity, current) and remote control of the circuit breaker are realized through the EMU system, filling the gap of the lack of intelligent interaction in traditional box-type substations.

[0109] Comparative analysis of the present invention and the prior art

[0110] 1. Structural comparison

[0111]

[0112]

[0113] 2. Functional comparison

[0114] Function Traditional solution The present invention Innovation point Device integration level Only power distribution function Integrated with photovoltaic, energy storage and power distribution Support "plug and play" for microgrid Intelligent level No remote monitoring EMU system + fiber optic communication Achieve unattended operation and maintenance Expansion flexibility Require customized transformation Modular cabinet directly connected to copper busbar The cost of adding a new circuit is reduced by 50%

[0115] The high-voltage switchgear of the present invention combines a disconnector, a vacuum circuit breaker, and an earthing switch to form an air-insulated inverted structure, which not only facilitates the connection of cables but also is equipped with a 0.2S-class epoxy-potted current transformer. A high-voltage live display is configured to indicate whether the high voltage is live and simultaneously transmit signals to the measurement and control device to achieve electrical interlocking between the high-voltage vacuum circuit breaker and the low-voltage side switch, that is, the closing of the low-voltage side circuit breaker is prohibited only when the high-voltage side is live.

[0116] The present invention designs and develops a new type of transformer column support structure, fabricates a welding platform tooling to raise the height of the transformer, and shortens the copper busbar connection between the high- and low-voltage sides. The bottom of the platform is a steel plate with mesh holes, and the platform is detachable, which facilitates overall replacement. A communication cabinet is placed under the platform, which houses equipment such as an uninterruptible power supply (UPS), a communication switch, and an optical fiber box, and can monitor signals such as current, voltage, switch opening and closing positions, temperature, and humidity inside the box transformer in real time, and can remotely control the circuit breaker inside the box transformer.

[0117] The low-voltage indoor switchgear of the present invention adopts a modular structure. Six low-voltage switchgears are placed back to back, eliminating the maintenance passage and the busbar bridge, greatly reducing the size of the box body in the width direction. Power is taken from the low-voltage side of the dry-type transformer, and after passing through a 4-pole disconnector and a 4-pole frame circuit breaker, it enters the low-voltage power distribution cabinet to achieve electrical isolation between the low-voltage side busbar circuit and the low-voltage side of the dry-type transformer. The outgoing molded case circuit breakers in the low-voltage power distribution cabinet are arranged in a double-layer front and back, making full use of the space inside the cabinet. At the same time, a door baffle is provided on the right side of the cabinet to facilitate the fixing of the box door; there is a 3-pole disconnector and a frame circuit breaker in the photovoltaic grid-connected cabinet, and there is an outgoing molded case circuit breaker at the bottom to achieve the collection of 6-way currents; the energy storage grid-connected cabinet also has a 3-pole disconnector and a frame circuit breaker, and there is a collection of 5-way currents at the bottom.

[0118] The above are only the preferred embodiments of the present invention, and do not impose any form of restriction on the structure of the present invention. Any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention all fall within the scope of the technical solution of the present invention.

Claims

1. A new energy distributed photovoltaic double-layer box-type substation, comprising a box body shell (14), a high-voltage chamber (12), a transformer chamber (3) and a low-voltage chamber (13), characterized in that: A reverse-mounted vacuum circuit breaker unit (1) is arranged in the high-voltage chamber (12), and the reverse-mounted vacuum circuit breaker unit (1) includes: a disconnector (15), a vacuum circuit breaker (16) and an earthing switch (17); The high-voltage cabinet arranges the disconnector (15) below the vacuum circuit breaker (16), and the earthing switch (17) above the vacuum circuit breaker (16); the lower side of the disconnector (15) is connected to the power grid, and the upper side of the earthing switch (17) is connected to the high-voltage side of the transformer.

2. The new energy distributed photovoltaic double-layer box-type substation according to claim 1, characterized in that: The transformer chamber (3) is arranged in a double layer, with an SCB12 dry-type transformer installed on the upper layer and a detachable platform arranged on the lower layer, and an uninterruptible power supply UPS (6), a communication switch and an energy management system EMU are installed at the bottom of the platform.

3. The new energy distributed photovoltaic double-layer box-type substation according to claim 1, characterized in that: The low-voltage chamber (13) includes 6 modular cabinets arranged back-to-back, integrating low-voltage incoming line cabinets (2), distribution cabinets, photovoltaic grid-connected cabinets and energy storage cabinets, and the cabinets are connected by direct-connected copper bars, and the outgoing line circuit breakers adopt a double-layer front-back arrangement structure.

4. The new energy distributed photovoltaic double-layer box-type substation according to claim 1, characterized in that: The reverse-mounted vacuum circuit breaker unit (1) in the high-voltage chamber (12) is electrically interlocked with the low-voltage circuit breaker, and the high-voltage vacuum circuit breaker is automatically cut off in case of a low-voltage circuit breaker failure; The vacuum circuit breaker (16) adopts electric operation, and is equipped with a ring network cast current transformer (9) and a zero-sequence current transformer, and realizes high-voltage overcurrent, quick-break and zero-sequence protection through a microcomputer protection device; The disconnector (15) is located at the bottom of the high-voltage switch unit, and the earthing switch (17) is located at the top of the high-voltage switch unit, respectively used for the disconnection of incoming and outgoing lines.

5. The new energy distributed photovoltaic double-layer box-type substation according to claim 1, characterized in that: The reverse-mounted vacuum circuit breaker unit (1) integrates a disconnector (15), a vacuum circuit breaker (16) and an earthing switch (17), and is vertically installed in the high-voltage unit.

6. The new energy distributed photovoltaic double-layer box-type substation according to claim 1, characterized in that: A locking device is set between the vacuum circuit breaker (16) and the disconnector (15): the disconnector (15) cannot be operated when the vacuum circuit breaker (16) is in the closed position, and the disconnector (15) can be opened and closed when the vacuum circuit breaker (16) is in the open position; A locking device is set between the disconnector (15) and the earthing switch (17): the disconnector (15) is allowed to be closed when the earthing switch (17) is in the open position; A locking device is set between the earthing switch (17) and the incoming line through an electromagnetic lock: the earthing switch (17) can be closed when there is no power at the upper port; A locking device is set between the high-voltage chamber door and the earthing switch (17), and the high-voltage chamber door is allowed to be opened when the earthing switch is closed.

7. The new energy distributed photovoltaic double-layer box-type substation according to claim 1, characterized in that: ​ ​ The bottom of the platform of the transformer room (3) is provided with a perforated steel plate, and a forced air cooling system of a fan is installed. The starting threshold of the fan is that the transformer temperature ≥ 80°C.

8. The new energy distributed photovoltaic double-layer box-type substation according to claim 1, characterized in that: The photovoltaic grid-connected cabinet in the low-voltage chamber (13) is provided with a 3-pole disconnector and a frame circuit breaker, which supports the collection of 6-way currents; the energy storage grid-connected cabinet is provided with 5-way current collection interfaces.

9. The control method of the new energy distributed photovoltaic double-layer box-type substation according to any one of claims 1 to 8, characterized in that, It includes the following control steps: The vacuum circuit breaker (16) and the disconnector (17) are locked through the main shaft limit disc of the vacuum circuit breaker (16). When the vacuum circuit breaker (16) is in the off position, the limit disc of the vacuum circuit breaker (16) rotates. At this time, the limit disc does not restrict the rotation of the main shaft of the disconnector (15), and then the disconnector (15) is switched on and off. When the vacuum circuit breaker (16) is in the on state, the disconnector (15) is stuck by the limit disc and cannot be switched off. The disconnector (15) and the earthing switch (17) are locked through an interlocking slide plate. When the disconnector (15) is in the on state, the interlocking slide plate cannot move because it is blocked by the main shaft connecting rod of the disconnector (15), and the main shaft operation hole of the earthing switch (17) is blocked by the interlocking slide plate and cannot operate the earthing switch (17). When the disconnector (15) is in the off state, the main shaft connecting rod of the disconnector (15) releases the restriction on the interlocking slide plate. At this time, the interlocking slide plate can move up and down, and the interlocking slide plate releases the block of the operation hole of the earthing switch (17) to operate the earthing switch (17) for switching on and off. An electromagnetic lock is arranged at the interlocking slide plate to realize the interlock between the earthing switch (17) and the transformer side. When the transformer side is energized, even if the disconnector (15) has been switched off, but the electromagnetic lock detects that there is voltage on the transformer side. At this time, the electromagnetic lock is in the working state, and the lock tongue of the electromagnetic lock blocks the interlocking slide plate, making the interlocking slide plate unable to move, and thus unable to operate the earthing switch (17). When the electromagnetic lock detects that there is no voltage on the transformer side and the disconnector (15) has been switched off, the earthing switch (17) can be closed.

3. The earthing switch (17) and the cabinet door of the switch cabinet are locked through a cabinet door interlock. When the earthing switch (17) is closed, the dial on the main shaft of the earthing switch (17) releases the restriction on the cabinet door interlock installed on the cabinet door, and at this time the cabinet door can be opened. When the earthing switch (17) is switched off, the cabinet door interlock is blocked by the dial on the main shaft of the earthing switch (17) and the cabinet door cannot be opened.

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