CN214850040U - Transformer substation and photovoltaic system - Google Patents

Abstract

The application provides a transformer substation and a photovoltaic system. The transformer substation comprises a first low-voltage cabinet, a second low-voltage cabinet and a third low-voltage cabinet which are sequentially arranged along a first direction, wherein the first low-voltage cabinet comprises a first side face and a second side face which are opposite, the third low-voltage cabinet comprises a third side face and a fourth side face which are opposite, the second side face comprises a first interface area and a first mounting area, the fourth side face comprises a second interface area and a second mounting area, the second low-voltage cabinet is positioned between the first mounting area and the second mounting area, the second low-voltage cabinet comprises a fifth side face, the fifth side face faces an overhaul space between the first interface area and the second interface area, at least one of the first side face to the fifth side face is provided with a plurality of switches, and the switches are at least arranged in two layers in the second direction. The first low-voltage cabinet, the second low-voltage cabinet and the third low-voltage cabinet are compact in layout, and space utilization rate of a transformer substation is improved.

Description

Transformer substation and photovoltaic system

Technical Field

The application relates to the technical field of power generation, in particular to a transformer substation and a photovoltaic system.

Background

The photovoltaic system is a novel power generation system which directly converts solar radiation energy into electric energy by utilizing the photovoltaic effect of a solar cell semiconductor material, and has the characteristics of high reliability, long service life, no environmental pollution and the like. The main components of a photovoltaic system are solar cells, storage batteries, controllers, inverters, substations and the like.

The transformer substation mainly has the function of converting low-voltage alternating current electric energy generated by the inverter into medium-voltage alternating current electric energy and feeding the electric energy into a power grid. The transformer substation comprises a low-voltage cabinet, a transformer and a medium-voltage cabinet, wherein the low-voltage cabinet is connected with an inverter and transmits low-voltage alternating current electric energy generated by the inverter to the transformer, and the transformer converts the low-voltage alternating current electric energy into medium-voltage alternating current electric energy and transmits the medium-voltage alternating current electric energy to a power grid through the medium-voltage cabinet. However, the size of the current low-voltage cabinet is large, and the layout of the low-voltage cabinets is not compact, so that under the condition that the size of the shell of the standard container box is adopted by the whole transformer substation at present, the installation space reserved for the transformer and the medium-voltage cabinet is small, the capacity of the transformer substation is limited to be increased, and the number of switch circuits of the low-voltage cabinets is also limited.

How to realize the compact arrangement of the low-voltage cabinet to improve the utilization rate of the space of the transformer substation should be the research and development direction in the industry.

SUMMERY OF THE UTILITY MODEL

The application provides a transformer substation and photovoltaic system can realize the compact of low-voltage cabinet and arrange the utilization ratio in order to promote the space of transformer substation.

In a first aspect, the application provides a transformer substation, including first low-voltage cabinet, second low-voltage cabinet and the third low-voltage cabinet that arranges in proper order along first direction, first low-voltage cabinet includes relative first side and the second side that sets up, the third low-voltage cabinet includes relative third side and the fourth side that sets up, the second side includes first interface region and first installing zone, the fourth side faces towards the second side just includes second interface region and second installing zone, the second interface region with first interface region sets up relatively, the second interface region with be equipped with maintenance space between the first interface region, the second installing zone with first installing zone sets up relatively, the second low-voltage cabinet is located between the first installing zone and the second installing zone. It is understood that the first side and the third side are disposed away from the second low-voltage cabinet, and the second side and the fourth side are disposed toward the second low-voltage cabinet. The second low-voltage cabinet comprises a fifth side surface, the fifth side surface faces the maintenance space, that is, the fifth side surface, the first interface area and the second interface area jointly enclose the maintenance space, in other words, the first low-voltage cabinet, the second low-voltage cabinet and the third low-voltage cabinet are arranged around the maintenance space. First low-voltage cabinet, second low-voltage cabinet and the third low-voltage cabinet of this application arrange in proper order and can form "concave" shape structure. At least one of the first side surface, the first interface area, the third side surface, the second interface area and the fifth side surface is provided with a plurality of switches, the plurality of switches are at least arranged in two layers in a second direction, and the second direction is perpendicular to the first direction. In other words, only one of the first side, the first interface region, the third side, the second interface region and the fifth side may be provided with a plurality of switches, or two, three, four or five of the first side, the first interface region, the third side, the second interface region and the fifth side may be provided with a plurality of switches. For example, in a specific embodiment, only the first side, the third side, and the fifth side are provided with a plurality of switches, or in another specific embodiment, the first side, the first interface region, the third side, the second interface region, and the fifth side are provided with a plurality of switches, that is, at least two layers of switches are provided on two opposite surfaces of the first low-voltage cabinet and two opposite surfaces of the third low-voltage cabinet, and at least two layers of switches are provided on the fifth side of the second low-voltage cabinet facing the service space, so that the number of overall switches of the first low-voltage cabinet, the second low-voltage cabinet, and the third low-voltage cabinet is increased.

First low-voltage cabinet, second low-voltage cabinet and the third low-voltage cabinet overall arrangement that this application set up are compact, and overall dimension is little, is favorable to improving the inside space utilization of transformer substation, also under the unchangeable condition of overall dimension of transformer substation, adopts first low-voltage cabinet, second low-voltage cabinet and the third low-voltage cabinet of this application can reserve more installation space for other equipment in the transformer substation (for example, transformer and middling pressure cabinet etc.). At least one of the first side face, the first interface area, the third side face, the second interface area and the fifth side face is provided with a plurality of switches, specifically, two opposite surfaces of the first low-voltage cabinet and two opposite surfaces of the third low-voltage cabinet can be provided with at least two layers of switches, and the fifth side face, facing the overhaul space, of the second low-voltage cabinet can also be provided with at least two layers of switches, so that the number of switch circuits on the first low-voltage cabinet, the second low-voltage cabinet and the third low-voltage cabinet in a unit volume is increased. The utility model provides a space utilization of transformer substation and the way number of effectively having increased the switch can be improved in setting up of first low-voltage cabinet, second low-voltage cabinet and third low-voltage cabinet, provides the basis for the capacity of increase transformer substation and reduce the single cost of watt.

It should be noted that the first side surface, the first interface area, the third side surface, the second interface area, and the fifth side surface of the present application are all maintenance surfaces of a substation. First low-voltage cabinet, second low-voltage cabinet and third low-voltage cabinet are installed in the casing of container appearance usually, can set up first side door on the casing corresponding to first side, can set up the second side door on the casing corresponding to the third side, can set up the end door on the casing corresponding to the maintenance space. When the first low-voltage cabinet, the second low-voltage cabinet and the third low-voltage cabinet need to be overhauled, maintained or replaced, the end door, the first side door or the second side door can be opened to carry out overhauling, maintenance or replacement through the maintenance surface. Because the maintenance face corresponds and sets up in end door, first side door or second side door, make things convenient for the customer to maintain the operation like this, and saved the inner space of casing.

Specifically, the switches on the first side surface may be two layers, three layers, four layers, and the like, and the number of switches in each layer may be five, six, seven, and the like, which is not limited in this application. In addition, the settings of the switches on the first interface area, the third side, the second interface area, and the fifth side refer to the settings of the switches on the first side, and are not described herein again.

In a possible embodiment, the interior space of the second low-voltage cabinet is in communication with the interior space of the first low-voltage cabinet, and the interior space of the second low-voltage cabinet is in communication with the interior space of the third low-voltage cabinet. The communication between the inner space of the second low-voltage cabinet and the inner spaces of the first low-voltage cabinet and the third low-voltage cabinet includes, but is not limited to, the case where no outer shell is provided at the portion of the second low-voltage cabinet in contact with the first installation area and the second installation area, that is, both ends of the second low-voltage cabinet in the first direction are open, and the inner space of the second low-voltage cabinet is directly communicated with the inner spaces of the first low-voltage cabinet and the third low-voltage cabinet; or the shell of the second low-voltage cabinet is provided with a connecting hole, the shells of the first low-voltage cabinet and the third low-voltage cabinet are also provided with connecting holes, and the inner space of the second low-voltage cabinet is communicated with the inner spaces of the first low-voltage cabinet and the third low-voltage cabinet through the connecting holes; or a connector is arranged on the shell of the second low-voltage cabinet, and the inner space of the second low-voltage cabinet is communicated with the inner space of the first low-voltage cabinet and the inner space of the third low-voltage cabinet through the connector.

In one possible embodiment, the first low-voltage cabinet is provided with a first frame circuit breaker, the first low-voltage cabinet is provided with a plurality of switches connected to the first frame circuit breaker, the third low-voltage cabinet is provided with a second frame circuit breaker, the third low-voltage cabinet is provided with a plurality of switches connected to the second frame circuit breaker, and the second low-voltage cabinet is provided with a plurality of switches connected to the first frame circuit breaker and the second frame circuit breaker. Every switch all connects the dc-to-ac converter of the same kind, the low-voltage alternating current electric energy that the dc-to-ac converter produced passes through the switch input low-voltage cabinet (be first low-voltage cabinet, second low-voltage cabinet and third low-voltage cabinet), the switch can be connected with the frame circuit breaker (be first frame circuit breaker and second frame circuit breaker) through copper bar or cable, specifically, a plurality of switches of first low-voltage cabinet all are connected with first frame circuit breaker through copper bar or cable, a plurality of switches of third low-voltage cabinet all are connected with second frame circuit breaker through copper bar or cable. One part of a plurality of switches of the second low-voltage cabinet can be connected with the first frame circuit breaker through a copper bar or a cable, the other part can be connected with the second frame circuit breaker through the copper bar or the cable, and the first frame circuit breaker and the second frame circuit breaker are used for converging and intensively transmitting low-voltage alternating current electric energy input into the low-voltage cabinet to the transformer.

In a possible embodiment, the transformer substation comprises a transformer and a low-voltage connection copper bar, one end of the low-voltage connection copper bar is located at the position of the second low-voltage cabinet and is electrically connected to the first low-voltage cabinet, the second low-voltage cabinet and the third low-voltage cabinet, and the other end of the low-voltage connection copper bar is electrically connected to the transformer. Namely, the low-voltage alternating current electric energy of the first low-voltage cabinet, the second low-voltage cabinet and the third low-voltage cabinet is transmitted to the transformer through the low-voltage connecting copper bar.

In a possible embodiment, the first frame circuit breaker and the second frame circuit breaker are both electrically connected to the low-voltage connection copper bar. The low-voltage alternating current electric energy converged by the first frame circuit breaker and the second frame circuit breaker is converged by the low-voltage connecting copper bar and is transmitted to the transformer in a centralized manner, and the low-voltage alternating current electric energy is converted into medium-voltage alternating current electric energy through the transformer.

In one possible embodiment, the distance between two adjacent switches on each layer on the first interface region is 25mm-30mm, so as to realize compact arrangement of the switches and meet the heat dissipation requirement of the switches. Specifically, the distance between two adjacent switches on each layer is 25mm-30mm, so that the switches can be compactly arranged, the size of the first low-voltage cabinet in a third direction is reduced, and the heat dissipation requirement of the switches can be met, wherein the third direction is perpendicular to the first direction and the second direction. If the distance between two adjacent switches on each layer is smaller than 25mm, the distance between two adjacent switches on each layer is too small, heat cannot be dissipated timely, and the function of the first low-voltage cabinet is affected, and if the distance between two adjacent switches on each layer is larger than 30mm, the size of the first low-voltage cabinet in the third direction is increased, and the compact arrangement of the low-voltage cabinet is not facilitated. The switch settings on the first side, the third side, the second interface area and the fifth side refer to the first interface area, and are not described herein again.

In a possible embodiment, in the second direction, the switches of two adjacent layers are arranged in a staggered manner. Every layer all includes a plurality of switches, and adjacent two-layer switch can correspond the setting, also can the dislocation set. Taking the first low-voltage cabinet as an example, a plurality of switches of the first low-voltage cabinet are all connected with the first frame circuit breaker through copper bars or cables, and when the adjacent two-layer switches are arranged in a staggered mode in the second direction, wiring (copper bars or cables) of the adjacent two-layer switches can be staggered, so that the space inside the first low-voltage cabinet can be fully utilized, and connection wiring of the plurality of switches and the first frame circuit breaker is achieved.

In a possible embodiment, the second low-voltage cabinet is in contact with the first installation area and the second low-voltage cabinet is in contact with the second installation area. The second low-voltage cabinet is located between first installing zone and the second installing zone, and specifically, the second low-voltage cabinet all contacts with first installing zone and second installing zone, does not have the clearance between second low-voltage cabinet and the first installing zone and between second low-voltage cabinet and the second installing zone and also does not set up other structure like this, also the second low-voltage cabinet closely sets up with first low-voltage cabinet and third low-voltage cabinet, can reduce the whole size in the first direction of first low-voltage cabinet, second low-voltage cabinet and third low-voltage cabinet like this.

In a possible implementation manner, the transformer substation further includes a transformer, a medium voltage cabinet and a housing, the housing includes a low voltage chamber, a transformer chamber and a medium voltage chamber, which are sequentially connected in a third direction, the first low voltage cabinet, the second low voltage cabinet and the third low voltage cabinet are installed in the low voltage chamber, the transformer is installed in the transformer chamber, the medium voltage cabinet is installed in the medium voltage chamber, and low voltage ac power output by the first low voltage cabinet, the second low voltage cabinet and the third low voltage cabinet is converted into medium voltage ac power by the transformer and transmitted to the medium voltage cabinet. The transformer boosts the voltage from a low-voltage scene (usually 800V) to a medium-voltage scene by using the principle of electromagnetic induction, and can be an oil-immersed transformer and is insulated by means of insulating oil. The medium voltage cabinet adopts CCV combination mode, and C cabinet is the wire cabinet for connect main website and converge cabinet or next transformer substation, and the V cabinet is the circuit breaker cabinet, is connected with the middling pressure survey of transformer. The V cabinet is provided with a self-powered protection device for protecting the transformer. In other embodiments, the medium-voltage cabinet can also adopt a CVC fully-insulated gas-filled cabinet. The casing can be container formula appearance for install first low-voltage cabinet, second low-voltage cabinet, third low-voltage cabinet, transformer and middling pressure cabinet, and for these internal plant provide the protection, prevent that the internal plant of transformer substation from damaging, and be convenient for transportation and installation. Illustratively, the housing may take the form of a standard marine 20-foot container.

It can be understood that, under the condition that the shell adopts the standard overall dimension, the height space of the shell can be fully utilized to increase the dimensions of the first low-voltage cabinet, the second low-voltage cabinet and the third low-voltage cabinet in the second direction, so that when the number of switches is large, enough space can be provided for the routing of the plurality of switches inside the first low-voltage cabinet, the second low-voltage cabinet and the third low-voltage cabinet. The height size of the shell is maximized, high integration on space is formed, and a foundation is provided for capacity improvement of the transformer.

In a possible embodiment, the size of the second low-voltage cabinet in the first direction is smaller than the size of the first low-voltage cabinet in the third direction, and the number of switches of the fifth side in the first direction is the same as the number of switches of the first side in the third direction. Since the housing usually adopts the external dimensions of a standard marine 20-foot container or other standard dimensions, that is, the dimensions of the low-voltage chamber in the first direction are standard, since the two opposite surfaces of the first low-voltage cabinet and the two opposite surfaces of the third low-voltage cabinet are both provided with at least two layers of switches, the first low-voltage cabinet and the third low-voltage cabinet need to have larger dimensions for internal routing, in the case of the standard dimensions of the low-voltage chamber, the space left for the second low-voltage cabinet is limited, so that the dimensions of the second low-voltage cabinet in the first direction are smaller than those of the first low-voltage cabinet in the third direction, and the number of switches of the fifth side in the first direction can still be the same as the number of switches of the first side in the third direction, so as to increase the number of the switches connected to the inverter.

In a possible embodiment, the second low-voltage cabinet is fixedly connected to the first low-voltage cabinet and the third low-voltage cabinet, the first low-voltage cabinet is provided with a first sliding block, the third low-voltage cabinet is provided with a second sliding block, a first guide rail and a second guide rail are arranged at an interval in the low-voltage chamber, the first sliding block is slidably connected to the first guide rail, and the second sliding block is slidably connected to the second guide rail. It can be understood that first low-voltage cabinet, second low-voltage cabinet and third low-voltage cabinet can be the integral type structure, and first low-voltage cabinet, second low-voltage cabinet and the third low-voltage cabinet of integral type structure can be installed to the low-pressure chamber through the mode that first slider and first guide rail cooperation and second slider and second guide rail cooperation like this detachably. Like this when first low-voltage cabinet, second low-voltage cabinet and third low-voltage cabinet take place destructive accident so need whole change, can be convenient, quick first low-voltage cabinet, second low-voltage cabinet and the third low-voltage cabinet that will damage demolish and other normal first low-voltage cabinet of function, second low-voltage cabinet and third low-voltage cabinet of slidable mounting, overhaul convenient, change time is short, avoids influencing whole photovoltaic system's power supply. The first low-voltage cabinet, the second low-voltage cabinet and the third low-voltage cabinet of integral type structure can leave the factory and integrate in advance, just need not carry out the internal connection of first low-voltage cabinet, second low-voltage cabinet and third low-voltage cabinet like this when the field installation, and the installation effectiveness is high.

In a possible embodiment, the ends of the first and second guide rails may be provided with a limiting structure to limit the positions of the first, second and third low-voltage cabinets and prevent the first, second and third low-voltage cabinets from sliding on the first and second guide rails. In addition, the top and the bottom of low-voltage chamber all can set up fixing device, accessible fixing device is fixed first low-voltage cabinet, second low-voltage cabinet and third low-voltage cabinet to the low-voltage chamber after the position through limit structure preliminary location first low-voltage cabinet, second low-voltage cabinet and third low-voltage cabinet to the stability of reinforcing transformer substation. The problem of unstable structure appears in the in-process transformer substation of preventing transportation or installation, influences photovoltaic system's performance.

In other embodiments, the first low-voltage cabinet, the second low-voltage cabinet and the third low-voltage cabinet may also be of a split structure, so that the first low-voltage cabinet, the second low-voltage cabinet and the third low-voltage cabinet are respectively connected to the low-voltage chambers in a sliding manner. Compare in the first low-voltage cabinet of integral type structure, second low-voltage cabinet and third low-voltage cabinet, split type first low-voltage cabinet, second low-voltage cabinet and third low-voltage cabinet are convenient for change alone, exemplarily, when taking place destructive accident and only damaging first low-voltage cabinet, can only follow the low-voltage chamber roll-off with first low-voltage cabinet to it can to change the first low-voltage cabinet that the function is normal, and need not change undamaged second low-voltage cabinet and third low-voltage cabinet.

In a second aspect, the present application further provides a photovoltaic system. The photovoltaic system comprises an inverter and a transformer substation according to any one of the embodiments, the transformer substation is connected with the inverter, the transformer substation is used for converting low-voltage alternating current electric energy output by the inverter into medium-voltage alternating current electric energy, and the transformer substation is used for transmitting the medium-voltage alternating current electric energy to a power grid. The inverter is a device for converting direct current electric energy into alternating current electric energy, low-voltage alternating current electric energy generated by the inverter is transmitted to a transformer substation, and the transformer substation raises rated voltage to medium voltage. And the medium-voltage alternating current electric energy generated by the transformer substation is transmitted to a power grid to supply power to users. In other embodiments, the photovoltaic system further comprises a photovoltaic module, a dc combiner box, an ac combiner box, and a power grid. The photovoltaic module is used for converting light energy into direct current electric energy to complete energy conversion; the direct current combiner box is a wiring device which can ensure the orderly connection and the convergence function of the photovoltaic modules; the alternating current confluence box is used for converging the low-voltage alternating current electric energy output by the inverter and transmitting the converged electric energy to the transformer substation in a centralized manner; the substation converts low-voltage alternating current electric energy into medium-voltage alternating current electric energy, and feeds the medium-voltage alternating current electric energy into a power grid.

Through adopting the structural layout and the switch setting of first low-voltage cabinet, second low-voltage cabinet and third low-voltage cabinet of this application, can reduce the space of low-voltage chamber in order to increase the space of transformer room, be favorable to improving the capacity of transformer, and can increase the switch way number, the quantity of switch is more, and the dc-to-ac converter of access is just more, provides the basis for the capacity of increase transformer substation and reduction single watt cost.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the embodiments of the present application will be described below.

FIG. 1 is a schematic block diagram of a photovoltaic system provided in one possible embodiment of the present application;

fig. 2 is a schematic structural diagram of a substation provided in one possible embodiment of the present application;

fig. 3 is a schematic structural diagram of a low voltage cabinet group according to one possible embodiment of the present disclosure;

fig. 4 is an isometric view of a low-voltage cabinet group provided in one possible embodiment of the present application;

fig. 5 is a side view of a low voltage cabinet group provided in one possible embodiment of the present application;

fig. 6 is a partially exploded schematic view of a low voltage cabinet group according to one possible embodiment of the present disclosure;

fig. 7 is a front view of a low voltage cabinet group provided in one possible embodiment of the present application;

FIG. 8 is a schematic diagram of a switch distribution provided in one possible embodiment of the present application;

fig. 9 is a schematic structural diagram of a low voltage cabinet group according to one possible embodiment of the present disclosure;

fig. 10 is a schematic structural diagram of a low-voltage cabinet group mounted to a low-voltage chamber according to one possible embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a photovoltaic system 10. The photovoltaic system 10 is a novel power generation system that directly converts solar radiation energy into electrical energy by using the photovoltaic effect of a solar cell semiconductor material, and can effectively alleviate the problem that the current energy resources are increasingly reduced. The photovoltaic system 10 has the advantages of reproducibility, safety, reliability, no pollution, long service life and the like, and can be widely applied to the fields of photovoltaic power stations, communication and the like. The photovoltaic system 10 includes a dc module 11, an inverter module 12, and an ac module 13. The dc module 11 mainly includes a photovoltaic module 20 and a dc combiner box 30, the inverter module 12 mainly includes an inverter 40, and the ac module 13 mainly includes an ac combiner box 50 and a substation 60.

A plurality of photovoltaic modules 20 are assembled to form a photovoltaic array, and under the condition of illumination (no matter sunlight or illumination generated by other illuminants), the photovoltaic array converts light energy into direct current electric energy under the action of a photovoltaic effect (the photovoltaic effect refers to a phenomenon that a semiconductor generates electromotive force when being irradiated by light), so as to complete energy conversion. The photovoltaic module 20 generally refers to a solar cell module, and since the output voltage of a single solar cell is low and the electrodes of the unpackaged cells are easy to fall off due to the influence of the environment, a certain number of single cells must be sealed into the photovoltaic module 20 in a series-parallel connection mode to prevent the electrodes and interconnection lines of the cells from being corroded, and in addition, the cells are prevented from being broken due to the packing, thereby facilitating the outdoor installation. The photovoltaic module 20 is generally composed of a high-efficiency crystalline silicon solar cell, super white cloth grain toughened glass, a transparent back plate and an aluminum alloy frame, and has the characteristics of long service life, strong mechanical pressure resistance and external force resistance and the like.

The dc combiner box 30 means that a user can connect a certain number of photovoltaic modules 20 with the same specification in series to form a plurality of photovoltaic arrays, and then connect the photovoltaic arrays into the dc combiner box 30, and combine the photovoltaic arrays in the dc combiner box 30 and transmit the photovoltaic arrays to the inverter 40 in a centralized manner. In other words, the dc power generated by the photovoltaic module 20 is converged by the dc combiner box 30 and inputted to the subsequent devices of the photovoltaic system 10. The dc combiner box 30 may be a dc combiner box with a tracking function, or a dc combiner box without a tracking function, and the present application is not limited thereto. The dc combiner box 30 is a wiring device in the photovoltaic system 10 that ensures the orderly connection and combining function of the photovoltaic modules 20. The dc combiner box 30 can also ensure that the photovoltaic system 10 is easy to cut off the circuit during maintenance and inspection, and reduce the power failure range when the photovoltaic system 10 fails.

The inverter 40 is a device that converts direct-current electric energy into alternating-current electric energy. The dc power transmitted to the dc combiner box 30 is continuously transmitted to the inverter 40, the dc power is converted into low-voltage ac power (the rated voltage of the low-voltage ac power output by the inverter 40 is usually 800V) by the inverter 40, and the low-voltage ac power is transmitted to the ac combiner box 50. The inverter 40 is used as an important electrical device inside the photovoltaic system 10, and various protection functions of the device are relatively complete, and specifically, the device may have protection functions such as direct current bus overvoltage protection, alternating current overvoltage and undervoltage protection, alternating current frequency protection, polarity reversal protection, short circuit protection, island effect protection, over-temperature protection, direct current overload protection, and the like.

The ac combiner box 50 is used for combining the low-voltage ac power output by the inverter 40 and transmitting the combined power to the substation 60, so as to reduce the system wiring, facilitate the system maintenance, reduce the loss, and improve the system safety and reliability. Specifically, the ac combiner box 50 is installed between the ac output side of the inverters 40 and the grid-connected point or the load, and is internally provided with an input breaker, an output breaker, an ac lightning arrester, an optional intelligent monitoring instrument (monitoring signals such as system voltage, current, power, and electric energy), and the like, and mainly combines the low-voltage ac electric energy output by the plurality of inverters 40, and simultaneously protects the inverters 40 from being damaged by the ac grid-connected side or the load, and serves as an output disconnection point of the inverters 40, thereby improving the safety of the system and protecting the safety of installation and maintenance personnel.

The main function of the substation 60 is to convert the low-voltage ac power output by the inverter 40 into medium-voltage ac power received by the grid 70. The substation 60 connects the inverter 40 and the grid 70, and specifically, the substation 60 may connect the inverter 40 through the ac combiner box 50. It can be understood that the low-voltage ac power generated by the inverter 40 can be transmitted to the substation 60 through the ac combiner box 50, that is, the low-voltage ac power combined by the ac combiner box 50 is transmitted to the substation 60 (the substation 60 may be a box-type substation, which is a device that integrates devices such as a low-voltage cabinet, a transformer, and a medium-voltage cabinet into a steel structure container, and provides highly integrated power transformation and distribution for a medium-voltage grid-connected scene of a photovoltaic ground station), and the substation 60 raises the rated voltage to a medium voltage. The medium voltage ac power generated by the substation 60 is transmitted to the grid 70 to power the user.

It should be noted that the photovoltaic system 10 provided in this embodiment is only one implementation manner of the photovoltaic system, and the photovoltaic system 10 may further include other structures, for example, the photovoltaic system 10 may further include an energy storage device (not shown in fig. 1), the direct-current electric energy generated by the photovoltaic module 20 may be transmitted to the inverter 40 and also transmitted to the energy storage device, the energy storage device is used for storing the electric energy, and the commonly used energy storage device includes a storage battery, a capacitor, and the like.

As shown in fig. 2, fig. 2 is a schematic structural diagram of the substation 60. The substation 60 includes a low-voltage cabinet group 61, a transformer 62, a medium-voltage cabinet 63, and a housing 64. The low-voltage cabinet group 61, the transformer 62 and the medium-voltage cabinet 63 are all positioned in the shell 64, and the transformer 62 is connected with the low-voltage cabinet group 61 and the high-voltage cabinet 63.

The low-voltage cabinet group 61 includes a molded case circuit breaker (i.e., a switch), a frame circuit breaker, a surge protector, an auxiliary transformer, an information acquisition device (not shown in fig. 2), and the like, and these devices are connected by a copper busbar or a cable and combined inside the cabinet body to form a low-voltage power supply system. The information acquisition device can monitor the whole transformer substation 60, so that a user can monitor the working state of the transformer substation 60 in real time to ensure the normal operation of the photovoltaic system 10. The low-voltage ac power generated by the inverter 40 and converged by the ac combiner box 50 is transmitted to the low-voltage cabinet group 61, and is collected in the low-voltage cabinet group 61 and transmitted to the transformer 62.

The transformer 62 utilizes the principle of electromagnetic induction to boost voltage from a low voltage scenario (typically 800V) to a medium voltage scenario. The transformer 62 may be an oil-immersed transformer, and is insulated by insulating oil, and heat generated in the coil and the core is transferred to the heat dissipation portion of the transformer 62 by circulation of the insulating oil inside the transformer 62 to dissipate the heat.

Transformer 62 includes transformer 621 and heat dissipation part 622, and heat dissipation part 622 installs in the relative both sides of transformer 621, and transformer 621 can be gone out through heat dissipation part 622 in the heat energy of work production, avoids transformer 621 heat energy too high, influences transformer 621's normal work. It is understood that, heat dissipation holes (not shown in fig. 2) may be disposed on a portion of the housing 64 surrounding the transformer chamber 642, so as to cooperate with the heat dissipation portion 622 to dissipate heat generated by the transformer 621 in time.

The medium voltage side of the transformer 62 is connected to the medium voltage cabinet 63, and the medium voltage side connection cable may be a fully insulated, fully shielded silicone rubber cable to ensure safe operation of the medium voltage side.

The medium-voltage cabinet 63 adopts a CCV combined mode, the C cabinet is an outgoing line cabinet and is used for connecting a main station convergence cabinet or a next transformer substation, and the V cabinet is a breaker cabinet and is connected with the medium-voltage measurement of the transformer 62. The V-cabinet is equipped with a self-powered protection device to provide protection for the transformer 62. In other embodiments, the middle cabinet 63 may also be a CVC full-insulated gas-filled cabinet.

The housing 64 may be a housing having a container-type appearance, that is, the transformer substation 60 may be a box-type transformer substation, the container-type housing 64 is used for installing the low voltage cabinet group 61, the transformer 62 and the medium voltage cabinet 63, and the housing 64 may provide protection for the low voltage cabinet group 61, the transformer 62 and the medium voltage cabinet 63, so as to prevent the internal devices of the transformer substation 60 from being damaged, and facilitate transportation and installation. Illustratively, the housing 64 may take the form of a standard marine 20-foot container.

The inner cavity of the housing 64 is sequentially divided into a low pressure chamber 641, a transformer chamber 642 and a middle pressure chamber 643 along the third direction a3, and the low pressure chamber 641, the transformer chamber 642 and the middle pressure chamber 643 are integrally arranged in a "mesh" shape. In other embodiments, the layout of the low-voltage chamber 641, the transformer chamber 642 and the middle-voltage chamber 643 may be in a zigzag shape or other arrangement. Accordingly, the low-voltage cabinet group 61 is mounted to the low-voltage compartment 641, the transformer 62 is mounted to the transformer compartment 642, and the medium-voltage cabinet 63 is mounted to the medium-voltage compartment 643. The low-voltage ac power output from the low-voltage cabinet group 61 is converted into medium-voltage ac power by the transformer 62, and transmitted to the medium-voltage cabinet 63.

The structure of the housing 64 enclosing the low pressure chamber 641 includes an end door 6411, a first side door 6412, and a second side door 6413. End door 6411 is located on the side of low-voltage cabinet group 61 facing away from transformer 62, and first side door 6412 and second side door 6413 are located on opposite sides of low-voltage cabinet group 61. When the low-pressure tank group 61 needs to be repaired, maintained or replaced, the end door 6411, the first side door 6412 and the second side door 6413 can be selectively opened according to a specific repair position so that a worker can repair, maintain or replace the low-pressure tank group 61.

As shown in fig. 2, 3 and 4, fig. 3 is a schematic structural view of low-voltage cabinet group 61, and fig. 4 is an isometric view of low-voltage cabinet group 61. The low-voltage cabinet group 61 includes a first low-voltage cabinet 611, a second low-voltage cabinet 612, and a third low-voltage cabinet 613, which are sequentially arranged along a first direction a 1. The second low-voltage cabinet 612 is connected with the first low-voltage cabinet 611 and the third low-voltage cabinet 613, and the first low-voltage cabinet 611, the second low-voltage cabinet 612 and the third low-voltage cabinet 613 together enclose a service space 614. The first low-voltage cabinet 611, the second low-voltage cabinet 612 and the third low-voltage cabinet 613 are all installed in the low-voltage chamber 641, and the low-voltage ac power output by the first low-voltage cabinet 611, the second low-voltage cabinet 612 and the third low-voltage cabinet 613 is converted into medium-voltage ac power by the transformer 62 and transmitted to the medium-voltage cabinet 63.

First low-voltage cabinet 611 includes first side 6111 and second side 6112 that are oppositely disposed along first direction a1, where first side 6111 is the surface facing away from second low-voltage cabinet 612 and second side 6112 is the surface facing toward second low-voltage cabinet 612. The second side 6112 includes a first interface region 6113 and a first mounting region 6114.

It should be noted that the first side surface 6111 and the first interface area 6113 may be both provided with a plurality of switches 615, the plurality of switches 615 of the first side surface 6111 are arranged in at least two layers in the second direction a2 (see fig. 5), and the plurality of switches 615 of the first interface area 6113 are arranged in at least two layers in the second direction a2, where the second direction a2 is perpendicular to the first direction a 1.

The third low-voltage cabinet 613 comprises a third side 6131 and a fourth side 6132 which are oppositely arranged along the first direction a1, wherein the third side 6131 is the surface facing away from the second low-voltage cabinet 612, and the fourth side 6132 is the surface facing towards the second low-voltage cabinet 612. The fourth side 6132 includes a second interface region 6133 and a second mounting region 6134 (see fig. 6). The fourth side 6132 faces the second side 6112, the second interface region 6133 is disposed opposite to the first interface region 6113, an inspection space 614 is disposed between the second interface region 6133 and the first interface region 6113, and the second mounting region 6134 is disposed opposite to the first mounting region 6114.

It should be noted that the third side 6131 and the second interface region 6133 may both have a plurality of switches 615, the plurality of switches 615 of the third side 6131 are arranged in at least two layers in the second direction a2, and the plurality of switches 615 of the second interface region 6133 are arranged in at least two layers in the second direction a 2.

The second low-voltage cabinet 612 comprises a fifth side 6121 and a sixth side 6122 which are oppositely arranged along the third direction a3, wherein the fifth side 6121 is the surface facing the service space 614, and the sixth side 6122 is the surface facing the transformer 62. The second low-voltage cabinet 612 is located between the first mounting zone 6114 and the second mounting zone 6134. Specifically, second low-voltage cabinet 612 contacts first installation area 6114, and second low-voltage cabinet 612 contacts second installation area 6134, so that there is no gap or other structural members between second low-voltage cabinet 612 and first installation area 6114 and between second low-voltage cabinet 612 and second installation area 6134, that is, second low-voltage cabinet 612 is closely arranged with first low-voltage cabinet 611 and third low-voltage cabinet 613, so that the size of first low-voltage cabinet 611, second low-voltage cabinet 612 and third low-voltage cabinet 613 in first direction a1 can be reduced.

It should be noted that the fifth side 6121 may be provided with a plurality of switches 615 (see fig. 7), and the plurality of switches 615 of the fifth side 6121 are arranged in at least two layers in the second direction a 2.

It is understood that at least one of the first side 6111, the first interface region 6113, the third side 6131, the second interface region 6133, and the fifth side 6121 is provided with a plurality of switches, in other words, only one of the first side 6111, the first interface region 6113, the third side 6131, the second interface region 6133, and the fifth side 6121 may be provided with a plurality of switches 615, or two, three, four, or five of the first side 6111, the first interface region 6113, the third side 6131, the second interface region 6133, and the fifth side 6121 may be provided with a plurality of switches 615. Illustratively, in a specific embodiment, only the first side 6111, the third side 6131, and the fifth side 6121 are provided with the plurality of switches 615, or in another specific embodiment, the first side 6111, the first interface region 6113, the third side 6131, the second interface region 6133, and the fifth side 6121 are provided with the plurality of switches 615, which is described in the embodiment of the present application by taking as an example that the first side 6111, the first interface region 6113, the third side 6131, the second interface region 6133, and the fifth side 6121 are provided with the plurality of switches 615.

The first, second and third low- voltage cabinets 611, 612 and 613 of the present application may be surrounded to form a "concave" structure. First low-voltage cabinet 611, second low-voltage cabinet 612 and third low-voltage cabinet 613 that this application set up overall arrangement is compact, and overall size is little, is favorable to improving the inside space utilization of transformer substation 60, also under the unchangeable condition of overall size of transformer substation 60, adopts first low-voltage cabinet 611, second low-voltage cabinet 612 and third low-voltage cabinet 613 of this application can reserve more installation space for other equipment in transformer substation 60 (for example, transformer 62 and well voltage cabinet 63 etc.). At least one of the first side surface 6111, the first interface area 6113, the third side surface 6131, the second interface area 6133, and the fifth side surface 6121 is provided with a plurality of switches, specifically, at least two layers of switches 615 are respectively arranged on two opposite surfaces of the first low-voltage cabinet 611 and two opposite surfaces of the third low-voltage cabinet 613, and at least two layers of switches are also arranged on the fifth side surface 6121 of the second low-voltage cabinet 612 facing the service space 614, so that the number of switch circuits on the first low-voltage cabinet 611, the second low-voltage cabinet 612, and the third low-voltage cabinet 613 in a unit volume is increased. The arrangement of the first low-voltage cabinet 611, the second low-voltage cabinet 612 and the third low-voltage cabinet 613 can improve the space utilization rate of the transformer substation 60 and effectively increase the number of the switches 615, and a foundation is provided for increasing the capacity of the transformer substation 60 and reducing the cost of a single watt.

As shown in fig. 5 and 8, fig. 8 is a schematic structural diagram of the distribution of the switches 615. In the second direction a2, the switches 615 of two adjacent layers may be disposed correspondingly or offset. Taking the distribution of the switches 615 on the first side 6111 of the first low-voltage cabinet 611 as an example, the switches 615 on the first side 6111 are distributed in two layers along the second direction a2, and each layer includes a plurality of switches 615 spaced along the A3 direction.

Referring to fig. 5, the switches 615 of two adjacent layers may be correspondingly arranged, specifically, the first layer includes six switches 615 arranged at intervals along the third direction A3, the second layer includes six switches 615 arranged at intervals along the third direction A3, and the six switches 615 of the first layer and the six switches 615 of the second layer are arranged in one-to-one correspondence in the second direction a 2.

Referring to fig. 8, the switches 615 of two adjacent layers may be arranged in a staggered manner, specifically, the first layer includes six switches 615 arranged at intervals along the third direction A3, the second layer includes six switches 615 arranged at intervals along the third direction A3, and the six switches 615 of the first layer are arranged in a staggered manner with the six switches 615 of the second layer in the second direction a2, that is, the six switches 615 of the first layer and the six switches 615 of the second layer do not completely correspond to each other in the second direction a 2. The switches 615 on the first side surface 6111 are connected to the first frame circuit breaker 6115 (see fig. 9) inside the first low-voltage board 611 through copper bars or cables, and when the switches 615 on two adjacent layers are arranged in a staggered manner in the second direction a2, the wiring (copper bars or cables) of the switches on two adjacent layers can be staggered, so that the space inside the first low-voltage board 611 can be fully utilized, and the connection wiring between the switches 615 and the first frame circuit breaker 6115 is realized.

It should be noted that fig. 5 and fig. 8 only schematically show that the switches 615 on the first side 6111 are two layers, and the number of the switches 615 on each layer is six, in other embodiments, the switches 615 on the first side 6111 may also be three layers, four layers, and the like, and the number of the switches on each layer may also be five, seven, and the like, which is not limited in the present application. In addition, the settings of the switch 615 on the first interface area 6113, the third side 6131, the second interface area 6133, and the fifth side 6121 refer to the settings of the switch 615 on the first side 611, which is not described herein again.

Referring to fig. 4, taking the first interface zone 6113 as an example, the distance between two adjacent switches 615 on each layer of the first interface zone 6113 is 25mm to 30 mm. The distance between two adjacent switches 615 in each layer is 25mm-30mm, so that the switches 615 can be compactly arranged, the size of the first low-voltage cabinet 611 in the third direction a3 can be reduced, and the heat dissipation requirement of the switches 615 can be met. If the distance between two adjacent switches 615 on each floor is less than 25mm, the distance between two adjacent switches 615 on each floor is too small, heat cannot be dissipated in time, and the function of the first low-voltage cabinet 611 is affected, and if the distance between two adjacent switches 615 on each floor is greater than 30mm, the size of the first low-voltage cabinet 611 in the third direction a3 is increased, which is not favorable for compact arrangement of the low-voltage cabinet group 61. Referring to the arrangement of the switches 615 on the first side 6111, the third side 6131, the second interface region 6133, and the fifth side 6121, exemplarily, each layer on the first side 6111 is provided with 6 switches 615, the 6 switches 615 are divided into two groups of three switches 615, and a distance between two adjacent switches 615 in the same group is 25mm to 30 mm.

It is understood that, in the case of the standard external dimensions of the housing 64, the height space of the housing 64 can be fully utilized to increase the dimensions of the first, second and third low- voltage cabinets 611, 612 and 613 in the second direction a2, so that when the number of the switches 615 is large, enough space can be provided for the routing of the plurality of switches 615 inside the first, second and third low- voltage cabinets 611, 612 and 613. That is, the height dimension of the housing 64 is maximized to form a high integration in space, which provides a basis for the capacity increase of the transformer 62.

In a specific embodiment, the size of the second low-voltage cabinet 612 in the first direction a1 is smaller than the size of the first low-voltage cabinet a1 in the third direction A3, and the number of switches 615 on the fifth side 6121 in the first direction a1 is the same as the number of switches 615 on the first side 6111 in the third direction A3. Specifically, taking the substation shown in fig. 4 as an example, the size of the second low-voltage cabinet 612 in the first direction a1 is smaller than the size of the first low-voltage cabinet a1 in the third direction A3, the number of switches 615 of the fifth side 6121 in the first direction a1 is six, and the number of switches 615 of the first side 6111 in the third direction A3 is also six, it should be noted that the number of switches 615 of each floor may also be five, seven, and so on, as long as the number of switches 615 of the fifth side 6121 in the first direction a1 is the same as the number of switches 615 of the first side 6111 in the third direction A3. Since housing 64 is generally sized for a standard marine 20-size container or other standard size, in other words, the size of low-voltage compartment 641 in first direction a1 is standard, that is, the size of low-voltage compartment 641 in first direction a1 is fixed, since switches 615 on first low-voltage cabinet 611 and third low-voltage cabinet 613 are both double-sided and double-layered, so that first low-voltage cabinet 611 and third low-voltage cabinet 613 need to have larger size for internal routing, in the case of the standard size of low-voltage compartment 641, the space left for second low-voltage cabinet 612 is limited, so that the size of second low-voltage cabinet 612 in first direction a1 is smaller than the size of first low-voltage cabinet 611 in third direction A3, and the number of switches 615 on fifth side 6121 in first direction a1 can still be the same as the number of switches 611 on first side A3, so as to increase the size of first low-voltage cabinet 611, and increase the size of first low-voltage cabinet, The number of switches 615 in the second and third low-voltage cabinets 612 and 613 is increased, and the number of switches connected to the inverter 40 is increased.

The second low-voltage cabinet 612 connects the first low-voltage cabinet 611 and the third low-voltage cabinet 613 such that the inner space of the second low-voltage cabinet 612 communicates with the inner space of the first low-voltage cabinet 611 and the inner space of the second low-voltage cabinet 612 communicates with the inner space of the third low-voltage cabinet 613. It is understood that the communication between the inner space of the second low-voltage cabinet 612 and the inner space of the first low-voltage cabinet 611 and the communication between the inner space of the second low-voltage cabinet 612 and the inner space of the third low-voltage cabinet 613 include, but are not limited to, the following three cases: the contact part of the second low-voltage cabinet 612 with the first installation area 6114 and the second installation area 6134 is not provided with an outer shell, that is, two ends of the second low-voltage cabinet 612 in the first direction a1 are open, and the inner space of the second low-voltage cabinet 612 is directly communicated with the inner space of the first low-voltage cabinet 611 and the inner space of the third low-voltage cabinet 613; alternatively, a connecting hole (not shown) is formed in an outer shell of the second low-voltage cabinet 612, connecting holes are also formed in outer shells of the first low-voltage cabinet 611 and the third low-voltage cabinet 613, and an inner space of the second low-voltage cabinet 612 is communicated with inner spaces of the first low-voltage cabinet 611 and the third low-voltage cabinet 612 through the connecting hole, or a connector (not shown) is formed in an outer shell of the second low-voltage cabinet 612, and an inner space of the second low-voltage cabinet 612 is communicated with inner spaces of the first low-voltage cabinet 611 and the third low-voltage cabinet 613 through the connector.

As shown in fig. 9, fig. 9 is a schematic structural diagram of the low-voltage cabinet group 61. A first frame circuit breaker 6115 is arranged inside the first low-voltage cabinet 611 (the first frame circuit breaker 6115 is shown by a dashed line frame in fig. 9, which only schematically illustrates that the first frame circuit breaker 6115 is arranged inside the first low-voltage cabinet 611), a second frame circuit breaker 6135 is arranged inside the third low-voltage cabinet 613 (the second frame circuit breaker 6135 is shown by a dashed line frame in fig. 9, which only schematically represents that the second frame circuit breaker 6135 is arranged inside the third low-voltage cabinet 613), and a low-voltage connecting copper bar 6123 is arranged at the top of the second low-voltage cabinet 612. The plurality of switches 615 of the first low voltage cabinet 611 are connected to a first frame breaker 6115 and the plurality of switches 615 of the third low voltage cabinet 613 are connected to a second frame breaker 6135. The plurality of switches 615 of the second low-voltage cabinet 612 are connected to the first frame breaker 6115 and the second frame breaker 6135, for example, the layer of switches 615 of the second low-voltage cabinet 612 near the top can be connected to the first frame breaker 6115, and the layer of switches 615 of the second low-voltage cabinet 612 near the bottom can be connected to the second frame breaker 6135, that is, a part of the low-voltage ac power input to the second low-voltage cabinet 612 is transmitted to the first frame breaker 6115 for confluence, and another part of the low-voltage ac power input to the second low-voltage cabinet 612 is transmitted to the second frame breaker 6135 for confluence, and is transmitted to the transformer 62 in a centralized manner.

The switches 615 may be connected to the frame breakers (the first frame breaker 6115 and the second frame breaker 6135) through a copper bar or a cable, specifically, the switches 615 of the first low-voltage cabinet 611 are all connected to the first frame breaker 6115 through a copper bar or a cable, and the switches 615 of the third low-voltage cabinet 613 are all connected to the second frame breaker 6135 through a copper bar or a cable. The plurality of switches 615 of the second low-voltage cabinet 612 may also be connected to the first frame circuit breaker 6115 and the second frame circuit breaker 6135 through copper bars or cables. The first frame breaker 6115 and the second frame breaker 6135 are used for converging and intensively transmitting the low-voltage alternating-current electric energy input into the first low-voltage cabinet 611, the second low-voltage cabinet 612 and the third low-voltage cabinet 613 to the transformer 62.

It should be noted that each switch 615 is connected to one inverter 40, that is, the low-voltage ac power generated by the inverter 40 is input to the low-voltage cabinet group 61 through the switch 615. The greater the number of switches 615, the more inverters 40 that are connected, which is beneficial for reducing the single watt cost of the photovoltaic system 10.

One end of the low-voltage connecting copper bar 6123 is located at the position of the second low-voltage cabinet 612 and is electrically connected to the first low-voltage cabinet 611, the second low-voltage cabinet 612 and the third low-voltage cabinet 613, and the other end of the low-voltage connecting copper bar 6123 is electrically connected to the transformer 62, that is, the low-voltage ac power of the low-voltage cabinet group 61 is transmitted to the transformer 62 through the low-voltage connecting copper bar 6132. Specifically, the first frame circuit breaker 6115 of the first low-voltage cabinet 611 is electrically connected to the low-voltage connection copper bar 6123, the second frame circuit breaker 6135 of the second low-voltage cabinet 612 is electrically connected to the low-voltage connection copper bar 6123, and the second low-voltage cabinet 612 is electrically connected to the low-voltage connection copper bar 6123 through the first frame circuit breaker 6115 and the second frame circuit breaker 6135. The low-voltage ac power converged by the first frame circuit breaker 6115 and the second frame circuit breaker 6135 is converged and intensively transmitted to the transformer 62 by the low-voltage connecting copper bar 6123, and is converted into the medium-voltage ac power by the transformer 62.

In other embodiments, the plurality of switches 615 on the second low-voltage cabinet 612 may be electrically connected to the first frame breaker 6115, or the plurality of switches 615 on the second low-voltage cabinet 612 may be electrically connected to the second frame breaker 6135, that is, the plurality of switches 615 of the second low-voltage cabinet 612 may be electrically connected to only the first low-voltage cabinet 611 or only the third low-voltage cabinet 613.

The first low-voltage cabinet 611, the second low-voltage cabinet 612 and the third low-voltage cabinet 613 may be an integrated structure or a split structure. The first low-voltage cabinet 611, the second low-voltage cabinet 612 and the third low-voltage cabinet 613 which are of the integrated structure can be pre-integrated when leaving a factory, so that the wiring problem during field installation is avoided, and the installation efficiency is high. The split first low-voltage cabinet 611, the second low-voltage cabinet 612 and the third low-voltage cabinet 613 are convenient to overhaul and replace, and replacement cost is saved.

Referring to fig. 10, fig. 10 is a schematic structural view illustrating the mounting of the low-pressure cabinet group 61 to the low-pressure chamber 641. The second low-voltage cabinet 621 fixedly connects the first low-voltage cabinet 611 and the third low-voltage cabinet 613 to form an integrated structure. First, second, and third low- voltage cabinets 611, 612, and 613 of an integrated structure may be slidably connected to low-voltage chamber 641. Specifically, a first slider 6116 is disposed at the bottom of first low-pressure cabinet 611, a second slider 6136 is disposed at the bottom of third low-pressure cabinet 613, a first guide rail 6414 and a second guide rail 6415 are disposed at intervals at the bottom of low-pressure chamber 641 (it should be noted that fig. 10 only schematically illustrates the bottom structure of low-pressure chamber 641), first slider 616 is slidably connected to first guide rail 6414, and second slider 6136 is slidably connected to second guide rail 6415. In other words, first, second, and third low- pressure cabinets 611, 612, and 613 of an integrated structure may be detachably mounted to low-pressure chamber 641 by means of first slider 6116 engaging with first rail 6414 and second slider 6136 engaging with second rail 6415. Like this when first low-voltage cabinet 611, second low-voltage cabinet 612 and third low-voltage cabinet 613 take place destructive accident so need change, can be convenient, quick first low-voltage cabinet 611, second low-voltage cabinet 612 and the third low-voltage cabinet 613 that will damage demolish and slidable mounting other normal first low-voltage cabinet 611, second low-voltage cabinet 612 and third low-voltage cabinet 613 of function, overhaul convenience, change time weak point and efficient, avoid influencing the power supply of whole photovoltaic system 10.

The first low-voltage cabinet 611, the second low-voltage cabinet 12 and the third low-voltage cabinet 613 which are of the integrated structure can be pre-integrated in the factory, that is, the first low-voltage cabinet 611, the second low-voltage cabinet 612 and the third low-voltage cabinet 613 are already connected in the manufacturing process, so that the internal connection of the first low-voltage cabinet 611, the second low-voltage cabinet 12 and the third low-voltage cabinet 613 is not needed during field installation, the installation efficiency is high, and the construction period and the user investment are saved.

The ends of first rail 6414 and second rail 6415 may be provided with a limiting structure (not shown in fig. 10) to define the positions of first low-voltage cabinet 611, second low-voltage cabinet 612, and third low-voltage cabinet 613, preventing first low-voltage cabinet 611, second low-voltage cabinet 612, and third low-voltage cabinet 613 from sliding on first rail 6414 and second rail 6415.

The top and bottom of low-voltage chamber 641 may be provided with fixing devices (not shown in fig. 10), and after the positions of first low-voltage cabinet 611, second low-voltage cabinet 612 and third low-voltage cabinet 613 are preliminarily located by the limiting structure, first low-voltage cabinet 611, second low-voltage cabinet 612 and third low-voltage cabinet 613 may be fixed to low-voltage chamber 641 by the fixing devices, so as to enhance the stability of substation 60. The problem that the transformer station 60 is unstable in structure in the process of transportation or installation and influences the performance of the photovoltaic system 10 is solved.

In other embodiments, when the first low-voltage cabinet 611, the second low-voltage cabinet 612 and the third low-voltage cabinet 613 are of a split structure, the first low-voltage cabinet 611, the second low-voltage cabinet 612 and the third low-voltage cabinet 613 are respectively slidably connected to the low-voltage chamber 641. Compared with the first low-voltage cabinet 611, the second low-voltage cabinet 612 and the third low-voltage cabinet 613 which are of an integrated structure, the first low-voltage cabinet 611, the second low-voltage cabinet 612 and the third low-voltage cabinet 613 which are of a split structure are convenient to replace independently, for example, when a destructive accident only damages the first low-voltage cabinet 611, only the first low-voltage cabinet 611 can be slid out from the low-voltage chamber 641, and the first low-voltage cabinet 611 with a normal function can be replaced without replacing the second low-voltage cabinet 612 and the third low-voltage cabinet 613 which are not damaged, so that the equipment cost of the transformer substation 60 is saved.

Referring to fig. 2 and 10 in combination, when first low-voltage cabinet 611 needs to be serviced, first side door 6412 may be opened, and a worker services first low-voltage cabinet 611 through first side 6111. When the third low-voltage cabinet 613 needs to be serviced, the second side door 6413 can be opened, and a worker performs the servicing on the third low-voltage cabinet 613 through the third side 6131. Alternatively, the end door 6411 may be opened, and a worker enters the service space 614 to perform service on the first low-voltage cabinet 611, the second low-voltage cabinet 612, and the third low-voltage cabinet 613. In other words, the first side 6111 and the second side 6112 of the first low-pressure tank 611 may be subjected to double-sided maintenance by the first side door 6412 and the end door 6411, and the third side 6131 and the fourth side 6132 of the third low-pressure tank 613 may be subjected to double-sided maintenance by the second side door 6413 and the end door 6411. The switches 615 are all arranged on the maintenance surface (the maintenance surface includes a first side 6111, a second side 6112, a third side 6131, a fourth side 6132 and a fifth side 6121), so that the convenience of operation and maintenance of a customer is guaranteed, and the space of the shell 64 is saved.

By adopting the structural layout and the switch arrangement of the first low-voltage cabinet 611, the second low-voltage cabinet 612 and the third low-voltage cabinet 613, the space of the low-voltage chamber 641 can be reduced to increase the space of the transformer chamber 642, which is beneficial to improving the capacity of the transformer 62 and increasing the number of switch circuits. In a specific embodiment, the size of the low-voltage chamber 641 of the first low-voltage cabinet 611, the second low-voltage cabinet 612 and the third low-voltage cabinet 613 applied in the present application in the third direction A3 is substantially the same as the size of the medium-voltage chamber 643 in the third direction A3, that is, the low-voltage chamber 641 and the medium-voltage chamber 643 may be symmetrically arranged at both sides of the transformer chamber 642. In other embodiments, the size of low-pressure chamber 641 in third direction A3 may be smaller than that of middle-pressure chamber 643 in third direction A3 by optimizing the structures of first low-pressure cabinet 611, second low-pressure cabinet 612 and third low-pressure cabinet 613.

First low-voltage cabinet 611, second low-voltage cabinet 612 and third low-voltage cabinet 613 that this application set up overall arrangement is compact, and overall size is little, is favorable to improving the inside space utilization of transformer substation 60, also under the unchangeable condition of overall size of transformer substation 60, adopts first low-voltage cabinet 611, second low-voltage cabinet 612 and third low-voltage cabinet 613 of this application can reserve more installation space for other equipment in transformer substation 60 (for example, transformer 62 and well voltage cabinet 63 etc.). At least one of the first side surface 6111, the first interface area 6113, the third side surface 6131, the second interface area 6133, and the fifth side surface 6121 is provided with a plurality of switches, specifically, at least two layers of switches 615 are respectively arranged on two opposite surfaces of the first low-voltage cabinet 611 and two opposite surfaces of the third low-voltage cabinet 613, and at least two layers of switches are also arranged on the fifth side surface 6121 of the second low-voltage cabinet 612 facing the service space 614, so that the number of switch circuits on the first low-voltage cabinet 611, the second low-voltage cabinet 612, and the third low-voltage cabinet 613 in a unit volume is increased. The arrangement of the first low-voltage cabinet 611, the second low-voltage cabinet 612 and the third low-voltage cabinet 613 can improve the space utilization rate of the transformer substation 60 and effectively increase the number of the switches 615, and a foundation is provided for increasing the capacity of the transformer substation 60 and reducing the cost of a single watt.

The foregoing is a preferred embodiment of the present application, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present application, and these modifications and decorations are also regarded as the protection scope of the present application.

Claims (12)

1. A transformer substation is characterized by comprising a first low-voltage cabinet, a second low-voltage cabinet and a third low-voltage cabinet which are sequentially arranged along a first direction, wherein the first low-voltage cabinet comprises a first side surface and a second side surface which are oppositely arranged, the third low-voltage cabinet comprises a third side surface and a fourth side surface which are oppositely arranged, the second side surface comprises a first interface area and a first installation area, the fourth side surface faces the second side surface and comprises a second interface area and a second installation area, the second interface area is oppositely arranged with the first interface area, an overhaul space is arranged between the second interface area and the first interface area, the second installation area is oppositely arranged with the first installation area, the second low-voltage cabinet is positioned between the first installation area and the second installation area, the second low-voltage cabinet comprises a fifth side surface, and the fifth side surface faces the overhaul space, at least one of the first side surface, the first interface area, the third side surface, the second interface area and the fifth side surface is provided with a plurality of switches, the plurality of switches are at least arranged in two layers in a second direction, and the second direction is perpendicular to the first direction.

2. The substation of claim 1, wherein the interior space of the second low-voltage cabinet communicates with the interior space of the first low-voltage cabinet, and the interior space of the second low-voltage cabinet communicates with the interior space of the third low-voltage cabinet.

3. The substation according to claim 2, characterized in that the first low-voltage cabinet is provided with a first frame circuit breaker, a plurality of the switches of the first low-voltage cabinet are connected with the first frame circuit breaker, the third low-voltage cabinet is provided with a second frame circuit breaker, a plurality of the switches of the third low-voltage cabinet are connected with the second frame circuit breaker, and a plurality of the switches of the second low-voltage cabinet are connected with the first frame circuit breaker and the second frame circuit breaker.

4. The substation according to claim 3, characterized in that the substation comprises a transformer and a low-voltage connection copper bar, one end of the low-voltage connection copper bar is located at the position of the second low-voltage cabinet and is electrically connected to the first, second and third low-voltage cabinets, and the other end of the low-voltage connection copper bar is electrically connected to the transformer.

5. The substation of claim 4, wherein the first frame circuit breaker and the second frame circuit breaker are both electrically connected to the low voltage connection copper bar.

6. A substation according to claim 1, wherein the spacing between two adjacent switches on each level on the first interface zone is 25mm-30mm to achieve a compact arrangement of the switches and to meet the heat dissipation requirements of the switches.

7. A substation according to claim 1, wherein in the second direction the switches of two adjacent levels are misaligned.

8. The substation of claim 1, wherein the second low voltage cabinet is in contact with the first mounting area and the second low voltage cabinet is in contact with the second mounting area.

9. The substation according to claim 1, characterized in that the substation further comprises a transformer, a medium voltage cabinet and a housing, the housing comprises a low voltage chamber, a transformer chamber and a medium voltage chamber which are connected in sequence along a third direction, the first, second and third low voltage cabinets are mounted in the low voltage chamber, the transformer is mounted in the transformer chamber, the medium voltage cabinet is mounted in the medium voltage chamber, and low voltage alternating current electric energy output by the first, second and third low voltage cabinets is converted into medium voltage alternating current electric energy by the transformer and transmitted to the medium voltage cabinet.

10. A substation according to claim 9, wherein the second low-voltage cabinet has a smaller dimension in the first direction than the first low-voltage cabinet, and the number of switches of the fifth side in the first direction is the same as the number of switches of the first side in the third direction.

11. The substation according to claim 1, wherein the second low-voltage cabinet is fixedly connected with the first low-voltage cabinet and the third low-voltage cabinet, the first low-voltage cabinet is provided with a first sliding block, the third low-voltage cabinet is provided with a second sliding block, a first guide rail and a second guide rail are arranged in the low-voltage chamber at intervals, the first sliding block is slidably connected with the first guide rail, and the second sliding block is slidably connected with the second guide rail.

12. A photovoltaic system comprising an inverter and a substation according to any of claims 1 to 11, the substation being connected to the inverter and configured to convert low-voltage ac power output by the inverter into medium-voltage ac power.

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