New energy distributed photovoltaic double-layer box-type substation

Abstract

The present application relates to a kind of new energy distributed photovoltaic double-layer box-type substation, including box shell, high-voltage chamber, transformer chamber and low-voltage chamber, the high-voltage chamber is provided with inverted vacuum circuit breaker unit, integrated disconnecting switch, vacuum circuit breaker and grounding switch;High-voltage unit incoming line side is provided with high-voltage insulator, high-voltage lightning arrester and copper bar for connecting incoming line cable;Outgoing line side uses air insulation, and high-voltage current transformer and connecting copper bar are arranged.The new energy distributed photovoltaic double-layer box-type substation of the present application applies high-voltage cabinet inverted structure, transformer double-layer arrangement technology, low-voltage cabinet operation panel externalization and other technologies in the manufacture of box-type substation, reduces the area, compact structure, low cost, reliable performance and facilitates field construction and maintenance.

Description

Technical Field

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

[0002] With the development of the photovoltaic power generation market, more and more microgrid equipment is being used on a smaller scale. Currently, there is a lack of a new type of terminal transformer that integrates 10kV high-voltage power distribution, 0.4kV low-voltage power distribution, and can connect to photovoltaic power generation and energy storage equipment. Summary of the Invention

[0003] To address the shortcomings of the existing technology, this invention provides a new energy distributed photovoltaic double-layer box-type substation that reduces the size of the substation, occupies less land, has a compact structure, low cost, reliable performance, and is convenient for on-site construction and maintenance.

[0004] The technical solution adopted in this invention is:

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

[0006] The high-voltage room is equipped with an inverted vacuum circuit breaker unit, which includes: a disconnecting switch, a vacuum circuit breaker, and a grounding switch;

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

[0008] The high-voltage unit's incoming side is equipped with high-voltage insulators, high-voltage surge arresters, and copper busbars for connecting the incoming cables;

[0009] The outgoing line side is air-insulated and equipped with a high-voltage current transformer and connecting copper busbar.

[0010] Preferably, the transformer room is arranged in two layers. The upper layer is equipped with an SCB12 dry-type transformer, and the lower layer is equipped with a detachable platform. 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 room comprises modular cabinets arranged back-to-back, integrating a low-voltage incoming line cabinet, a distribution cabinet, a photovoltaic grid-connected cabinet, and an energy storage cabinet, with the cabinets connected by direct-connect copper busbars.

[0012] Furthermore, the outgoing circuit breaker adopts a double-layer front and rear arrangement structure.

[0013] Preferably, the high-voltage indoor inverted vacuum circuit breaker unit is electrically interlocked with the low-voltage circuit breaker, so that the high-voltage vacuum circuit breaker can automatically disconnect when the low-voltage circuit breaker fails.

[0014] The vacuum circuit breaker is electrically operated and equipped with a ring network cast current transformer and a zero-sequence current transformer. Through a microcomputer protection device, it realizes high-voltage overcurrent, instantaneous trip, and zero-sequence protection.

[0015] The disconnecting switch is located at the bottom of the high-voltage switch unit, and the grounding switch is located at the top of the high-voltage switch unit. They are used to disconnect the incoming and outgoing lines, respectively.

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

[0017] Preferably, the vacuum circuit breaker and the disconnecting switch are interlocked: the disconnecting switch cannot be operated when the vacuum circuit breaker is closed, and the disconnecting switch is opened or closed when the vacuum circuit breaker is open;

[0018] The disconnecting switch and the grounding switch are interlocked: the disconnecting switch is allowed to be closed when the grounding switch is in the open position;

[0019] The grounding switch and the incoming line are interlocked by an electromagnetic lock: the grounding switch can be closed when there is no power at the upper end;

[0020] The high-voltage room door is interlocked with the grounding switch, but the high-voltage room door is allowed to be opened when the grounding switch is closed.

[0021] Preferably, the bottom of the platform of the transformer room is provided with a steel plate with mesh and a forced air cooling system is installed with a fan. The fan start threshold is ≥80℃ for the transformer temperature.

[0022] Preferably, the photovoltaic grid-connected cabinet in the low-voltage room is equipped with an isolation switch and a frame circuit breaker to support current collection; the energy storage grid-connected cabinet is equipped with a current collection interface.

[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 interlocked by the main shaft limit plate of the vacuum circuit breaker. When the vacuum circuit breaker is in the open position, the limit plate of the vacuum circuit breaker rotates. At this time, the limit plate no longer restricts the rotation of the main shaft of the disconnecting switch, thus enabling the disconnecting switch to open or close. When the vacuum circuit breaker is in the closed position, the disconnecting switch is blocked by the limit plate and cannot be opened.

[0025] The disconnector and the grounding switch are interlocked via 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. The main shaft operating hole of the grounding switch is also blocked by the interlocking slide plate, preventing operation of the grounding 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 obstruction of the grounding switch operating hole, allowing the grounding switch to be opened or closed.

[0026] An electromagnetic lock is installed at the interlocking slide to achieve interlocking between the grounding switch and the transformer side. When the transformer side is energized, even if the isolating switch has been opened, the electromagnetic lock detects voltage on the transformer side. At this time, the electromagnetic lock is in working state, and the electromagnetic lock tongue blocks the interlocking slide, preventing the interlocking slide from moving and thus preventing the grounding switch from being operated. When the electromagnetic lock detects no voltage on the transformer side and the isolating switch has been opened, the grounding switch can be closed. The grounding switch and the switch cabinet door are interlocked through the cabinet door interlock. When the grounding switch is closed, the lever on the grounding switch main shaft releases the restriction on the cabinet door interlock installed on the cabinet door, and the cabinet door can be opened at this time. When the grounding switch is opened, the cabinet door interlock is blocked by the lever on the grounding switch main shaft, and the cabinet door cannot be opened.

[0027] The advantages of this invention over the prior art are:

[0028] This invention relates to a new energy distributed photovoltaic double-layer box-type substation, which applies technologies such as high-voltage switchgear inverted structure, transformer double-layer arrangement technology, and low-voltage switchgear operation panel external to the manufacturing of box-type substations, thereby reducing the footprint and lowering operation and maintenance costs.

[0029] Specifically as follows:

[0030] 1. High-voltage unit inverted structure integration:

[0031] Existing transformer substations typically use separate designs for high-voltage disconnect switches, vacuum circuit breakers, and grounding switches, resulting in large size and high cost. The inverted structure of this invention integrates all three components within an air-insulated unit, enhancing safety through a five-proof interlocking function while reducing size by 20%-30% (compared to common industry dimensions), thus minimizing the footprint.

[0032] 2. Transformer double-layer layout and space optimization:

[0033] In traditional prefabricated transformer substations, the transformer and high / low voltage switchgear are laid out in a single layer, resulting in long copper busbar connections and high losses. This invention, with its column support and double-layer arrangement, elevates the transformer, shortening the copper busbar length (measured reduction of 40%), and integrates UPS and communication equipment at the bottom, improving space utilization by over 50%.

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

[0035] Existing low-voltage switchgear requires a maintenance corridor (width ≥ 800mm), while the back-to-back modular design of this invention eliminates the corridor, compresses the cabinet width to 60% of the industry average (e.g., from 2.5m to 1.5m) through external operation and direct connection of copper busbars, and supports maintenance-free replacement, reducing operation and maintenance costs.

[0036] 4. Economic benefits:

[0037] Material costs are reduced by 15% (reduced copper busbar usage + simplified structure), and transportation costs are reduced by 30% (reduced volume).

[0038] 5. Function integration:

[0039] For the first time, a photovoltaic grid-connected cabinet (6 current collection), an energy storage cabinet (5 current collection), and a distribution cabinet are integrated into a single transformer substation, supporting flexible microgrid networking.

[0040] 6. Level of intelligence:

[0041] The EMU system enables remote monitoring (temperature, humidity, current) and circuit breaker remote control, filling the gap in traditional prefabricated substations that lack intelligent interaction. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the main structure of the new energy distributed photovoltaic double-layer box-type substation of the present invention;

[0043] Figure 2 This is a top view of the internal structure of the new energy distributed photovoltaic double-layer box-type substation of the present invention;

[0044] Figure 3 This is a schematic diagram of the internal structure of the new energy distributed photovoltaic double-layer box-type substation of the present invention;

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

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

[0047] Explanation of symbols for key components in the attached diagram:

[0048] In the picture:

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

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

[0051] 5. Copper busbars 6. Uninterruptible power supply (UPS)

[0052] 7. High-voltage sensor; 8. High-voltage inflation unit control panel

[0053] 9. Current transformer 10. Fan

[0054] 11. Transformer top cover; 12. High voltage compartment

[0055] 13. Low-pressure chamber 14. Enclosure of the enclosure.

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

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

[0058] 19. Interlocking skateboard. Detailed Implementation

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

[0060] The high-voltage sensor is horizontally installed at the power inlet and used in conjunction with an electromagnetic lock to lock the high-voltage chamber door. When the power inlet is detected to be energized, the electromagnetic lock is in a locked state, thus preventing the high-voltage chamber door from being opened.

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

[0062] The high-voltage chamber 12 is equipped with an inverted vacuum circuit breaker unit 1, which includes: a disconnecting switch (15), a vacuum circuit breaker (16), and a grounding switch (17).

[0063] The high-voltage switchgear places the disconnecting switch 15 below the vacuum circuit breaker 16 and the grounding switch 17 above the vacuum circuit breaker 16; the lower side of the disconnecting switch 15 is connected to the power grid, and the upper side of the grounding switch 17 is connected to the high-voltage side of the transformer; this arrangement is an inverted structure.

[0064] When the transformer is being inspected, the vacuum circuit breaker 16 is disconnected, the isolating switch 15 is further disconnected, and the grounding switch 17 is closed. The disconnection of the vacuum circuit breaker 16 ensures that the main circuit is de-energized, the disconnection switch 15 disconnects the connection with the grid side and forms a clear break, and the grounding switch 17 is closed to further ensure that one side of the transformer body is grounded, reducing safety hazards.

[0065] The existing switchgear has the vacuum circuit breaker 16 in the middle position, the disconnecting switch 15 on the upper side of the vacuum circuit breaker 16, and the grounding switch 17 on the lower side of the vacuum circuit breaker 16. When the main body needs to be inspected, the vacuum circuit breaker 16 is disconnected and then the disconnecting switch 15 is disconnected, which cannot guarantee a clear break on the grid side. At the same time, when the grounding switch 17 is closed, it is necessary to ensure that there is no power on the grid side. Otherwise, the grounding switch 17 cannot be closed, and the transformer body cannot be guaranteed to be in a grounded state.

[0066] The inverted structure is suitable for the outgoing line cabinets of step-up transformers and the incoming line cabinets of step-down transformers, while the existing conventional structure is suitable for the outgoing line cabinets of step-down transformers. This design allows the grounding switch 17 to be located near the power inlet, ensuring grounding of the high-voltage inlet during high-voltage room maintenance and guaranteeing electrical safety.

[0067] The high-voltage unit incoming side is equipped with a high-voltage insulator, a high-voltage surge arrester 4, and a copper busbar 5 for connecting the incoming cable;

[0068] The outgoing side is air-insulated and equipped with a high-voltage current transformer 9 and connecting copper busbars.

[0069] High-voltage compartment 12 is connected to the high-voltage side of the primary winding of the transformer, with the transformer as the boundary; it contains components such as inverted vacuum circuit breaker unit 1, high-voltage insulator, high-voltage surge arrester 4, high-voltage current transformer 9, high-voltage sensor 7, electromagnetic lock, microcomputer protection, busbar, etc.

[0070] The low-voltage compartment 13 is connected to the low-voltage side of the transformer's secondary winding, with the transformer as the boundary; it contains components such as a frame circuit breaker, surge protector, monitoring and control device, and busbar.

[0071] Preferably, the transformer room 3 is arranged in two layers. The upper layer is equipped with an SCB12 dry-type transformer, and the lower layer is equipped with a detachable platform. The bottom of the platform is equipped with an uninterruptible power supply UPS6, a communication switch and an energy management system EMU.

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

[0073] Preferably, the inverted vacuum circuit breaker unit 1 in the high-voltage compartment 12 is electrically interlocked with the low-voltage circuit breaker, so that the high-voltage vacuum circuit breaker can automatically disconnect when the low-voltage circuit breaker fails.

[0074] Vacuum circuit breaker 16 is electrically operated and equipped with ring network cast current transformer 9 and zero sequence transformer to realize high voltage overcurrent, instantaneous trip and zero sequence protection through microcomputer protection device;

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

[0076] Preferably, the inverted vacuum circuit breaker unit 1 integrates a disconnecting switch 15, a vacuum circuit breaker 16, and a grounding switch 17, and is vertically installed within the high-voltage unit.

[0077] Preferably, the vacuum circuit breaker 16 and the disconnecting switch 15 are interlocked: in the vacuum circuit breaker

[0078] When the 16-closed position is reached, the isolating switch 15 cannot be operated; when the vacuum circuit breaker is in the open position (16-open), the isolating switch 15 can be opened or closed.

[0079] The disconnector switch 15 and the grounding switch 17 are interlocked: the disconnector switch 15 is allowed to be closed when the grounding switch 17 is in the open position.

[0080] The grounding switch 17 is interlocked with the incoming line via an electromagnetic lock: the grounding switch 17 can be closed when there is no power at the upper end.

[0081] The high-voltage chamber door is interlocked with the grounding switch 17, allowing the high-voltage chamber door to be opened when the grounding switch is closed.

[0082] Preferably, the bottom of the platform of the transformer room 3 is provided with a steel plate with mesh and a forced air cooling system is installed with a fan. The fan start threshold is ≥80℃ for the transformer temperature.

[0083] Preferably, the photovoltaic grid-connected cabinet in the low-voltage room 13 is equipped with a 3-pole isolating switch and a frame circuit breaker, supporting 6-way current collection; the energy storage grid-connected cabinet is equipped with 5-way current collection interfaces.

[0084] The high-pressure inflation unit control panel 8 is located on the front of the housing.

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

[0086] Vacuum circuit breaker 16 and disconnector 17 are locked together by the main shaft limit plate of vacuum circuit breaker 16. When vacuum circuit breaker 16 is in the open position, the limit plate of vacuum circuit breaker 16 rotates. At this time, the limit plate no longer restricts the rotation of the main shaft of disconnector 15, and thus the disconnector 15 can be opened or closed. When vacuum circuit breaker 16 is in the closed position, disconnector 15 is blocked by the limit plate and cannot be opened.

[0087] The disconnector switch 15 and the grounding switch 17 are interlocked by an interlocking sliding plate. When the disconnector switch 15 is in the closed state, the interlocking sliding plate cannot move because it is blocked by the main shaft connecting rod of the disconnector switch 15. The main shaft operating hole of the grounding switch 17 is blocked by the interlocking sliding plate and cannot be operated. When the disconnector switch 15 is in the open state, the main shaft connecting rod of the disconnector switch 15 releases the restriction on the interlocking sliding plate. At this time, the interlocking sliding plate can move up and down, and the interlocking sliding plate releases the blockage of the operating hole of the grounding switch 17, allowing the grounding switch 17 to be opened and closed.

[0088] An electromagnetic lock is installed at the interlocking slide to achieve interlocking between the grounding switch 17 and the transformer side.

[0089] When the transformer side is energized, even if the isolating switch 15 has been opened, the electromagnetic lock detects voltage on the transformer side. At this time, the electromagnetic lock is in working condition, and the electromagnetic lock tongue blocks the interlocking slide, preventing the interlocking slide from moving and thus preventing the grounding switch 17 from being operated. When the electromagnetic lock detects no voltage on the transformer side and the isolating switch 15 has been opened, the grounding switch 17 can be closed. The grounding switch 17 and the switch cabinet door are interlocked through the cabinet door interlock. When the grounding switch 17 is closed, the lever on the main shaft of the grounding switch 17 releases the restriction on the cabinet door interlock installed on the cabinet door, and the cabinet door can be opened at this time. When the grounding switch 17 is opened, the cabinet door interlock is blocked by the lever on the main shaft of the grounding switch 17, and the cabinet door cannot be opened.

[0090] Limit switches are installed between vacuum circuit breaker 16 and disconnector 15.

[0091] When the circuit is tripped, the operating port of the disconnector switch 15 can be opened to perform the opening and closing operation of the disconnector switch 15.

[0092] Limit switches are provided for disconnecting switch 15 and grounding switch 17. When grounding switch 17 is in the open position, the operating hole of disconnecting switch 15 can be opened to perform the opening and closing operation of disconnecting switch 15.

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

[0094] Limit switches are installed between the high-voltage chamber door and the grounding switch 17. The high-voltage chamber door is opened when the grounding switch 17 is closed.

[0095] The transformer support column is assembled using #8 channel steel with a modular design and overall structural strength simulated using a digital platform. Ventilation baffles at the bottom enhance ventilation and improve the overall heat dissipation of the transformer compartment.

[0096] This invention relates to a new energy distributed photovoltaic double-layer prefabricated substation, which applies technologies such as high-voltage switchgear inverted structure, transformer double-layer arrangement, and external low-voltage switchgear operation panel to the manufacturing of prefabricated substations, resulting in significant cost and performance advantages, as detailed below:

[0097] 1. High-voltage unit inverted structure integration:

[0098] Existing prefabricated substations typically use separate designs for the high-voltage disconnect switch, vacuum circuit breaker, and grounding switch, resulting in large size and high cost. The inverted structure of this invention integrates all three components within an air-insulated unit, enhancing safety through a five-proof interlocking function while reducing size by 20%-30% (comparison to common industry dimensions), thus solving the problem of large footprint in traditional prefabricated substations.

[0099] 2. Transformer double-layer layout and space optimization:

[0100] In traditional prefabricated transformer substations, the transformer and high / low voltage switchgear are laid out in a single layer, resulting in long copper busbar connections and high losses. This invention, with its column support and double-layer arrangement, elevates the transformer, shortening the copper busbar length (measured reduction of 40%), and integrates UPS and communication equipment at the bottom, improving space utilization by over 50%.

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

[0102] Existing low-voltage switchgear requires a maintenance corridor (width ≥ 800mm), while the back-to-back modular design of this invention eliminates the corridor, compresses the cabinet width to 60% of the industry average (e.g., from 2.5m to 1.5m) through external operation and direct connection of copper busbars, and supports maintenance-free replacement, reducing operation and maintenance costs.

[0103] 4. Economic benefits:

[0104] Material costs are reduced by 15% (reduced copper busbar usage + simplified structure), and transportation costs are reduced by 30% (reduced volume).

[0105] 5. Function integration:

[0106] For the first time, a photovoltaic grid-connected cabinet (6 current collection), an energy storage cabinet (5 current collection), and a distribution cabinet are integrated into a single transformer substation, supporting flexible microgrid networking.

[0107] 6. Level of intelligence:

[0108] The EMU system enables remote monitoring (temperature, humidity, current) and circuit breaker remote control, filling the gap in traditional prefabricated substations that lack intelligent interaction.

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

[0110] 1. Structural Comparison

[0111]

[0112]

[0113] 2. Function Comparison

[0114] Function Traditional solution This invention Innovation Equipment integration Power distribution function only Integrating photovoltaics, energy storage, and power distribution Supports "plug and play" microgrids Level of intelligence No remote monitoring EMU system + fiber optic communication Achieve unattended operation and maintenance Expanding flexibility Customized modification required Modular cabinet direct connection copper busbar The cost of adding new circuits is reduced by 50%.

[0115] This invention's high-voltage switchgear combines a disconnecting switch, a vacuum circuit breaker, and a grounding switch into an air-insulated inverted structure, facilitating cable connection and incorporating a 0.2S-class epoxy-cast current transformer. A high-voltage energized indicator is included to show whether the high voltage is live, and simultaneously transmits signals to the monitoring and control device, achieving electrical interlocking between the high-voltage vacuum circuit breaker and the low-voltage side switch; that is, the low-voltage side circuit breaker cannot be closed only when the high-voltage side is energized.

[0116] This invention designs and develops a novel transformer column support structure, and fabricates a welding platform fixture to raise the transformer's height, shortening the copper busbar connections on the high and low voltage sides. The platform's bottom is a perforated steel plate, allowing for easy access and disassembly for convenient overall replacement. A communication cabinet is placed beneath the platform, housing an uninterruptible power supply (UPS), communication switch, fiber optic box, and other equipment. This cabinet monitors real-time signals such as current, voltage, switch open / closed positions, temperature, and humidity within the transformer substation, and enables remote control of the circuit breakers within the substation.

[0117] This invention relates to a modular structure for low-voltage indoor switchgear, with six low-voltage cabinets placed back-to-back, eliminating maintenance access and busbar bridges and significantly reducing the width of the enclosure. Power is drawn from the low-voltage side of the dry-type transformer, passing through a 4-pole disconnecting switch and a 4-pole frame circuit breaker before reaching the low-voltage distribution cabinet, achieving electrical isolation between the low-voltage busbar circuit and the low-voltage side of the dry-type transformer. The outgoing molded case circuit breakers in the low-voltage distribution cabinet are arranged in a double-layer front-to-back configuration, making full use of the cabinet space. A door baffle is also provided on the right side of the cabinet for easy securing of the cabinet door. The photovoltaic grid-connected cabinet has a 3-pole disconnecting switch and a frame circuit breaker inside, with outgoing molded case circuit breakers at the bottom, enabling six current collection channels. The energy storage grid-connected cabinet also has a 3-pole disconnecting switch and a frame circuit breaker, with five current collection channels at the bottom.

[0118] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the structure of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall 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 shell (14), a high-voltage compartment (12), a transformer compartment (3), and a low-voltage compartment (13), characterized in that: The high-voltage chamber (12) is equipped with an inverted vacuum circuit breaker unit (1), which includes: a disconnecting switch (15), a vacuum circuit breaker (16), and a grounding switch (17). The high-voltage switchgear has the disconnecting switch (15) located below the vacuum circuit breaker (16) and the grounding switch (17) located above the vacuum circuit breaker (16); the lower side of the disconnecting switch (15) is connected to the power grid, and the upper side of the grounding switch (17) is connected to the high-voltage side of the transformer. The disconnector (15) is located at the bottom of the high-voltage switch unit, and the grounding switch (17) is located at the top of the high-voltage switch unit. They are used to disconnect the incoming and outgoing lines respectively. The inverted vacuum circuit breaker unit (1) integrates the disconnector (15), vacuum circuit breaker (16), and grounding switch (17), and is installed vertically inside the high-voltage unit. When the main transformer is being overhauled, the vacuum circuit breaker (16) is disconnected, the isolating switch (15) is further disconnected, and the grounding switch (17) is closed. The vacuum circuit breaker (16) is disconnected to ensure that the main circuit has been de-energized. The isolating switch (15) is disconnected to cut off the connection with the grid side and form a clear break. The grounding switch (17) is closed to further ensure that one side of the transformer body is grounded. The transformer room (3) adopts a double-layer arrangement. The upper layer is equipped with an SCB12 dry-type transformer, and the lower layer is equipped with a detachable platform. The bottom of the platform is equipped with an uninterruptible power supply (UPS) (6), a communication switch and an energy management system (EMU). The low-voltage room (13) includes a 6-sided modular cabinet arranged back to back, which integrates a low-voltage incoming cabinet (2), a distribution cabinet, a photovoltaic grid-connected cabinet and an energy storage cabinet. The cabinets are connected by direct copper busbars, and the outgoing circuit breakers adopt a double-layer front and rear arrangement structure.

2. The new energy distributed photovoltaic double-layer box-type substation according to claim 1, characterized in that: The inverted vacuum circuit breaker unit (1) in the high-voltage compartment (12) is electrically interlocked with the low-voltage circuit breaker; The vacuum circuit breaker (16) is electrically operated and is equipped with a ring network cast current transformer (9) and a zero-sequence transformer. The high-voltage overcurrent, instantaneous trip, and zero-sequence protection are achieved through a microcomputer protection device. The disconnecting switch (15) is located at the bottom of the high-voltage switch unit, and the grounding switch (17) is located at the top of the high-voltage switch unit, respectively used for disconnecting the incoming and outgoing lines.

3. The new energy distributed photovoltaic double-layer box-type substation according to claim 1, characterized in that: The inverted vacuum circuit breaker unit (1) integrates a disconnecting switch (15), a vacuum circuit breaker (16), and a grounding switch (17), and is installed vertically within the high-voltage unit.

4. The new energy distributed photovoltaic double-layer box-type substation according to claim 1, characterized in that: The vacuum circuit breaker (16) and the disconnecting switch (15) are interlocked: the disconnecting switch (15) cannot be operated when the vacuum circuit breaker (16) is closed, and the disconnecting switch (15) is opened and closed when the vacuum circuit breaker (16) is open. The isolating switch (15) and the grounding switch (17) are interlocked: the isolating switch (15) is allowed to be closed when the grounding switch (17) is in the open position. The grounding switch (17) is locked to the incoming line by an electromagnetic lock: the grounding switch (17) is closed when there is no power at the upper end. The high-voltage room door is interlocked with the grounding switch (17), allowing the high-voltage room door to be opened when the grounding switch is closed.

5. 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 steel plate with mesh and a forced air cooling system is installed with a fan. The fan start threshold is ≥80℃ for the transformer temperature.

6. 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 room (13) is equipped with a 3-pole isolating switch and a frame circuit breaker, supporting 6 current collections; the energy storage grid-connected cabinet is equipped with 5 current collection interfaces.

7. The control method for a new energy distributed photovoltaic double-layer box-type substation according to any one of claims 1 to 6, characterized in that, The following control steps are included: The vacuum circuit breaker (16) and the disconnector (17) are locked by the main shaft limit plate of the vacuum circuit breaker (16). When the vacuum circuit breaker (16) is in the open position, the limit plate of the vacuum circuit breaker (16) rotates. At this time, the limit plate no longer restricts 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 position, the disconnector (15) is blocked by the limit plate and cannot be opened. The disconnector switch (15) and the grounding switch (17) are interlocked by the interlocking slide plate. When the disconnector switch (15) is in the closed state, the interlocking slide plate cannot move because it is blocked by the main shaft connecting rod of the disconnector switch (15). The main shaft operating hole of the grounding switch (17) is blocked by the interlocking slide plate and cannot be operated. When the disconnector switch (15) is in the open state, the main shaft connecting rod of the disconnector switch (15) releases the restriction on the interlocking slide plate. At this time, the interlocking slide plate moves up and down, and the interlocking slide plate releases the blockage of the operating hole of the grounding switch (17) to perform the opening and closing operation of the grounding switch (17). An electromagnetic lock is installed at the interlocking slide to lock the grounding switch (17) and the transformer side. 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. 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 (17) is closed. The grounding switch (17) and the switch cabinet door are locked through the cabinet door interlock. When the grounding switch (17) is closed, the lever on the main shaft of the grounding switch (17) releases the cabinet door interlock restriction installed on the cabinet door. At this time, the cabinet door is opened. When the grounding switch (17) is opened, the cabinet door interlock is blocked by the lever on the main shaft of the grounding switch (17), and the cabinet door cannot be opened.

Images