Smart panel (distribution board and incoming / outgoing distribution board), power distribution system, and incoming / outgoing power distribution system

Abstract

To implement "space saving", "electrical circuit reduction", and the like by, for example, connecting respective terminals projecting upward with a low-voltage breaker and a high voltage power transmission unit using electrical circuits in a board frame the whole of which exists above a transformer.SOLUTION: A distribution board 1 includes terminals 4L, 4H projecting upward connected with a low-voltage breaker 3 and a high voltage power transmission unit 5 using electrical circuits 6L, 6H in a board frame 2, the whole of which exists above a transformer 4. In a plan view, the board frame 2 may have a longitudinal length longer than that of the transformer 4 by 10 cm or longer and 40 cm or shorter; for example, a transformation output terminal 9 capable of outputting transformation output current S from an instrument transformer 7 in the board frame 2 to electric and electronic equipment outside the board frame 2 may be added; the transformer 4 may support low voltage / high voltage board frame units 2A, 2B. A power distribution system 20 including the distribution board 1 and the like may comprise: a vacuum circuit breaker 23a, an isolator 23b, a load break switch 23c on an electrical circuit between a system K and a plurality of distribution boards 1 coupled and connected using a coupling electrical circuit 6C; and a power generation unit 21 or a conversion unit 22, a power storage unit 24 connected to the transformation output terminal 9, and the like that are provided outside the board frame 2.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a distribution board having a panel housing, a low-voltage circuit breaker, a transformer, and a high-voltage power transmission section, a power receiving and distribution board having a panel housing, a low-voltage circuit breaker, a transformer, a high-voltage circuit breaker, etc., a power distribution system having a distribution board, and a power receiving and distribution system having a power receiving and distribution board.

Background Art

[0002] Conventionally, a power receiving and distribution board equipped with a plurality of equipment panels has been known (see Patent Document 1). This power receiving and distribution board includes a monitoring panel and a control and protection panel in which an intake opening is formed and which can supply power to a load, and a power conversion board and an associated transformer board equipped with an air-cooled power converter and an associated transformer that convert DC power or AC power from a power supply source into power, step down / step up the voltage, and supply it to the load. The power receiving and distribution board has a row board configuration in which an auxiliary equipment board in which an exhaust opening is formed and which takes in DC power or AC power from a power supply source is juxtaposed in a predetermined direction in sequence. Further, in this power receiving and distribution board, each equipment board communicates with each other, sucks outside air into the row board through the intake opening, and discharges it outside the row board through the exhaust opening. The cooling air generated by this cools the power converter.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the power receiving and distribution board described in Patent Document 1, since a plurality of equipment boards are simply arranged side by side in a predetermined direction in accordance with the flow of current, a large installation space is required for the side-by-side arrangement, and there is a problem that the cables (circuits) connecting between the equipment boards become very long.

[0005] In view of such points, the present invention aims to provide a distribution board, a power receiving and distribution board, a power distribution system, and a power receiving and distribution system that can achieve "space saving" and "shortening of the electric circuit" by connecting each terminal protruding upward to a low-voltage circuit breaker or a high-voltage power transmission unit with an electric circuit within a board housing entirely above the transformer.

Means for Solving the Problems

[0006] The distribution board 1 according to the present invention includes one board housing 2, a low-voltage circuit breaker 3 capable of interrupting a low-voltage alternating current L from outside the board housing 2, a transformer 4 that transforms the low-voltage alternating current L passing through the low-voltage circuit breaker 3 into a higher-voltage high-voltage alternating current H, and a high-voltage power transmission unit 5 that transmits the high-voltage alternating current H from the transformer 4 to the outside of the board housing 2. In the board housing 2, the low-voltage circuit breaker 3 and the high-voltage power transmission unit 5 are provided. Outside the board housing 2, the transformer 4 is attached from below. The entire board housing 2 is disposed above the upper surface 4U of the transformer 4. From the upper surface 4U of the transformer 4, a low-voltage terminal 4L for inputting the low-voltage alternating current L to the transformer 4 and a high-voltage terminal 4H for outputting the high-voltage alternating current H from the transformer 4 are provided so as to protrude upward. In the board housing 2, a low-voltage electric circuit 6L connects between the upwardly protruding low-voltage terminal 4L and the low-voltage circuit breaker 3, and a high-voltage electric circuit 6H connects between the upwardly protruding high-voltage terminal 4H and the high-voltage power transmission unit 5. This is the first feature.

[0007] A second feature of the distribution board 1 according to the present invention is that, in addition to the first feature, in a plan view, the board housing 2 is 10 cm or more and 40 cm or less longer in the front-rear length than the transformer 4.

[0008] The third feature of the switchboard 1 according to the present invention is that, in addition to the above first or second feature, inside the cabinet housing 2, there is an instrument transformer 7 connected to a step-down branch circuit 6S branched from the high-voltage circuit 6H and transforming the high-voltage alternating current H flowing through the high-voltage circuit 6H into a lower-voltage step-down output current S, a voltmeter 8 for measuring the voltage of the high-voltage circuit 6H based on the step-down output current S from the instrument transformer 7, and a step-down output terminal 9 capable of outputting the step-down output current S from the instrument transformer 7 to electrical and electronic devices outside the cabinet housing 2.

[0009] The fourth feature of the switchboard 1 according to the present invention is that, in addition to the above first or second feature, inside the cabinet housing 2, there is a zero-phase voltage detector 10 connected to a zero-phase branch circuit 6Z branched from the high-voltage circuit 6H, and a zero-phase voltage output terminal 11 capable of outputting the output from the zero-phase voltage detector 10 to electrical and electronic devices outside the cabinet housing 2.

[0010] The fifth feature of the switchboard 1 according to the present invention is that, in addition to the above first or second feature, the high-voltage circuit 6H is three-phase three-wire, and inside the cabinet housing 2, there is an instrument transformer 7 connected to step-down branch circuits 6S branched from at least two of the three-phase three-wire of the high-voltage circuit 6H and transforming the high-voltage alternating current H flowing through the high-voltage circuit 6H into a lower-voltage step-down output current S, and instrument current transformers 12 for transforming the high-voltage alternating current H flowing through the high-voltage circuit 6H into a smaller-current transformed output current R are provided respectively on at least two of the three-phase three-wire of the high-voltage circuit 6H. There are at least two step-down output terminals 9 capable of outputting the step-down output current S from the instrument transformer 7 to electrical and electronic devices outside the cabinet housing 2, and at least two transformed output terminals 13 capable of outputting the transformed output current R from the instrument current transformers 12 to electrical and electronic devices outside the cabinet housing 2.

[0011] The sixth feature of the switchboard 1 according to the present invention is that, in addition to the above first or second feature, the transformer 4 is grounded at the grounding point 4', and in the cabinet housing 2, a grounding resistor 14 is provided between the transformer 4 and the grounding point 4', and a zero-phase current transformer 15 is provided between the grounding resistor 14 and the grounding point 4', and a zero-phase current output terminal 16 capable of outputting the output from the zero-phase current transformer 15 to electrical and electronic equipment outside the cabinet housing 2 is provided.

[0012] The seventh feature of the switchboard 1 according to the present invention is that, in addition to the above first or second feature, a single-phase transformer 17 different from the transformer 4 is provided in the cabinet housing 2 in the low-voltage circuit 6L.

[0013] The eighth feature of the switchboard 1 according to the present invention is that, in addition to the above first or second feature, the high-voltage power transmission unit 5 has a high-voltage switch 5a capable of opening and closing the high-voltage circuit 6H or a high-voltage circuit breaker 5b capable of interrupting, and the cabinet housing 2 includes a low-voltage cabinet housing part 2A in which the low-voltage circuit breaker 3 is provided inside, and a high-voltage cabinet housing part 2B in which the high-voltage switch 5a or the high-voltage circuit breaker 5b is provided inside, and the weight of the low-voltage cabinet housing part 2A and the weight of the high-voltage cabinet housing part 2B are supported by the transformer 4.

[0014] Due to these features, a low-voltage circuit breaker 3 and a high-voltage power transmission unit 5 are provided in the cabinet housing 2, and by packaging them in a one-package form with the entire cabinet housing 2 attached above the transformer 4, unlike Patent Document 1, since the equipment for performing high-voltage power transmission and the transformer 4 are arranged vertically, the installation space becomes narrower by the amount of this vertical arrangement ("space saving"), and since on-site assembly work is not required, the construction period can be shortened. Also, even if water submerges up to the height of the transformer 4, each device such as the low-voltage circuit breaker 3 and the high-voltage power transmission unit 5 inside the cabinet housing 2 will not be submerged. In addition to this, by connecting the upwardly protruding low-voltage terminals 4L·high-voltage terminals 4H, the low-voltage circuit breaker 3, and the high-voltage power transmission unit 5 with the low-voltage circuit 6L·high-voltage circuit 6H inside the cabinet housing 2, the lengths of the low-voltage circuit 6L and the high-voltage circuit 6H inside the cabinet housing 2 become shorter ("shortening of the circuit"), and by the amount of this shortness, the possibility of inadvertently contacting high-voltage parts such as the high-voltage circuit 6H during inspection etc. is reduced. Since the switchboard 1 according to the present invention is of a vertical stacking type, it can be said to be a "smart board" because it saves space compared to the conventional side-by-side type switchboard.

[0015] Also, by making the cabinet 2 longer than the transformer 4 by 10 cm or more and 40 cm or less in the front-rear length in plan view, the cabinet 2 will protrude forward and / or backward from the transformer 4. By passing the low-voltage circuit 6L, the high-voltage circuit 6H, etc. downward from the lower surface of this protruding part, the space through which each circuit 6L, 6H passes can be secured behind the transformer 4 or the like.

[0016] Furthermore, by having a voltage output terminal 9 in the cabinet 2 that can output the voltage output current S from the instrument transformer 7 provided in the voltage transformation branch circuit 6S branched from the high-voltage circuit 6H to electrical and electronic devices outside the cabinet 2, along with "space saving", even if there is a cabinet 2 above the transformer 4 that generates high heat, since there are no electrical and electronic devices such as an uninterruptible power supply device, which is a heat-sensitive storage unit, inside the cabinet 2, the risk of failure due to heat from the transformer 4 is suppressed ("suppression of failure of heat-sensitive devices"). At the same time, even when a user directly touches an uninterruptible power supply device or the like to perform setting changes, operations, etc., since there is no uninterruptible power supply device or the like inside the cabinet 2, work inside the cabinet 2 is not required, and the risk of electric shock by contacting the high-voltage circuit 6H or the like is reduced ("reduction of electric shock risk").

[0017] And by having a zero-phase voltage output terminal 11 in the cabinet 2 that can output the output from the zero-phase voltage detector 10 provided in the zero-phase branch circuit 6Z branched from the high-voltage circuit 6H to electrical and electronic devices outside the cabinet 2, along with "space saving", the risk of failure of heat-sensitive ground-fault overvoltage relays and the like due to heat from the transformer 4 is suppressed, and "suppression of failure of heat-sensitive devices" is achieved. Even when a user directly touches a ground-fault overvoltage relay or the like to perform setting changes, operations, etc., "reduction of electric shock risk" can be achieved.

[0018] In addition, a voltage output terminal 9 capable of outputting a voltage output current S from an instrument transformer 7 provided in a voltage division branch circuit 6S branched from at least two of the three-phase three-wire lines of the high-voltage circuit 6H to an electrical and electronic device outside the panel housing 2, and a current output terminal 13 capable of outputting a current output current R from an instrument current transformer 12 provided in at least two of the three-phase three-wire lines of the high-voltage circuit 6H to an electrical and electronic device outside the panel housing 2 are provided. By doing so, along with "space saving", the risk of failure due to heat from the transformer 4 for a power meter that is vulnerable to heat is suppressed, "failure suppression of heat-sensitive devices" is achieved, and "reduction of electric shock risk" can be achieved even when a user directly touches a power meter or the like to perform setting changes, operations, etc. In addition, a ground resistor 14 provided between the transformer 4 and the ground point 4', and a zero-phase current output terminal 16 capable of outputting the output from a zero-phase current transformer 15 provided between the ground resistor 14 and the ground point 4' to an electrical and electronic device outside the panel housing 2 are provided. By doing so, along with "space saving", the risk of failure due to heat from the transformer 4 for a ground fault overcurrent relay that is vulnerable to heat is suppressed, "failure suppression of heat-sensitive devices" is achieved, and "reduction of electric shock risk" can be achieved even when a user directly touches a ground fault overcurrent relay or the like to perform setting changes, operations, etc. In addition, in the case where there is no ground resistor 14, a ground fault current that becomes a very large value (for example, 600 A or 1400 A, etc.) is significantly reduced (for example, to about 1 A, etc.) by the amount of the ground resistor 14 provided, so that a great deal of "reduction of electric shock risk" can be achieved. In addition, by having a single-phase transformer 17 provided in the low-voltage circuit 6L inside the panel housing 2, as in the conventional example of FIG. 25, as a preparation for a power outage of the system K, a low-voltage self-supporting (emergency) outlet or the like, a power storage unit that supplies power to this outlet or the like, and a transformer that charges this power storage unit are required. Different from the case where the power storage unit is connected to a transformer outside the panel housing 2 such as another existing electrical room, even during a power outage of the system K, there is no need to separately prepare a transformer for self-supporting use (and it can also cope with the case where there is no other existing electrical room or the like in the vicinity). The distribution board 1 alone can be prepared for a power outage of the system K, and "space saving" can also be achieved by the amount of the built-in transformer. In addition, by supporting the weight of the low-voltage switchboard housing part 2A incorporating the low-voltage circuit breaker 3 and the weight of the high-voltage switchboard housing part 2B incorporating the high-voltage circuit breaker with the transformer 4, in addition to "space saving" and "shortening of the circuit", the installation of the switchboard 1 becomes possible simply by fixing the transformer 4, and "ease of installation" can also be achieved.

[0019] The power receiving and distribution board 1' according to the present invention is a power receiving and distribution board having a board housing 2 and a transformer 4 connected between a system K and a load capable of consuming power received from the system K outside the board housing 2, wherein the board housing 2 includes a low-voltage switchboard housing part 2A provided therein with a low-voltage circuit breaker 3 capable of interrupting a low-voltage circuit 6L between the transformer 4 and the load, and a high-voltage switchboard housing part 2B provided therein with a high-voltage switch 5a capable of opening and closing a high-voltage circuit 6H between the system K and the transformer 4 or a high-voltage circuit breaker 5b capable of interrupting the high-voltage circuit 6H, and a first feature is that the transformer 4 supports the weight of the low-voltage switchboard housing part 2A and the weight of the high-voltage switchboard housing part 2B.

[0020] A second feature of the power receiving and distribution board 1' according to the present invention is that, in addition to the first feature, as the support of the weight of the low-voltage switchboard housing part 2A and the weight of the high-voltage switchboard housing part 2B by the transformer 4, the high-voltage switchboard housing part 2B is attached to the transformer 4 from above, the low-voltage switchboard housing part 2A is attached to the high-voltage switchboard housing part 2B from one side in plan view, and the lower end of the low-voltage switchboard housing part 2A extends to the lower part of the transformer 4.

[0021] A third feature of the power receiving and distribution board 1' according to the present invention is that, in addition to the second feature, a suspension tool 4T is provided at a position eccentric to one side in plan view of the transformer 4.

[0022] Due to these features, by supporting the weight of the low-voltage switchboard housing part 2A incorporating the low-voltage circuit breaker 3 and the weight of the high-voltage switchboard housing part 2B incorporating the high-voltage circuit breaker with the transformer 4, unlike Patent Document 1, since the high-voltage side equipment, the low-voltage side equipment, and the transformer 4 are arranged in a so-called vertical stack, the installation space becomes narrower by the amount of this vertical stack arrangement ("space saving"), and since on-site assembly work is not required, the construction period can be shortened. In addition, inside the switchboard housing 2, by connecting the upwardly protruding low-voltage terminals 4L and high-voltage terminals 4H, and the low-voltage circuit breaker 3 and high-voltage circuit breaker with the low-voltage circuit 6L and high-voltage circuit 6H, the lengths of the low-voltage circuit 6L and high-voltage circuit 6H in the low-voltage switchboard housing 2A and high-voltage switchboard housing 2B become shorter ( "shortening of the circuit"), and for that length, the possibility of accidentally contacting high-voltage parts such as the high-voltage circuit 6H during inspection etc. is reduced. Also, the installation of the power distribution board 1' can be achieved by simply fixing the transformer 4, and "ease of installation" can also be achieved. In addition, since the power distribution board 1' according to the present invention is also of the vertical stacking type, it can be said to be a "smart board" because it saves space compared to the conventional horizontally arranged switchboards.

[0023] Furthermore, as support for the transformers 4 in the low-voltage switchboard housing 2A and high-voltage switchboard housing 2B, the high-voltage switchboard housing 2B is attached to the transformer 4 from above, the low-voltage switchboard housing 2A is attached to the high-voltage switchboard housing 2B from one side in plan view, and the lower end of the low-voltage switchboard housing 2A is extended to the lower part of the transformer 4. By doing so, only the high-voltage switchboard housing 2B is placed on the transformer 4, and reduction of the installation area (or the exclusive area in plan view), that is, further "space saving" can be achieved. While achieving this "space saving", the internal volume (internal space) of the low-voltage switchboard housing 2A can be ensured by the amount that the low-voltage switchboard housing 2A is suspended down to the lower part of the transformer 4. Also, a suspension tool 4T may be provided at a position eccentric to one side in plan view of the transformer 4.

[0024] The power distribution system 20 according to the present invention is a power distribution system having a power distribution board 1 having the above-described first or second feature, a power generation unit 21, and a conversion unit 22 that converts the direct current or alternating current from the power generation unit 21 into a low-voltage alternating current L. The power distribution boards 1 are plural, a connection circuit 6C is connected between the plural power distribution boards 1, and the high-voltage alternating current H is transmitted from the high-voltage power transmission unit 5 of the plural connected power distribution boards 1 to the system K. A vacuum circuit breaker 23a, a circuit breaker 23b, and / or a load switch 23c are provided in the circuit connecting the system K and the plural connected power distribution boards 1, which is the first feature.

[0025] The second feature of the power distribution system 20 according to the present invention is a power distribution system having a switchboard 1 having the third feature described above, a power generation unit 21, and a conversion unit 22 that converts a direct current or an alternating current from the power generation unit 21 into a low-voltage alternating current L. There is one switchboard 1, and the high-voltage alternating current H is transmitted from the high-voltage power transmission unit 5 of the one switchboard 1 to the system K. Outside the switchboard housing 2, the power generation unit 21, the conversion unit 22, and a power storage unit 24 connected to the transformer output terminal 9 are provided.

[0026] The third feature of the power distribution system 20 according to the present invention is a power distribution system having a switchboard 1 having the fourth feature described above, a power generation unit 21, and a conversion unit 22 that converts a direct current or an alternating current from the power generation unit 21 into a low-voltage alternating current L. There is one switchboard 1, and the high-voltage alternating current H is transmitted from the high-voltage power transmission unit 5 of the one switchboard 1 to the system K. Outside the switchboard housing 2, the power generation unit 21, the conversion unit 22, and a ground fault overvoltage relay 25 connected to the zero-phase voltage output terminal 11 are provided.

[0027] The fourth feature of the power distribution system 20 according to the present invention is a power distribution system having a switchboard 1 having the fifth feature described above, a power generation unit 21, and a conversion unit 22 that converts a direct current or an alternating current from the power generation unit 21 into a low-voltage alternating current L. Outside the switchboard housing 2, at least two wattmeters 28 are provided, which are connected to the transformer output terminal 9 and the converter output terminal 13 and measure the power amount of the high-voltage circuit 6H.

[0028] The fifth feature of the power distribution system 20 according to the present invention is a power distribution system having a switchboard 1 having the sixth feature described above, a power generation unit 21, and a conversion unit 22 that converts a direct current or an alternating current from the power generation unit 21 into a low-voltage alternating current L. Outside the switchboard housing 2, a ground fault overcurrent relay 29 connected to the zero-phase converter output terminal 16 is provided.

[0029] Due to these features, by providing a vacuum circuit breaker 23a, a circuit breaker 23b, or a load switch 23c in the circuit between a plurality of switchboards 1 connected by the connecting circuit 6C and the system K, the switchboard 1 can be used in a power distribution system 20 with a large total power generation, and each switchboard 1 itself and its high-voltage power transmission section 5 can be simplified.

[0030] Also, by providing a power generation section 21, a conversion section 22, and a power storage section 24 connected to the transformer output terminal 9 outside the switchboard housing 2, the switchboard housing 2 and the transformer 4 can be arranged vertically to achieve "space saving", and even if the switchboard housing 2 is above the transformer 4 that generates high heat, "failure suppression of heat-sensitive devices" can be realized for the power storage section 24 such as an uninterruptible power supply device that is vulnerable to heat. At the same time, even when the user directly touches the power storage section 24 to make setting changes, operations, etc., since there is no power storage section 24 inside the switchboard housing 2, work inside the switchboard housing 2 becomes unnecessary, and "reduction of electric shock risk" by contacting the high-voltage circuit 6H, etc., can be achieved.

[0031] Furthermore, by providing a ground fault overvoltage relay 25 connected to the power generation section 21, the conversion section 22, and the zero-phase voltage output terminal 11 outside the switchboard housing 2, further "space saving" can be achieved, and "failure suppression of heat-sensitive devices" can also be achieved for the ground fault overvoltage relay 25 that is vulnerable to heat. At the same time, "reduction of electric shock risk" can be achieved even when the user directly touches the ground fault overvoltage relay 25 to make setting changes, operations, etc.

[0032] In addition, by providing a wattmeter 28 connected to the transformer output terminal 9 and the converter output terminal 12 outside the switchboard housing 2 to measure the power amount of the high-voltage circuit 6H, further "space saving", "failure suppression of heat-sensitive devices", and "reduction of electric shock risk" can be achieved. In addition, based on the transformer output current S from at least two instrument transformers 7 and the converter output current R from the instrument current transformer, accurate measurement of the power amount required during power sales, etc., becomes possible. In addition, by providing a ground fault overcurrent relay 29 connected to the zero-phase variable output terminal 15 outside the panel housing 2, further "space saving", "failure suppression of heat-sensitive devices", and "reduction of electric shock risk" can be achieved. In addition, even for the ground fault current significantly reduced by the grounding resistor 14, based on the output from the zero-phase current transformer 15, when a ground fault occurs, the ground fault overcurrent relay 29 can quickly detect it, enabling removal of the ground fault location and the like.

[0033] The power distribution and reception system 20' according to the present invention is a power distribution and reception panel 1' having the above-described first to third features and a power distribution and reception system having a load 30, wherein the transformer 4 is a three-winding transformer having a primary winding, a secondary winding, and a tertiary winding, or a two-winding transformer having a primary winding and a secondary winding, and the load 30 includes a charger for a vehicle incorporating a storage battery, which is the first feature.

[0034] Due to this feature, by using a three-winding or two-winding transformer 4 and including a charger for a vehicle incorporating a storage battery such as an EV (electric vehicle) in the load 30, in an automobile dealership or a gas station having the power distribution and reception system 20', in recent years when EVs that do not emit exhaust gas have begun to spread widely due to the increasing awareness of issues such as global warming prevention and dependence on fossil fuels, rapid charging with a practical charging time of several minutes to several tens of minutes and compatibility with EVs of various charging capacities can be achieved.

Effects of the Invention

[0035] According to the switchboard, power distribution and reception panel, power distribution system, and power distribution and reception system of the present invention, "space saving" and "circuit shortening" can be realized by connecting each upwardly protruding terminal to a low-voltage circuit breaker or a high-voltage power transmission section with an electric circuit inside the panel housing that is entirely above the transformer.

Brief Description of the Drawings

[0036]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

Figure 23

Figure 24

Figure 25

Embodiments for Carrying Out the Invention

[0037] Hereinafter, embodiments of the present invention will be described with reference to the drawings. <Overall Configuration of the First Embodiment of Switchboard 1> As shown in FIGS. 1 to 15, the first embodiment of the switchboard 1 according to the present invention has a switchboard housing 2, a low-voltage circuit breaker 3, a transformer 4, and a high-voltage power transmission unit 5 to be described later, and in the switchboard housing 2, there are a low-voltage circuit 6L and a high-voltage circuit 6H to be described later. This switchboard 1 may have a voltage division branch circuit 6S, an instrument transformer 7, a voltmeter 8, and a voltage transformation output terminal 9 to be described later in the switchboard housing 2. Further, the switchboard 1 may have a zero-phase branch circuit 6Z, a zero-phase voltage detector 10, and a zero-phase voltage output terminal 11 to be described later in the switchboard housing 2. In the first embodiment of the switchboard 1, the main differences of the first modification shown in FIGS. 6 to 8 are that the high-voltage switch 5a is a high-voltage circuit breaker 5b or the like, and the main differences of the second modification shown in FIGS. 9 to 11 are that it has a gallery 2e and a hook rod storage space 2n.

[0038] Here, the current, voltage, power, and capacity in the present invention may be values within the rated range. In this case, they can be referred to as rated current, rated voltage, rated power, and rated capacity. These rated current, etc. can also be said to be the limit values of current, etc. compensated by the manufacturer for the safe use of electrical products. Furthermore, the rated value can also be said to be the usage limit and conditions under which safe and proper operation is guaranteed for equipment (electrical and electronic equipment) and devices. When the current in the present invention is alternating current, the value of the current (current value), the value of the voltage (voltage value), the value of the power (power value), and the value of the capacity (capacity value) may be effective values. In addition, the "electric circuit" in the present invention is something that conducts electricity (current), and includes conductors such as copper, aluminum, silver, gold, nichrome, etc., cables in which this conductor is covered with an insulator, and general electric wires.

[0039] Moreover, the electrical and electronic equipment installed outside the switchboard housing 2 is not particularly limited. For example, it may be a power storage unit 24 such as an uninterruptible power supply device, a ground fault overvoltage relay 25, a control device 26 of the conversion unit 22, a digital multi-relay 27, or other relays such as a watt-hour meter 28 and a ground fault overcurrent relay 29. Furthermore, the weight (total weight) of the switchboard 1 is not particularly limited. For example, it may be 500 kg or more and 5000 kg or less, preferably 1000 kg or more and 4000 kg or less, and more preferably 1500 kg or more and 3000 kg or less (such as 1900 kg). It can be said that the switchboard 1 is lightweight, and it can also be said that the cost of the installation work can be reduced.

[0040] <switchboard housing 2> As shown in FIGS. 1 to 15, the switchboard housing 2 is a housing that incorporates the equipment of the first embodiment of the switchboard 1 described above, and it can also be said that there is only one in one switchboard 1. Inside the panel housing 2, a low-voltage circuit breaker 3 and a high-voltage power transmission unit 5, which will be described later, are provided. Outside the panel housing 2, a transformer 4, which will be described later, is attached from below, and the entire panel housing 2 is arranged above the upper surface 4U of the transformer 4. The panel housing 2 may have any configuration as long as it houses the equipment of the switchboard 1. For example, it may be formed in a substantially rectangular parallelepiped shape or a cubic shape as a whole, and is also called a cubicle. Hereinafter, the panel housing 2 will be mainly described as being substantially rectangular parallelepiped-shaped.

[0041] The panel housing 2 may have one or more doors 2a that can be opened and closed. The door 2a may be provided on the front side and / or the rear side of the panel housing 2. In this case, it can be said that the wiring work inside the panel housing 2 can be carried out from the front or the rear when installing the switchboard 1. Also, a door handle may be provided on the door 2a. Note that the panel housing 2 (main body 2c) may have a location where the door 2a is not provided (a location that does not open and close), such as the high-voltage terminal (high-voltage output terminal) 4H side of the transformer 4 described later. The side plate of this non-opening and closing location may be bolted or the like so that wiring work and the like are easy when installing the switchboard 1. The panel housing 2 may have a roof 2b and a main body 2c. The roof 2b is provided on the upper part of the main body 2c, and the upper surface of the roof 2b may be inclined backward (rearward). The roof 2b may protrude forward and / or rearward, or leftward and / or rightward from the main body 2c. In this case, it can be said that the left-right length (width) and the front-rear length (depth) of the panel housing 2 in plan view are the left-right length and the front-rear length of the roof 2b.

[0042] The panel housing 2 may have an exhaust space (exhaust port) 2d. The exhaust space 2d may be provided with a filter 2d', or the opening of the exhaust space 2d may be covered with a mesh member that partitions the inside and outside of the panel housing 2. The location where the exhaust space 2d is provided is not particularly limited. For example, if the roof 2b protrudes forward and / or rearward with respect to the main body 2c, it may be provided on the protruding lower surface of the roof 2b, or alternatively, it may be provided at any location on the upper part of the panel housing 2. The tray housing 2 may have a grille 2e and may be provided with a filter. The location where the grille 2e is provided is not particularly limited. For example, it may be provided at the lower part of the left and / or right side surfaces of the main body 2c and substantially at the center in the front-rear direction (see FIG. 10 in particular).

[0043] The size of the tray housing 2 is not particularly limited. However, the front-rear length (depth) of the tray housing 2, for example, in a plan view, may have a difference in the front-rear length (depth) from the transformer 4 described later of 10 cm or more and 40 cm or less, preferably 10 cm or more and 35 cm or less, more preferably 15 cm or more and 31 cm or less (such as 21 cm or 30.5 cm). Incidentally, the difference in the front-rear length between the tray housing 2 and the transformer 4 may be such that the tray housing 2 is longer than the transformer 4, or conversely, the tray housing 2 may be shorter than the transformer 4. In addition, the front-rear length of the tray housing 2 may be substantially the same as that of the transformer 4. In this case, "substantially the same" means that the difference in the front-rear length is 2 cm or less in total in the front and / or rear directions. Also, in a plan view, the size of the tray housing 2 may have substantially the same left-right length (width) as the transformer 4 described later. In this case, "substantially the same" means that the difference in the left-right length is 1 cm or less on each of the left and right sides (2 cm or less in total for the left and right). In addition, the difference in the left-right length between the tray housing 2 and the transformer 4 may be, for example, more than 2 cm and 40 cm or less, preferably more than 2 cm and 30 cm or less, more preferably more than 2 cm and 20 cm or less. Incidentally, the difference in the left-right length between the tray housing 2 and the transformer 4 may be such that the tray housing 2 is longer than the transformer 4, or conversely, the tray housing 2 may be shorter than the transformer 4.

[0044] The specific size of the tray housing 2 is, for example, the left - right length of the roof 2b is 70 cm or more and 170 cm or less, preferably 80 cm or more and 150 cm or less, more preferably 90 cm or more and 130 cm or less (such as 120 cm or 103 cm). Or when the roof 2b in the tray housing 2 protrudes forward and backward from the main body 2c, for example, the front - rear length of the roof 2b is 70 cm or more and 160 cm or less, preferably 80 cm or more and 140 cm or less, more preferably 90 cm or more and 120 cm or less (such as 100 cm or 94.5 cm), the front - rear length of the main body 2c (including the thickness of the door 2a) is 70 cm or more and 160 cm or less, preferably 80 cm or more and 140 cm or less, more preferably 90 cm or more and 120 cm or less (such as 100 cm or 94.5 cm), and the up - down length (height) may be 70 cm or more and 130 cm or less, preferably 80 cm or more and 120 cm or less, more preferably 90 cm or more and 110 cm or less.

[0045] When the roof 2b of the tray housing 2 is tilted backward, the difference in the up - down length from the front upper end to the rear upper end of the roof 2b may be, for example, 1 cm or more and 10 cm or less, preferably 2 cm or more and 7 cm or less, more preferably 3 cm or more and 5 cm or less (such as 3.6 cm). In particular, as shown in FIG. 11, the bottom plate 2f of the main body 2c of the panel housing 2 has a transformer base portion 2g attached to the upper surface 4U of a transformer 4 described later (in a plan view, a low-voltage terminal (low-voltage input terminal) 4L and a high-voltage terminal (high-voltage output terminal) 4H will be located at this transformer base portion 2g), one or more high-voltage openings 2h for inserting a high-voltage circuit (high-voltage cable) 6H that conducts a high-voltage alternating current H to the outside of the panel housing 2, one or more low-voltage openings 2j for inserting one or more low-voltage circuits (low-voltage cables) 6L that conduct a low-voltage alternating current L from the outside of the panel housing 2, and one or more control openings 2k for inserting a control line from a control device 26 of a conversion unit 22 described later located outside the panel housing 2. The panel housing 2 may have such features. When the panel housing 2 is longer in the front-back direction than the transformer 4 by a predetermined length (for example, 10 cm or more and 40 cm or less) in a plan view, and the panel housing 2 protrudes forward and / or backward from the transformer 4, high-voltage openings 2h, low-voltage openings 2j, and control openings 2k may be provided on the lower surface of this protruding portion. Further, holes for inserting a low-voltage input terminal 4L and a high-voltage output terminal 4H that protrude upward from the upper surface 4U of the transformer 4 (erected) may be formed in the bottom plate 2f. In this case, the holes to be inserted will be provided in the transformer base portion 2g described above in a plan view. In addition, a heat insulating material (not shown) that blocks heat from the transformer 4 may be provided on the bottom plate 2f.

[0046] Here, as shown in FIGS. 3 to 8, in the distribution board 1 of the first embodiment, one panel housing 2 can be said to include a low-voltage panel housing portion 2A in which a low-voltage circuit breaker 3 described later is provided inside, and a high-voltage panel housing portion 2B in which a high-voltage switch 5a described later or a high-voltage circuit breaker 5b described later is provided inside. Also, since the entire panel housing 2 to which the transformer 4 described later is attached from below is arranged above the upper surface 4U of the transformer 4, naturally, both the low-voltage panel housing portion 2A and the high-voltage panel housing portion 2B are arranged above the upper surface 4U of the transformer 4 in a state of being attached to the transformer 4. Therefore, it can be said that the weight of the low-voltage panel housing portion 2A and the weight of the high-voltage panel housing portion 2B are supported by the transformer 4.

[0047] <Low-voltage circuit breaker 3> As shown in FIGS. 3, 5, 6, 8, 12 to 15, the low-voltage circuit breaker 3 is a device capable of interrupting the low-voltage alternating current L from outside the above-described panel housing 2. In other words, it is a device provided in the low-voltage circuit 6L described later and capable of interrupting the low-voltage circuit 6L. Note that the low-voltage circuit breaker 3 is provided inside the panel housing 2 (the first embodiment of the distribution board 1 has the low-voltage circuit breaker 3 inside the panel housing 2). For example, when the low-voltage circuit 6L extends further from the low-voltage circuit breaker 3 and is connected to the conversion unit 22 outside the panel housing 2, the low-voltage circuit breaker 3 interrupts between the conversion unit 22 and the transformer 4. The low-voltage circuit breaker 3 may be a wiring circuit breaker (MCCB, Molded Case Circuit Break), or may be an earth leakage circuit breaker (ELCB, Earth Leakage Circuit Breaker). Note that in one distribution board 1, not only one low-voltage circuit breaker 3 may exist, but a plurality (for example, four or five) may exist. Further, the low-voltage circuit breaker 3 may be provided with an instrument current transformer (particularly, a clamp type current transformer) 3', or may be provided with a meg measurement switch (MG) or may be reversely connectable.

[0048] <Transformer 4> As shown in FIGS. 1 to 15, the transformer 4 is a device that transforms (boosts) the low-voltage alternating current L from outside the above-described panel housing 2 into a higher-voltage high-voltage alternating current H, that is, a so-called transformer (TR). Note that a transformer is an abbreviation for transformer. Also, it can be said that only one transformer 4 exists in the first embodiment of one distribution board 1. The above-described panel housing 2 is attached to the transformer 4 from above. That is, the transformer 4 is installed outside the panel housing 2, eliminating the need for a ventilation fan inside the panel housing 2 and the auxiliary power supply for the ventilation fan. It can be said that the repair painting of the transformer 4 (main body) can be easily performed, maintenance can be performed over a long period (for example, 20 years or more), and integrated shipping eliminates the need for assembly work at the installation site. Also, it can be said that the transformer 4 will be connected between the power grid K (high-voltage circuit 6H side) and the conversion unit 22 (low-voltage circuit 6L side) in the power distribution system 20 described later. The capacity of the transformer 4 (unit: VA, continuous rating) is not particularly limited. For example, it may be 50 kVA or more and 2000 kVA or less, preferably 100 kVA or more and 1500 kVA or less, and more preferably 200 kVA or more and 1000 kVA or less (such as 300 kVA or 500 kVA).

[0049] The configuration of the transformer 4 is not particularly limited. For example, it may be a two-winding transformer (two-winding transformer) having a primary winding and a secondary winding, a three-winding transformer (three-winding transformer) having a primary winding, a secondary winding, and a tertiary winding, or a transformer having four or more windings. Hereinafter, the transformer 4 will be mainly described assuming it is a two-winding transformer. For the transformer 4 which is a two-winding transformer, for example, its primary side may be the high-voltage circuit 6H side and its secondary side may be the low-voltage circuit 6L side. In this case, specific values are not particularly limited. For example, the voltage of the primary side which is the high-voltage circuit 6H side may be 5000 V or more and 40000 V or less, preferably 5500 V or more and 30000 V or less, and more preferably 6000 V or more and 25000 V or less (such as 6600 V or 22000 V), or the voltage of the secondary side which is the low-voltage circuit 6L side may be 100 V or more and 1000 V or less, preferably 150 V or more and 800 V or less, and more preferably 200 V or more and 600 V or less (such as 440 V, 254 V, 550 V, 318 V).

[0050] The connection method of the primary and secondary sides of the transformer 4 is not particularly limited either. For example, the primary side which is the high-voltage circuit 6H side may be delta connection (Δ connection), and the secondary side which is the low-voltage circuit 6L side may be star connection (Y connection) (that is, Δ-Y connection). Alternatively, in the order of the primary side and the secondary side, it may be Δ-Δ connection, Y-Δ connection, or Y-Y connection (in these cases, both the primary side and the secondary side are three-phase three-wire (3φ3W)). The low-voltage terminal (low-voltage input terminal) 4L of the transformer 4 is a terminal for inputting a low-voltage alternating current L to the transformer 4, and the high-voltage terminal (high-voltage output terminal) 4H is a terminal for outputting a high-voltage alternating current H from the transformer 4. Each of these terminals 4L and 4H may be provided in a protruding manner (vertically installed) from the bottom plate 2f within the panel housing 2, and the arrangement of each terminal 4L and 4H in a plan view is not particularly limited. For example, three lines for each of the terminals 4L and 4H may be arranged side by side in a substantially horizontal row (substantially in a horizontal line). The lower part of the transformer 4 may be attached and installed to the foundation via a fixing member (not shown) such as a screw using an installation member 4a (a pair of left and right bar members having a substantially L-shaped cross section, or a substantially U-shaped installation member in a plan view including a pair of left and right bar members having a substantially L-shaped cross section and a connecting bar member connecting their rear ends). This foundation may be a solid foundation made of a material such as concrete and having a uniform thickness, a cinder block foundation having a recess, etc., or a plurality of pile members driven into the installation surface M. In addition, when the foundation of the transformer 4 is a pile member, it can be said that the construction cost can be reduced. The transformer 4 may be an oil-immersed transformer (self-cooled, air-cooled, water-cooled, etc.) or a dry-type transformer (self-cooled, air-cooled, water-cooled, etc.). In addition, it may have an anti-mixing plate or be a type B grounding (EB). Further, the transformer 4 may be grounded at the grounding point 4' in addition to the type B grounding. In particular, in the case of FIG. 15 showing Modification 3 described later, it is grounded (so-called neutral point grounding) by an electric circuit from the neutral point of the Y connection on the secondary side to the grounding point 4' in the transformer 4 with a delta connection on the primary side and a Y connection on the secondary side.

[0051] The specific size of the transformer 4 is such that, for example, the body part has a left-right length (width) of 70 cm or more and 170 cm or less, preferably 80 cm or more and 150 cm or less, more preferably 90 cm or more and 130 cm or less (such as 120 cm or 101 cm), a front-rear length (depth) of 45 cm or more and 110 cm or less, preferably 50 cm or more and 100 cm or less, more preferably 55 cm or more and 90 cm or less (such as 79 cm or 60 cm), and an up-down length (height) of 70 cm or more and 130 cm or less, preferably 80 cm or more and 120 cm or less, more preferably 90 cm or more and 110 cm or less. Therefore, if the vertical length of the transformer 4 is 100 cm, for example, the equipment mounted above the transformer 4, such as the panel housing 2 and each device inside it, will be at a position higher than 100 cm from the installation surface M. Thus, even if the water submerges up to a height of about 100 cm, each device will not be submerged. It can be said that the transformer 4 is waterproof.

[0052] When the installation member 4a of the transformer 4 is the above-described substantially U-shaped installation member in plan view and the fixing member is a screw, for example, the left-right interval between the left and right installation members 4a is 40 cm or more and 80 cm or less, preferably 45 cm or more and 70 cm or less, more preferably 50 cm or more and 60 cm or less (such as 54 cm), the left-right interval between the left and right fixing members is 45 cm or more and 85 cm or less, preferably 50 cm or more and 75 cm or less, more preferably 55 cm or more and 65 cm or less (such as 60 cm), and the left-right interval between the left and right outer ends of the left and right installation members 4a may be 50 cm or more and 90 cm or less, preferably 55 cm or more and 80 cm or less, more preferably 60 cm or more and 70 cm or less (such as 64 cm). Also, for the transformer 4, the front-rear interval between the front and rear fixing members for fixing to each installation member 4a is 40 cm or more and 80 cm or less, preferably 45 cm or more and 70 cm or less, more preferably 50 cm or more and 60 cm or less (such as 55 cm), the front-rear length of the left and right installation members 4a is 45 cm or more and 85 cm or less, preferably 50 cm or more and 75 cm or less, more preferably 55 cm or more and 65 cm or less (such as 60 cm), and the front-rear length of the substantially U-shaped installation member as a whole in plan view may be 50 cm or more and 90 cm or less, preferably 55 cm or more and 80 cm or less, more preferably 60 cm or more and 70 cm or less (such as 64 cm).

[0053] <High-voltage power transmission section 5> As shown in FIGS. 3 to 8 and 12 to 15, the high-voltage power transmission section 5 is a part that transmits the high-voltage alternating current H from the above-described transformer 4 to the outside of the panel housing 2 (such as the power transmission panel 23 and the system K described later). When a first embodiment of a plurality of switchboards 1 has a power distribution system 20 to be described later, it is natural that there are also a plurality of high-voltage power transmission units 5. Power may be transmitted from these plurality of high-voltage power transmission units 5 to the outside of the switchboard housing 2. Additionally, when one power distribution system 20 has one switchboard 1, there is also one high-voltage power transmission unit 5, and power may be transmitted from this one high-voltage power transmission unit 5 to the outside of the switchboard housing 2. The high-voltage power transmission unit 5 is not particularly limited in its configuration. For example, it may have at least a high-voltage switch (load switch) 5a to be described later, or may have at least a high-voltage circuit breaker (vacuum circuit breaker) 5b or a circuit breaker 5c to be described later. Additionally, the high-voltage power transmission unit 5 may have a circuit protector 5d, an instrument current transformer 12(5e), a power supply circuit breaker 5f, a spare circuit breaker 5g, a voltage test terminal 5h, a current test terminal 5j, etc.

[0054] <High-voltage switch (load switch) 5a> As shown in FIGS. 3, 4, 12, 13, and 15, the high-voltage switch 5a can be said to be a load switch (Load Break Switch, LBS) (hereinafter also referred to as "load switch 5a"). It is provided in a high-voltage circuit 6H to be described later and is a device that opens and closes (in a three-phase three-wire bundle) the high-voltage circuit 6H in a state where a high-voltage alternating current H (load current) is flowing, and is also called a high-voltage alternating current load switch. The load switch 5a may have power fuses (such as four or three) or current-limiting fuses. The load switch 5a may be provided, for example, between the transformer 4 and the zero-phase voltage detector 10 (branch point of the zero-phase branch circuit 6Z) in the high-voltage circuit 6H. In addition, it can be said that one or a plurality (such as two) of load switches 5a are provided in the switchboard housing 2 (the switchboard 1 has one or a plurality of load switches 5a in the switchboard housing 2). Further, the load switch 5a may be an insulator barrier type or an inrush current suppression type switch, and the opening and closing of the load switch 5a may be performed by a hook operation. Alternatively, the load switch 5a may be opened by a voltage removal device (trip coil) and manually restored (recovered, closed). In this case, the load switch 5a is connected to the under-voltage relay 34 and the capacitor removal power supply device 35 described later. When a power outage occurs in the system K, etc., the under-voltage relay 34 detects a state where the voltage of the high-voltage alternating current H flowing through the high-voltage circuit 6H has fallen below (become insufficient) a predetermined value, and the load switch 5a is opened by the voltage removal device by the power supply from the capacitor removal power supply device 35.

[0055] <High-voltage circuit breaker (vacuum circuit breaker) 5b, disconnecting switch 5c> As shown in FIGS. 6, 7, and 14, it can be said that the high-voltage circuit breaker 5b is a vacuum circuit breaker (hereinafter also referred to as "vacuum circuit breaker 5b"), which is provided in the high-voltage circuit 6H described later and is a device that opens and closes the high-voltage circuit 6H in a state where the high-voltage alternating current H (load current) is flowing (in a three-phase three-wire collective manner), and arc extinction is performed in the vacuum valve. The vacuum circuit breaker 5b may be provided, for example, between the instrument current transformer 12 (5e) and the disconnecting switch 5c. It can be said that the vacuum circuit breaker 5b is provided in the panel housing 2 (the distribution board 1 has the vacuum circuit breaker 5b in the panel housing 2). Further, the vacuum circuit breaker 5b may be of an electric spring operation (capacitor trip) type. As shown in FIGS. 6, 7, and 14, the disconnecting switch (DS) 5c is provided in the high-voltage circuit 6H described later and is a device that opens and closes the high-voltage circuit 6H in a state where the high-voltage alternating current H (load current) is not flowing. The disconnecting switch 5c does not have a function of interrupting the current, and the disconnecting switch 5c is opened and closed after the current is interrupted by another circuit breaker. The disconnecting switch 5c may be provided, for example, between the instrument voltage transformer 7 (branch point of the voltage transformation branch circuit 6S) and the zero-phase voltage detector 10 (branch point of the zero-phase branch circuit 6Z). Furthermore, it can be said that the circuit breaker 5c is provided inside the panel housing 2 (the distribution board 1 has the circuit breaker 5c inside the panel housing 2). Also, the opening and closing of the circuit breaker 5c may be performed by hook operation.

[0056] <Circuit Protector 5d> As shown in FIGS. 12 to 15, the circuit protector (CP) 5d is provided between the instrument transformer 7 and the voltmeter 8 in the voltage transformation branch circuit 6S described later, and is a device capable of interrupting the voltage transformation branch circuit 6S. Furthermore, it can be said that the circuit protector 5d is provided inside the panel housing 2 (the distribution board 1 has the circuit protector 5d inside the panel housing 2).

[0057] <Current Transformer for Instrumentation 12(5e)> As shown in FIGS. 14 and 15, the current transformer for instrumentation (CT) 12 (hereinafter also referred to as "current transformer for instrumentation 5e") is provided in the high-voltage circuit 6H described later, and is a device that converts the high-voltage alternating current H flowing through the high-voltage circuit 6H into a transformed output current R of a smaller current. The transformed output current R output from the current transformer for instrumentation 5e is output outside the panel housing 2 via the transformed output terminal 13(5e') and the like described later. It can be said that the current transformer for instrumentation 5e is provided inside the panel housing 2 (the distribution board 1 has the current transformer for instrumentation 5e inside the panel housing 2). The number of turns (number of windings) of the winding of the current transformer for instrumentation 5e around the coil is not particularly limited. For example, it may be 10 or more and 10,000 or less, preferably 100 or more and 6,000 or less, more preferably 500 or more and 4,000 or less (such as 1,500 turns). Since it can be said that the number of turns of the high-voltage circuit 6H is 1 with respect to the number of turns of the current transformer for instrumentation 5e, the transformation ratio between the primary side (high-voltage circuit 6H side) and the secondary side (output side) of the current transformer for instrumentation 5e is 1: the number of turns of the current transformer for instrumentation 5e. The value of the transformation ratio is also not particularly limited. For example, it may be 1:10 or more and 1:10,000 or less, preferably 1:100 or more and 1:6,000 or less, more preferably 1:500 or more and 1:4,000 or less (such as 1:1,500). The rated current range in the current transformer 5e for the instrument is not particularly limited. For example, it may be 15 A or more and 1800 A or less, preferably 20 A or more and 1650 A or less, and more preferably 25 A or more and 1500 A or less (such as 60 A). In addition, the maximum value of the current range actually flowing through the current transformer 5e for the instrument may be 10 times or more and 20 times or less the maximum value of the rated current range of the current described above. For example, it may be 100 kA or less, preferably 80 kA or less, and more preferably 60 kA or less (such as 40 kA).

[0058] As shown in FIGS. 14 and 15, the current output terminal 13 (hereinafter also referred to as the "current output terminal 5e'") is a terminal capable of outputting the output from the current transformer 5e for the instrument to the electrical and electronic equipment provided outside the above-described panel housing 2. It can be said that the current output terminal 5e' is provided inside the panel housing 2 (the distribution board 1 has the current output terminal 5e' inside the panel housing 2). Here, the electrical and electronic equipment provided outside the panel housing 2 is not particularly limited. For example, it may be the digital multi-relay 27 described later, the watt-hour meter 28 described later, or the like. The current output terminal 5e' may be provided on a terminal block inside the panel housing 2. As shown in FIGS. 14 and 15, the circuit between the current transformer 5e and the current output terminal 5e' is the current output circuit 6R'. It can also be said that this current output circuit 6R' is provided inside the panel housing 2 (the distribution board 1 has the current output circuit 6R' inside the panel housing 2). The current output circuit 6R' may be a set of multiple wires according to the power distribution method (power transmission method), such as a set of three wires for three-phase three-wire (3φ3W). In the current output circuit 6R', a current output current R of a smaller current (for example, about 10 A) corresponding to the high-voltage alternating current H flowing through the high-voltage circuit 6H is output from the current transformer 5e for the instrument and flows through the current output circuit 6R'. The above-described current output terminal 5e' may be provided at one end of the current output circuit 6R' closer to the outside of the panel housing 2. The current output terminal 5e' may be provided on the exterior of the panel housing 2, and only the side of the hole for inserting the input terminal may be exposed outside the panel housing 2.

[0059] <Power supply circuit breaker 5f, spare circuit breaker 5g, etc.> As shown in FIG. 14, the power cutoff switch 5f is provided in a power branch circuit 6D branched from between the circuit protector 5d and the voltmeter 8 in the above-described transformer output circuit 6S'. It is a device capable of cutting off the power branch circuit 6D. It can be said that the power cutoff switch 5f is provided inside the panel housing 2 (the distribution board 1 has the power cutoff switch 5f inside the panel housing 2). For example, when the power branch circuit 6D is connected to a power storage unit 24 such as an uninterruptible power supply device outside the panel housing 2, the power cutoff switch 5f cuts off the between the power storage unit 24 and the circuit protector 5d (or the voltmeter 8). The power cutoff switch 5f may be a wiring cutoff switch or a leakage cutoff switch.

[0060] As shown in FIG. 14, the spare cutoff switch 5g is provided in a spare branch circuit 6Y branched from between the circuit protector 5d and the voltmeter 8 in the above-described transformer output circuit 6S'. It is a device capable of cutting off the spare branch circuit 6Y. It can be said that the spare cutoff switch 5g is provided inside the panel housing 2 (the distribution board 1 has the spare cutoff switch 5g inside the panel housing 2). The spare cutoff switch 5g may be a wiring cutoff switch or a leakage cutoff switch like the power cutoff switch 5f. Also, the distribution board 1 may be provided at one end of the spare branch circuit 6Y closer to the outside of the panel housing 2 and have a spare output terminal (not shown) capable of outputting the transformer output current S from the above-described instrument transformer 7 to an electrical and electronic device outside the panel housing 2. In this case, the spare output terminal may also be provided on a terminal block inside the panel housing 2. As shown in FIG. 14, the voltage test terminal (VTT) 5h is provided between the voltmeter 8 and the circuit protector 5d (or the branch point of the power branch circuit 6D and the spare branch circuit 6Y) in the above-described transformer output circuit 6S'. It is a terminal for testing and measuring the instrument transformer 7 and the transformer output current S. It can be said that the voltage test terminal 5h is provided inside the panel housing 2 (the distribution board 1 has the voltage test terminal 5h inside the panel housing 2). As shown in FIG. 14, the current test terminal (CTT) 5j is provided between the current transformer 5e for instrument and the current output terminal 5e' in the current output circuit 6R', and is a terminal for test measurement of the current transformer 5e and the current output current R. It can be said that the current test terminal 5j is provided inside the panel housing 2 (the distribution board 1 has the current test terminal 5j inside the panel housing 2).

[0061] <Low-voltage circuit 6L, high-voltage circuit 6H, transformer branch circuit 6S, zero-phase branch circuit 6Z> As shown in FIGS. 3 to 8 and 12 to 15, the low-voltage circuit 6L is a circuit that connects between the above-described low-voltage circuit breaker 3 and the transformer 4 (low-voltage terminal 4L) and conducts a low-voltage alternating current L, and can also be said to be a low-voltage cable. Also, since the circuit connecting between the low-voltage circuit breaker 3 and any device outside the panel housing 2 (such as the conversion unit 22 of the power distribution system 20 described later) conducts a low-voltage alternating current L, it can be said that the circuit connecting between the low-voltage circuit breaker 3 and any device outside the panel housing 2 is also the low-voltage circuit 6L. The low-voltage circuit 6L may be grouped in a set of three for three-phase three-wire (3φ3W) or single-phase three-wire (1φ3W), or grouped in a set of two for single-phase two-wire (1φ2W), etc., depending on the power distribution method (power transmission method). In this case, the set of multiple low-voltage circuits 6L may be housed in a low-voltage pipe 6L' such as a single cable hose inserted through the low-voltage opening 2j of the panel housing 2 described above. As shown in FIGS. 3 to 8 and 12 to 15, the high-voltage circuit 6H is a circuit that connects between the above-described transformer 4 (high-voltage terminal 4H) and the high-voltage power transmission unit 5 and conducts a high-voltage alternating current H, and can also be said to be a high-voltage cable. In addition, since the circuit connecting between the high-voltage power transmission unit 5 and any device outside the panel housing 2 (such as the system K described later) also conducts a high-voltage alternating current H, it can be said that the circuit connecting between the high-voltage power transmission unit 5 and any device outside the panel housing 2 is also the high-voltage circuit 6H. The high-voltage circuit 6H also forms a set of three wires for three-phase three-wire (3φ3W) or single-phase three-wire (1φ3W), and a set of two wires for single-phase two-wire (1φ2W), etc. Depending on the power distribution method (power transmission method), a plurality of wires can be grouped into one set. In this case, the plurality of high-voltage circuits 6H in a set may be housed in a high-voltage pipe 6H' such as a single cable cylindrical body or a cable hose inserted through the high-voltage opening 2h of the above-described panel housing 2.

[0062] As shown in FIGS. 13 to 15, the transformer branch circuit 6S is a circuit that branches from the high-voltage circuit 6H inside the panel housing 2, and an instrument transformer 7 described later is provided. The transformer branch circuit 6S is a circuit that connects between the above-described high-voltage circuit 6H and the instrument transformer 7, and this transformer branch circuit 6S is provided inside the panel housing 2 (the first embodiment of the distribution board 1 has a transformer branch circuit 6S inside the panel housing 2). The transformer branch circuit 6S may form a set of three wires for three-phase three-wire (3φ3W), etc., and a plurality of wires may be grouped into one set depending on the power distribution method (power transmission method). The transformer branch circuit 6S may branch from any of the high-voltage circuits 6H. For example, when the distribution board 1 has a load switch 5a or the like, the transformer branch circuit 6S branches from between the zero-phase voltage detector 10 (branch point of the zero-phase branch circuit 6Z) in the high-voltage circuit 6H and the system K side. When the distribution board 1 has a vacuum circuit breaker 5b or a circuit breaker 5c or the like, the transformer branch circuit 6S may branch from between the vacuum circuit breaker 5b and the circuit breaker 5c in the high-voltage circuit 6H.

[0063] As shown in FIGS. 13 to 15, the zero-phase branch circuit 6Z is a circuit that branches from the above-described high-voltage circuit 6H, and a zero-phase voltage detector 10 described later is provided. The zero-phase branch circuit 6Z is a circuit that connects the high-voltage circuit 6H described above to the zero-phase voltage detector 10. This zero-phase branch circuit 6Z is provided inside the panel housing 2 (the distribution board 1 has the zero-phase branch circuit 6Z inside the panel housing 2). The zero-phase branch circuit 6Z may be grouped in multiple sets according to the power distribution method (power transmission method), such as three-phase three-wire (3φ3W), with three wires in one set. The zero-phase branch circuit 6Z may branch from any part of the high-voltage circuit 6H. For example, when the distribution board 1 has a load switch 5a or the like, the zero-phase branch circuit 6Z may branch from between the load switch 5a and the instrument transformer 7 (the branch point of the voltage transformation branch circuit 6S) in the high-voltage circuit 6H. When the distribution board 1 has a vacuum circuit breaker 5b, a circuit breaker 5c, or the like, the zero-phase branch circuit 6Z may branch from between the circuit breaker 5c and the system K side in the high-voltage circuit 6H.

[0064] <Instrument transformer 7, voltmeter 8, voltage transformation output terminal 9, etc.> As shown in FIGS. 4, 7, 12 to 15, the instrument transformer (Voltage Transformer, VT) 7 is provided in the voltage transformation branch circuit 6S described above and is a device that transforms (steps down) the high-voltage alternating current H flowing through the high-voltage circuit 6H into a lower-voltage voltage transformation output current S. The voltage transformation output current S output from the instrument transformer 7 is output outside the panel housing 2 via the voltage transformation output terminal 9 and the like described later. Conversely, the instrument transformer 7 is provided inside the panel housing 2 (the first embodiment of the distribution board 1 has the instrument transformer 7 inside the panel housing 2). Note that there may be not only one instrument transformer 7 in one distribution board 1 but also multiple (such as two) instrument transformers 7. The capacity of the instrument transformer 7 is not particularly limited. For example, it may be 10 VA or more and 500 VA or less, preferably 20 VA or more and 300 VA or less, and more preferably 40 VA or more and 200 VA or less (such as 100 VA). The instrument transformer 7 is not limited to its configuration and may be a transformer with three or more windings, but it will be mainly described as a two-winding transformer.

[0065] The instrument transformer 7, which is a two-winding transformer, for example, its primary side may be the high-voltage circuit 6H side, and its secondary side may be the voltmeter 8 side. In this case, the specific values are not particularly limited. For example, the voltage of the primary side, which is the high-voltage circuit 6H side, may be 5000V or more and 40000V or less, preferably 5500V or more and 30000V or less, more preferably 6000V or more and 25000V or less (such as 6600V or 22000V), or the voltage of the secondary side, which is the voltmeter 8 side, may be 10V or more and 600V or less, preferably 20V or more and 400V or less, more preferably 50V or more and 300V or less (such as 110V). The instrument transformer 7 may have a power fuse (PF) on its primary side and / or secondary side.

[0066] As shown in FIGS. 3, 6, 12 to 15, the voltmeter 8 is a device that measures the voltage of the high-voltage circuit 6H described above based on the transformed output current S output from the instrument transformer 7 described above, and it can also be said that it is connected to the high-voltage circuit 6H via the instrument transformer 7. In addition, the voltmeter 8 is provided in the panel housing 2 (the distribution board 1 has the voltmeter 8 in the panel housing 2). The voltmeter 8 may have any configuration, and it may be an analog voltmeter or the like. As shown in FIGS. 12 to 14, the circuit between the instrument transformer 7 and the voltmeter 8 is the transformed output circuit 6S'. This transformed output circuit 6S' is also provided in the panel housing 2 (the distribution board 1 has the transformed output circuit 6S' in the panel housing 2). The transformed output circuit 6S' may be a set of multiple wires according to the power distribution method (power transmission method), such as a set of three wires for three-phase three-wire (3φ3W). In the transformed output circuit 6S', a transformed output current S (at least a part thereof) of a lower voltage (for example, 110V) corresponding to the voltage of the high-voltage alternating current H flowing in the high-voltage circuit 6H is output from the instrument transformer 7 and flows through the transformed output circuit 6S'.

[0067] As shown in FIGS. 12 to 15, the transformer output terminal 9 is a terminal capable of outputting the transformer output current S from the above-described instrument transformer 7 to electrical and electronic equipment outside the panel housing 2. The transformer output terminal 9 is provided inside the panel housing 2 (the distribution board 1 has the transformer output terminal 9 inside the panel housing 2). Here, the electrical and electronic equipment provided outside the panel housing 2 is not particularly limited, and for example, it may be a power storage unit 24 described later, a watt-hour meter 28 described later, etc. In this case, it can also be said that the transformer output terminal 9 is a power output terminal. The transformer output terminal 9 may also be provided on a terminal block inside the panel housing 2. In addition, in one distribution board 1, there may be not only one transformer output terminal 9 but also a plurality of them.

[0068] As shown in FIGS. 12 to 15, the circuit between the instrument transformer 7 and the transformer output terminal 9 is the above-described transformer output circuit 6S' and a power supply branch circuit 6D branched from between the instrument transformer 7 and the voltmeter 8 in the transformer output circuit 6S'. This power supply branch circuit 6D is also provided inside the panel housing 2 (the distribution board 1 has the power supply branch circuit 6D inside the panel housing 2). The power supply branch circuit 6D may be a set of multiple lines according to the power distribution method (power transmission method), such as a set of three lines for three-phase three-wire (3φ3W). Also in the power supply branch circuit 6D, a transformer output current S (at least a part of it) obtained by stepping down the voltage of the high-voltage alternating current H flowing through the high-voltage circuit 6H (for example, 110V, etc.) is output from the instrument transformer 7 and flows into the power supply branch circuit 6D. The above-described transformer output terminal 9 may be provided at one end of the power supply branch circuit 6D closer to the outside of the panel housing 2. The transformer output terminal 9 may be provided on the (outer casing of) the panel housing 2, and only the side of the hole for inserting the input terminal may be exposed outside the panel housing 2.

[0069] <Zero-phase voltage detector 10, zero-phase voltage output terminal 11, etc.> As shown in FIGS. 13 to 15, the zero-phase voltage detector (Zero Phase Potential Device, ZPD) 10 is provided in the zero-phase branch circuit 6Z described above, and is used to detect whether a ground fault (such as a complete single-line ground fault in a three-phase three-wire system) occurs in any of the systems such as the high-voltage circuit 6H side of the power distribution system 20 described later, and whether a zero-phase voltage is generated on the high-voltage circuit 6H side. Note that the zero-phase voltage detector 10 is also called a zero-phase voltage transformer (Zero Phase Voltage Transformer, ZVT) or the like. The output from the zero-phase voltage detector 10 is output outside the panel housing 2 via the zero-phase voltage output terminal 11 described later. Conversely, the zero-phase voltage detector 10 is provided inside the panel housing 2 (the first embodiment of the distribution board 1 has the zero-phase voltage detector 10 inside the panel housing 2). In addition, the zero-phase voltage detector 10 may be of type A grounding (EA).

[0070] As shown in FIGS. 13 to 15, the zero-phase voltage output terminal 11 is a terminal capable of outputting the output from the zero-phase voltage detector 10 to the electrical and electronic equipment provided outside the panel housing 2 described above. The zero-phase voltage output terminal 11 is provided inside the panel housing 2 (the distribution board 1 has the zero-phase voltage output terminal 11 inside the panel housing 2). Here, the electrical and electronic equipment provided outside the panel housing 2 is not particularly limited, and for example, it may be a ground fault overvoltage relay 25 described later. The zero-phase voltage output terminal 11 may be provided on a terminal block (Terminal Block, TB) inside the panel housing 2. Note that there may be not only one zero-phase voltage output terminal 11 in one distribution board 1, but also a plurality of them.

[0071] As shown in FIGS. 13 to 15, the circuit between the zero-phase voltage detector 10 and the zero-phase voltage output terminal 11 is the zero-phase voltage output circuit 6Z', and this zero-phase voltage output circuit 6Z' is also provided inside the panel housing 2 (the distribution board 1 has the zero-phase voltage output circuit 6Z' inside the panel housing 2). The zero-phase voltage output circuit 6Z' may be a set of multiple wires according to the power distribution method (power transmission method), such as a set of three wires for a three-phase three-wire (3φ3W) system. In the zero-phase voltage output circuit 6Z', when the zero-phase voltage detector 10 detects a zero-phase voltage, a zero-phase voltage output current Z of a lower voltage (for example, about 6 to 9 V, etc.) corresponding to the zero-phase voltage generated in the power distribution system 20 or the like is output from the zero-phase voltage detector 10 and flows into the zero-phase voltage output circuit 6Z'. One end of the zero-phase voltage output circuit 6Z' near the outside of the panel housing 2 may be provided with the above-described zero-phase voltage output terminal 11. The zero-phase voltage output terminal 11 may be provided on the (outer casing of) the panel housing 2, and only the side of the hole for inserting the input terminal may be exposed outside the panel housing 2.

[0072] <Modification Example 3 of the First Embodiment of the Switchboard 1> As shown in FIG. 15, Modification Example 3 of the first embodiment of the switchboard 1 has instrument transformers 7, instrument current transformers 12 provided in at least two of the three-phase three-wire lines of the high-voltage circuit 6H, and their output terminals 9, 13, or has a grounding resistor 14 and a zero-phase current transformer 15 and its output terminal 16 provided between the transformer 4 and the ground point 4', or has a single-phase transformer 17. These are the main differences.

[0073] <Instrument transformers 7, instrument current transformers 12, their output terminals 9, 13> As shown in FIG. 15, in Modification Example 3, each of the above-described instrument transformers 7 is connected to a voltage transformation branch circuit 6S branched from at least two of the three-phase three-wire lines of the high-voltage circuit 6H. In this case, each of the instrument transformers 7 strictly transforms the high-voltage alternating current H flowing through at least two of the three-phase three-wire lines of the high-voltage circuit 6H into a lower-voltage voltage transformation output current S through the voltage transformation branch circuit 6S branched therefrom. Also, at least two instrument transformers 7 are provided in the panel housing 2 (Modification Example 3 of the first embodiment of the switchboard 1 has at least two instrument transformers 7 in the panel housing 2). As shown in Fig. 15, in Modification 3, the current transformer 12(5e) for instruments described above is provided in at least two of the three-phase three-wire lines of the high-voltage circuit 6H. In this case, each of the current transformers 12(5e) for instruments will strictly convert the high-voltage alternating current H flowing in at least two of the three-phase three-wire lines of the high-voltage circuit 6H into a converted output current R with a smaller current. Also, at least two current transformers 12(5e) for instruments are provided in the panel housing 2 (Modification 3 of the first embodiment of the distribution board 1 has at least two current transformers 12(5e) for instruments) in the panel housing 2). As shown in Fig. 15, in Modification 3, the voltage output terminals 9 capable of outputting the voltage output current S from the voltage transformer 7 to the electrical and electronic equipment outside the panel housing 2 are provided in at least two places such as inside the above-mentioned panel housing 2 (Modification 3 of the first embodiment of the distribution board 1 has at least two voltage output terminals 9 inside the panel housing 2, etc.). Also, in Modification 3, the converted output terminals 13 capable of outputting the converted output current R from the current transformer 12 to the electrical and electronic equipment outside the panel housing 2 are provided in at least two places such as inside the above-mentioned panel housing 2 (Modification 3 of the first embodiment of the distribution board 1 has at least two converted output terminals 13 inside the panel housing 2, etc.).

[0074] <Grounding resistor 14, zero-phase current transformer 15, zero-phase converted output terminal 16, etc.> As shown in Fig. 15, the grounding resistor 14 is a resistor provided in the circuit (so-called grounding circuit) between the above-mentioned transformer 4 and the grounding point 4'. Incidentally, the grounding resistor 14 is also called a neutral grounding resistor (NGR), etc. The resistance value of the grounding resistor 14 is not particularly limited. For example, it may be 10 Ω or less, or 100 Ω or less, or may be 1 Ω or more and 10 Ω or less, or 1 Ω or more and 100 Ω or less. Also, the grounding resistor 14 is provided in the panel housing 2 (the distribution board 1 has the grounding resistor 14 in the panel housing 2). As shown in Fig. 15, the zero-phase current transformer (ZCT) 15 is provided between the above-described grounding resistor 14 and the grounding point 4'. It is a device that detects whether a ground fault (such as a complete single-line ground fault in a three-phase three-wire system) has occurred in any of the systems such as the high-voltage circuit 6H side of the power distribution system 20 or the transformer 4 described later, and whether a zero-phase current has been generated in the high-voltage circuit 6H side or the transformer 4, etc. Also, the output from the zero-phase current transformer 15 is output outside the panel housing 2 via the zero-phase current output terminal 16 described later. Conversely, the zero-phase current transformer 15 is provided inside the panel housing 2 (the first embodiment of the distribution board 1 has the zero-phase current transformer 15 inside the panel housing 2). Incidentally, a disconnection terminal 4b may also be provided in the grounding circuit (such as between the zero-phase current transformer 15 and the grounding point 4') between the transformer 4 and the grounding point 4'. Incidentally, the zero-phase current transformer 15 may be provided between the disconnection terminal 4b and the grounding point 4'.

[0075] As shown in Fig. 15, the zero-phase current output terminal 16 is a terminal capable of outputting the output from the zero-phase current transformer 15 to the electrical and electronic equipment provided outside the above-described panel housing 2. The zero-phase current output terminal 16 is provided inside the panel housing 2 (the distribution board 1 has the zero-phase current output terminal 16 inside the panel housing 2). Here, the electrical and electronic equipment provided outside the panel housing 2 is not particularly limited, and for example, it may be a ground fault overcurrent relay 29 described later, etc. The zero-phase current output terminal 16 may be provided on a terminal block (TB) inside the panel housing 2. Incidentally, in one distribution board 1, there may be not only one zero-phase current output terminal 16 but also a plurality of them.

[0076] As shown in FIG. 15, the circuit between the zero-phase current transformer 15 and the zero-phase current output terminal 16 is the zero-phase current output circuit 6Z”. This zero-phase current output circuit 6Z” is also provided inside the switchboard housing 2 (the distribution board 1 has the zero-phase current output circuit 6Z” inside the switchboard housing 2). The zero-phase current output circuit 6Z” consists of one wire for single-phase single-wire (1φ1W), two wires in a set for single-phase two-wire (1φ2W), and three wires in a set for single-phase three-wire (1φ3W), three-phase three-wire (3φ3W), etc. Depending on the power distribution method (power transmission method), multiple wires can be grouped as a set. In the zero-phase current output circuit 6Z”, when the zero-phase current transformer 15 detects a zero-phase current, a zero-phase current output current Z’ of a smaller current (for example, about 0.1 A or about 1 A, etc.) corresponding to the zero-phase current generated in the power distribution system 20, the grounding circuit, etc. is output from the zero-phase current transformer 15 and flows through the zero-phase current output circuit 6Z”. One end of the zero-phase current output circuit 6Z” closer to the outside of the switchboard housing 2 may be provided with the above-mentioned zero-phase current output terminal 16. The zero-phase current output terminal 16 is provided on the (outer casing of) the switchboard housing 2, and only the side of the hole for inserting the input terminal may be exposed outside the switchboard housing 2.

[0077] <Single-phase transformer 17, etc.> As shown in FIG. 15, the single-phase transformer 17 is a transformer provided in the above-mentioned low-voltage circuit 6L (particularly, the circuit between the low-voltage circuit breaker 3 and the transformer 4). It is a device that transforms (step-down, etc.) the low-voltage alternating current L from the transformer 4 and the low-voltage alternating current L from outside the switchboard housing 2, that is, a so-called transformer. Different from the delta connection (Δ connection) and star connection (Y connection) of the above-mentioned transformer 4, single-phase one-wire (1φ1W) and single-phase three-wire (1φ3W) are input and output (for example, the primary side is single-phase one-wire (1φ1W) and the secondary side is single-phase three-wire (1φ3W), etc.). Also, the single-phase transformer 17 is provided inside the switchboard housing 2 (the distribution board 1 has the single-phase transformer 17 inside the switchboard housing 2) and may be grounded. As shown in FIG. 15, in Modification 3, a single-phase voltage transformer circuit breaker 18 may be provided. This single-phase voltage transformer circuit breaker 18 is a circuit breaker provided in the above-described low-voltage circuit 6L (particularly, the circuit between the single-phase transformer 17 and the low-voltage circuit breaker 3). The single-phase voltage transformer circuit breaker 18 may be a wiring circuit breaker, or may be a leakage circuit breaker, among others. The single-phase transformer 17 and the single-phase voltage transformer circuit breaker 18 described so far may each exist only once in one switchboard 1, or a plurality (for example, four, five, etc.) may exist. The number of single-phase transformers 17 and the number of single-phase voltage transformer circuit breakers 18 may be the same or different. The low-voltage circuit 6L passing through the single-phase transformer 17 and the single-phase voltage transformer circuit breaker 18 may be connected to the conversion unit 22 outside the switchboard housing 2, and the conversion unit 22 may be connected to the power generation unit 21 or the energy storage device 37.

[0078] Further, in Modification 3 of the first embodiment of the switchboard 1, as the high-voltage power transmission unit 5, it may have a high-voltage switch (load switch) 5a, or may have an instrument transformer 7 and a voltage output terminal 9 provided via a voltage division branch circuit 6S to at least two of the three-phase three-wire of the above-described high-voltage circuit 6H. Alternatively, it may have an instrument transformer 7 and a voltage output terminal 9, or may have a circuit protector 5d, a voltmeter 8, a zero-phase voltage detector 10, a zero-phase voltage output terminal 11, or may have another circuit protector 5d between the instrument transformer 7 provided via a voltage division branch circuit 6S to at least two wires and the voltage output terminal 9. Furthermore, in Modification 3 of the first embodiment of the switchboard 1, a clamp-type instrument current transformer 3' is provided in the low-voltage circuit breaker 3. The configurations, functions, effects, and usage modes of Modification 3 and the like of the first embodiment of the switchboard 1 are the same as those of the first embodiment of the switchboard 1 and its Modifications 1 and 2.

[0079] <Second Embodiment of Switchboard 1, Receiving and Distributing Switchboard 1'> As shown in FIGS. 16 to 24, the main feature of the second embodiment of the switchboard 1 and the receiving and distributing switchboard 1' is that a low-voltage switchboard housing (section) 2A and a high-voltage switchboard housing (section) 2B described later are supported by the transformer 4. Here, the second embodiment of the distribution board 1 also includes a board housing 2, a low-voltage circuit breaker 3 capable of interrupting the low-voltage alternating current L from outside the board housing 2, a transformer 4 that transforms the low-voltage alternating current L passing through the low-voltage circuit breaker 3 into a higher-voltage high-voltage alternating current H, and a high-voltage power transmission unit 5 that transmits the high-voltage alternating current H from the transformer 4 outside the board housing 2. On the other hand, the receiving and distribution board 1' is a board having a board housing 2 and a transformer 4 connected between the power grid K and a load capable of consuming the power received from the power grid K outside the board housing 2. However, in terms of the exterior of the second embodiment of the distribution board 1 and the receiving and distribution board 1', the weight of the low-voltage board housing (section) 2A in which the low-voltage circuit breaker 3 is provided inside, and the weight of the high-voltage board housing (section) 2B in which the high-voltage switch 5a or the high-voltage circuit breaker 5b is provided inside are supported by the transformer 4, which is common. The common exterior enables both "space saving", "shortening of the circuit", and "ease of installation". In addition, the second embodiment of the distribution board 1 and the receiving and distribution board 1' can both be said to be "smart boards". Hereinafter, the second embodiment of the distribution board 1 and the board housing 2 of the receiving and distribution board 1' with a common exterior will be explained in detail.

[0080] <The board housing 2 in the second embodiment of the distribution board 1 and the receiving and distribution board 1'> As shown in FIGS. 16 to 24, the board housing 2 in the second embodiment of the distribution board 1 and the receiving and distribution board 1' includes a low-voltage board housing (section) 2A described later and a high-voltage board housing (section) 2B described later. Note that the board housing 2 may include a housing of the board other than the low-voltage board housing (section) 2A and the high-voltage board housing (section) 2B. For example, it may include a power storage unit 24 such as an uninterruptible power supply device described later, a ground fault overvoltage relay 25, a control device 26 of the conversion unit 22, a digital multi-relay 27, a watt-hour meter 28, a ground fault overcurrent relay 29, and a device housing 20a such as a control box or a cubicle that incorporates a communication device or the like. Also, the weight of the board housing 2 (the sum of the weight of the low-voltage board housing (section) 2A and the weight of the high-voltage board housing (section) 2B) may be lighter than the weight of the transformer 4 described above. The specific value of the weight of the board housing 2 is not particularly limited. For example, it may be 100 kg or more and 500 kg or less, preferably 150 kg or more and 450 kg or less, and more preferably 200 kg or more and 400 kg or less (such as 300 kg). Still, in the substation switchboard 1', the high-voltage alternating current H received from the system K is input from the high-voltage terminal 4H to the transformer 4, stepped down by the transformer 4, and then output from the low-voltage terminal 4L to the load 30 or the like. Therefore, in the switchboard 1 (power distribution system 20), it was the high-voltage output terminal 4H, but in the substation switchboard 1' (substation power distribution system 20'), it can be said to be the high-voltage input terminal 4H. In the switchboard 1 (power distribution system 20), it was the low-voltage input terminal 4H, but in the substation switchboard 1' (substation power distribution system 20'), it can be said to be the low-voltage output terminal 4H. Therefore, the transformer 4 in the switchboard 1 (power distribution system 20) and the substation switchboard 1' (substation power distribution system 20') can be said to commonly have the high-voltage terminal 4H and the low-voltage terminal 4L. Also, in FIG. 22, among the three (three lines) high-voltage terminals 4H that protrude upward from the upper surface U of the transformer 4 into the switchboard housing 2, instrument current transformers 12 (5e) shown in a square shape are provided on two lines. Also, since the instrument current transformer 12 (5e) is provided on the high-voltage terminal 4H that protrudes upward into the switchboard housing 2, of course, the instrument current transformer 12 (5e) will exist inside the switchboard housing 2.

[0081] <Low-voltage switchboard housing (section) 2A, high-voltage switchboard housing (section) 2B> As shown in FIGS. 16 to 21 and 23, the low-voltage switchboard housing (section) 2A is included in the above-described switchboard housing 2 and is a switchboard housing in which the above-described low-voltage circuit breaker 3 is provided inside. Also, the high-voltage switchboard housing (section) 2B is included in the above-described switchboard housing 2 and is a switchboard housing in which the above-described high-voltage switch 5a or high-voltage circuit breaker 5b is provided inside. Still, the weights of these switchboard housings (sections) 2A and 2B may be supported by the above-described transformer 4. As such a support, the high-voltage switchboard housing (section) 2B is attached to the above-described transformer 4 from above, the low-voltage switchboard housing (section) 2A is attached to the high-voltage switchboard housing (section) 2B from one side (for example, from the front) in plan view, and the lower end of the low-voltage switchboard housing (section) 2A may extend to the lower part of the transformer 4. Here, "the lower end of the low-voltage switchboard housing (section) 2A extends to the lower part of the transformer 4" means that the lower end of the low-voltage switchboard housing (section) 2A extends to the vicinity of the lower end of the transformer 4 (above the lower end of the transformer 4 and within the range of the part from 1 / 4 (one-fourth) to 1 / 3 (one-third) of the vertical length of the transformer 4 from the bottom), or the lower end of the low-voltage switchboard housing (section) 2A is at approximately the same height as the lower end of the transformer 4. However, it does not include the case where the lower end of the low-voltage switchboard housing (section) 2A extends below the lower end of the transformer 4. Also, even if the lower end of the low-voltage switchboard housing (section) 2A is at approximately the same height as the lower end of the transformer 4, the low-voltage switchboard housing (section) 2A may not be installed with respect to the installation surface, and only the transformer 4 may be installed with respect to the installation surface. Conversely, the low-voltage switchboard housing (section) 2A may also be installed with respect to the installation surface.

[0082] The low-voltage switchboard housing (section) 2A and the high-voltage switchboard housing (section) 2B are not particularly limited in their specific configurations. For example, each of them may be formed in a substantially rectangular parallelepiped shape or a cubic shape as a whole, and is also called a cubicle. Incidentally, the upper surfaces (ceiling plates) of the low-voltage switchboard housing (section) 2A and the high-voltage switchboard housing (section) 2B may be inclined backward. Hereinafter, the low-voltage switchboard housing (section) 2A and the high-voltage switchboard housing (section) 2B will be mainly described as being substantially rectangular parallelepiped-shaped respectively. The low-voltage switchboard housing (section) 2A and the high-voltage switchboard housing (section) 2B may each have one or more doors (such as two double-leaf doors or one side-opening door) 2Aa, 2Ba that can be opened and closed. In particular, the side where the door 2Ba is provided in the low-voltage switchboard housing (section) 2A may be defined as the front side of the low-voltage switchboard housing (section) 2A (not only for the low-voltage switchboard housing (section) 2A but also for the second embodiment of the switchboard 1 and the receiving and distributing switchboard 1'). Also, the side where the door 2Ba is provided in the high-voltage switchboard housing (section) 2B may be defined as the rear side of the high-voltage switchboard housing (section) 2B (not only for the high-voltage switchboard housing (section) 2B but also for the second embodiment of the switchboard 1 and the receiving and distributing switchboard 1'). Incidentally, the doors 2Aa, 2Ba in the low-voltage switchboard housing (section) 2A and the high-voltage switchboard housing (section) 2B may each be in the form of a sweep-out window. Alternatively, the low-voltage switchboard housing (section) 2A and the high-voltage switchboard housing (section) 2B may be partitioned by a partition plate 2S (see FIGS. 16 and 23(a)). Also, since the front-rear length of the high-voltage switchboard housing (section) 2B is longer than the front-rear length of the transformer 4, the rear portion 2Bb of the high-voltage switchboard housing (section) 2B may protrude rearward beyond the transformer 4 (see FIG. 16). Further, a projecting eaves portion 2Ab may be provided at the upper end of the low-voltage switchboard housing (section) 2A (see FIG. 16).

[0083] The sizes of the switchboard housings (sections) 2A and 2B are not particularly limited. For the low-voltage switchboard housing (section) 2A, for example, the left-right length (width) is 990 mm, the front-rear length (depth) excluding the eaves portion 2Ab is 350 mm (480 mm including the eaves portion 2Ab), the up-down length (height) on the front side is 1860 mm, and the up-down length on the rear side is 1850 mm. Or the left-right length is 700 mm or more and 1600 mm or less, preferably 800 mm or more and 1400 mm or less, more preferably 900 mm or more and 1200 mm or less. The front-rear length excluding the eaves portion 2Ab is 200 mm or more and 650 mm or less, preferably 250 mm or more and 550 mm or less, more preferably 300 mm or more and 450 mm or less (350 mm or more and 800 mm or less, preferably 400 mm or more and 700 mm or less, more preferably 450 mm or more and 600 mm or less including the eaves portion 2Ab). The up-down length on the front side or the rear side may be 1550 mm or more and 2450 mm or less, preferably 1650 mm or more and 2250 mm or less, more preferably 1750 mm or more and 2050 mm or less. Regarding the size of the high-voltage panel housing (section) 2B, for example, the left-right length (width) is 990 mm, the front-back length (depth) is 950 mm, the up-down length (height) on the front side is 1070 mm, and the up-down length on the rear side is 1040 mm; or the left-right length is 700 mm or more and 1600 mm or less, preferably 800 mm or more and 1400 mm or less, more preferably 900 mm or more and 1200 mm or less; or the front-back length is 650 mm or more and 1550 mm or less, preferably 750 mm or more and 1350 mm or less, more preferably 850 mm or more and 1150 mm or less; or the up-down length on the front side or the rear side is 800 mm or more and 1700 mm or less, preferably 900 mm or more and 1500 mm or less, more preferably 1000 mm or more and 1300 mm or less.

[0084] The low-voltage panel housing (section) 2A and the high-voltage panel housing (section) 2B may have an air intake port 2P for inhaling air from the outside to the inside and an exhaust port 2d for discharging air from the inside to the outside. The positions of these air intake port 2p and exhaust port 2d are not particularly limited. For example, the air intake port 2p may be provided on the rear surface of the low-voltage panel housing (section) 2A (opening into the gap with the transformer 4) or on the lower surface of the rearward protruding rear portion 2Bb of the high-voltage panel housing (section) 2B. Also, the exhaust port 2d may be provided on the lower surface of the eaves portion 2Ab of the low-voltage panel housing (section) 2A. By providing the air intake port 2p and the exhaust port 2d at these locations, it can be said that they are less conspicuous than when a gallery or the like is provided on the side surface of each panel housing (section) 2A, 2B, and the appearance is improved. Generally speaking, the air intake port 2p may be provided at the lower part of the low-voltage panel housing (section) 2A and the high-voltage panel housing (section) 2B, and the exhaust port 2d may be provided at the low-voltage panel housing (section) 2A and the high-voltage panel housing (section) 2B (above the transformer 4). Here, an opening (so-called ventilation port) through which air passes may also be provided in the partition plate 2S between the low-voltage panel housing (section) 2A and the high-voltage panel housing (section) 2B. Since the air inside the high-voltage panel housing (section) 2B passes to the inside of the low-voltage panel housing (section) 2A which is the outside, it can be said that this ventilation port is an exhaust port 2d for the high-voltage panel housing (section) 2B and an air intake port 2p for the low-voltage panel housing (section) 2A. In addition, the low-voltage switchboard housing (section) 2A may have an insertion section 2Ac for inserting a low-voltage circuit breaker 3 which is a bus plug-in breaker (see FIGS. 16, 17, and 20). In particular, the low-voltage circuit breaker 3 of the bus plug-in breaker in a state of being inserted into this insertion section 2Ac is shown in FIG. 23(b). Note that the low-voltage circuit breaker 3 may not only be inserted into this insertion section 2Ac but also be disposed inside the high-voltage switchboard housing (section) 2B (from the perspective of the low-voltage switchboard housing (section) 2A, it is, so to speak, on the back side), and the low-voltage circuit breaker 3 disposed on this back side does not have to be a bus plug-in breaker. Also, an insertion hole for a high-voltage cable which is a high-voltage electric circuit 6H may be provided on the lower surface of the rear protruding rear section 2Bb in the high-voltage switchboard housing (section) 2B. As a result, the high-voltage cable will hang downward from the lower surface of the rear section 2Bb of the high-voltage switchboard housing (section) 2B, and even if the high-voltage electric circuit 6H (high-voltage cable) is disposed, it will not interfere with the front-to-rear length of the second embodiment of the switchboard 1 or the switchboard 1'. Furthermore, an insertion hole for a low-voltage cable which is a low-voltage electric circuit 6L may also be provided on the lower surface of the low-voltage switchboard housing (section) 2A. As a result, the low-voltage cable will hang downward from the lower surface of the low-voltage switchboard housing (section) 2A, and even if the low-voltage electric circuit 6L (low-voltage cable) is disposed, it will not interfere with the front-to-rear length of the second embodiment of the switchboard 1 or the switchboard 1'.

[0085] <The transformer 4, the hanging tool 4T, etc. in the second embodiment of the switchboard 1 and the switchboard 1'> On the other hand, in the second embodiment of the switchboard 1 and the switchboard 1', from the perspective of the transformer 4, it can be said that the transformer 4 supports the weight of the above-described low-voltage switchboard housing (section) 2A and the weight of the above-described high-voltage switchboard housing (section) 2B. Also, the transformer 4 may be a two-winding transformer (two-winding transformer) having a primary winding and a secondary winding, a three-winding transformer (three-winding transformer) having a primary winding, a secondary winding, and a tertiary winding, or a transformer with four or more windings in the second embodiment of the switchboard 1 and the switchboard 1'. In addition, the transformer 4 may have a hanging tool 4T which will be described later.

[0086] As shown in FIG. 16, the lifting tool 4T is a part that hooks the crane hook itself, the wire for the sling, the ring, etc. at the tip of the wire rope when lifting, transporting, loading, installing, etc. the transformer 4 itself, or the entire second embodiment of the switchboard 1 or the entire power receiving and distributing board 10 with a crane or the like. The specific configuration of the lifting tool 4T is not particularly limited, and for example, it may be hook-shaped or annular. The position where the lifting tool 4T is provided may be at least an eccentric position on one side in the plan view of the transformer 4. This eccentric distance is such that when lifted, the entire second embodiment of the switchboard 1 or the entire power receiving and distributing board 10 is substantially horizontal, depending on the weight of the later-described low-voltage panel housing (part) 2A after being cantilevered. Two or more lifting tools 4T may be provided for one transformer 4. For example, they may be provided in a pair on the left and right near the remaining two sides (the left side and the right side) other than the two sides (the front side and the rear side) on one side and the other side in the plan view of the above-described upper surface 4U. Alternatively, only one may be provided (that is, near the approximate center in the plan view of the above-described upper surface 4U). Also, the lifting tool 4T may be provided at a position other than an eccentric position on one side in the plan view of the transformer 4. For example, it may be provided at a position that is not eccentric (such as the approximate center position in the front-rear direction). The reference numeral of the lifting tool at this non-eccentric position in FIG. 16 is 4T'. The weight of the transformer 4 in the second embodiment of the switchboard 1 and the power receiving and distributing board 1' described so far may be heavier than the weight of the board housing 2 (the sum of the weight of the low-voltage panel housing (part) 2A and the weight of the high-voltage panel housing (part) 2B) to be described later. The specific value of the weight of the transformer 4 is not particularly limited, and for example, it may be 1000 kg or more and 2000 kg or less, preferably 1300 kg or more and 1800 kg or less, and more preferably 1400 kg or more and 1700 kg or less (such as 1550 kg).

[0087] As shown in FIG. 24 and the like, the transformer 4 in the second embodiment of the switchboard 1 and the receiving and distributing switchboard 1' is a three-winding transformer. However, in the second embodiment of the switchboard 1 and the receiving and distributing switchboard 1', a two-winding transformer may also be used, and grounding of type B (EB) from the transformer 4 or grounding of type D (ED) via the grounding resistor 14 and the disconnection terminal 4b may be performed. In addition, as shown in FIG. 24 and the like, in the second embodiment of the switchboard 1 and the receiving and distributing switchboard 1', an instrument current transformer 2q (partially a clamp-type current transformer 2q'), a fuse (F, Fuse) 2r, a voltmeter 2s, a voltage change-over switch (VS, Voltage change over Switch) 2t, an ammeter 2u, an ammeter change-over switch (AS, Ammeter change over Switch) 2v, and a wattmeter (for example, based on the output of the voltmeter 2s and the output of each instrument current transformer 2q, wattmeters for measuring the power of the load 30 (charger 30a) to be described later, the power of the power generation unit 21 to be described later, and the power of the power storage unit 24, etc.) 2w may also be provided in the low-voltage circuit 6L inside the low-voltage switchboard housing (section) 2A. Also, in the second embodiment of the switchboard 1 and the receiving and distributing switchboard 1', a synchronizing detector 2x may be provided between two transformer branch circuits 6S branched from the high-voltage circuit 6H inside the high-voltage switchboard housing (section) 2B, or alternatively, a power storage unit 24 such as an uninterruptible power supply device to be described later may also be provided. The configurations, functions, effects, and usage modes of the second embodiment of the other switchboard 1, the receiving and distributing switchboard 1', etc. are the same as those of the first embodiment of the switchboard 1 and its modification examples 1 to 3.

[0088] <Power distribution system 20> As shown in FIGS. 12 to 15, the power distribution system 20 includes the first and second embodiments of the switchboard 1 described above, a power generation unit 21 to be described later, and a conversion unit 22, and may have a power transmission board 23 including a connection circuit 6C, a vacuum circuit breaker 23a, a circuit breaker 23b, etc. to be described later, or a power storage unit 24 such as an uninterruptible power supply device to be described later and a ground fault overvoltage relay 25. The power distribution system 20 may have a control device 26 of the conversion unit 22 to be described later, a digital multi-relay 27, and a power storage unit. In a power distribution system 20, the number of switchboards 1 is one or more, and the number of cabinet enclosures 2 and the number of transformers 4 are the same, and the number may be one or more. Note that in the power distribution system 20 shown in Fig. 12, the number of switchboards 1 is more than one.

[0089] In addition, in the high-voltage circuit 6H outside the cabinet enclosure 2 of the power distribution system 20, between the cabinet enclosure 2 and the system K, there may be a voltage and current transformer (VCT) 31a, a power meter 31b for purchased electricity, a power meter 31c for sold electricity, or on a utility pole, there may be a pole air switch (PAS) 31d, a protective relay device (Storage Over Current Ground, SOG) 31e attached to the pole air switch 31d, etc. Note that in the voltage and current transformer 31a in Figs. 12 to 14, K indicates the system K side, and L indicates the load side. Also, each of the power meters 31b and 31c may be Class II electrical appliances, and the pole air switch 31d may separately incorporate a voltage transformer (VT), a zero-phase voltage detector (ZPD), a lightning arrester (LA), etc. These voltage and current transformers 31a, power meter 31b for purchased electricity, power meter 31c for sold electricity, pole air switch 31d, and protective relay device 31e may be considered to be possessed by the system on the system K side (power company side) described later. Note that in the power distribution system 20, the main difference in the first modification example shown in Fig. 13 is that the number of switchboards 1 is one, etc., and the main differences in the second modification example shown in Fig. 14 are that the number of switchboards 1 is one, and the high-voltage switch (load switch) 5a has become a high-voltage circuit breaker (vacuum circuit breaker) 5b and a circuit breaker 5c, etc.

[0090] <Power generation unit 21> As shown in FIGS. 12 to 15, the power generation unit 21 is a part that generates electricity, and it may have any configuration. For example, it may perform solar power generation, wind power generation, hydroelectric power generation, geothermal power generation, solar thermal power generation, power generation using heat existing in nature such as heat in the atmosphere, or power generation using biomass (organic matter derived from animals and plants that can be used as an energy source). In addition, the power generation unit 21 may perform power generation using ocean thermal energy conversion, wave power, tidal current (ocean current), or tide.

[0091] In one power distribution system 20, the number of power generation units 21 is not particularly limited. For example, it may be one or a plurality. The power generation unit 21 is provided outside the above-described panel housing 2 (the power distribution system 20 has the power generation unit 21 outside the panel housing 2). The generated power (capacity) of the power generation unit 21 is not particularly limited either. For example, it may be 100 kW or more and 30000 kW or less, preferably 300 kW or more and 20000 kW or less, and more preferably 500 kW or more and 10000 kW or less. The following particularly describes the solar power generation unit 21 that performs solar power generation.

[0092] The solar power generation unit 21 includes solar cells 21a. In addition, the solar power generation unit 21 may have a pyrheliometer that measures solar radiation intensity, a current collection unit that collects direct current from the solar cells 21a, connection boxes, etc. and sends it to the conversion unit 22 described later. The number of solar cells 21a in the solar power generation unit 21 may be plural, and these plural solar cells 21a may be connected in series to form a solar cell string. In the solar power generation unit 21, it may have a connection box in which a plurality of solar cell strings are connected in parallel, and there may be a plurality of such connection boxes.

[0093] <Solar cell 21a> As shown in FIGS. 12 to 15, each solar cell 21a generates DC power between the + terminal and the - terminal when irradiated with light. The solar cell 21a is usually in the form of a panel, and the power generation amount varies depending on the angle at which it is installed. The solar cell 21a may be installed at a predetermined angle via a pedestal (not shown) or the like outside the above-described board housing 2. In this case, the area under the pedestal may be used as a turf growing area or a cultivated land for crops. Also, among the plurality of solar cells 21a, the - terminal of another solar cell 21a is connected to the + terminal of a certain solar cell 21a, and the - terminal of yet another solar cell 21a is connected to the + terminal of another solar cell 21a. Subsequently, this is repeated to connect a plurality of solar cells 21a in series to form one solar cell string.

[0094] In this way, the voltage between the + terminal and the - terminal of the entire solar cell string in which a plurality of solar cells 21a are connected in series is the sum of the DC voltages generated by each solar cell 21a, and varies depending on the weather, time, etc. The power output from the power output terminal of the solar cell string is the sum of the powers of each solar cell 21a, and may be 500 W or more and 6000 W or less. The plurality of above-described solar cell strings are connected in parallel to one connection box. Therefore, the voltage between the + terminal and the - terminal of each solar cell string is the same. However, with respect to one connection box, currents of a plurality of solar cell strings flow in, and the power collected in the connection box may be 2.5 kW or more and 90 kW or less.

[0095] <Converter unit 22> As shown in FIGS. 12 to 15, the conversion unit 22 is a part that converts the DC current or AC current from the above-described power generation unit 21 into a low-voltage AC current L. The conversion unit 22 may include an inverter or the like that converts the DC current from the solar cell 21a into an AC current. Additionally, it may include a controller that controls the AC voltage and frequency converted by this inverter, an air circuit breaker (ACB), or the like. Note that the conversion unit 22 is also called a power conditioner (abbreviation for power conditioner). In a power distribution system 20, the number of conversion units 22 is not particularly limited. For example, there may be a plurality (e.g., 4 or 5, etc.) or there may be only one.

[0096] The conversion unit 22 is provided outside the above-described switchboard housing 2 (the power distribution system 20 has the conversion unit 22 outside the switchboard housing 2). The low-voltage alternating current L from outside the switchboard housing 2 described in the first and second embodiments of the switchboard 1 is the low-voltage alternating current L from the conversion unit 22 provided outside the switchboard housing 2. The conversion unit 22 may be provided, for example, in an equipment housing 20a such as a control box or a cubicle. The conversion power (capacity) that the conversion unit 22 can convert is not particularly limited. For example, it may be 30 kW or more and 10,000 kW or less, preferably 50 kW or more and 5,000 kW or less, and more preferably 100 kW or more and 2,000 kW or less (such as 250 kW or 500 kW). In addition, the conversion power of the conversion unit 22 may be smaller than the power generation of the above-described solar power generation unit 21 (in other words, the power generation may be larger than the conversion power). In this case, it can be said that the solar cell 21a is overloaded with respect to the conversion unit 22. In addition, the conversion unit 22 may have an under-voltage relay (UVR), an over-voltage relay (OVR), an under-frequency relay (UFR), an over-frequency relay (OFR), or may have a passive or active single-operation protection device.

[0097] <Connecting circuit 6C> As shown in FIG. 12, when one power distribution system 20 has the first and second embodiments of a plurality of switchboards 1, the connecting circuit 6C is a circuit that connects and connects between these plurality of switchboards 1. Here, the "electric circuit that connects and links between multiple switchboards 1" refers to, as shown in FIG. 12, a plurality of electric circuits that continuously connect between two adjacent switchboards 1 among the multiple switchboards 1, grouped together (or each) as a connection circuit 6C, or alternatively, from the main circuit, the same number of circuits as the number of switchboards 1 branch out, each switchboard 1 is connected to each branched circuit, and the entire combination of these main circuits and the branched circuits may be regarded as the connection circuit 6C. In addition, since the connection circuit 6C also conducts a high-voltage alternating current H, it can also be said to be a high-voltage circuit 6H. The connection circuit 6C also forms a set of multiple lines according to the power distribution method (power transmission method), such as a set of three lines for three-phase three-wire (3φ3W) or single-phase three-wire (1φ3W), and a set of two lines for single-phase two-wire (1φ2W), etc.

[0098] <Power transmission board 23> As shown in FIG. 12, the power transmission board 23 is a board that encloses an electric circuit (a part of the high-voltage circuit 6H) that connects between the first and second embodiments of the multiple switchboards 1 connected by the above-described connection circuit 6C and the system K to be described later. The vacuum circuit breaker 23a, the circuit breaker 23b, and / or the load switch 23c provided in this electric circuit are provided inside the power transmission board housing 23'. Here, "the power transmission board 23 has a vacuum circuit breaker 23a, a circuit breaker 23b, and / or a load switch 23c" includes the case where the power transmission board 23 has a vacuum circuit breaker 23a and a circuit breaker 23b, the case where it has only a load switch 23c, and the case where it has all of the vacuum circuit breaker 23a, the circuit breaker 23b, and the load switch 23c. In addition, the configurations, structures, shapes, dimensions, etc. of these vacuum circuit breakers 23a, circuit breakers 23b, and load switches 23c are the same as those of the above-described vacuum circuit breaker 5b, circuit breaker 5c, and load switch 5a, and can be appropriately changed in accordance with the gist of the present invention. The vacuum circuit breaker 23a of the power transmission board 23 may be electrically operated and have a function of suppressing inrush current, or may not have a power fuse. Furthermore, the switchboard 23 may have, within the switchboard housing 23', the above-described step-down branch circuit 6S, instrument transformer 7, step-down output circuit 6S', voltmeter 8, step-down output terminal 9 (terminal block including the same), or zero-phase branch circuit 6Z, zero-phase voltage detector 10, zero-phase voltage output circuit 6Z', zero-phase voltage output terminal 11 (terminal block including the same). Additionally, the switchboard 23 may have, within the switchboard housing 23', the above-described circuit protector 5d, instrument current transformer 5e (number of turns: 250 turns, etc.), current output circuit 6R', current output terminal 5e', power supply branch circuit 6D, power supply circuit breaker 5f, spare branch circuit 6Y, spare circuit breaker 5g, voltage test terminal 5h, and current test terminal 5j. Each of these configurations, structures, shapes, dimensions, etc. is the same as described above and can be appropriately changed in accordance with the gist of the present invention. In addition, the switchboard 23 may have, within the switchboard housing 23', an under-voltage relay 23d provided between the voltmeter 8 and the voltage test terminal 5h in the step-down branch circuit 6S, or may further have a separate spare branch circuit 6Y' and a separate spare circuit breaker 23e. Instead of the current output terminal 5e', the switchboard 23 may have an ammeter (analog or digital) 23f and an over-current relay 23g provided between the ammeter and the current test terminal 5j. When the power distribution system 20 includes the switchboard 23, each of the one or more switchboards 1 may have, within its board housing 2, a step-down branch circuit 6S, an instrument transformer 7 (number of instrument transformers 7: one, number of power fuses: two, etc.), a step-down output circuit 6S', and a voltmeter 8, but may not have a step-down output terminal 9 (terminal block including the same), or may not have a zero-phase branch circuit 6Z, a zero-phase voltage detector 10, a zero-phase voltage output circuit 6Z', or a zero-phase voltage output terminal 11 (terminal block including the same). Further, in this case, the high-voltage power transmission section 5 of each switchboard 1 may not have a circuit protector 5d, an instrument current transformer 5e, a current output circuit 6R', a current output terminal 5e', a power supply branch circuit 6D, a power supply circuit breaker 5f, a spare branch circuit 6Y, a spare circuit breaker 5g, a voltage test terminal 5h, a current test terminal 5j, etc. As the switchboard 1, simplification of the switchboard 1 itself and the high-voltage power transmission section 5 can be achieved.

[0099] <Power storage unit 24> As shown in FIGS. 12 to 15, the power storage unit 24 is a part for storing power. It is connected to the above-described voltage transformation output terminal 9 (to the instrument transformer 7 via the voltage transformation output terminal 9 etc.), and the voltage transformation output current S output from the instrument transformer 7 is input. Even when a power outage or voltage fluctuation occurs, it is a part that continues to supply power to the ground fault overvoltage relay 25 described later, the control device 26 described later, the digital multi-relay 27, etc. The power storage unit 24 may be, for example, the uninterruptible power supply device 24 described later, or may be a capacitor (an electronic component that stores (stores) electric energy as electricity, also called a condenser, and can be said to continue to supply power to the ground fault overvoltage relay 25, the control device 26, the digital multi-relay 27, etc. for several seconds in the event of a power outage, etc.). In addition, the power storage unit 24 may be a storage battery (battery) such as a lead storage battery, a lithium ion storage battery, a nickel-hydrogen storage battery, or a nickel-cadmium storage battery, or may store hydrogen generated by electrolysis of water using the generated power from the power generation unit 21 etc., and take out power with a fuel cell etc. when necessary. Further, it may be a device that stores (stores) kinetic energy as power using a flywheel etc., or stores (stores) potential energy as power by pumping water. Hereinafter, the power storage unit 24 will be mainly described as being the uninterruptible power supply device 24.

[0100] The uninterruptible power supply (UPS) 24, which is one type of the above-described power storage unit 24, is also connected to the voltage transformation output terminal 9 (to the instrument transformer 7 via the voltage transformation output terminal 9 etc.) as described above, and the voltage transformation output current S output from the instrument transformer 7 is input. Even when a power outage or voltage fluctuation occurs, it is a power supply device that continues to supply power to the ground fault overvoltage relay 25 described later, the control device 26 described later, the digital multi-relay 27, etc. In one power distribution system 20, the number of power storage units 24 such as uninterruptible power supply devices and the number of the above-described instrument transformers 7 may be the same or different, and the number may be one or more. The power storage unit 24 such as the uninterruptible power supply device may be provided outside the above-described panel housing 2 (the power distribution system 20 may have the power storage unit 24 outside the panel housing 2), and the power storage unit 24 may be provided, for example, inside the equipment housing 20a such as a control box or a cubicle. In addition, the power storage unit 24 such as the uninterruptible power supply device may be provided with a power outlet 24a for powering the control device 26, digital multi-relay 27, monitoring device 36, etc. to be described later and for backup during a power outage (of system K), and in addition, a power outlet 24b that does not perform backup during a power outage may be provided. In addition, the power storage unit 24 such as the uninterruptible power supply device may be connected to the transformer output terminal 9 (to the instrument transformer 7 via the transformer output terminal 9 etc.) via the single-winding transformer 42 and the power outlet 33 to be described later.

[0101] <Ground fault overvoltage relay 25> As shown in FIGS. 12 to 14, the ground fault overvoltage relay (Over Voltage Ground Relay, OVGR) 25 is connected to the above-described zero-phase voltage output terminal 11 (to the zero-phase voltage detector 10 via the zero-phase voltage output terminal 11 etc.), and the zero-phase voltage output current Z output from the zero-phase voltage detector 10 (a lower-voltage zero-phase voltage output current Z corresponding to the zero-phase voltage generated on the high-voltage circuit 6H side etc.) is input. When the zero-phase voltage output current Z exceeds a certain value (the value of the operating voltage) for a certain time (such as an operating time of about 1 second), it is a device that outputs a stop signal such as stopping the conversion of the above-described conversion unit 22. The output signal from the ground fault overvoltage relay 25 is input to the control device 26 to be described later of the conversion unit 22. In addition, it may be directly input to the conversion unit 22 or input to the above-described low-voltage circuit breaker 3 to cut off the low-voltage circuit 6L. In one power distribution system 20, the number of the ground fault overvoltage relays 25 is the same as the number of the above-described zero-phase voltage detectors 10, and the number may be one or more. The ground fault overvoltage relay 25 is provided outside the above-described switchboard housing 2 (the power distribution system 20 has the ground fault overvoltage relay 25 outside the switchboard housing 2), and the ground fault overvoltage relay 25 may be provided, for example, inside an equipment housing 20a such as a control box or a cubicle. The power supply of the ground fault overvoltage relay 25 is connected to the power storage unit 24 such as the above-described uninterruptible power supply device, and is input from the power storage unit 24.

[0102] <Control device 26> As shown in FIGS. 12 to 15, the control device 26 is connected to the above-described ground fault overvoltage relay 25, inputs the stop signal output from the ground fault overvoltage relay 25, and controls to stop the conversion of the above-described conversion unit 22, etc. It may be a smart logger, a sequencer, a computer, or the like. In one power distribution system 20, the number of control devices 26 may be one or more. The control device 26 is provided outside the above-described switchboard housing 2 (the power distribution system 20 has the control device 26 outside the switchboard housing 2), and the control device 26 may be provided, for example, inside an equipment housing 20a such as a control box or a cubicle. The power supply of the control device 26 is connected to the power storage unit 24 such as the above-described uninterruptible power supply device, and is input from the power storage unit 24. Also, the monitoring, setting change, operation, etc. of the control device 26 may be directly touched and performed by the user, or may be remotely performed via the Internet, a telephone line, or the like.

[0103] <Digital multi-relay 27> As shown in FIGS. 14 and 15, a digital multi-relay (DMR) 27 has an input terminal connected to the above-described current transformation output terminal 5e' (instrument current transformer 5e via the current transformation output terminal 5e' etc.), and the current transformation output current R output from the instrument current transformer 5e (a smaller current transformation output current R corresponding to the high-voltage alternating current H flowing in the high-voltage circuit 6H) is input. At the same time, it has another input terminal connected to the above-described voltage transformation output terminal 9 (to the instrument voltage transformer 7 via the voltage transformation output terminal 9 etc.), and the voltage transformation output current S output from the instrument voltage transformer 7 is input. The digital multi-relay 27 may output a stop signal such as stopping the conversion of the above-described conversion unit 22 when the input current transformation output current R or voltage transformation output current S exceeds a certain value (the value of the operating voltage) for a certain period of time (such as an operating time of about 1 second), but it may not output a stop signal. In addition, based on the current transformation output current R and voltage transformation output current S, the digital multi-relay 27 may calculate, in addition to the current value and voltage value of the high-voltage alternating current H flowing in the high-voltage circuit 6H, the power value, power quantity value, etc. by multiplying these, and output each value. Note that each output signal from the digital multi-relay 27 is not input to the above-described control device 26 of the conversion unit 22, but may be input to the control device 26, and each value may also be output to a terminal such as a remote computer via the Internet, a telephone line, etc. When the digital multi-relay 27 outputs a stop signal to the conversion unit 22, it may be directly input to the conversion unit 22 or input to the above-described low-voltage circuit breaker 3 to cut off the low-voltage circuit 6L. In one power distribution system 20, the number of digital multi-relays 27 and the number of the above-described instrument current transformers 5e may be the same or different, and the number may be one or more. The digital multi-relay 27 is provided outside the above-described panel housing 2 (the power distribution system 20 has the digital multi-relay 27 outside the panel housing 2), and the digital multi-relay 27 may be provided, for example, inside an equipment housing 20a such as a control box or a cubicle. The power supply of the digital multi-relay 27 can be said to be connected to the power storage unit 24 such as the above-mentioned uninterruptible power supply device and input from the power storage unit 24. Instead of the digital multi-relay 27, a digital multimeter or an over current ground relay (OCGR) may be used.

[0104] <Modification Example 3 of the Power Distribution System 20> As shown in FIG. 15, the main differences of the modification example 3 of the power distribution system 20 include that there is one switchboard 1, and a watt-hour meter 28 that measures the power amount of the high-voltage circuit 6H based on the outputs from the potential transformers 7 and current transformers 12(5e) provided on at least two of the three-phase three-wire of the high-voltage circuit 6H, a grounding resistor 15 and a zero-phase current transformer 16 provided between the transformer 4 and the ground point 4', a ground fault overcurrent relay 29 connected to the zero-phase current transformer 16, and a single-phase transformer 17.

[0105] <Watt-Hour Meter 28> As shown in FIG. 15, the watt-hour meter (WH) 28 is connected to at least two of the above-mentioned voltage output terminals 9 and current output terminals 13 (connected to the potential transformers 7 and current transformers 12(5e) via the voltage output terminals 9, current output terminals 13, etc.). The voltage output current S output from at least two potential transformers 7 (a lower-voltage voltage output current S corresponding to the voltage of the high-voltage alternating current H flowing through at least two of the three-phase three-wire of the high-voltage circuit 6H) and the current output current R output from at least two current transformers 12(5e) (a smaller-current current output current R corresponding to the high-voltage alternating current H flowing through at least two of the three-phase three-wire of the high-voltage circuit 6H) are input. Based on these voltage output current S and current output current R, it is a device that measures the power amount of the power flowing through the high-voltage circuit 6H. In this way, the watt-hour meter 28 is not based on the transformed output current S and the transformed output current R corresponding to only one of the three-phase three-wire high-voltage circuit 6H, but on the transformed output current S and the transformed output current R corresponding to the high-voltage alternating current H flowing through at least two of the three-phase three-wire high-voltage circuit 6H. Therefore, it is possible to accurately measure the amount of electric power required during power sales and the like, and the watt-hour meter 28 may be of the type with verification (ordinary grade, etc.). In addition, the watt-hour meter 28 may have a communication function. In one power distribution system 20, the number of the instrument transformers 7 and the instrument current transformers 12(5e) is twice or three times the number of the watt-hour meters 28, and the specific number of the watt-hour meters 28 may be one or more. The watt-hour meter 28 is provided outside the above-described panel housing 2 (the power distribution system 20 has the watt-hour meter 28 outside the panel housing 2), and the watt-hour meter 28 may be provided, for example, inside an equipment housing 20a such as a control box or a cubicle.

[0106] <Ground fault overcurrent relay 29> As shown in FIG. 15, the ground fault overcurrent relay (Over Current Ground Relay, OCGR) 29 is connected to the above-described zero-phase transformed output terminal 16 (to the zero-phase current transformer 15 via the zero-phase transformed output terminal 16 etc.), and the zero-phase current output current Z' output from the zero-phase current transformer 15 (the zero-phase current output current Z' of a smaller current corresponding to the zero-phase current generated in the power distribution system 20, the grounding circuit, etc.) is input. When the zero-phase current output current Z' exceeds a certain value (the value of the operating voltage) for a certain time (such as an operating time of about 1 second), it is a device that outputs a stop signal such as stopping the conversion of the above-described conversion unit 22. Incidentally, the ground fault overcurrent relay 29 may be connected to the circuit between the transformed output terminal 9 and the power storage unit 24 such as an uninterruptible power supply device. The output signal from the ground fault overcurrent relay 29 is input to the control device 26 described later of the conversion unit 22. However, alternatively, it may be directly input to the conversion unit 22 or input to the above-described low-voltage circuit breaker 3 to cut off the low-voltage circuit 6L. In a power distribution system 20, the number of the ground fault overcurrent relays 29 is the same as the number of the zero-phase current transformers 15 described above, and the number may be one or more. The ground fault overcurrent relay 29 is provided outside the above-described switchboard housing 2 (the power distribution system 20 has the ground fault overcurrent relay 29 outside the switchboard housing 2), and the ground fault overcurrent relay 29 may be provided, for example, inside an equipment housing 20a such as a control box or a cubicle. The power supply of the ground fault overcurrent relay 29 is connected to the power storage unit 24 such as the above-described uninterruptible power supply device and is input from the power storage unit 24. Further, the power supply of the ground fault overcurrent relay 29 may have a leakage current display.

[0107] <Equipment housing 20a, monitoring housing 20b (monitoring device 36), existing electrical room 20c, etc.> As shown in FIG. 15, the equipment housing 20a incorporates the power storage unit 24 such as the uninterruptible power supply device described so far, the control device 26 of the conversion unit 22, the digital multi-relay 27, the watt-hour meter 28, and the ground fault overcurrent relay 29. In addition, inside the equipment housing 20a, a single-winding transformer 42 and a socket 33 are provided in the circuit from the transformer output terminal 9 to the power storage unit 24 such as the uninterruptible power supply device, and an under voltage relay (UVR) 34 and a condenser trip device (CTD) 35 may be provided in a circuit branched from the circuit between the single-winding transformer 42 and the transformer output terminal 9. Note that the digital multi-relay 27 inside the equipment housing 20a measures the value of the power, and may have the functions of a reverse power relay (RPR) and an over voltage ground relay (OVGR) as described above in the second embodiment of the switchboard 1 and the power receiving and distribution board 1'. Data on the amount of power, RPR signals, and OVGR signals may be exchanged between the digital multi-relay 27 and the control device 26. Note that the digital multi-relay 27 may be connected via equipment and cables inside the existing electrical room 20c described later. Furthermore, the control device 26 may be connected to a monitoring housing 20b (monitoring device 36), which will be described later, outside the equipment housing 20a (and outside the panel housing 2 of the distribution board 1), and to the above-described conversion unit 22 via a cable or the like, and may exchange data with the monitoring device 36, which will be described later, or control and monitor the conversion unit 22.

[0108] As shown in FIG. 15, the monitoring device 36 is built into a monitoring housing 20b, which is a housing separate from the above-described equipment housing 20a and panel housing 2 (provided inside the monitoring housing 20b), and is a device that monitors the power generation amount (electric power amount) by the above-described power generation unit 21, the electric power amount converted by the conversion unit 22, and the like. The specific configuration of the monitoring device 36 is not particularly limited. For example, the monitoring content of the power distribution system 20 may include, in addition to the above-described power generation amount and conversion amount, the solar radiation intensity, temperature, weather, etc. at the installation location of the power distribution system 20. These monitoring contents may be displayed on a user terminal (desktop PC, notebook PC, mobile phone, smartphone, tablet terminal, PDA (personal digital assistant), etc.) used by a remote or local user (administrator) via wireless (such as wireless LAN) or wired (such as cable) or the Internet. In that regard, the monitoring device 36 can also be said to be a communication device. Note that the monitoring device 36 may be built into the above-described equipment housing 20a together with other devices instead of the monitoring housing 20b. Furthermore, the monitoring device 36 may be connected to the above-described control device 26 wirelessly or by wire (such as LAN). The equipment housing 20a and the monitoring housing 20b described so far may be attached to the above-described panel housing 2 from the outside, or may be installed at a location different from the installation location of the panel housing 2. As shown in FIG. 15, the existing electrical room 20c may be a room in a predetermined existing building or a housing of a predetermined existing panel, and is a room or housing different from the above-described equipment housing 20a, monitoring housing 20b, and panel housing 2. Any equipment may be provided in this existing electrical room 20c. For example, a circuit breaker 20c1, an instrument transformer 20c2, a gas circuit breaker (GCB) 20c3, one or more instrument current transformers 20c4, one or more overcurrent relays 20c5, a vacuum circuit breaker (VCB) 20c6, and a current test terminal (CTT) 20c7 may be provided in the circuit between the system K and the distribution board 1. The configurations, functions, effects, and usage modes of other modification examples 3, etc. of the power distribution system 20 are the same as those of the power distribution system 20 and its modification examples 1 and 2.

[0109] <Power receiving and distribution system 20’> As shown in FIG. 24, the power receiving and distribution system 20’ according to the present invention has a load 30 to be described later and the transformer 4 described above. The power receiving and distribution system 20’ consumes at least the power from the system K through the transformer 4 by the load 30. The power receiving and distribution system 20’ may have the above-described power generation unit 21, conversion unit 22, and / or a power storage device 37 to be described later, or may have the above-described power receiving and distribution board 1’, etc. Of course, the power receiving and distribution board 1’ may also have a panel housing 2 (low-voltage panel housing 2A or high-voltage panel housing 2B), a low-voltage circuit breaker 3, a high-voltage switch 5a, a high-voltage circuit breaker 5b, a low-voltage circuit 6L, a high-voltage circuit 6H, etc. When the power receiving and distribution system 20’ has the power generation unit 21, conversion unit 22, and / or the power storage device 37, the load 30 may consume the power from the system K through the transformer 4, the power from the conversion unit 22, and / or the power from the power storage device 37. Furthermore, the statement in the present invention that "the load 30 consumes the power from the system K via the transformer 4, the power from the conversion unit 22, and / or the power from the power storage device 37" means that the load 30 consumes at least one of the power from the system K via the transformer 4, the power from the conversion unit 22, and the power from the power storage device 37.

[0110] Here, the "power from the system K via the transformer 4" in the present invention means not only all of the power from the system K via the transformer 4 (the received power received from the system K), but also at least a part of the received power. Also, the "power from the conversion unit 22" in the present invention means not only all of the power generated by the power generation unit 21 and converted by the conversion unit 22 (the generated power), but also at least a part of the generated power. Furthermore, the "power from the power storage device 37" in the present invention means not only all of the power output (discharged) from the power storage device 37 (the stored power), but also at least a part of the stored power. In addition, in the power receiving and distribution system 20', when the generated power of the power generation unit 21 is 0 (zero), the load 30 consumes at least one of the stored power and the received power as described above. However, when the generated power of the power generation unit 21 is greater than 0, it is assumed that the load 30 consumes at least the generated power and the stored power, and may also consume the received power as necessary. In addition, in the power receiving and distribution system 20', when the stored power is 0 (zero) when the power storage device 37 is connected to the load 30, the connected load 30 consumes only the received power. However, when the stored power is already greater than 0 (connected after charging some power to the power storage device 37 at another location) when the power storage device 37 is connected to the load 30, it is assumed that the load 30 consumes at least the stored power, and may also consume the received power as necessary.

[0111] <Load 30, Charger 30a> As shown in FIG. 24, the load 30 is at least a load (load facility) that consumes the received power received from the above-described system K. That is, the value of the power consumption (capacity) of the load 30 may be larger than the value of the received power received by the power receiving and distributing system 20' from the system K (even if only a part of the power consumption of the load 30 is covered by the received power). The load 30 may be, for example, an automobile dealership, a gas station, a rental car store (rental car shop), include a charger 30a described later in a factory or workplace, or include equipment that uses electric power such as electric and electronic devices (general lighting loads 30b1 such as incandescent lamps, fluorescent lamps, and mercury lamps (lighting fixtures), general power loads 30b2 such as air conditioners, motors, and pumps, etc.), and may also include the factory or workplace itself. In addition, the load 30 may include equipment that uses electric power such as electric and electronic devices in a company or other corporation or individual, an office of a government agency or union, a house, a store, a warehouse, a garage, a parking lot, a bicycle parking lot, a school building, a lecture hall, a gymnasium, a research facility, a hospital or clinic, a hotel, a theater, a cinema, a stadium, a baseball field, etc., or may include the office of a company itself, etc., and may include a combination of these. Such a load 30 can be said to include a secondary-side load 30' and a tertiary-side load 30'' when the transformer 4 is a three-winding transformer having a primary winding, a secondary winding, and a tertiary winding, and can be said to be only the secondary-side load 30' when the transformer 4 is a two-winding transformer having a primary winding and a secondary winding. Hereinafter, in particular, the charger 30a will be explained in detail.

[0112] The charger 30a may have any configuration such as a rapid charger, a normal charger, or an ultra-rapid charger. Here, the "charger 30a" in the present invention refers to an installation-type charging device or charging facility used for charging vehicles with built-in batteries (storage batteries) such as electric vehicles (EVs), plug-in hybrid vehicles, and electric two-wheelers, and is also referred to as a charging stand, charging station, charging spot, etc. In addition, the charger 30a may be a charging device or charging facility used for charging communication devices such as smartphones and mobile phones with built-in batteries (storage batteries), portable PCs (personal computers), and electrical products, in addition to vehicles. The output from the charger 30a to an electric vehicle or the like may be a direct current or an alternating current, and it may be possible to output only one of them or both. On the other hand, an electric vehicle or the like may input a direct current or an alternating current via a plug or the like, and it may be possible to input only one of them or both. In addition, the charger 30a may be configured to perform rapid charging when the output from the charger 30a is a direct current and normal charging when the output from the charger 30a is an alternating current. The charger 30a may separately have a power storage unit for storing power such as power from the power storage device 37 or received power, or may have a conversion unit (AC / DC converter, DC / AC inverter (DC / AC converter), DC / DC converter, etc.) for converting the current from the power storage device 37 from alternating current to direct current or from direct current to alternating current.

[0113] <Power storage device 37> As shown in FIG. 15, the power storage device 37 is a device that stores power such as power (received power) from the system K via the transformer 4 and power (generated power) from the above-described power generation unit 21 and conversion unit 22, and is provided outside the panel housing 2, different from the power storage unit 24 of the above-described uninterruptible power supply device. The power storage device 37 may also be, for example, a storage battery (battery) such as a lead storage battery, a lithium-ion storage battery, a nickel-hydrogen storage battery, or a nickel-cadmium storage battery, or hydrogen generated by electrolysis of water using the generated power from the power generation unit 21 or the conversion unit 22, etc. is stored, and when necessary, power is taken out by a fuel cell or the like. In addition, it may be a device that stores (stores) as kinetic energy using a flywheel or the like, stores (stores) as potential energy by pumping water, or stores (stores) as electrical energy as it is using a capacitor or the like. When such a power storage device 37 is a three-winding transformer in which the transformer 4 has a primary winding, a secondary winding, and a tertiary winding, it may be connected to the tertiary side and / or the secondary side of the transformer 4. The stored power from this power storage device 37 will be consumed by at least one of the above-described secondary side load 30' and tertiary side load 30". When the transformer 4 is a two-winding transformer having a primary winding and a secondary winding, it is connected to the secondary side of the transformer 4, and the stored power from this power storage device 37 will be consumed by the secondary side load 30'. In addition, since the charging into the power storage device 37 and the discharging from the power storage device 37 are performed with a direct current, a conversion unit that converts an alternating current into a direct current or converts the direct current from the power storage device 37 into an alternating current to the load 30 may be connected between the power storage device 37 and the load 30. The configurations, functions, effects, and usage modes of the other power distribution and reception system 20' and the like are the same as those of the power distribution system 20 and its modification examples 1 to 3.

[0114] <Others> The present invention is not limited to the above-described embodiments. Each configuration or the overall structure, shape, dimensions, etc. of the switchboard 1, the power distribution and reception board 1', the power distribution system 20, the power distribution and reception system 20', etc. can be appropriately changed in accordance with the gist of the present invention. The distribution board 1 and the incoming and outgoing distribution board 1' do not have a power storage unit 24 such as an uninterruptible power supply device connected to the instrument transformer 7 (transformer output terminal 9) and a ground fault overvoltage relay 25 connected to the zero-phase voltage detector 10 (zero-phase voltage output terminal 11) inside the board housing 2. In addition, they may not have a power storage unit such as an uninterruptible power supply device not connected to the instrument transformer 7 (transformer output terminal 9) and a ground fault overvoltage relay not connected to the zero-phase voltage detector 10 (zero-phase voltage output terminal 11). The distribution board 1 and the incoming and outgoing distribution board 1' may be resistant to heavy salt. The distribution board 1 and the incoming and outgoing distribution board 1' may be provided with a power storage unit 24 such as an uninterruptible power supply device, a ground fault overvoltage relay 25, a control device 26 of the conversion unit 22, a digital multi-relay 27, a watt-hour meter 28, a ground fault overcurrent relay 29, etc. inside the board housing 2. In this case, the board housing 2 may not be provided with a transformer output terminal 9, a zero-phase voltage output terminal 11, a converter output terminal 13, a zero-phase converter output terminal 16, etc. Also, the distribution board 1 and the incoming and outgoing distribution board 1' may not have a single-phase transformer disconnector 18.

[0115] In a plan view, the board housing 2 may be less than 10 cm longer or at most 40 cm longer than the transformer 4 in terms of the front-back length. The board housing 2 may not have a gallery 2e. The board housing 2 may have a space (hook rod storage space) 2n for storing operation hook rods such as load switches 5a and circuit breakers 5c (see FIG. 9 in particular). The board housing 2 may have an intake space (intake port) 2p. The intake space 2p may also have a filter 2p' or the opening of the intake space 2p may be covered with a mesh member that partitions the inside and outside of the board housing 2. The location where the intake space 2p is provided is not particularly limited. For example, if the main body 2c of the board housing 2 protrudes forward and / or backward with respect to the transformer 4, it may be provided on the protruding lower surface of the main body 2c, or may be provided at any location in the lower part of the board housing 2 (see FIG. 5 in particular). When the power storage unit 24 is a storage battery (battery) or the like, the power storage unit 24 may be connected to the conversion unit 22 described above or a circuit such as the low-voltage circuit 6L, charge the generated power output from the power generation unit 21 or the like, or flow the charged power to the load side for consumption (self-consumption) by the load. If power selling is possible, the charged power may be flowed to the system K side.

[0116] In the power distribution system 20 or the power receiving and distribution system 20', if the equipment housing 20a and the conversion unit 22 are installed outside the panel housing 2, they may be installed at any location and may be installed at a position separated from the panel housing 2 by a predetermined distance (for example, about 1 to 10 m, etc.) in a plan view (for example, the equipment housing 20a may also be installed beside the conversion unit 22). The power distribution system 20 may not have the digital multi-relay 27 or the power storage unit 24.

[0117] The exterior of the power receiving and distribution board 1' may be not only the exterior of the second embodiment of the distribution board 1 (the configuration of the panel housing 2, etc.) but also the exterior of the first embodiment of the distribution board 1 (the configuration of the panel housing 2, etc.). The power receiving and distribution system 20' may not have the power generation unit 21, the conversion unit 22, or the power storage device 37. In this case, the power receiving and distribution system 20' may be first installed without the power generation unit 21, the conversion unit 22, or the power storage device 37, and then the power generation unit 21, the conversion unit 22, or the power storage device 37 may be retrofitted. As the support of the low-voltage panel housing 2A and the high-voltage panel housing 2B by the transformer 4, the arrangement of the low-voltage panel housing 2A and the high-voltage panel housing 2B may be the reverse of the above. The transformer 4 may not have the suspension tool 4T. The distribution board 1, the power receiving and distribution board 1', the power distribution system 20, and the power receiving and distribution system 20' may not have the control device 26, the transformation transformer 31a for quotation, the electricity meter 31b for power purchase, the electricity meter 31c for power selling, the pole-mounted air switch 31d, or the protective relay device 31e. Conversely, they may have a surge protective device (SPD). Regarding the system K related to the distribution board 1, the power receiving and distribution board 1', the power distribution system 20, and the power receiving and distribution system 20' described so far, details will be given below.

[0118] <System K> As shown in FIGS. 12 to 14, 24, etc., System K transmits (receives power) to the switchboard 1, the receiving and distributing switchboard 1', the power distribution system 20, and the receiving and distributing power system 20'. It refers to the entire system for an electric power company or the like to supply electricity to consumers, and can also be called the power system K. Specifically, System K is equipped with facilities such as substations, transmission lines, and distribution lines, and may include power plants. Also, System K may have the above-mentioned metering transformer 31a, power consumption meter 31b for purchasing electricity, power generation meter 31c for selling electricity, pole-mounted air switch 31d, and protective relay device 31e. The electric power handled by such a System K may be either AC or DC. Hereinafter, it will be described assuming it is AC. In System K, since most of the transmitted power is AC, it is transmitted by the three-phase three-wire (3φ3W) system on the transmission line. In order to reduce the transmission loss during transmission, the basic long-distance transmission section is transmitted at as high a voltage as possible (for example, 6600V, 22000V, etc.). The electric power transmitted by System K is stepped down in voltage in several stages near the consumption area, and distribution is also carried out by the single-phase two-wire (1φ2W) system or the like after the pole-mounted transformer and the like. System K may be a system of an electric power company or the like (commercial power system), or a system independently owned by an organization such as an enterprise or a local government, or a system inside a plant (independent power system).

Industrial Applicability

[0119] The switchboard and the power distribution system of the present invention can be used for a solar power generation unit or the like regardless of its power generation amount or scale. In addition to the solar power generation unit, it can be used in a device that generates electricity by a generator (such as an AC motor) rotated by wind power, hydraulic power, wave power, geothermal energy, etc., and can be used indoors or outdoors. The receiving and distributing switchboard and the receiving and distributing power system of the present invention can be used for any load equipment other than just a charger, and can also be used in any power contract or connection mode, and can be used indoors or outdoors.

Explanation of Signs

[0120] 1 Distribution board 1’ Incoming and distribution board 2 Cabinet 2A Low-voltage cabinet (section) 2B High-voltage cabinet (section) 3 Low-voltage circuit breaker 4 Transformer 4L Low-voltage terminal 4H High-voltage terminal 4’ Grounding point 4T Lifting tool 5 High-voltage power transmission section 5a High-voltage switch 5b High-voltage circuit breaker 6L Low-voltage circuit 6H High-voltage circuit 6S Transformer branch circuit 6Z Zero-phase branch circuit 6C Connecting circuit 7 Instrument transformer 8 Voltmeter 9 Transformer output terminal 10 Zero-phase voltage detector 11 Zero-phase voltage output terminal 12 Instrument current transformer 13 Current transformer output terminal 14 Grounding resistor 15 Zero-phase current transformer 16 Zero-phase current transformer output terminal 17 Single-phase transformer 20 Power distribution system 20’ Incoming and power distribution system 21 Power generation section 22 Conversion section 23a Vacuum circuit breaker 23b Circuit breaker 23c Load switch 24 Energy storage section 25 Earth fault overvoltage relay 28 Watt-hour meter 29 Earth fault overcurrent relay 30 Load L Low-voltage alternating current H High-voltage alternating current S Transformer output current R Current transformer output current K System

Claims

1. A switchboard having a switchboard housing (2), a low-voltage circuit breaker (3) capable of interrupting a low-voltage alternating current (L) from outside the switchboard housing (2), a transformer (4) for transforming the low-voltage alternating current (L) passing through the low-voltage circuit breaker (3) into a higher-voltage high-voltage alternating current (H), and a high-voltage power transmission section (5) for transmitting the high-voltage alternating current (H) from the transformer (4) outside the switchboard housing (2), wherein the low-voltage circuit breaker (3) and the high-voltage power transmission section (5) are provided inside the switchboard housing (2), the transformer (4) is attached from below outside the switchboard housing (2), the entire switchboard housing (2) is disposed above the upper surface (4U) of the transformer (4), a low-voltage terminal (4L) for inputting a low-voltage alternating current (L) to the transformer (4) and a high-voltage terminal (4H) for outputting a high-voltage alternating current (H) from the transformer (4) project upward from the upper surface (4U) of the transformer (4), a low-voltage circuit (6L) connects between the low-voltage terminal (4L) projecting upward and the low-voltage circuit breaker (3) inside the switchboard housing (2), and a high-voltage circuit (6H) connects between the high-voltage terminal (4H) projecting upward and the high-voltage power transmission section (5). The switchboard is characterized by this.

2. The switchboard according to claim 1, wherein the switchboard housing (2) is 10 cm or more and 40 cm or less longer in the front-rear length than the transformer (4) in a plan view.

3. Inside the switchboard housing (2), an instrument transformer (7) connected to a transformer branch circuit (6S) branched from the high-voltage circuit (6H) and transforming the high-voltage alternating current (H) flowing through the high-voltage circuit (6H) into a lower-voltage transformer output current (S), a voltmeter (8) for measuring the voltage of the high-voltage circuit (6H) based on the transformer output current (S) from the instrument transformer (7), and a transformer output terminal (9) capable of outputting the transformer output current (S) from the instrument transformer (7) to electrical and electronic equipment outside the switchboard housing (2) are provided. The switchboard according to claim 1 or 2 is characterized by this.

4. Inside the switchboard housing (2), a zero-phase voltage detector (10) connected to a zero-phase branch circuit (6Z) branched from the high-voltage circuit (6H), and a zero-phase voltage output terminal (11) capable of outputting the output from the zero-phase voltage detector (10) to electrical and electronic equipment outside the switchboard housing (2) are provided. The switchboard according to claim 1 or 2 is characterized by this.

5. The high-voltage circuit (6H) is three-phase three-wire, Inside the switchboard housing (2), An instrument transformer (7) is connected to a voltage transformation branch circuit (6S) branched from at least two of the three-phase three-wire of the high-voltage circuit (6H), and transforms a high-voltage alternating current (H) flowing through the high-voltage circuit (6H) into a lower-voltage transformed output current (S). An instrument current transformer (12) that rectifies the high-voltage alternating current (H) flowing through the high-voltage circuit (6H) into a smaller rectified output current (R) is provided in at least two of the three-phase three-wire of the high-voltage circuit (6H). The distribution board according to claim 1 or 2, characterized in that at least two voltage transformation output terminals (9) capable of outputting the voltage transformation output current (S) from the instrument transformer (7) to electrical and electronic equipment outside the panel housing (2) and at least two current transformation output terminals (13) capable of outputting the current transformation output current (R) from the instrument current transformer (12) to electrical and electronic equipment outside the panel housing (2) are provided.

6. The transformer (4) is grounded at the grounding point (4'). Inside the panel housing (2), A grounding resistor (14) is provided between the transformer (4) and the grounding point (4'). A zero-phase current transformer (15) is provided between the grounding resistor (14) and the grounding point (4'). The distribution board according to claim 1 or 2, characterized in that a zero-phase current transformation output terminal (16) capable of outputting the output from the zero-phase current transformer (15) to electrical and electronic equipment outside the panel housing (2) is provided.

7. Inside the panel housing (2), The distribution board according to claim 1 or 2, characterized in that a single-phase transformer (17) different from the transformer (4) is provided in the low-voltage circuit (6L).

8. The high-voltage power transmission section (5) has a high-voltage switch (5a) capable of opening and closing the high-voltage circuit (6H) or a high-voltage circuit breaker (5b) capable of interrupting it. The panel housing (2) includes a low-voltage panel housing section (2A) in which the low-voltage circuit breaker (3) is provided inside, and a high-voltage panel housing section (2B) in which the high-voltage switch (5a) or the high-voltage circuit breaker (5b) is provided inside. The distribution board according to claim 1 or 2, characterized in that the transformer (4) supports the weight of the low-voltage panel housing section (2A) and the weight of the high-voltage panel housing section (2B).

9. A power distribution board having a panel housing (2) and a transformer (4) connected between the system (K) outside the panel housing (2) and a load capable of consuming the power received from the system (K). The switchboard housing (2) includes a low-voltage switchboard housing (2A) provided therein with a low-voltage circuit breaker (3) capable of interrupting a low-voltage circuit (6L) between the transformer (4) and a load, and a high-voltage switchboard housing (2B) provided therein with a high-voltage switch (5a) capable of opening and closing a high-voltage circuit (6H) between the system (K) and the transformer (4) or a high-voltage circuit breaker (5b) capable of interrupting the high-voltage circuit (6H). The power distribution board is characterized in that the transformer (4) supports the weight of the low-voltage switchboard housing (2A) and the weight of the high-voltage switchboard housing (2B).

10. As the support of the weight of the low-voltage switchboard housing (2A) and the weight of the high-voltage switchboard housing (2B) by the transformer (4), the high-voltage switchboard housing (2B) is attached to the transformer (4) from above, the low-voltage switchboard housing (2A) is attached to the high-voltage switchboard housing (2B) from one side in plan view, The power distribution board according to claim 9, wherein a lower end of the low-voltage switchboard housing (2A) extends to a lower part of the transformer (4).

11. The power distribution board according to claim 10, wherein a suspension tool (4T) is provided at an eccentric position on one side in plan view of the transformer (4).

12. A power distribution system having the power distribution board (1) according to claim 1 or 2, a power generation unit (21), and a conversion unit (22) for converting a direct current or an alternating current from the power generation unit (21) into a low-voltage alternating current (L), wherein there are a plurality of the power distribution boards (1), a connection circuit (6C) connects between the plurality of the power distribution boards (1), and a high-voltage alternating current (H) is transmitted from a high-voltage power transmission unit (5) of the plurality of connected power distribution boards (1) to the system (K), and a vacuum circuit breaker (23a), a circuit breaker (23b), and / or a load switch (23c) are provided in a circuit connecting the system (K) and the plurality of connected power distribution boards (1).

13. A power distribution system having the power distribution board (1) according to claim 3, a power generation unit (21), and a conversion unit (22) for converting a direct current or an alternating current from the power generation unit (21) into a low-voltage alternating current (L), wherein there is one power distribution board (1), and a high-voltage alternating current (H) is transmitted from a high-voltage power transmission unit (5) of the one power distribution board (1) to the system (K), and a power generation unit (21), a conversion unit (22), and a power storage unit (24) connected to the transformer output terminal (9) are provided outside the switchboard housing (2).

14. A power distribution system having the switchboard (1) according to claim 4, a power generation unit (21), and a conversion unit (22) that converts direct current or alternating current from the power generation unit (21) into low-voltage alternating current (L), wherein there is one said switchboard (1), and high-voltage alternating current (H) is transmitted from the high-voltage power transmission unit (5) of the one switchboard (1) to the system (K), outside the switchboard housing (2), there are provided the power generation unit (21), the conversion unit (22), and a ground fault overvoltage relay (25) connected to the zero-phase voltage output terminal (11). A power distribution system characterized by this.

15. A power distribution system having the switchboard (1) according to claim 5, a power generation unit (21), and a conversion unit (22) that converts direct current or alternating current from the power generation unit (21) into low-voltage alternating current (L), wherein outside the switchboard housing (2), there is provided an electricity meter (28) connected to at least two of the said transformer output terminals (9) and the inverter output terminals (13) and measuring the amount of electric power of the high-voltage circuit (6H). A power distribution system characterized by this.

16. A power distribution system having the switchboard (1) according to claim 6, a power generation unit (21), and a conversion unit (22) that converts direct current or alternating current from the power generation unit (21) into low-voltage alternating current (L), wherein outside the switchboard housing (2), there is provided a ground fault overcurrent relay (29) connected to the zero-phase inverter output terminal (16). A power distribution system characterized by this.

17. A power receiving and distribution system having the power receiving and distribution board (1') according to any one of claims 9 to 11 and a load (30), wherein the transformer (4) is a three-winding transformer having a primary winding, a secondary winding, and a tertiary winding, or a two-winding transformer having a primary winding and a secondary winding, the load (30) includes a charger for a vehicle with a built-in battery. A power receiving and distribution system characterized by this.

Images