KR102713564B1 - Distribution board with inverter - Google Patents

Abstract

The present invention relates to an inverter-integrated distribution board, comprising: a main transformer installed inside a case and connected to an AC system; an inverter unit having a circuit breaker installed inside the case and converting direct current power output from a solar module into alternating current power and outputting the same to the main transformer; and wherein the circuit breaker protects the solar module from an accident in the AC system and protects the AC system from a failure of the solar module.

Description

Distribution board with inverter {Distribution board with inverter}

The present invention relates to an inverter-integrated switchboard, and more particularly, to an inverter-integrated switchboard that protects a solar power generation system from an accident in an AC system and protects the AC system from a failure in the solar power generation system by a circuit breaker built into an inverter section installed inside the switchboard.

A grid-connected solar power generation system that is operated in conjunction with an AC power grid converts the direct current output from a solar module into alternating current by an inverter and is connected to the AC power grid through a distribution panel. In order to protect the solar power generation system from an accident in the AC power grid and to protect the AC power grid from a failure of the solar power generation system, it is common to form an inverter by adding a protective function to the inverter according to the facility standards and to install various protective functions on the distribution panel.

Typically, in a grid-connected solar power generation system, a distribution board with an installed capacity exceeding 500 kW includes a load breaking switch (LBS), a power fuse (PF), a metering outfit (MOF), a vacuum circuit breaker (VCB), a main transformer (TR), an air circuit breaker (ACB), and protective relaying equipment, and an inverter unit is connected to the distribution board with a cable at a specified distance.

The inverter section is installed separately from the switchboard at a predetermined distance, and the switchboard and the inverter section are generally connected by a cable. Therefore, a trench is formed between the switchboard and the inverter section, and the cable is buried in the trench to connect them, which creates a problem in that separate electrical work is required.

In addition, in order to protect the switchboard from accidents due to damage or breakage of the cable, an air circuit breaker (ACB) and protective relay equipment must be installed on the secondary side of the main transformer (TR), which results in problems of reduced installation space and increased costs.

Patent Publication No. 10-1266963 relates to an inverter-integrated power distribution board, which allows the inverter module and power distribution module to share and use a single transformer, so not only is a circuit breaker built into the inverter module, but an air circuit breaker is also installed in the power distribution module, which results in problems of reduced installation space and increased costs.

Patent Publication No. 10-2088056 relates to a solar power generation switchboard system. In order to use the system for a long time without breakdowns and to make maintenance easy through an efficient structure, various parts and devices that receive electricity from a power provider and supply electricity to facilities that require electricity consumption are mounted in each location on the switchboard body. An inverter module is provided inside the switchboard system body and is protected by a module cover so that maintenance can be performed in the event of a breakdown. The module cover is openable, so a circuit breaker is built into the inverter module and an air circuit breaker is also installed inside the switchboard body, which causes problems of reduced installation space and increased costs.

Patent Publication No. 10-1987325 relates to a solar power inverter with heat dissipation and earthquake resistance functions. Since it has an aluminum heat dissipation plate and a vibration-proof section, a circuit breaker is built into the inverter and an air circuit breaker is also installed in the distribution board connected to it, which causes problems of reduced installation space and increased cost.

Patent Publication No. 10-1013108 relates to an integrated green distribution board. In order to integrate a substation room, an inverter room, a power control room, monitoring equipment, communication equipment of a power exchange, and a KEPCO distribution board into a single distribution board, an inverter is installed in the first area of the distribution board. However, since an air circuit breaker and a high-speed wiring circuit breaker are also installed in the transformer, there are problems of a reduction in installation space and an increase in cost because a circuit breaker is built into the inverter and an air circuit breaker is also installed in the distribution board.

Patent Registration No. 10-1266963 Patent Registration No. 10-2088056 Patent Registration No. 10-1987325 Patent Registration No. 10-1013108

The purpose of the present invention is to reduce installation space and suppress cost increases by installing a switchboard and an inverter as an integrated unit and sharing a circuit breaker.

In addition, another object of the present invention is to reduce installation costs by installing a switchboard and an inverter as an integrated unit and omitting a circuit breaker and a protection relay.

In addition, another purpose of the present invention is to install a distribution panel and an inverter as an integrated unit, thereby reducing the installation space in a limited space and increasing the solar power installation capacity.

In addition, another object of the present invention is to reduce electrical work costs by installing a switchboard and an inverter as an integrated unit and sharing a circuit breaker.

In addition, another purpose of the present invention is to shorten the electrical work period by installing the switchboard and inverter as an integrated unit and sharing the circuit breaker.

Another purpose of the present invention is to reduce loss due to voltage drop by installing a switchboard and an inverter as an integrated unit.

In addition, another object of the present invention is to protect a solar power generation system from an accident in an AC system by a circuit breaker built into an inverter unit and to protect the AC system from a failure of the solar power generation system.

The problems to be solved by the present invention are not limited to the above purpose, and other technical problems not explicitly stated above can be easily understood by a person having ordinary knowledge in the technical field to which the present invention belongs through the composition and operation of the present invention below.

In order to solve the above problem, the present invention includes the following configuration.

The present invention relates to an inverter-integrated distribution board, comprising: a main transformer installed inside a case and connected to an AC system; an inverter unit having a circuit breaker installed inside the case and converting direct current power output from a solar module into alternating current power and outputting the same to the main transformer; and wherein the circuit breaker protects the solar module from an accident in the AC system and protects the AC system from a failure of the solar module.

The main transformer and the inverter section installed inside the outer case of the present invention are characterized in that they are directly connected by a busbar or a busduct.

The circuit breaker of the present invention is characterized in that it is an AC air circuit breaker.

The AC circuit breaker of the present invention is characterized in that it is connected to a busbar or a bus duct.

The AC circuit breaker of the present invention is characterized by protecting the solar module from an accident in the AC system and protecting the AC system from a failure of the solar module.

The effect of the present invention is that it is possible to reduce installation space and suppress cost increases by installing a switchboard and an inverter as an integrated unit and sharing a circuit breaker.

In addition, another effect of the present invention is that it enables installation of a switchboard and an inverter as an integrated unit and omitting a circuit breaker and protective relay equipment, thereby reducing installation costs.

In addition, another effect of the present invention is that it is possible to increase the solar power installation capacity by reducing the installation space in a limited space by installing the distribution panel and the inverter as an integrated unit.

In addition, another effect of the present invention makes it possible to reduce electrical work costs by installing the switchboard and inverter as an integrated unit and sharing a circuit breaker.

In addition, another effect of the present invention is that it is possible to shorten the electrical work period by installing the switchboard and inverter as an integrated unit and sharing the circuit breaker.

In addition, another effect of the present invention is that it makes it possible to reduce loss due to voltage drop by installing the switchboard and inverter as an integrated unit.

In addition, another effect of the present invention makes it possible to protect a solar power generation system from an accident in an AC system by a circuit breaker built into an inverter unit and to protect the AC system from a failure of the solar power generation system.

The effects of the present invention are not limited to the above effects, and other effects not explicitly stated above can be easily understood by those skilled in the art through the composition and operation of the present invention.

Figure 1 illustrates a circuit diagram of an inverter-integrated switchboard according to the present invention.
Figure 2 illustrates a circuit diagram of an inverter unit built into an inverter-integrated switchboard according to the present invention.
Figure 3 illustrates a front view of the exterior of the inverter-integrated switchboard of the present invention.
Figure 4 illustrates a perspective view of the exterior and interior of the inverter-integrated switchboard of the present invention.
Figure 5 illustrates an exterior and internal perspective plan view of the inverter-integrated switchboard of the present invention.
Fig. 6 illustrates another embodiment of a circuit diagram of an inverter-integrated switchboard according to the present invention.
Figure 7 illustrates an exterior and internal perspective view of another embodiment of the inverter-integrated switchboard of the present invention.
Figure 8 shows a circuit diagram in which a conventional switchboard and an inverter unit are connected.
Figure 9 shows a front view of the casing of a conventional switchboard.
Figure 10 illustrates a plan view of a conventional switchboard case and inverter section installed on multiple concrete pads.

Hereinafter, the overall configuration and operation according to a preferred embodiment of the present invention will be described. These embodiments are exemplary and do not limit the configuration and operation of the present invention. Other configurations and operations that are not explicitly shown in the embodiments may be easily understood by a person having ordinary knowledge in the technical field to which the present invention belongs through the embodiments of the present invention below, and may be considered as technical ideas of the present invention.

Figure 1 illustrates a circuit diagram of an inverter-integrated switchboard according to the present invention.

Referring to Fig. 1, the housing of the inverter-integrated switchboard of the present invention is divided into areas of a high-voltage panel (100), a transformer panel (300), a low-voltage panel (400), and an inverter panel (500), and an inverter section (510) is installed in the inverter panel (500) inside the housing.

The above-mentioned high voltage switch (100) includes a load switch (11), a lightning arrester (12), an instrument transformer (13, 14), an instrument transformer (21), a protection relay (22), a vacuum circuit breaker (23), an instrument current transformer (24), and a surge absorber (25).

The above load switch (11) is installed at the inlet of the distribution panel and is connected to the AC system through a power cable to protect the AC system, and the lightning arrester (12) is connected immediately behind the above load switch (11) to discharge abnormal voltage that occurs externally and enters through the line.

The above-mentioned instrument transformer (13, 14) transforms high voltage into low voltage and large current into small current and supplies it to the power meter, and the above-mentioned instrument transformer (21), the above-mentioned protection relay (22), the above-mentioned vacuum circuit breaker (23), and the above-mentioned instrument current transformer (24) detect the status and isolate it from the above-mentioned AC system when an accident occurs in the AC system.

The above surge absorber (25) prevents abnormal voltages such as line opening/closing surges and momentary transient voltages from having a negative effect.

The above transformer board (300) includes a main transformer (310), and the main transformer (310) converts the receiving voltage or distribution voltage into a voltage suitable for the load or converts the voltage of solar power generated from the inverter board (500) into a step-up voltage and also performs the function of blocking high frequencies.

The above low-voltage panel (400) supplies power to the distribution panel, including the internal power supply unit and rectifier base, which are connected to the secondary side of the main transformer (310) through a wiring circuit breaker.

The above inverter board (500) includes an inverter section (510) that is directly connected to the secondary side of the main transformer (310) via a busbar or bus duct (520) and converts direct current power supplied from a solar power generation system into alternating current power and supplies it to the alternating current system.

FIG. 8 illustrates a circuit diagram in which a conventional switchboard and an inverter unit (51) are connected. Since the conventional switchboard and the inverter unit (51) are connected via a cable (52), in order to protect the internal circuit and AC system from a current leakage or ground fault that may occur due to damage to the cable (52), a grounding type instrument transformer (41), a protective relay (42), an air circuit breaker (ACB) (43), and a surge protective device (SPD) (44) must be installed in the conventional switchboard, and the inverter unit (51) must also have a built-in circuit breaker, etc., in order to protect the internal circuit and the solar power generation system.

Ultimately, it is necessary to secure space to install the grounding type instrument transformer (41), the protective relay (42), the air circuit breaker (ACB: Air Circuit Breaker) (43), and the surge protective device (SPD: Surge Protective Device) (44) inside the casing of the switchboard, and furthermore, the inverter section must have a circuit breaker, etc. built into it according to industrial standards or certification review criteria.

In contrast, in the present invention, the inverter unit (510) is installed integrally inside the casing of the switchboard and directly connected to the secondary side of the main transformer (310) by a busbar or bus duct (520), thereby omitting and eliminating the grounding type instrument transformer (41), the protection relay (42), the air circuit breaker (ACB: Air Circuit Breaker) (43), and the surge protective device (SPD: Surge Protective Device) (44).

Figure 9 illustrates a front view of the casing of a conventional switchboard, and Figure 10 illustrates a plan view of the casing of a conventional switchboard and an inverter section installed on a plurality of concrete pads. The conventional inverter section (51) is installed outside the casing of the switchboard, and the inverter section (51) and the switchboard are connected by cables.

The interior of the conventional switchboard case is divided into areas such as a high-voltage panel (10, 20), a transformer panel (30), and a low-voltage panel (40), and an inverter section (51) is installed at a certain interval outside the conventional switchboard case.

The conventional switchboard housing and the inverter unit (51) are installed on top of the primary pad concrete (61) and the secondary pad concrete (62), and the inverter unit (51) is connected to the switchboard using a cable (52). Therefore, electrical work must be performed to install the primary pad concrete (61) and the secondary pad concrete (62), and electrical work must be performed to form a trench and bury the cable (52).

However, in the present invention, since the inverter unit (510) is installed integrally inside the casing of the switchboard, only one pad concrete needs to be installed, and since the inverter unit (510) is directly connected to the secondary side of the main transformer (310) by a busbar or bus duct (520), there is no need for electrical work to bury the cable (52).

In addition, in the present invention, the inverter unit (510) is directly connected to the secondary side of the main transformer (310) by a busbar or bus duct (520), so that loss due to voltage drop in the conventional cable (52) can be reduced.

Meanwhile, prior art patent publication No. 10-1266963 also discloses an inverter-integrated distribution board, which eliminates the transformer built into the inverter module to block high frequencies and allows such high frequency blocking to be accomplished in the transformer section within the distribution module, thereby allowing the inverter module and distribution module to share and use a single transformer section.

That is, the inverter-integrated switchboard disclosed in the prior art, Patent Publication No. 10-1266963, not only has a circuit breaker built into the inverter module, but also has an air circuit breaker installed in the switchboard, which causes problems of reduced installation space and increased cost. In addition, there is no description of a specific connection method when the inverter module is built into the inverter-integrated switchboard.

Figure 2 illustrates a circuit diagram of an inverter unit built into an inverter-integrated switchboard according to the present invention.

Referring to FIG. 2, the inverter unit (510) of the present invention receives a DC voltage from a solar module and includes a DC load switch (511), a DC surge protector (512), an insulation resistance detector (513), a DC EMI filter (514), a DC bus (515), an IGBT inverter unit (516), an AC filter circuit (517), an AC air circuit breaker (518), and an AC surge protector (519) to convert the DC voltage into an AC voltage.

In addition, the inverter unit (510) generally has various switches, circuit breakers, protectors, etc. built in to protect the internal circuit from overvoltage or overcurrent. In the case where the inverter unit (510) is directly connected to the secondary side of the main transformer (310) of the present invention by a busbar or bus duct (520), the AC air circuit breaker (518) is directly connected to the secondary side of the main transformer (310), so that not only can the internal circuit of the inverter unit (512) be protected from AC system or external overvoltage or overcurrent, but also overvoltage or overcurrent from the solar module or the internal circuit of the inverter unit (512) can be blocked from flowing into the main transformer (310).

Ultimately, in the present invention, the grounding type instrument transformer (41), protective relay (42), air circuit breaker (ACB: Air Circuit Breaker) (43), surge protective device (SPD: Surge Protective Device) (44), etc., which are connected between the main transformer (31) and the inverter unit (51) in the conventional switchboard are eliminated, and the main transformer (310) and the inverter unit (510) are directly connected by a busbar or bus duct (520).

Figure 3 illustrates a front view of the exterior of the inverter-integrated switchboard of the present invention.

Referring to FIG. 3, the housing of the inverter-integrated switchboard of the present invention is divided into areas of a high-voltage panel (100), a transformer panel (300), a low-voltage panel (400), and an inverter panel (500), and a main transformer (310) is installed inside the transformer panel (300), and an inverter section (510) is installed inside the inverter panel (500).

The above main transformer (310) is installed inside the transformer panel (300), so it may be a mold transformer that is vulnerable to moisture.

Figure 4 illustrates a perspective view of the exterior and interior of the inverter-integrated switchboard of the present invention.

Referring to Fig. 4, the exterior of the inverter-integrated switchboard of the present invention is divided into areas of a high-voltage panel (100), a transformer panel (300), a low-voltage panel (400), and an inverter panel (500), and a main transformer (310) is installed inside the transformer panel (300).

Figure 5 illustrates an exterior and internal perspective plan view of the inverter-integrated switchboard of the present invention.

Referring to FIG. 5, the housing of the inverter-integrated switchboard of the present invention is divided into a high-voltage panel (100), a transformer panel (300), a low-voltage panel (400), and an inverter panel (500), and a main transformer (310) is installed inside the transformer panel (300), and an inverter section (510) is installed inside the inverter panel (500), so that the main transformer (310) and the inverter section (510) are connected to each other by a busbar or bus duct (520).

Fig. 6 illustrates another embodiment of a circuit diagram of an inverter-integrated switchboard according to the present invention.

Referring to Fig. 6, the interior of the housing of a conventional switchboard is divided into an extra-high voltage panel (10), a transformer panel (30), and a low voltage panel (40), and an inverter section (51) is installed at a certain interval on the exterior of the housing of the conventional switchboard, and the inverter section (51) is connected to a grounding type instrument transformer (41), a protective relay (42), an air circuit breaker (ACB) (43), a surge protective device (SPD) (44), etc., which are installed inside the low voltage panel (40).

The configuration (A) in which an inverter unit (51) is installed at a certain interval outside the housing of a conventional switchboard and a grounding type instrument transformer (41), a protective relay (42), an air circuit breaker (ACB: Air Circuit Breaker) (43), a surge protective device (SPD: Surge Protective Device) (44), etc. are installed inside the housing of a low-voltage panel (40), is changed to the configuration (B) in which the inverter unit (510) installed in the inverter panel (500) of the present invention is directly connected to the main transformer (310) installed in the transformer panel (300) by a busbar or bus duct (520).

Ultimately, the interior of the outer case of the inverter-integrated switchboard of the present invention is divided into a high-voltage panel (100), a transformer panel (300), an inverter panel (500), and a low-voltage panel (400). The main transformer (310) installed in the transformer panel (300) is directly connected to the inverter section (510) installed in the inverter panel (500) by a busbar or bus duct (520), and an internal power supply section (46) and a rectifier panel (47) are installed in the low-voltage panel (400).

Figure 7 illustrates a front view of the casing of another embodiment of the inverter-integrated switchboard of the present invention.

Referring to FIG. 7, the interior of the outer case of the inverter-integrated switchboard of the present invention is divided into a high-voltage panel (100), a transformer panel (300), an inverter panel (500), and a low-voltage panel (400). The main transformer (310) installed in the transformer panel (300) is directly connected to the inverter section (510) installed in the inverter panel (400) by a busbar or bus duct (520), and an internal power supply section (46) and a rectifier board (47) are installed in the low-voltage panel (500).

The conventional switchboard housing and the inverter unit (51) are installed on top of the primary pad concrete (61) and the secondary pad concrete (62), and the inverter unit (51) is connected to the switchboard using a cable (52). Therefore, electrical work must be performed to install the primary pad concrete (61) and the secondary pad concrete (62), and electrical work must be performed to form a trench and bury the cable (52).

However, in the present invention, since the inverter unit (510) is installed integrally inside the casing of the switchboard, only one pad concrete needs to be installed, and since the inverter unit (510) is directly connected to the secondary side of the main transformer (310) by a busbar or bus duct (520), there is no need for electrical work to bury the cable (52).

In addition, in the present invention, the inverter unit (510) is directly connected to the secondary side of the main transformer (310) by a busbar or bus duct (520), so that loss due to voltage drop in the conventional cable (52) can be reduced.

In addition, since the inverter unit (510) is directly connected to the secondary side of the main transformer (310) via a busbar or bus duct (520), it is possible to omit or remove the conventional grounding type instrument transformer (41), the protective relay (42), the air circuit breaker (ACB: Air Circuit Breaker) (43), and the surge protective device (SPD: Surge Protective Device) (44).

Therefore, in the present invention, the main transformer (310) of the existing switchboard is shared between the switchboard and the inverter unit (510), so that both the main transformer (310) function of the switchboard and the main transformer (310) function of the inverter unit (510) can be performed, and the AC air circuit breaker (518) of the inverter unit (510) is shared between the switchboard and the inverter unit (510), so that the solar power generation system can be protected from an accident in the AC system by the AC air circuit breaker (518) built into the inverter unit (510), and the AC system can be protected from a failure of the solar power generation system.

10, 20, 100: Extra high voltage plate
11: Load switch
12: Lightning arrester
13, 14, 15: Instrument transformer
21: Instrument transformer
22: Protective relay
23: Vacuum circuit breaker
24, 44: Instrument transformer
25: Surge absorber
30, 300: Transformer board
310: Main transformer
40, 400: Low pressure plate
41: Grounding type instrument transformer
42: Protective relay
43: Air Circuit Breaker (ACB)
45: Surge Protective Device (SPD)
46: Internal power supply unit
47: Stationary base
48: Circuit breaker for wiring
51, 510: Inverter section
52: Cable
500: Inverter board
511: DC load switch
512:: DC Surge Protector
513: Insulation resistance detector
514: DC EMI Filter
515: DC Bus
516: IGBT inverter unit
517: AC filter circuit
518: AC Air Circuit Breaker
519: AC Surge Protector
520: Busbar, Busduct

Claims (5)

In the inverter-integrated distribution board,
A main transformer installed inside the enclosure and connected to the AC system;
An inverter unit is installed inside the above-mentioned outer case and has a built-in circuit breaker that converts direct current power output from a solar module into alternating current power and outputs it to the main transformer;
An inverter-integrated distribution board, characterized in that the main transformer and the inverter section installed inside the outer case are directly connected to a busbar or busduct, and the circuit breaker protects the solar module from an accident in the AC system section and protects the AC system section from a failure of the solar module.
In the first paragraph,
An inverter-integrated distribution board, characterized in that the main transformer and the inverter section installed inside the above-mentioned housing are directly connected by a busbar or busduct.
In the first paragraph,
An inverter-integrated distribution board characterized in that the circuit breaker is an AC air circuit breaker. In the third paragraph,
An inverter-integrated switchboard characterized in that the above-mentioned AC circuit breaker is connected to a busbar or bus duct.
In paragraph 4,
An inverter-integrated distribution board characterized in that the above-mentioned AC circuit breaker protects the solar module from an accident in the AC system and protects the AC system from a failure of the solar module.