Distributed photovoltaic box transformer substation

Abstract

The utility model discloses a distributed photovoltaic box transformer substation, which comprises a high-voltage chamber, a low-voltage chamber and a transformer chamber which are arranged in a delta shape, a transformer is arranged in the transformer chamber, a combined vacuum circuit breaker, a metering current transformer, a confluence cable and an outgoing cable are arranged in the high-voltage chamber, the combined vacuum circuit breaker is connected with the confluence cable, and the metering current transformer is connected with the outgoing cable. An SVG high-voltage chamber is further arranged on the side, away from the transformer chamber, of the high-voltage chamber, an SVG vacuum circuit breaker and an SVG incoming cable are arranged in the SVG high-voltage chamber, and the SVG vacuum circuit breaker is communicated with a reactive power compensation device outside the SVG high-voltage chamber through the SVG incoming cable. According to the invention, reactive power is compensated through the reactive power compensation device, so that the power factor of the system is maintained within a reasonable range. The invalid power in the power grid is reduced, and the efficiency of the power grid is improved. Meanwhile, the voltage of the power grid can be adjusted and kept at a stable level, the voltage fluctuation of the power grid can be reduced, and the stability of the power grid is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of power transformation, in particular to a distributed photovoltaic box transformer. Background Art

[0002] There are two types of photovoltaic application markets: centralized and distributed. In terms of share, my country's photovoltaic power stations are mainly large-scale centralized. According to data, in 2020, large-scale centralized power stations accounted for 67.8%, and distributed power stations accounted for 32.2%. With the integrated development of photovoltaics in the fields of construction, transportation, etc., and the scale of household applications, distributed photovoltaics will accelerate development. It is expected that the proportion of distributed photovoltaic power stations will also increase in the future and become the mainstream of future development.

[0003] Existing distributed photovoltaics will generate a large amount of reactive power, resulting in a decrease in the power factor of the system. Low power factor will increase the ineffective power in the power grid and reduce the efficiency of the power grid. At the same time, voltage fluctuations will occur under low load, which will affect the stability of the power grid, making the power grid unstable and possibly causing equipment damage or abnormal operation. Utility Model Content

[0004] The main purpose of the utility model is to provide a distributed photovoltaic box transformer, aiming to solve the problem that the existing distributed box transformers generate a large amount of reactive power, resulting in reduced grid efficiency and insufficient grid stability.

[0005] To achieve the above-mentioned purpose, the utility model provides a distributed photovoltaic box transformer, comprising a high-voltage chamber, a low-voltage chamber and a transformer chamber arranged in a herringbone shape, wherein the high-voltage chamber and the low-voltage chamber are adjacently arranged and located on the same side of the transformer chamber, a transformer is arranged in the transformer chamber, a combined vacuum circuit breaker, a metering current transformer, a bus cable and an outgoing cable are arranged in the high-voltage chamber, the combined vacuum circuit breaker is connected to the bus cable, one end of the bus cable is connected to an external booster station, and the other end is connected to the outgoing cable through the metering current transformer, an SVG high-voltage chamber is also arranged on the side of the high-voltage chamber away from the transformer chamber, an SVG vacuum circuit breaker and an SVG incoming cable are arranged in the SVG high-voltage chamber, the SVG vacuum circuit breaker is connected to the reactive compensation device outside the SVG high-voltage chamber through the SVG incoming cable, and the SVG vacuum circuit breaker is connected to the metering current transformer.

[0006] Preferably, a low-voltage cabinet is provided in the low-voltage room, and the low-voltage cabinet includes a low-voltage frame circuit breaker, a surge, a UPS power supply, a plastic case and an auxiliary transformer. The UPS power supply supplies power to the secondary components in the distributed photovoltaic box transformer, and the low-voltage side of the transformer is connected to the low-voltage frame circuit breaker through a copper busbar.

[0007] Preferably, the combined vacuum circuit breaker comprises a first high-voltage current transformer, a first high-voltage lightning arrester, a first vacuum circuit breaker, a first isolating switch and a first grounding switch, and the first vacuum circuit breaker is connected to the high-voltage terminal of the transformer through a copper braided belt.

[0008] Preferably, the SVG vacuum circuit breaker comprises a second high-voltage current transformer, a second high-voltage lightning arrester, a second vacuum circuit breaker, a second isolating switch and a second grounding switch, and a zero-sequence current transformer is provided on the incoming side of the SVG incoming cable.

[0009] Preferably, a cable chamber is further provided on the side of the high-voltage chamber facing the SVG high-voltage chamber, the bus cable and the outgoing cable are both located in the cable chamber, and the combined vacuum circuit breaker is connected to the bus cable via an insulating terminal.

[0010] Preferably, a high-voltage PT is connected between the insulating terminal and the combined vacuum circuit breaker via a TMY, and a fuse is provided on the TMY.

[0011] Preferably, the high-voltage chamber is isolated from the SVG high-voltage chamber by a steel plate, a wall bushing is provided on the steel plate, and the SVG vacuum circuit breaker is connected to the bus cable via a TMY penetrating the wall bushing.

[0012] Preferably, the transformer is an oil-immersed transformer, and the transformer plates are exposed on the outside of the distributed photovoltaic box transformer.

[0013] Preferably, the top wall of the high-pressure chamber, the top wall of the SVG high-pressure chamber and the top wall of the low-pressure chamber are all arranged in a pitched roof structure with an inclination angle of 4° to 6°.

[0014] Preferably, both the high-voltage chamber and the SVG high-voltage chamber are provided with electromagnetic doors.

[0015] In the technical solution of the utility model, by setting an SVG high-voltage chamber on one side of the high-voltage chamber, the SVG vacuum circuit breaker is connected to the reactive power compensation device outside the SVG high-voltage chamber through the SVG incoming cable. The reactive power compensation device can compensate for reactive power by controlling capacitance or inductance to maintain the power factor of the system within a reasonable range. This helps to reduce the reactive power in the power grid and improve the efficiency of the power grid. At the same time, the voltage of the power grid can be adjusted to keep it at a stable level, which can reduce the voltage fluctuation of the power grid and improve the stability of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0017] Figure 1 This is a schematic cross-sectional structural diagram of a distributed photovoltaic box transformer according to an embodiment of the utility model;

[0018] Figure 2 This is a schematic diagram of a top view of a distributed photovoltaic box transformer according to an embodiment of the utility model;

[0019] Figure 3 It is a schematic diagram of the side structure of a distributed photovoltaic box transformer according to an embodiment of the utility model.

[0020] Description of Figure Numbers:

[0021] Label name Label name 1 Distributed photovoltaic box-type transformer 20 Low pressure room 10 High Pressure Chamber 21 Auxiliary transformer 11 Combined vacuum circuit breaker 22 Low voltage cabinet 12 Metering current transformer 30 Transformer room 13 Bus cable 31 transformer 14 Outgoing cable 32 pieces scattered 15 Cable room 40 SVG High Voltage Chamber 16 High Voltage PT 41 SVG vacuum circuit breaker 17 Fuse 42 SVG incoming cable 18 Wall bushing 50 Top wall

[0022] The purpose, features and advantages of the present invention will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in this embodiment to clearly and completely describe the technical solution in this embodiment. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0024] It should be noted that all directional indications in this embodiment (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0025] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0026] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In addition, the technical solutions of the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention. It should be understood that the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0028] The utility model provides a distributed photovoltaic box transformer 1.

[0029] Please combine Figure 1 and Figure 2 The distributed photovoltaic box transformer 1 of this embodiment includes a high-voltage chamber 10, a low-voltage chamber 20 and a transformer chamber 30 arranged in a herringbone shape. The high-voltage chamber 10 and the low-voltage chamber 20 are adjacent to each other and are located on the same side of the transformer chamber 30. A transformer 31 is arranged in the transformer chamber 30. A combined vacuum circuit breaker 11, a metering current transformer 12, a bus cable 13 and an outgoing cable 14 are arranged in the high-voltage chamber 10. The combined vacuum circuit breaker 11 is connected to the bus cable 13. One end of the bus cable 13 is connected to an external booster station, and the other end is connected to the outgoing cable 14 through the metering current transformer 12. An SVG high-voltage chamber 40 is also arranged on the side of the high-voltage chamber 10 away from the transformer chamber 30. An SVG vacuum circuit breaker 41 and an SVG incoming cable 42 are arranged in the SVG high-voltage chamber 40. The SVG vacuum circuit breaker 41 is connected to the reactive power compensation device outside the SVG high-voltage chamber 40 through the SVG incoming cable 42, and the SVG vacuum circuit breaker 41 is connected to the metering current transformer 12.

[0030] In this embodiment, the high-voltage chamber 10, the low-voltage chamber 20 and the transformer chamber 30 are arranged in a herringbone shape, with a compact structure and a smaller space, thereby occupying less space. The bus cable 13 is connected to the external booster station, and then the current is output through the outgoing cable 14. It can be understood that the number of bus cables 13 is multiple, and the multiple bus cables 13 are arranged in parallel and are all connected to the outgoing cable 14. By integrating and adding a reactive compensation device, the reactive power is effectively controlled, the current level in the system is reduced, thereby reducing the loss.

[0031] In the technical solution of the utility model, by setting an SVG high-voltage chamber 40 on one side of the high-voltage chamber 10, the SVG vacuum circuit breaker 41 is connected to the reactive power compensation device outside the SVG high-voltage chamber 40 through the SVG incoming cable 42. The reactive power compensation device can compensate for reactive power by controlling capacitance or inductance to maintain the power factor of the system within a reasonable range. This helps to reduce the reactive power in the power grid and improve the efficiency of the power grid. At the same time, the voltage of the power grid can be adjusted to keep it at a stable level, which can reduce the voltage fluctuation of the power grid and improve the stability of the power grid.

[0032] In one embodiment, a low-voltage cabinet 22 is provided in the low-voltage chamber 20, and the low-voltage cabinet 22 includes a low-voltage frame circuit breaker, a surge, a UPS power supply, a plastic shell and an auxiliary transformer 21. The UPS power supply supplies power to the secondary components in the distributed photovoltaic box transformer 1, and the low-voltage side of the transformer 31 is connected to the low-voltage frame circuit breaker through a copper bus. The low-voltage frame circuit breaker is used to control and protect the low-voltage circuit, and can cut off the power supply in time when the circuit fails to protect the safety of equipment and personnel. The UPS power supply (uninterruptible power supply) is used to provide a stable power supply. When the main power supply fails, the UPS can immediately switch to a backup power supply to ensure the continuous power supply of the circuit. Through the cooperation of these components, the low-voltage cabinet 22 can provide a stable and reliable power supply, and effectively control and protect the low-voltage circuit. By connecting to the low-voltage frame circuit breaker, the auxiliary transformer 21 can provide the required power to the secondary components in the distributed photovoltaic box transformer 1. This can ensure the normal operation of the photovoltaic system and provide necessary power protection.

[0033] Specifically, the combined vacuum circuit breaker 11 includes a first high-voltage current transformer, a first high-voltage lightning arrester, a first vacuum circuit breaker, a first isolating switch and a first grounding switch, and the first vacuum circuit breaker is connected to the high-voltage terminal of the transformer 31 through a copper braid. The first high-voltage current transformer is used to measure the current in the circuit to monitor and protect the circuit, the first high-voltage lightning arrester is used to absorb the overvoltage that may be generated in the circuit to protect the equipment from damage caused by voltage overload, the first vacuum circuit breaker is used to control the on and off of the circuit, and is mainly used to disconnect or connect the circuit. The first vacuum circuit breaker has the ability to quickly disconnect and connect, so as to quickly cut off the power supply when a circuit fails to protect the safety of equipment and personnel.

[0034] Furthermore, the SVG vacuum circuit breaker 41 includes a second high-voltage current transformer, a second high-voltage lightning arrester, a second vacuum circuit breaker, a second isolating switch and a second grounding switch, and a zero-sequence current transformer is provided on the incoming side of the SVG incoming cable 42. It can be understood that the structure of the SVG vacuum circuit breaker 41 is consistent with that of the combined vacuum circuit breaker 11, both of which include a high-voltage current transformer, a high-voltage lightning arrester, a vacuum circuit breaker, an isolating switch and a grounding switch. The second high-voltage current transformer is used to measure the current in the circuit to monitor and protect the circuit. The second high-voltage lightning arrester is used to absorb the overvoltage that may be generated in the circuit to protect the equipment from voltage overload damage. The second vacuum circuit breaker is used to control the on and off of the circuit, mainly used to disconnect or connect the circuit. The second vacuum circuit breaker has the ability to quickly disconnect and connect, so as to quickly cut off the power supply when a circuit fails to protect the safety of equipment and personnel. Zero-sequence current refers to the additional current generated when the three phases in the power grid are unbalanced. It may be caused by unbalanced load, nonlinear load or fault in the power grid. Setting a zero-sequence current transformer can monitor the zero-sequence current in the power grid in real time, thereby helping to control and adjust the operation of SVG.

[0035] In one embodiment, a cable chamber 15 is further provided on the side of the high-voltage chamber 10 facing the SVG high-voltage chamber 40. The bus cable 13 and the outgoing cable 14 are both located in the cable chamber 15, and the combined vacuum circuit breaker 11 is connected to the bus cable 13 through an insulating terminal. The bus cable 13 and the outgoing cable 14 are both located in the cable chamber 15. The insulating terminal is usually made of insulating material and is used to isolate the conductive part in the circuit from the external environment, thereby providing insulation protection, thereby preventing leakage or breakdown of the circuit, and protecting the safety of equipment and personnel. The insulating terminal is usually designed to be an interface that can be connected to a cable, a wire or other electrical equipment. The combined vacuum circuit breaker 11 is connected to the bus cable 13 through the insulating terminal, which can reduce the exposed part of the cable or wire, thereby reducing the risk of electrical contact and improving the safety of electrical equipment.

[0036] Furthermore, a high-voltage PT is connected between the insulating terminal and the combined vacuum circuit breaker 11 through TMY, and a fuse 17 is provided on TMY. TMY is a hard copper busbar, and the high-voltage PT is used to measure the voltage in the power grid and reduce it to a safe measurement range. The fuse 17 is provided on TMY to protect the circuit connected to TMY. The fuse 17 can quickly disconnect the power supply when a short circuit or overload occurs in the circuit to prevent damage to the equipment and threats to personnel safety.

[0037] In one embodiment, the high-voltage chamber 10 is isolated from the SVG high-voltage chamber 40 by a steel plate, a wall bushing 18 is provided on the steel plate, and the SVG vacuum circuit breaker 41 is connected to the bus cable 13 through the TMY provided in the wall bushing 18. The steel plate isolation can effectively isolate the high-voltage chamber 10 from the SVG high-voltage chamber 40, reducing the risk of mutual influence, cross interference and electromagnetic interference that may occur between the two areas, helping to improve the safety of equipment operation and prevent accidents caused by external factors or equipment failures.

[0038] Preferably, the transformer 31 is an oil-immersed transformer 31, and the sheet 32 ​​of the transformer 31 is exposed on the outside of the distributed photovoltaic box transformer 1. The oil-immersed transformer 31 uses oil as a heat dissipation material. Oil as an insulating medium has good insulation properties and can effectively prevent the breakdown of current between windings and between windings and the ground, thereby improving the reliability and safety of the transformer 31. At the same time, oil has a high heat capacity and thermal conductivity, and can effectively absorb and conduct the heat generated by the transformer 31, so that the temperature inside the transformer 31 is kept within a safe range, thereby improving the operating efficiency and life of the transformer 31. The oil tank sheet 32 ​​exposed to the outside can make it easier for the transformer 31 to dissipate heat. When the transformer 31 is running, a certain amount of heat will be generated inside the oil tank. The exposed oil tank sheet 32 ​​helps to dissipate heat through natural convection and radiation, thereby keeping the temperature of the transformer 31 within a suitable range and improving the operating efficiency and life of the transformer 31.

[0039] See also Figure 3 Furthermore, the top wall of the high-pressure chamber 10, the top wall of the SVG high-pressure chamber 40, and the top wall 50 of the low-pressure chamber 20 are all in a sloping roof structure with an inclination angle of 4° to 6°. It can be understood that the top wall 50 of the SVG high-pressure chamber 40 and the low-pressure chamber 20 are both in a sloping roof structure with a high middle and low sides, and the top wall is composed of two inclined plates, and the two inclined plates are inclined downward from the middle to the sides, and the inclination angle is 4° to 6°. The inclined roof can prevent the accumulation of impurities such as rain, snow, and dust, and at the same time can reduce wind pressure and extend the overall life of the high-pressure chamber 10 and the SVG high-pressure chamber 40.

[0040] In one embodiment, electromagnetic doors are provided in both the high-voltage chamber 10 and the SVG high-voltage chamber 40. The electromagnetic doors have a rapid response capability to opening and closing, and can be closed immediately when a person enters or leaves the high-voltage chamber 10 and the SVG high-voltage chamber 40, thereby reducing the loss of cold and hot air, thereby reducing energy waste. At the same time, compared with traditional manual doors, the automatic opening and closing function of the electromagnetic doors can save manpower and improve work efficiency, especially in occasions where frequent entry and exit are required.

[0041] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A distributed photovoltaic box transformer, characterized in that: The utility model comprises a high-voltage chamber, a low-voltage chamber and a transformer chamber arranged in a herringbone shape, wherein the high-voltage chamber and the low-voltage chamber are arranged adjacent to each other and are located on the same side of the transformer chamber, a transformer is arranged in the transformer chamber, a combined vacuum circuit breaker, a metering current transformer, a bus cable and an outgoing cable are arranged in the high-voltage chamber, the combined vacuum circuit breaker is connected to the bus cable, one end of the bus cable is connected to an external booster station, and the other end is connected to the outgoing cable through the metering current transformer, an SVG high-voltage chamber is also arranged on the side of the high-voltage chamber away from the transformer chamber, an SVG vacuum circuit breaker and an SVG incoming cable are arranged in the SVG high-voltage chamber, the SVG vacuum circuit breaker is connected to the reactive power compensation device outside the SVG high-voltage chamber through the SVG incoming cable, and the SVG vacuum circuit breaker is connected to the metering current transformer.

2. The distributed photovoltaic box-type transformer according to claim 1, characterized in that: A low-voltage cabinet is arranged in the low-voltage room, and the low-voltage cabinet includes a low-voltage frame circuit breaker, a surge, a UPS power supply, a plastic case and an auxiliary transformer. The UPS power supply supplies power to the secondary components in the distributed photovoltaic box transformer, and the low-voltage side of the transformer is connected to the low-voltage frame circuit breaker through a copper busbar.

3. The distributed photovoltaic box-type transformer according to claim 1, characterized in that: The combined vacuum circuit breaker comprises a first high-voltage current transformer, a first high-voltage lightning arrester, a first vacuum circuit breaker, a first isolating switch and a first grounding switch, and the first vacuum circuit breaker is connected to the high-voltage terminal of the transformer through a copper braided belt.

4. The distributed photovoltaic box-type transformer according to claim 1, characterized in that: The SVG vacuum circuit breaker comprises a second high-voltage current transformer, a second high-voltage lightning arrester, a second vacuum circuit breaker, a second isolating switch and a second grounding switch. A zero-sequence current transformer is provided on the incoming side of the SVG incoming cable.

5. The distributed photovoltaic box-type transformer according to any one of claims 1 to 4, characterized in that: A cable chamber is further provided on one side of the high-voltage chamber facing the SVG high-voltage chamber. The bus cable and the outgoing cable are both located in the cable chamber. The combined vacuum circuit breaker is connected to the bus cable via an insulating terminal.

6. The distributed photovoltaic box-type transformer according to claim 5, characterized in that: A high-voltage PT is also connected between the insulating terminal and the combined vacuum circuit breaker via a TMY, and a fuse is arranged on the TMY.

7. The distributed photovoltaic box-type transformer according to any one of claims 1 to 4, characterized in that: The high-voltage chamber is isolated from the SVG high-voltage chamber by a steel plate, a wall bushing is provided on the steel plate, and the SVG vacuum circuit breaker is connected to the bus cable via a TMY penetrating the wall bushing.

8. The distributed photovoltaic box-type transformer according to any one of claims 1 to 4, characterized in that: The transformer is an oil-immersed transformer, and the transformer pieces are exposed on the outside of the distributed photovoltaic box transformer.

9. The distributed photovoltaic box-type transformer according to any one of claims 1 to 4, characterized in that: The top wall of the high-pressure chamber, the top wall of the SVG high-pressure chamber and the top wall of the low-pressure chamber are all arranged in a pitched roof structure with an inclination angle of 4° to 6°.

10. The distributed photovoltaic box-type transformer according to any one of claims 1 to 4, characterized in that: The high-voltage chamber and the SVG high-voltage chamber are both provided with electromagnetic doors.

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