JP2014033587A - Housing structure and power conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a housing structure which can reduce the risk of electrification in a live wire part without performing large scale work such as to shield a solar cell module, when a power conditioner in which a junction box is incorporated is maintained.SOLUTION: A housing structure includes: a housing 50 where one face side is set to be an opening 50a; an input plate 60 which is loaded with terminal stands 21 to 25 to which an output cable 81 from an external power source is connected and which take in external power, switches 31 to 33 and 35 to which output from the terminal stands is connected, and turns a loading face 60a loaded with the terminal stands and the switches to an opening side and is stored in the housing; and a substrate 70 which is loaded with a control device 90 to which output from the switches is connected and which operates with the output, turns a loading face 70a loaded with the control device to the opening side and is stored in the housing at a part inner than the input plate to the opening. The input plate can rotatably be supported to the opening side with one side as an axis to the housing.

Description

  The present invention relates to a housing structure and a power conditioner.

  In recent years, there has been an increasing interest in reducing CO2 emissions that cause global warming, and alternative energy for fossil fuels that are expected to be depleted. Solar energy is a clean and inexhaustible energy source. The solar power generation system by is attracting attention.

  In a solar power generation system, DC power generated by a series of solar cell modules (strings) connected in series is input to a power conditioner and converted into AC power that can be used in general electrical equipment. Yes. In the case where there are a plurality of solar cell module rows, a configuration in which a plurality of pairs of output cables are connected in parallel in a connection box and collected into a pair of cables and then input to the power conditioner is common.

  Recently, however, the connection box has been abolished for the purpose of space saving and cost reduction, and a power conditioner incorporating the function of the connection box as disclosed in Patent Document 1 has been developed.

JP 2008-92628 A

  In such a power conditioner with a built-in junction box function, a plurality of pairs of output cables from the solar cell module array (strings) are directly connected to the power conditioner. In addition, although the output cable is connected to the electrical switch in the power conditioner in the example of patent document 1, it is generally connected to the terminal block in a power conditioner.

  In any case, the output cable from the solar cell module row (strings) is directly connected to the power conditioner because the connection box is omitted, and the connection portion (the primary side of the electric switch in Patent Document 1) In general, the terminal block portion) is in a live state during the day when the solar cell is generating power.

  Therefore, when maintaining the power conditioner, since there is a live part inside, the operator needs to be careful not to get an electric shock. If a board is placed at the back of the inverter casing, when the board is repaired or replaced, the board on which the terminal block or switch, etc., is placed (see below) It is also necessary to remove the plate. Note that the terminal block and switch are used for installation work and emergency shutdown, so the input board on which they are installed is placed in an easy-to-operate place inside the housing, that is, on the front side of the housing opening. Often done.

  Therefore, when removing the input plate, in order to prevent electric shock more reliably, cover the entire surface of the solar cell module with a light shielding sheet so that power generation is not possible, and then connect it to the terminal block or switch. It is necessary to remove the output cable from the solar cell module and remove the board on which the terminal block and the switch are mounted. However, there is a problem that work such as covering the entire surface of the solar cell module is very large and time-consuming.

  The present invention has been made in view of the above, and when performing maintenance of a power conditioner with a built-in junction box function, it is possible to use a live line portion without performing a large-scale operation such as shielding a solar cell module. The object is to obtain a housing structure that can reduce the risk of electric shock.

  In order to solve the above-described problems and achieve the object, the present invention provides a housing having an opening on one side, a terminal block to which an output cable from an external power source is connected to take in an external power source, and a terminal block. The switch to which the output is connected is mounted, the terminal board and the mounting surface on which the switch is mounted are directed to the opening side, and the output from the switch is connected to the input plate accommodated in the housing. A control device that operates by output is mounted, and a mounting surface on which the control device is mounted is directed to the opening side, and the substrate is housed in a housing that is deeper than the input plate with respect to the opening. Is characterized in that it is supported so as to be pivotable toward the opening with one side as an axis relative to the housing.

  According to the present invention, there is an effect that it is possible to reduce the risk of electric shock at a live line portion without performing a large-scale operation such as shielding a solar cell module.

FIG. 1 is a circuit block diagram showing a configuration of a photovoltaic power generation system including a power conditioner according to an embodiment of the present invention. FIG. 2 is an external perspective view of the power conditioner. FIG. 3 is an external perspective view of the power conditioner with the housing cover removed. FIG. 4 is a sectional view of the power conditioner viewed from the side. FIG. 5 is a cross-sectional view of the power conditioner as viewed from the side, showing a state where the input plate is rotated.

  Hereinafter, a power conditioner and a control device thereof according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment.
FIG. 1 is a circuit block diagram showing a configuration of a photovoltaic power generation system 100 including a power conditioner 1 according to an embodiment of the present invention. First, the whole structure of the photovoltaic power generation system 100 including the power conditioner 1 according to the embodiment will be described with reference to FIG.

  The solar cell modules 11, 12, 13, 14, 15 installed on the roof are connected in series about several to a dozen or so, and the output cable from the series unit (strings) is the input terminal block of the power conditioner 1. 21, 22, 23, 24, 25. The power conditioner 1 is provided with a plurality of input terminal blocks 21, 22, 23, 24, and 25, and output cables from a plurality of strings can be connected thereto.

  In the inverter 1, the input switches are connected to the DC switches 31, 32, 33 in units of one set of input terminal blocks (1 string) or two sets of input terminal blocks (2 strings). Further, backflow prevention diodes 41, 42, 43, 44, and 45 are inserted in units of input terminal blocks (string units). Further, the output sides of the plurality of DC switches 31, 32, 33 are grouped together and connected to the input of the collective DC switch 35.

  On the output side of the collective DC switch 35, a noise filter 2, an input capacitor 3, a booster circuit 4, and a bus capacitor 5 are connected in order. The booster circuit 4 is composed of L, a switch element, a diode, a capacitor, and the like. The bus capacitor 5 has a configuration in which two capacitors are connected in series, and a balance circuit 6 is connected thereto.

  The inverter circuit 7, the filter circuit 8, and the noise filter 9 are sequentially connected to the next stage of the bus capacitor 5. The filter circuit 8 includes a reactor and a capacitor. The output side of the noise filter 9 is divided into two systems, one connected to the interconnected MC 51 and the other connected to the self-supporting MC 52. The output of the interconnecting MC 51 is connected to the power system (three-phase in this embodiment) via the interconnecting terminal block 53, and the output of the self-supporting MC 52 is connected to the load via the self-supporting terminal block 54.

  Further, the input side of the power supply circuit 10 is connected to a DC voltage unit such as both ends of the input capacitor 3, and the output side is connected to various circuits such as the control circuit 20, the gate circuit 30, and the display unit 40. The various circuits are connected to relevant locations in the power conditioner 1.

  Next, the outline | summary of operation | movement of the solar power generation system 100 which concerns on this Embodiment is demonstrated.

  The solar cell modules 11, 12, 13, 14, and 15 generate direct-current power by receiving sunlight, but the voltage value per one is about 20 or 30V, and it is difficult to use as it is, so several modules About tens or more are connected in series to increase the DC voltage per string.

  The direct current power of the solar cell modules 11, 12, 13, 14, 15 is temporarily stored in the input capacitor 3 via the DC switches 31, 32, 33 and the collective DC switch 35. Here, the DC switches 31, 32, 33 have a junction box function capable of connecting or cutting off the DC power from the solar cell modules 11, 12, 13, 14, 15 in units of one string or two strings. The backflow prevention diodes 41, 42, 43, 44, 45 prevent the power stored in the input capacitor 3 from backflowing when the output of the solar cell modules 11, 12, 13, 14, 15 decreases. Moreover, it is for preventing the damage by the reverse connection of a solar cell module string.

  The DC power stored in the input capacitor 3 is boosted by the booster circuit 4 and stored in the next-stage bus capacitor 5. The boosted voltage is controlled so as to have a voltage value suitable for the inverter circuit 7 in the next stage to convert it into alternating current. This step-up operation is executed by the step-up circuit 4 by a gate signal from the gate circuit 30 in accordance with a command from the control circuit 20. In the present embodiment, a multi-level chopper method is adopted as the booster circuit 4.

  The bus capacitor 5 has two capacitors connected in series. However, if the voltage balance of each capacitor is lost, the AC output from the inverter circuit 7 may be distorted or the withstand voltage of each element may be exceeded. The balance circuit 6 by the switch element and L is connected, and the voltage balance of each capacitor is taken. The control of the balance circuit 6 is executed by the control circuit 20.

  Next, the inverter circuit 7 converts the DC power stored in the bus capacitor 5 into AC power. This inverter power conversion operation is performed by the inverter circuit 7 in accordance with a gate signal from the gate circuit 30 in accordance with a command from the control circuit 20. In the present embodiment, a three-level inverter system is adopted as the inverter circuit 7.

  Since the output of the inverter circuit 7 has a step-like discontinuous component, it is adjusted to a smooth sine wave by the filter circuit 8 at the next stage. When this sine wave output is in the interconnected operation mode, it is interconnected to the power system via the interconnected MC 51 and is consumed by the three-phase load in the facility, or the surplus is reversed to the power system (power sale) Or In the case of the independent operation mode, the load is supplied to the load connected to the independent terminal block 54 via the independent MC 52. Switching between the interconnection operation mode and the independent operation mode is executed by the control circuit 20 in response to a user operation or automatically.

  Further, the display unit 40 displays an instantaneous value and an integrated power amount of the generated power generated by the solar power generation system 100, and the user can grasp the operation status of the solar power generation system 100 by viewing it. it can.

  Next, the power conditioner 1 having the housing structure according to the present invention will be described with reference to FIGS. FIG. 2 is an external perspective view of the power conditioner 1. FIG. 3 is an external perspective view of the power conditioner 1 with the housing cover removed. FIG. 4 is a cross-sectional view of the power conditioner 1 as viewed from the side.

  The power conditioner 1 is installed on a wall, and a plurality of pairs (five pairs in this example) of output cables 81 from the solar cell modules (external power sources) 11, 12, 13, 14, and 15 are provided from the lower part of the casing 50 to the casing. 50. As shown in FIG. 3, the five pairs of output cables 81 taken into the housing 50 are connected to input terminal blocks (terminal blocks) 21, 22, 23, 24, and 25, respectively.

  The outputs of the input terminal blocks 21, 22, 23, 24, 25 are connected to the inputs of DC switches (switches) 31, 32, 33 at the next stage. A plurality of outputs (three in this example) of the DC switches 31, 32, and 33 are aggregated and connected to the input of one collective DC switch (switch) 35.

  The input terminal blocks 21, 22, 23, 24, 25, the DC switches 31, 32, 33, and the collective DC switch 35 are mounted on a mounting surface 60 a of the input plate 60 formed of a printed board or a sheet metal plate. The The input plate 60 is accommodated in a housing 50 having an opening 50a on one side. The input plate 60 is disposed so that the mounting surface 60a faces the opening 50a.

  Accordingly, the DC switches 31, 32, 33, the collective DC switch 35, and the like can be operated through the opening 50a of the housing 50. The input plate 60 is fixed in the housing 50 by, for example, screwing its four corners. The opening 50a of the housing 50 is closed with a housing cover 49 as shown in FIG.

  The casing 50 also accommodates a power board on which the booster circuit 4 and the inverter circuit 7 and the like (see also FIG. 1) are mounted, and a control board on which the control circuit 20 (see also FIG. 1) and the like are mounted. Yes. In the following description, the booster circuit 4, the inverter circuit 7, and the control circuit 20 mounted on the power board and the control board are collectively referred to as a control device 90, and the power board and the control board are collectively referred to as a board 70 ( (See also FIG. 4).

  The control device 90 is mounted on the mounting surface 70 a of the substrate 70. The substrate 70 is provided inside the housing 50 and at a position behind the input plate 60 with respect to the opening 50a. The substrate 70 is disposed such that the mounting surface 70a faces the opening 50a side of the housing 50. The output of the collective DC switch 35 is connected to a control device 90 mounted on a substrate 70 disposed in the back of the housing 50. The control device 90 is operated by the output from the collective DC switch 35.

  FIG. 5 is a cross-sectional view of the power conditioner 1 viewed from the side, and shows a state where the input plate 60 is rotated. As shown in FIG. 5, the input plate 60 is supported by the housing 50 so as to be rotatable about its one side as an axis. In the present embodiment, it is supported so as to be rotatable about a support shaft 92 provided along the lower side of the input plate 60. By removing the screws that fix the four corners of the input plate 60, the input plate 60 can be rotated.

  In addition, a stopper 91 that restricts the rotation of the input plate 60 within a predetermined range is provided. The input terminal blocks 21, 22, 23, 24, and 25 to which the output cable 81 is connected are provided close to one side of the mounting surface 60a of the input plate 60 that is rotatably supported.

  Here, if the DC switches 31, 32, 33 are turned off, the connection between the solar cell modules 11, 12, 13, 14, 15 of the series connected to the DC switches and the main circuit of the power conditioner is cut off. can do. If the collective DC switch 35 is turned off, the connection between the solar cell modules 11, 12, 13, 14, 15 of the entire series and the power conditioner main circuit can be cut off. However, even if each DC switch 31, 32, 33, 35 is turned OFF, the input terminal blocks 21, 22, 23, 24, 25 and the input part of the DC switch 31, 32, 33 are connected to the solar cell module 11, The outputs of 12, 13, 14, and 15 are applied and are in a live line state.

  It is difficult to perform maintenance on the control device 90 located behind the input plate 60 while avoiding contact with the input unit that is in a live line state. On the other hand, in the power conditioner 1 having the housing structure according to the present embodiment, as shown in FIG. 5, the input plate 60 is rotated toward the opening 50 a to facilitate access to the control device 90. be able to.

  When the input plate 60 is rotated, the DC switches 31, 32, 33, and the collective DC switch 35 are all turned OFF, and a fixing tool such as a screw fixing the input plate 60 is removed. Then, the input plate 60 is rotated toward the opening 50a around the support shaft 92 provided along the lower side of the input plate 60.

  Since the stopper 91 that restricts the rotation of the input plate 60 within a predetermined range is provided, it is possible to avoid the input plate 60 from falling too much and the charging unit coming into contact with other parts. The stopper 91 is not limited to the example illustrated in FIG. 5, and may be any stopper that can regulate the rotation of the input plate 60 within a predetermined range. For example, a protrusion that contacts the input plate 60 when it is rotated by a predetermined range may be formed on the inner side of the housing 50, and this protrusion may be used as a stopper. The back surface 60b of the mounting surface 60a is electrically insulated so that even if the back surface 60b is touched, there is no electric shock.

  By rotating the input plate 60, the input plate 60 can be moved from the front surface of the mounting surface 70a of the substrate 70, so that maintenance work such as removal or replacement of the substrate 70 can be facilitated. it can. If the DC switches 31, 32, 33 and the collective DC switch 35 are turned off, the power board, the control board, etc. are all in a non-live line state.

  In addition, since the back surface 60b of the input plate 60 is also insulated, there is no risk of electric shock in the area where the operator works, and the safety of maintenance work can be improved. Therefore, since it is not necessary to perform a large-scale work such as covering the entire surface of the solar cell modules 11, 12, 13, 14, and 15, the maintenance work for the power board, the control board, etc. can be simplified and the safety can be improved. Can be planned.

  Further, the input terminal blocks 21, 22, 23, 24, 25 to which the output cable 81 is connected are provided close to one side of the mounting surface 60a of the input plate 60 that is rotatably supported. The output cable 81 can be connected to the input terminal blocks 21, 22, 23, 24, 25 from one side that is rotatably supported. As a result, as shown in FIG. 5, the output cable 81 does not easily interfere with the rotation of the input plate 60. Further, the deformation of the output cable 81 itself accompanying the rotation of the input plate 60 can be suppressed, and the deterioration of the output cable 81 can be suppressed.

  In the present embodiment, the support shaft 92 is provided along the lower side which is one side of the input plate 60. However, the support shaft 92 may be provided substantially parallel to one side of the input plate 60 and in the vicinity of the one side. Good. If comprised in this way, it will become possible to aim at the simplification of maintenance work, such as a power board and a control board, and the improvement of safety | security by rotating the input board 60. FIG.

  Furthermore, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention in the implementation stage. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent requirements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the above embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and is described in the column of the effect of the invention. In the case where a certain effect can be obtained, a configuration from which this configuration requirement is deleted can be extracted as an invention. Furthermore, the constituent elements over different embodiments may be appropriately combined.

  As described above, the housing structure according to the present invention is useful for a power conditioner for photovoltaic power generation to which a solar cell module is connected.

  DESCRIPTION OF SYMBOLS 1 Power conditioner, 2,9 Noise filter, 3 Input capacitor, 4 Booster circuit, 5 Bus capacitor, 6 Balance circuit, 7 Inverter circuit, 8 Filter circuit, 10 Power supply circuit, 11, 12, 13, 14, 15 Solar cell Module, 20 Control circuit (CPU) 21, 22, 23, 24, 25 Input terminal block, 30 Gate circuit, 31, 32, 33 DC switch, 35 Collective DC switch, 40 Display unit, 41, 42, 43 , 44, 45 Backflow prevention diode, 49 Housing cover, 50 Housing, 50a Opening, 51 Interconnection MC, 52 Self-supporting MC, 53 Interconnection terminal block, 54 Self-supporting terminal block, 60 Input plate, 60a Mounting surface, 60b Back surface , 70 substrate, 70a mounting surface, 81 output cable, 90 control device, 91 stopper, 92 support shaft, 1 0 solar power system.

Claims (5)

A housing with an opening on one side,
A terminal block to which an output cable from an external power source is connected to take in the external power source and a switch to which an output from the terminal block is connected are mounted, and a mounting surface on which the terminal block and the switch are mounted An input plate housed in the housing toward the opening;
A control device that is connected to the output from the switch and operates according to the output is mounted, the mounting surface on which the control device is mounted is directed to the opening side, and the back of the input plate with respect to the opening. A substrate housed in the housing
The case structure, wherein the input plate is rotatably supported on the opening side with one side as an axis with respect to the case. The housing structure according to claim 1,
The external power source is a solar cell module,
The power conditioner characterized in that the control device includes an inverter that converts DC power into AC power.   The power conditioner according to claim 2, wherein a back side of the mounting surface of the input plate is insulated.   The power conditioner according to claim 2, further comprising a stopper that restricts rotation of the input plate within a predetermined range.   5. The power conditioner according to claim 2, wherein the terminal block is provided close to one side of the mounting surface of the input plate that is rotatably supported. 6.

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