Distributed photovoltaic power supply and distribution system and box transformer substation

Abstract

The invention discloses a distributed photovoltaic power supply and distribution system and a box transformer substation, a low-voltage side 800 / 380V bus transformer is arranged in the box transformer substation, and functions of an external switching station and a switch cabinet are integrated in the box transformer substation and led out through a feed-out switch. According to the scheme, by changing the original power utilization system design and optimizing the power supply points of the power supply and distribution design, the power supply and distribution cost is reduced, so that the construction cost of a distributed photovoltaic project is reduced, and stable operation of the power supply and distribution system can be ensured. The power supply and distribution system is simple in design and extremely high in applicability, is configured and produced by a box transformer substation manufacturer after a drawing is designed, and can be used after wiring debugging according to the drawing after being transported to a site. A 10kV switch cabinet, a transformer and a low-voltage cabinet in the original power supply and distribution design are omitted, the area of a prefabricated cabin is reduced, so that the construction cost is reduced, the number of external equipment is reduced, operation faults of the system can be reduced, meanwhile, the construction cost can be reduced, stable operation of the system is facilitated, and the system has the advantages of being convenient in construction process, low in fault rate and convenient to overhaul.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic power supply and distribution, and in particular to a distributed photovoltaic power supply and distribution box transformer device and a power supply and distribution system. Background Art

[0002] The photovoltaic industry is developing rapidly, and its application scenarios have expanded from ground-based to water surfaces, rooftops, and more. This patent uses distributed power generation as an example. When distributed photovoltaics first emerged, the equipment required for grid connection was very simple, requiring only grid connection cabinets and protection. However, with continuous development, the corresponding requirements have gradually improved.

[0003] Currently, distributed photovoltaic systems connected to the 10kV grid must be equipped with a switchgear and corresponding protection and monitoring equipment. Traditional power supply designs for equipment and the lighting and air conditioning within the switchgear all derive their power from the switchgear's 10kV busbar. This requires a 10kV switchgear, an SC13-50kVA-10kV / 0.38kV transformer, a low-voltage distribution cabinet, and an additional 10 square meters of prefabricated cabin space, resulting in a very high overall cost. Summary of the Invention

[0004] Due to the above-mentioned defects in the prior art, the present invention provides a distributed photovoltaic power supply and distribution box transformer device and a power supply and distribution system to solve the problems of large prefabricated cabin area and high overall cost of the existing traditional power supply and distribution system.

[0005] To achieve the above object, the present invention provides the following technical solutions: In the distributed photovoltaic power supply and distribution system, a low-voltage side 800 / 380V busbar transformer is installed in the box-type transformer, and the functions of the external switchgear and switch cabinet are integrated in the box-type transformer and brought out through the feeder switch.

[0006] The transformer capacity is calculated based on actual considerations, including the installation space for the internal power transformer of the box-type transformer, the cross-sectional current carrying capacity of the high-voltage side busbar, and the configuration of the low-voltage side busbar switch.

[0007] The feeder switch is configured on the low-voltage side according to the number of power consumption points and load conditions inside the box-type transformer, as well as the number of power consumption points and load conditions inside the switchgear.

[0008] The feeder switch includes a three-phase socket, a single-phase socket, a box transformer lighting power supply, a transformer room temperature control power supply, a compartment indoor environment controller power supply, a low-voltage room air-conditioning power supply, a high-voltage room air-conditioning power supply, a primary compartment distribution box power supply, a secondary compartment distribution box power supply, a DC device power supply, several UPS power supplies and several backup switches.

[0009] The UPS power supply includes a high-voltage circuit breaker control power supply, a low-voltage circuit breaker control power supply, a box-type transformer measurement and control device power supply, a fire device alarm power supply and a backup power supply.

[0010] It also includes a backup power supply, which automatically switches to the backup power supply when the box transformer fails.

[0011] The distributed photovoltaic power supply and distribution box transformer includes a high-voltage room, a transformer room, and a low-voltage room. The low-voltage room includes the station distribution interval and the main incoming line interval; the high-voltage room is equipped with an incoming line cabinet and an outgoing line cabinet; the transformer room is equipped with a main step-up transformer in the box transformer; the low-voltage side 800 / 380V busbar transformer and feed switch are arranged in the station distribution interval, and the inverter unit is arranged in the main incoming line interval.

[0012] Both the high-pressure room and the low-pressure room are equipped with temperature and humidity controllers, heaters and industrial-grade air conditioners.

[0013] The high-voltage room, transformer room and low-voltage room are each equipped with one intelligent smoke detector and one fire sound and light alarm.

[0014] The box-type transformer shell is made of a single layer of cold-rolled steel plate, and the protection grade is IP54.

[0015] Compared with the prior art, the above invention has the following advantages or beneficial effects: 1. This solution reduces the cost of power supply and distribution by changing the original power system design and optimizing the power supply points of the power supply and distribution design, thereby reducing the construction cost of distributed photovoltaic projects and ensuring the stable operation of the power supply and distribution system.

[0016] 2. The power supply and distribution system is simple in design and highly applicable. After the design drawings are issued, it will be configured and produced by the box transformer manufacturer. After it is transported to the site, it can be used after wiring and debugging according to the drawings.

[0017] 3. Eliminate the 10kV switchgear, transformers, and low-voltage cabinets in the original power supply and distribution design, reduce the area of ​​the prefabricated cabin, and thus reduce construction costs. Reducing external equipment can reduce system operation failures and construction costs, which is more conducive to the stable operation of the system. It has the advantages of convenient construction technology, low failure rate, and convenient maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention and its features, configurations, and advantages will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings. Like reference numerals indicate like parts throughout the drawings. The drawings are not necessarily drawn to scale, emphasis being placed on illustrating the subject matter of the present invention.

[0019] Figure 1 This is the electrical connection diagram of the station distribution bay of the present invention.

[0020] Figure 2 This is the electrical connection diagram of the main incoming line interval of the present invention.

[0021] Figure 3 It is a schematic diagram of the box-type transformer structure of the present invention. DETAILED DESCRIPTION

[0022] In order to enable people in this technical field to better understand the solution of this application, the technical solution in the embodiment of this application will be clearly and completely described below in combination with the drawings in the embodiment of this application. Obviously, the described embodiment is only an embodiment of a part of this application, not all embodiments.

[0023] Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative work should fall within the scope of protection of this application.

[0024] The principle of the power supply and distribution system design described in this proposal is to convert the original 10kV busbar at the power source point to the 800V busbar on the low-voltage side of the box-type transformer. During the box-type transformer design, the transformer used for power supply within the original box-type transformer was taken into account for the power load of the switchgear station, and the transformer capacity was increased. Based on actual calculations, the installation space for the transformer within the box-type transformer, the cross-sectional current carrying capacity of the high-voltage busbar, and the configuration of the low-voltage busbar switch were considered. The low-voltage side panel was also designed based on the number and load of power points within the box-type transformer, as well as the number and load of power points within the switchgear station. During installation, cables were used to connect each power point in the switchgear station according to the drawings, achieving a system design in which the low-voltage side of the box-type transformer provides power to the entire station. This eliminated the 10kV switchgear, transformer, and low-voltage cabinets from the original power supply and distribution design, reducing the area of ​​the prefabricated cabin and thus lowering construction costs. It was estimated that the cost of each box-type transformer could be reduced by 200,000 yuan.

[0025] In the distributed photovoltaic power supply and distribution system, a low-voltage side 800 / 380V busbar transformer is installed in the box-type transformer, and the functions of the external switchgear and switch cabinet are integrated in the box-type transformer and brought out through the feeder switch.

[0026] Specific embodiments, such as Figure 1 、 Figure 2 As shown, The distributed photovoltaic power supply and distribution system includes a boost unit, an inverter unit, and a low-voltage output unit. The low-voltage output unit includes an 800 / 380V busbar transformer and several feeder switches. The feeder switches include three-phase sockets, single-phase sockets, a box-type lighting power supply, a transformer room temperature control power supply, a compartment indoor environment controller power supply, a low-voltage room air-conditioning power supply, a high-voltage room air-conditioning power supply, a primary compartment distribution box power supply, a secondary compartment distribution box power supply, a DC device power supply, several UPS power supplies, and several backup switches.

[0027] The UPS power supply includes a high-voltage circuit breaker control power supply, a low-voltage circuit breaker control power supply, a box-type transformer measurement and control device power supply, a fire device alarm power supply and a backup power supply.

[0028] The transformer capacity is calculated based on actual considerations, including the installation space for the internal power transformer of the box-type transformer, the cross-sectional current carrying capacity of the high-voltage side busbar, and the configuration of the low-voltage side busbar switch.

[0029] The feeder switch is configured on the low-voltage side according to the number of power consumption points and load conditions inside the box-type transformer, as well as the number of power consumption points and load conditions inside the switchgear.

[0030] It also includes a backup power supply. When the box-type transformer fails, it automatically switches to the backup power supply to ensure reliable power supply.

[0031] In this embodiment, the inverter unit includes 6 string inverters and a backup switch.

[0032] The distributed photovoltaic power supply and distribution box transformer includes a high-voltage room, a transformer room, and a low-voltage room. The low-voltage room includes the station distribution interval and the main incoming line interval; the high-voltage room is equipped with an incoming line cabinet and an outgoing line cabinet; the transformer room is equipped with a main step-up transformer in the box transformer; the low-voltage side 800 / 380V busbar transformer and feed switch are arranged in the station distribution interval, and the inverter unit is arranged in the main incoming line interval.

[0033] Specific embodiments, such as Figure 3 As shown, The distributed photovoltaic power distribution box-type transformer consists of a high-voltage compartment, a transformer compartment, and a low-voltage compartment. The low-voltage compartment includes the station distribution bay and the main incoming line compartment. The high-voltage compartment houses the incoming and outgoing line cabinets. The transformer compartment houses the main step-up transformer. The low-voltage side 800 / 380V busbar transformer and feeder switch are located in the station distribution bay, and the inverter unit is located in the main incoming line compartment. Both the high-voltage and low-voltage compartments are equipped with temperature and humidity controllers, heaters, and industrial-grade air conditioners. In this example, a 1.5P industrial air conditioner is used. The high-voltage compartment is equipped with electromagnetic locks to meet the "five protection" requirements.

[0034] The high-voltage room, transformer room and low-voltage room are each equipped with one intelligent smoke detector and one fire sound and light alarm.

[0035] The transformer housing is made of single-layer cold-rolled steel plate with a protection level of IP54. The color of the transformer housing is selected according to the specific application location.

[0036] This distributed photovoltaic power supply and distribution system breaks the original barrier of separately designed internal power supply for switchgear and box-type transformers. By expanding and renovating the internal power supply transformer of the box-type transformer and renovating the internal power supply system of the box-type transformer, it can realize power supply to the interior of the box-type transformer and the switchgear from the box-type transformer, reducing equipment investment and lowering the system failure rate.

[0037] Change the way equipment, power and lighting are supplied in traditional distributed photovoltaic switch stations, thereby reducing the overall construction cost of photovoltaic projects.

[0038] This design system is simple and highly applicable. It can be purchased after the design drawings are issued, configured and produced by the box transformer manufacturer, and can be used after wiring and debugging on site according to the drawings.

[0039] In addition, the symbols and numbers in the figure are only used to distinguish the components. Unused items can use different identification methods without affecting the solution itself.

[0040] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or are inherent to these processes, methods, products or apparatuses.

[0041] In this application, terms such as "upper," "lower," "left," "right," "front," "back," "top," "bottom," "inner," "outer," "center," "vertical," "horizontal," "transverse," and "longitudinal" indicate positions or locations based on the positions or locations shown in the accompanying drawings. These terms are primarily intended to better describe this application and its embodiments and are not intended to limit the devices, elements, or components indicated to having a specific orientation, or to being constructed or operated in a specific orientation.

[0042] Furthermore, some of the above terms may be used to express other meanings besides indicating a position or location. For example, the term "on" may also be used to indicate a dependency or connection in certain circumstances. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0043] Furthermore, the terms "installed," "disposed," "provided with," "connected," "connected," and "socketed" should be interpreted broadly. For example, they can refer to fixed connections, removable connections, or integral structures; mechanical connections or electrical connections; direct connections, indirect connections through an intermediary, or internal communication between two devices, elements, or components. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0044] Those skilled in the art should understand that they can implement variations by combining the prior art with the above embodiments, which will not be described in detail here. Such variations do not affect the essence of the present invention and will not be described in detail here.

[0045] The above describes the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and the devices and structures that are not described in detail should be understood to be implemented in a common manner in the art; any technician familiar with the art can use the above-mentioned disclosed methods and technical contents to make many possible changes and modifications to the technical solutions of the present invention without departing from the scope of the technical solutions of the present invention, or modify them into equivalent embodiments of equivalent changes, which does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention that do not depart from the content of the technical solutions of the present invention are still within the scope of protection of the technical solutions of the present invention.

Claims

1. Distributed photovoltaic power supply and distribution system, characterized by: An 800 / 380V busbar transformer on the low-voltage side is installed in the box-type transformer, integrating the functions of the external switchgear and switch cabinet into the box-type transformer and leading out through the feeder switch.

2. The distributed photovoltaic power supply and distribution system according to claim 1, characterized in that: The transformer capacity is calculated based on actual considerations, including the installation space for the internal power transformer of the box-type transformer, the cross-sectional current carrying capacity of the high-voltage side busbar, and the configuration of the low-voltage side busbar switch.

3. The distributed photovoltaic power supply and distribution system according to claim 1, characterized in that: The feeder switch is configured on the low-voltage side according to the number of power consumption points and load conditions inside the box-type transformer, as well as the number of power consumption points and load conditions inside the switchgear.

4. The distributed photovoltaic power supply and distribution system according to claim 3, characterized in that: The feeder switch includes a three-phase socket, a single-phase socket, a box transformer lighting power supply, a transformer room temperature control power supply, a compartment indoor environment controller power supply, a low-voltage room air-conditioning power supply, a high-voltage room air-conditioning power supply, a primary compartment distribution box power supply, a secondary compartment distribution box power supply, a DC device power supply, several UPS power supplies and several backup switches.

5. The distributed photovoltaic power supply and distribution system according to claim 4, characterized in that: The UPS power supply includes a high-voltage circuit breaker control power supply, a low-voltage circuit breaker control power supply, a box-type transformer measurement and control device power supply, a fire device alarm power supply and a backup power supply.

6. The distributed photovoltaic power supply and distribution system according to claim 1, characterized in that: It also includes a backup power supply, which automatically switches to the backup power supply when the box transformer fails.

7. Distributed photovoltaic power supply and distribution box transformer, characterized by: It includes a high-voltage room, a transformer room, and a low-voltage room, wherein the low-voltage room includes the station distribution interval and the main incoming line interval; the high-voltage room is provided with an incoming line cabinet and an outgoing line cabinet; the transformer room is provided with a main step-up transformer in the box transformer; the low-voltage side 800 / 380V busbar transformer and feeder switch according to any one of claims 1 to 6 are provided in the station distribution interval, and the inverter unit is provided in the main incoming line interval.

8. The distributed photovoltaic power supply and distribution box transformer according to claim 7 is characterized in that: Both the high-pressure room and the low-pressure room are equipped with temperature and humidity controllers, heaters and industrial-grade air conditioners.

9. The distributed photovoltaic power supply and distribution box transformer according to claim 7 is characterized by: The high-voltage room, transformer room and low-voltage room are each equipped with one intelligent smoke detector and one fire sound and light alarm.

10. The distributed photovoltaic power supply and distribution box transformer according to claim 7, characterized in that: The box-type transformer shell is made of a single layer of cold-rolled steel plate, and the protection grade is IP54.

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