JP6315173B2 - DC junction box - Google Patents

Description

  The present invention relates to a DC junction box to which an external power source such as a solar battery or a storage battery is connected.

  Conventionally, in a power supply system using a plurality of solar cell modules as an external power source, a connection box and a power conditioner are provided between the solar cell module and the distribution board (for example, see Patent Document 1). The junction box is responsible for collecting the output of each solar cell module. The power conditioner includes a DC-DC converter circuit that converts the output of the solar cell module into DC power suitable for the inverter circuit, and an inverter circuit that converts the DC output of the DC-DC converter circuit to AC.

JP 2012-168699 A

  The DC-DC converter circuit has a circuit configuration according to the type and specification of the external power supply. When the specification of the external power supply is changed due to replacement or expansion of the external power supply, it is necessary to replace the DC-DC converter circuit. is there. However, when the DC-DC converter circuit provided in the power conditioner is formed of a substrate integrated with the inverter circuit, it is difficult to replace only the DC-DC converter circuit.

  Moreover, since the power conditioner is often installed indoors in contrast to the connection box that is often installed outdoors, it is desired to reduce the size of the power conditioner.

  The present invention has been made in view of the above reasons, and an object of the present invention is to provide a DC connection box that can easily cope with replacement and expansion of an external power source and that can reduce the size of other connected devices. There is.

The DC junction box of the present invention is connected to a first external power source that generates DC power, a first conversion module that converts power between DC and DC, and a second external that stores DC power. A plurality of conversion modules including at least a second conversion module connected to a power source and converting power between direct current and direct current ; and at least one arrangement space in which the conversion modules are arranged in a line. And a housing for housing the conversion module, and a connection portion for connecting each of the conversion modules and an external device.

  In the DC junction box, the external device is preferably a conversion device that converts power between direct current and alternating current.

  The DC connection box includes a conductive bar that connects each of the conversion modules and the connection portion, the casing has one arrangement space, and the conversion modules are arranged side by side. It is preferable that it is provided along the direction and is arranged between one side wall of the housing and the arrangement space.

  The DC connection box includes a conductive bar that connects each of the conversion modules and the connection portion, the housing has the two arrangement spaces, and the conversion modules are arranged side by side. It is preferable to be provided along the direction and disposed between the arrangement spaces.

  In the DC junction box, the conversion modules are preferably housed in independent cases, and the case is preferably attached to the housing using a detachable attachment member.

  In this DC junction box, it is preferable that the dimension of the case is an integral multiple of a predetermined unit dimension in the direction in which the conversion modules are arranged side by side.

  In this DC connection box, it is preferable that at least one of the conversion module and the connection portion includes a circuit breaker.

  As described above, in the present invention, a plurality of conversion modules that are provided between a plurality of external power supplies and external devices and are connected to the external power supplies are arranged in the housing. Therefore, it is possible to select a conversion module according to the type and specification of the external power supply, and it is possible to easily cope with replacement and expansion of the external power supply. Furthermore, since the conversion module for converting power is housed in the casing of the DC connection box, there is an effect that it is possible to reduce the size of other connected devices.

It is the external appearance front view which removed the cover of the DC connection box in embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is an external view of the DC junction box in embodiment of this invention, (a) is a front view, (b) is a top view, (c) is a side view. It is sectional drawing which removed the cover of the DC junction box in embodiment of this invention, (a) is the longitudinal cross-sectional view seen from the side, (b) is the horizontal sectional view seen from upper direction. It is the external appearance front view which removed the cover of the DC connection box of another structure in embodiment of this invention. It is a block block diagram of the electric power supply system in embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment)
The DC junction box 1 of this embodiment is used in a power supply system using the solar cell module 10 as an external power source (see FIG. 5). The power supply system includes a plurality of solar cell modules 10, a DC connection box 1, and a power conversion device 11. And the solar cell module 10 generates electric power using the power converter circuit (DC-DC converter circuit) with which the conversion module 2 provided in DC connection box 1 is provided, and the inverter circuit 12 provided in the power converter device 11. FIG. Converts DC power and outputs the power to the system or stand-alone.

  The output of each solar cell module 10 is connected to the DC connection box 1. The DC junction box 1 includes a number of conversion modules 2 corresponding to the number of solar cell modules 10, and one solar cell module 10 is connected to one conversion module 2. In the example of the power supply system shown in FIG. 5, two solar cell modules 10 and two conversion modules 2 are illustrated. The conversion module 2 is composed of a DC-DC converter circuit that converts the output of the solar cell module 10 into desired DC power. Further, the DC connection box 1 includes a connection unit 4 that collects the output of each conversion module 2. The outputs of the conversion modules 2 are combined into one and output to the power conversion device 11 that is an external device. To do.

  The power converter 11 includes an inverter circuit 12 that converts power between direct current and alternating current, converts the output of the DC connection box 1 into alternating current power, and connects the system output to the commercial power supply system, the load Is output to the self-sustained output that makes the operation independent.

  Below, the structure of the DC junction box 1 of this embodiment is demonstrated using FIG. 1, FIG. 2 (a)-(c), FIG. 3 (a), and (b). In the following description, the upper, lower, left, and right directions in FIG.

  The DC junction box 1 of the present embodiment includes a plurality of conversion modules 2, a housing 3, and a connection unit 4. The plurality of conversion modules 2 are each connected to an external power source (for example, a solar battery, a storage battery, or the like) that performs one of generation and storage of DC power, and converts power between DC and DC. The housing 3 has at least one arrangement space 33 in which the conversion modules 2 are arranged in a line, and houses the conversion module 2. The connection unit 4 connects each conversion module 2 and an external device.

  2A is an external front view of the DC connection box 1, FIG. 2B is an external plan view of the DC connection box 1, and FIG. 2C is an external side view of the DC connection box 1. FIG. The housing 3 includes a rectangular box-shaped body 31 having a rectangular opening on the front surface and a cover 32 that closes the opening of the body 31.

  FIG. 1 is a front view of the DC connection box 1 with the cover 32 removed, FIG. 3A is a longitudinal sectional view as seen from the side of the DC connection box 1 with the cover 32 removed, FIG. The horizontal sectional view seen from the upper direction of the DC connection box 1 in the state which removed the cover 32 to b) is shown.

  As shown in FIG. 1, a plurality of (five in the example shown in FIG. 1) conversion modules 2 are arranged in a line in the vertical direction in the housing 3.

  The conversion module 2 is housed in an independent rectangular parallelepiped case 20 as an outer shell, and a power conversion circuit (DC-DC converter circuit) is provided inside the case 20.

  Furthermore, the conversion module 2 includes a first terminal block 21 and a second terminal block 22 provided so as to be exposed from the case 20. The first terminal block 21 is provided so as to be exposed from the lower left corner of the case 20. The first terminal block 21 is composed of a pair of screw-type terminals 211 provided side by side in the vertical direction, to which the solar cell module 10 is connected via a cable (not shown). Functions as an input terminal. The second terminal block 22 is provided so as to be exposed from the upper left corner of the case 20. The second terminal block 22 is composed of three screw-type terminals 221 arranged side by side in the vertical direction, and two of the three terminals 221 function as output terminals of the power conversion circuit. The remaining one terminal 221 functions as a ground terminal. Each terminal 221 of the second terminal block 22 is connected to a conductive bar 55 to be described later via a connection member 53. In this embodiment, among the three terminals 221, as an example, the lower terminal 221 and the central terminal 221 are set as output terminals of the power conversion circuit, and the upper terminal 221 is set as a ground terminal. It is not limited to this combination. Moreover, although the terminals 211 and 221 are configured by screwing, they may be configured by different connection methods (for example, a bragg-in type).

  Furthermore, the conversion module 2 includes a circuit breaker 23. The circuit breaker 23 is a leakage breaker that breaks the circuit when a leakage occurs, and is electrically connected between the first terminal block 21 and the power conversion circuit to protect the power conversion circuit. Instead of the circuit breaker 23, a switch that conducts or breaks the circuit by manual operation may be used.

  The case 20 is provided with projecting pieces 24 projecting from the upper and lower ends of the left and right side surfaces, and each projecting piece 24 has a hole penetrating in the front-rear direction. Then, the case 20 is attached to the housing 3 by fixing the removable screw 25 (attachment member) to the housing 3 through the holes formed in the protruding pieces 24.

A first support member 34 and a second support member 35 that support the case 20 are provided on the back surface of the body 31 of the housing 3. The 1st support member 34 and the 2nd support member 35 are formed in the rail shape which the front surface protruded. A plurality of screw holes (not shown) are formed on the projecting front surfaces of the first and second support members 34 and 35, and screws 25 are attached to the screw holes.

  The first support member 34 is formed long in the vertical direction and is disposed along the right wall of the body 31. The second support member 35 is formed long in the vertical direction and is disposed along the left wall of the body 31. The width of the front surface of the second support member 35 is formed wider than the width of the front surface of the first support member 34. A space between the first support member 34 and the second support member 35 is an arrangement space 33 in which the conversion modules 2 are arranged side by side. As shown in FIG. 1, the case 20 is attached using screws 25 so as to bridge the first support member 34 and the second support member 35, and the five conversion modules 2 are arranged in the arrangement space 33. They are arranged in a line in the vertical direction.

  A conductive unit 5 is provided on the left side of each conversion module 2. The conductive unit 5 is provided on the front surface of the second support member 35, and is composed of three conductive members 51 and a third support member 52 that supports each conductive member 51. When distinguishing the three conductive members 51, they are referred to as a first conductive member 511, a second conductive member 512, and a third conductive member 513. The third support member 52 is formed in a rail shape with the front surface protruding, and is made of an electrically insulating material. A flat conductive member 51 is provided on the front surface of the third support member 52 along the vertical direction. The first conductive member 511, the second conductive member 512, and the third conductive member 513 are arranged in this order from the left. Has been. In addition, each conductive member 51 is formed so that a part detours to the back side of the front surface of the third support member 52.

  Each conductive member 51 is electrically connected to each terminal 221 of the second terminal block 22 using a connection member 53 having conductivity. In the present embodiment, the first conductive member 511 is a terminal 221 (output terminal) on the lower side of the second terminal block 22, the second conductive member 512 is a terminal 221 (output terminal) at the center of the second terminal block 22, The third conductive member 513 is connected to the upper terminal 221 (ground terminal) of the second terminal block 22.

  And the 1st-3rd conductive members 511-513 of the adjacent conductive unit 5 are electrically connected through the connection member 54 which has electroconductivity. That is, each first conductive member 511 is connected by the connecting member 54 to form one first conductive bar 551, and the terminal 221 (output terminal) of each conversion module 2 is electrically connected to the first conductive bar 551. Connected. Further, each second conductive member 512 is connected by the connecting member 54 to form one second conductive bar 552, and the terminal 221 (output terminal) of each conversion module 2 is electrically connected to the second conductive bar 552. Connected. Further, each third conductive member 513 is connected by the connecting member 54 to form one third conductive bar 553, and the terminal 221 (ground terminal) of each conversion module 2 is electrically connected to the third conductive bar 553. Connected. When the first to third conductive bars 551 to 553 are not distinguished, they are simply referred to as the conductive bars 55. As described above, each conductive bar 55 is provided along the vertical direction and is disposed between the left wall of the housing 3 (body 31) and the placement space 33, so that the space in the housing 3 is effectively utilized. can do. The first and second conductive bars 551 and 552 are connected to the connecting portion 4 via a cable (not shown), and the third conductive bar 553 is connected to the ground terminal block 6 via a cable (not shown). Is done.

  The connection unit 4 is attached to a fourth support member 36 provided on the lower side of the conversion module 2 on the back surface of the body 31. The 4th supporting member 36 is formed in the rail shape which the front surface protruded, and the connection part 4 is attached to the front surface. The connection unit 4 includes a third terminal block 41, a fourth terminal block 42, and a circuit breaker 43. The third terminal block 41 includes a pair of screw-type terminals 411, one terminal 411 is connected to the first conductive bar 551 via a cable (not shown), and the other terminal 411 is a cable ( (Not shown) to the second conductive bar 552. That is, the output terminal 221 of each conversion module 2 is electrically connected to the third terminal block 41. The fourth terminal block 42 includes a pair of screw-type terminals 421, and each terminal 421 is connected to the power converter 11 via a cable (not shown). The circuit breaker 43 is a leakage breaker that breaks the circuit when a leakage occurs, and is electrically connected between the third terminal block 41 and the fourth terminal block 42. As described above, the output of each conversion module 2 is combined into one by the connection unit 4, the first conductive bar 551, and the second conductive bar 552, and is output to the inverter circuit 12 of the power converter 11.

  The ground terminal block 6 is provided below the second support member 35 on the back surface of the body 31. The ground terminal block 6 includes a pair of terminals 61 that are electrically connected to each other. The third conductive bar 553 is connected to one terminal 61 via a cable (not shown), and the other terminal 61 has a housing. A ground wire (not shown) drawn from the outside of the body 3 is connected. Thereby, the terminal 221 (ground terminal) of the second terminal block 22 of each conversion module 2 is grounded via the ground terminal block 6 and the third conductive bar 553. The ground terminal block 6 and the housing 3 may be electrically connected so that the housing 3 is also grounded.

  Note that the external power source connected to the DC junction box 1 of the present embodiment is not limited to the solar cell module 10. The external power source may be configured to perform one of direct-current power generation and power storage, and may be configured of a storage battery, for example. Further, the external device connected to the DC connection box 1 is not limited to the power conversion device 11 including the inverter circuit 12. For example, the external device may be composed of a DC device that is driven by DC power.

  The conversion module 2 includes a plurality of types of DC-DC converter circuits having specifications corresponding to different types of external power supplies. The conversion module 2 is selected from a plurality of types according to the type of external power supply to be connected. For example, for the conversion module 2 to which a storage battery is connected as an external power source, a type including a DC-DC converter that performs bidirectional power conversion is selected in order to cope with charging and discharging of the storage battery.

  As described above, in the DC connection box 1 of the present embodiment, the power conversion circuit (DC-DC converter circuit) conventionally provided in the power conditioner is modularized and stored in the housing 3. Therefore, the conversion module 2 corresponding to the external power source can be selected, and various external power sources can be easily handled. Further, the DC-DC converter circuit can be omitted from the external device connected to the DC connection box 1, and the external device can be miniaturized.

  Furthermore, the conversion module 2 of this embodiment is accommodated in the case 20, and the case 20 is attached to the housing 3 using a removable screw 25. Therefore, when a failure or the like occurs in the conversion module 2 or when the type of the conversion module 2 is changed, the conversion module 2 can be easily replaced, so that workability is improved.

  Further, the size of the case 20 may be different depending on the type of the conversion module 2. For example, when an external power supply having a relatively large capacity is connected, the conversion module 2 is accommodated in a relatively large case 20. Here, when the vertical dimension of the case 20 in FIG. 1 is the unit dimension L1, as shown in FIG. 4, the vertical dimension of the large case 20 is set to L2, which is twice the unit dimension L1. Form. Although not shown, the vertical dimension of the case 20 may be an integer multiple of 3 or more of the unit dimension L1. Thus, by forming the vertical dimension of the case 20 to be an integral multiple of the unit dimension L1, the number of cases 20 to be attached can be adjusted, and the case 20 can be attached using the existing arrangement space 33.

  Moreover, in this embodiment, since the conductive unit 5 is provided for each conversion module 2 and the conductive bar 55 is divided into a plurality of parts, the length of the conductive bar 55 is easily adjusted according to the number of the conversion modules 2. be able to. The conductive bar 55 may be formed in a long shape with one member without being divided.

  In the present embodiment, the housing 3 includes one arrangement space 33, but may include two arrangement spaces 33. For example, a configuration in which the arrangement spaces 33 in which the conversion modules 2 are arranged in one row in the vertical direction is arranged in the left-right direction and the conversion modules 2 are arranged in two rows may be employed. In this case, by arranging the conductive bar 55 along the vertical direction between the arrangement spaces 33, the distance between the conductive bar 55 and each conversion module 2 can be easily connected, and the space in the housing 3 is also effective. Can be used.

DESCRIPTION OF SYMBOLS 1 DC junction box 2 Conversion module 20 Case 21 1st terminal block 22 2nd terminal block 23 Circuit breaker 3 Housing | casing 4 Connection part 41 3rd terminal block 42 4th terminal block 43 Circuit breaker 5 Conductive unit 51 Conductive member 55 Conductive bar 6 Ground terminal block

Claims (7)

A first external power source that generates DC power is connected, a first conversion module that converts power between DC and DC, and a second external power source that stores DC power are connected, and DC and DC A plurality of conversion modules including at least a second conversion module that performs power conversion with
A housing having at least one arrangement space in which the conversion modules are arranged in a line, and housing the conversion module;
A DC connection box comprising: a connection portion that connects each of the conversion modules and an external device. The DC connection box according to claim 1, wherein the external device is a converter that converts power between direct current and alternating current. A conductive bar that connects each of the conversion modules and the connecting portion;
The housing has one arrangement space,
The said conductive bar is provided along the direction where the said conversion module is arrange | positioned side by side, and is arrange | positioned between the one side wall of the said housing | casing, and the said arrangement | positioning space. DC junction box. A conductive bar that connects each of the conversion modules and the connecting portion;
The casing has two arrangement spaces,
The DC connection box according to claim 1, wherein the conductive bar is provided along a direction in which the conversion modules are arranged side by side, and is arranged between the arrangement spaces. Each of the conversion modules is housed in an independent case,
The DC connection box according to any one of claims 1 to 4, wherein the case is attached to the housing using a detachable attachment member. 6. The DC junction box according to claim 5, wherein a dimension of the case is formed to be an integral multiple of a predetermined unit dimension in a direction in which the conversion modules are arranged side by side.   At least one of the conversion module and the connection portion includes a circuit breaker.
  The DC junction box according to any one of claims 1 to 6, wherein

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