Power supply system

Abstract

This provides a power supply system that eliminates the need for wiring between enclosures, without compromising functionality or expandability, and can be installed in a small space on the ground. [Solution] The power supply system includes a DC / AC converter, a first DC / DC converter, a first housing housing the DC / AC converter, and a second housing housing the first DC / DC converter. The DC / AC converter and the first DC / DC converter are electrically connected via a DC bus. The first housing has a first connection part, and the second housing has a second connection part. The second connection part is connected to the first connection part when the first housing is placed on top of the second housing. The first DC / DC converter is connected to the DC bus by the second connection part being connected to the first connection part.

Description

Technical Field

[0001] The present disclosure relates to a power supply system.

Background Art

[0002] Hybrid energy storage systems are known. For example, Patent Document 1 below discloses a system including a solar cell, a storage battery, and a power conditioner. The power conditioner converts DC power generated by the solar cell into AC power and supplies it to a load, and also charges the storage battery with the generated power of solar power generation.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A distributed power system has been proposed that allows for the addition of storage batteries or EV (Electric Vehicle) chargers / dischargers after the installation of a solar power generation system. For example, in the power system 900 shown in Figure 1, the system can be operated as a solar power generation system by installing a DC / AC converter 902, a DC / DC converter 904 for solar power generation, a power switch 916, and a solar power generation module (hereinafter referred to as a PV (Photovoltaic) module) 912. That is, the power generated by the PV module 912 (DC power) is converted by the DC / DC converter 904 to generate DC power, which is then converted to AC power by the DC / AC converter 902 and supplied to the power switch 916. The power switch 916 is, for example, a relay switch. The power switch 916 receives external control and switches the connection between the DC / AC converter 902 and the grid 924. Regarding the connection between the DC / AC converter 902 and the distribution board 920, the power switch 916 includes a path (wiring) that constantly connects the two. In other words, while the PV module 912 is generating power, the output power of the DC / AC converter 902 is output to the distribution board 920, allowing the load 922 to be operated without using commercial power supplied from the grid 924. If there is surplus power generated by the PV module 912, it is also possible to supply (sell) the surplus power to the grid 924.

[0005] Subsequently, by installing a DC / DC converter 906 and battery 910 for storage batteries, or a DC / DC converter 908 for electric vehicles, as needed, a battery storage system or an electric vehicle charging / discharging system can be added to the solar power generation system. Battery 910 is a rechargeable secondary battery. Electric vehicle 914 is equipped with a rechargeable secondary battery. Battery 910 is charged by the voltage (charging voltage) generated when DC power converted from AC power of grid 924 by DC / AC converter 902 is converted by DC / DC converter 906 for storage batteries. Battery 910 is also charged by the voltage (charging voltage) generated when DC power converted from DC power of PV module 912 by DC / DC converter 904 is converted by DC / DC converter 906 for storage batteries. The discharge power of battery 910 is converted by DC / DC converter 906, input to DC / AC converter 902, converted to AC power, and supplied to distribution board 920. Similarly, the DC / DC converter 908 charges and discharges the onboard battery of the electric vehicle 914.

[0006] However, the system illustrated in Figure 1 has the following problems (a) to (d). (a) During installation, electrical wiring (hereinafter simply referred to as wiring) must be installed between the DC / AC converter 902, the multiple DC / DC converters 904, 906, and 908, and the storage battery 910, which takes time to install and carries a high risk of wiring errors. (b) DC / AC converter 902, as well as DC / DC converters 904, 906, and 908, etc., must be anchored to the building by driving anchors into the wall, and reinforcement may be required depending on the strength of the wall. (c) Installing numerous pieces of equipment and wiring outdoors occupies a large amount of wall space, detracting from the building's aesthetics. (d) In order to suppress the leakage of interference waves from the wiring, noise filters and the like must be installed in each of the DC / AC converters 902, as well as DC / DC converters 904, 906, and 908, which increases the cost and size of the converters.

[0007] The above problems can be overcome by housing the DC / AC converter 902, the DC / DC converter 904 for solar power generation, the DC / DC converter 906 for storage batteries, the storage battery 910, and the DC / DC converter 908 for electric vehicles, along with the wiring between them, in a common enclosure from the start. However, in that case, the advantage of system expandability, that is, the ability to add new functions (e.g., a battery storage system or an EV charging / discharging system) by expanding the system as appropriate after introducing a part of the system configuration shown in Figure 1 (e.g., a PV system), would be lost.

[0008] Therefore, the purpose of this disclosure is to provide a power supply system that does not impair functional expandability, does not require wiring work between enclosures outside the enclosure, and can be installed in a small space on the ground. [Means for solving the problem]

[0009] A power supply system according to a certain aspect of the present disclosure includes a DC / AC converter, a first DC / DC converter, a first housing housing the DC / AC converter, and a second housing housing the first DC / DC converter, wherein the DC / AC converter and the first DC / DC converter are electrically connected via a DC bus, the first housing has a first connection part, and the second housing has a second connection part, the second connection part being connected to the first connection part when the first housing is placed on top of the second housing, and the first DC / DC converter is connected to the DC bus by the second connection part being connected to the first connection part. [Effects of the Invention]

[0010] According to this disclosure, it is possible to provide a power supply system that does not impair functional expandability, does not require wiring work between enclosures, and can be installed in a small space on the ground. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a block diagram showing the configuration of the power supply system. [Figure 2] Figure 2 is a block diagram showing the configuration of a power supply system according to an embodiment of this disclosure. [Figure 3] Figure 3 is a two-view drawing (front view and right side view) showing the shape of the DC / DC converter. [Figure 4] Figure 4 is a block diagram showing a power supply system according to the first modified example, which is the power supply system shown in Figure 2 with a solar power generation system installed. [Figure 5] Figure 5 is a block diagram showing a power supply system according to a second modified example, which is the power supply system shown in Figure 2 with an energy storage system installed. [Figure 6] Figure 6 is a block diagram showing a power supply system according to a third modified example, which is a configuration in which a power storage system is added to the power supply system (photovoltaic power generation system) shown in Figure 4, or a configuration in which a photovoltaic power generation system is added to the power supply system (photovoltaic power generation system) shown in Figure 5. [Figure 7] Figure 7 is a block diagram showing a power supply system according to the fourth modified example, which is the power supply system shown in Figure 6 with an additional photovoltaic power generation system. [Figure 8] Figure 8 is a block diagram showing a power supply system according to the fifth modified example, in which the storage battery and the DC / DC converter for the storage battery are housed in a single enclosure, as shown in Figure 2. [Figure 9] Figure 9 is a block diagram showing a power supply system according to the sixth modified example, in which, in the configuration shown in Figure 2, a DC / AC converter and one DC / DC converter are housed in a single enclosure. [Modes for carrying out the invention]

[0012] [Description of Embodiments in this Disclosure] The embodiments of this disclosure are listed and described below. At least some of the embodiments described below may be combined in any way.

[0013] (1) The power supply system according to the first aspect of the present disclosure includes a DC / AC converter, a first DC / DC converter, a first housing that houses the DC / AC converter, and a second housing that houses the first DC / DC converter. The DC / AC converter and the first DC / DC converter are electrically connected via a DC bus. The first housing has a first connection portion, and the second housing has a second connection portion. The second connection portion is connected to the first connection portion in a state where the first housing is disposed on the second housing. The first DC / DC converter is connected to the DC bus when the second connection portion is connected to the first connection portion. Thereby, without impairing the functional expandability, wiring work between the housings outside the housing is unnecessary and the installation work becomes easy, and the power supply system can be installed in a small space on the ground. Therefore, since it is not necessary to arrange the converters and the wiring connecting the converters on the wall surface of the building, the appearance of the building is not impaired.

[0014] (2) In the above (1), the first connection portion may be disposed on the lower surface of the first housing, and the second connection portion may be disposed on the upper surface of the second housing. The second connection portion may be connected to the first connection portion when the first housing is disposed on the second housing. Thereby, wiring work between the housings is unnecessary and the installation work becomes easier. In addition, since the wiring is housed in the housing made of a conductive member such as metal, the noise filter can be simplified.

[0015] (3) In the above (1) or (2), the power supply system further includes a storage battery and a third housing that houses the storage battery. The third housing is disposed under the second housing. The first DC / DC converter may output the power generated by converting the discharge power of the storage battery to the DC bus, and may generate the charging power of the storage battery by converting the power supplied from the DC bus. Thereby, the heavy storage battery is disposed at the bottom most, and the power supply system can be installed stably.

[0016] (4) In the above (3), the second housing and the third housing may be integrally formed. Thereby, the installation of the power supply system becomes easier.

[0017] (5) In the above (3), the first housing and the second housing may be integrally formed. This makes it easier to install the power supply system.

[0018] (6) In any one of the above (1) to (5), the second housing may further have a third connection part connected to the DC bus. Thereby, in order to expand the function of the power supply system, a new housing configured similarly to the second housing that houses a new DC / DC converter can be easily added.

[0019] (7) In the above (6), the power supply system may further include a second DC / DC converter and a third housing that houses the second DC / DC converter. The third housing may have a fourth connection part. The second DC / DC converter may be connected to the DC bus via the third connection part and the fourth connection part in a state where the second housing is disposed above the third housing. Thereby, a power supply system including two DC / DC converters (for example, a DC / DC converter for solar power generation and a DC / DC converter for a storage battery) can be easily installed. Adding the third housing to an existing power supply system does not increase the installation area.

[0020] (8) In the above (7), the third connection part may be disposed on the lower surface of the second housing, the fourth connection part may be disposed on the upper surface of the third housing, and the second DC / DC converter may be connected to the DC bus via the third connection part and the fourth connection part by disposing the second housing above the third housing. Thereby, a power supply system including two DC / DC converters can be installed more easily.

[0021] (9) In the above (7) or (8), the power supply system may further include a storage battery and a fourth housing that houses the storage battery. The fourth housing may be disposed below the third housing. The second DC / DC converter may convert the power output from the storage battery and output it to the DC bus, and may also convert the power supplied from the DC bus to generate the charging power of the storage battery. Thereby, the heavy storage battery is disposed at the bottom most, and the power supply system can be installed stably.

[0022] (10) In (9) above, the third enclosure and the fourth enclosure may be formed as a single unit. This makes it easier to install the power supply system.

[0023] (11) In (9) above, the first enclosure and the second enclosure may be formed as a single unit. This makes it easier to install the power supply system.

[0024] (12) In any one of (7) to (11) above, the power supply system may further include a third DC / DC converter and a fifth housing housing the third DC / DC converter, the fifth housing having a fifth connector and a sixth connector, the third connector may be connected to the fifth connector when the second housing is placed on top of the fifth housing, the fourth connector may be connected to the sixth connector when the fifth housing is placed on top of the third housing, the third DC / DC converter may be connected to the DC bus by the connection of the third connector and the fifth connector, and the second DC / DC converter may be connected to the DC bus by the connection of the fourth connector and the sixth connector. This makes it easy to install a power supply system including three DC / DC converters with different functions (for example, a DC / DC converter for solar power generation, a DC / DC converter for EVs, and a DC / DC converter for storage batteries).

[0025] (13) In (12) above, the fifth connection may be located on the top surface of the fifth housing, the sixth connection may be located on the bottom surface of the fifth housing, the third connection may be connected to the fifth connection by the second housing being located on top of the fifth housing, and the fourth connection may be connected to the sixth connection by the fifth housing being located on top of the third housing. This makes it easier to install a power supply system including three DC / DC converters with different functions.

[0026] (14) In any one of (1) to (13) above, the power supply system may further include a first control unit housed in a first enclosure and controlling a DC / AC converter, a second control unit housed in a second enclosure and controlling a first DC / DC converter, a first signal line housed in the first enclosure and connected to the first control unit, and a second signal line housed in the second enclosure and connected to the second control unit, wherein the first signal line and the second signal line may be connected by connecting a first connector and a second connector. This eliminates the need for external wiring work to connect the control unit that controls the DC / AC converter and the control unit that controls the DC / DC converter, making installation work easier.

[0027] (15) In any one of (1) to (14) above, the first housing may have a first guide mechanism located on the bottom surface of the first housing, and the second housing may have a second guide mechanism located on the top surface of the second housing, and the first housing may be placed on top of the second housing such that the first guide mechanism and the second guide mechanism are interlocked. This makes it easier to place the first housing on top of the second housing and makes it easier to install the power supply system.

[0028] [Details of the embodiments of this disclosure] In the following embodiments, identical parts are assigned the same reference numeral. Their names and functions are also identical. Therefore, detailed descriptions of them will not be repeated.

[0029] (System Configuration) Referring to Figure 2, the power supply system 100 according to the embodiment of this disclosure includes a DC / AC converter 102, DC / DC converters 104, 106 and 108, control units 122, 124, 126 and 128, and a battery 110. The DC / AC converter 102 and control unit 122 are housed in a housing 142. The DC / DC converter 104 and control unit 124 are housed in a housing 144. The DC / DC converter 106 and control unit 126 are housed in a housing 146. The DC / DC converter 108 and control unit 128 are housed in a housing 148. The battery 110 is housed in a housing 150. The housings 142 to 150 are stacked so that housing 150 is at the bottom and housing 142 is at the top, and are arranged outdoors. Housing 150 is fixed to a base 140 (made of concrete, etc.) installed on the ground via anchor bolts or the like. Note that in Figure 2, each element is shown at an arbitrary scale, and it is not intended to represent a comparison of the sizes of the elements (the same applies to Figures 3 and beyond).

[0030] Housings 142 to 150 are formed from conductive materials such as metal. A connector 160 connected to the DC / AC converter 102 by wiring 120 is located on the bottom surface of housing 142. Connectors 162 and 164 are located on the top and bottom surfaces of housing 144, respectively. Connectors 166 and 168 are located on the top and bottom surfaces of housing 146, respectively. Connectors 170 and 172 are located on the top and bottom surfaces of housing 148, respectively. Connector 174 is located on the top surface of housing 150.

[0031] Connectors 160 through 174 are connectors for electrical connections, and are either plugs or receptacles. For example, connectors 160, 164, 168, and 172 located on the bottom of each housing are receptacles of the same type, while connectors 162, 166, 170, and 174 located on the top of each housing are plugs corresponding to the receptacles. Each connector has multiple metal terminals. For example, if each of connectors 160, 164, 168, and 172 has, for example, female terminals, then each of connectors 162, 166, 170, and 174 has male terminals. For example, if each of connectors 160, 164, 168, and 172 has, for example, male terminals, then each of connectors 162, 166, 170, and 174 has female terminals. As housings 142 and 150 are stacked as described above, connectors 160, 164, 168, and 172 are connected to connectors 162, 166, 170, and 174, respectively (i.e., the corresponding male and female terminals are connected).

[0032] The DC / AC converter 102 is connected to the power grid 134 via a power switch 116. The DC / AC converter 102, under the control of the control unit 122, converts DC power and AC power bidirectionally. That is, the DC / AC converter 102 converts the AC power supplied from the power grid 134 into DC power and outputs it via the wiring 120. The DC / AC converter 102 also converts the DC power input via the wiring 120 into AC power and outputs it to the power switch 116. The connector 160 includes terminals connected to the DC power input / output section of the DC / AC converter 102 via the wiring 120 and terminals connected to the control unit 122. The wiring 120 consists of two wires for transmitting DC power (hereinafter also referred to as the DC bus). A capacitor is connected between the two wires. The DC / AC converter 102 is implemented, for example, by a bridge circuit using multiple semiconductor switching elements (such as FETs (Field Effect Transistors)).

[0033] The control unit 122 monitors the current value using the current measurement unit 118 and enables grid connection with the power system 134 and independent operation in the event of a power outage in the power system 134 via the power switch 116. The control unit 122 controls each switching element (for example, using PWM (Pulse Width Modulation) control) to realize the power conversion function of the DC / AC converter 102. Furthermore, as will be described later, the control unit 122 communicates with the control units 124, 126, and 128 to instruct the operation of the DC / DC converters 104, 106, and 108, respectively.

[0034] The power switch 116 is, for example, a relay switch that, under external control, connects the DC / AC converter 102 to the grid 134. Regarding the connection between the DC / AC converter 102 and the distribution board 130, the power switch 116 includes a path (wiring) that permanently connects the two. If the DC / AC converter 102 is connected to the grid 134 by the power switch 116, the AC power generated by the DC / AC converter 102 is used by the load 132 via the distribution board 130, any surplus power is supplied to the grid 134 (sold electricity), and any power shortage of the load 132 is supplied from the grid 134 (purchased electricity). If the DC / AC converter 102 is not connected to the grid 134 by the power switch 116, the AC power generated by the DC / AC converter 102 is used only by the load 132 (standalone operation).

[0035] The DC / DC converter 104, under the control of the control unit 124, converts (e.g., boosts) the input DC voltage to a predetermined DC voltage and outputs it. The input section of the DC / DC converter 104 is connected to the PV module 112, and the output section of the DC / DC converter 104 is connected to the terminals of the connector 162. The PV module 112 consists of multiple series-connected solar cells arranged on a plane and sealed using tempered glass or the like. The PV module 112 functions as a DC power supply. The connector 162 includes terminals connected to the DC power output section of the DC / DC converter 104 and terminals connected to the control unit 122. Each terminal of the connector 162 is also connected to the corresponding terminal on the connector 164.

[0036] The DC / DC converter 104 converts the voltage of the generated power (DC power) input from the PV module 112 into a predetermined DC voltage and outputs it to the terminals of the connector 162. As a result, the output power of the DC / DC converter 104 is input to the DC / AC converter 102 via connectors 162 and 160, and the DC / AC converter 102 converts it into AC power as described above. That is, the generated power of the PV module 112 is supplied to the load 132 and the grid 134 via the distribution board 130. The DC / DC converter 104 is implemented, for example, by a bridge circuit using multiple semiconductor switching elements. The control unit 124 receives instructions from the control unit 122 and controls each switching element of the DC / DC converter 104 to realize the power conversion function of the DC / DC converter 104.

[0037] The DC / DC converter 106 is a bidirectional converter that, under the control of the control unit 126, converts the input DC voltage into a predetermined DC voltage and outputs it. The first input / output section of the DC / DC converter 106 is connected to a rechargeable secondary battery (hereinafter referred to as the on-board battery) installed in the electric vehicle 114, and the second input / output section of the DC / DC converter 106 is connected to the terminals of connector 166. Connector 166 includes terminals connected to the second input / output section of the DC / DC converter 106 and terminals connected to the control unit 126. Each terminal of connector 166 is also connected to the corresponding terminal of connector 168. As a result, as described above, the DC power converted from the AC power of the grid 134 by the DC / AC converter 102 is input to the second input / output section of the DC / DC converter 106 via connectors 160, 162, 164, and 166.

[0038] The DC / DC converter 106 converts (steps down) the DC voltage input to the second input / output unit to a predetermined DC voltage (the charging voltage of the onboard battery) and outputs it from the first input / output unit. This charges the onboard battery of the electric vehicle 114. The discharge power of the onboard battery of the electric vehicle 114 is converted (stepped up) by the DC / DC converter 106 and input to the DC / AC converter 102 via connectors 166, 164, 162, and 160, and converted to AC power by the DC / AC converter 102 as described above. At this time, the power switch 116 connects the DC / AC converter 102 to the distribution board 130, and this AC power is supplied to the distribution board 130. The DC / DC converter 106 can be implemented, for example, by a bridge circuit using multiple semiconductor switching elements. The control unit 126 receives instructions from the control unit 122 and controls each switching element of the DC / DC converter 106 to realize the power conversion function of the DC / DC converter 106.

[0039] The DC / DC converter 108 is a bidirectional converter that, under the control of the control unit 128, converts the input DC voltage into a predetermined DC voltage and outputs it. The first input / output section of the DC / DC converter 108 is connected to the terminals of connector 172, and the second input / output section of the DC / DC converter 108 is connected to connector 170. Connector 170 includes terminals connected to the second input / output section of the DC / DC converter 108 and terminals connected to the control unit 128. Note that each terminal on connector 170 connected to the control unit 128 is also connected to the corresponding terminal on connector 172. The storage battery 110 is a rechargeable secondary battery. Connector 174 includes terminals connected to the storage battery 110. As described above, the DC power converted from the AC power of the grid 134 by the DC / AC converter 102 is input to the second input / output section of the DC / DC converter 108 via connectors 160, 162, 164, 166, 168, and 170. The DC / DC converter 108 converts (steps down) the DC voltage input to the second input / output unit to a predetermined DC voltage (the charging voltage of the battery 110) and outputs it from the first input / output unit. As a result, the battery 110 is charged by the charging voltage supplied via connectors 172 and 174.

[0040] The discharge power (DC voltage) of the battery 110 is input to the first input / output section of the DC / DC converter 108 via connectors 174 and 172, and is converted (boosted) by the DC / DC converter 108. The converted voltage is input to the DC / AC converter 102 via connectors 170, 168, 166, 164, 162, and 160, and is converted to AC power by the DC / AC converter 102 as described above. At this time, the power switch 116 connects the DC / AC converter 102 to the distribution board 130, and this AC power is supplied to the distribution board 130. The DC / DC converter 108 is realized by, for example, a bridge circuit using multiple semiconductor switching elements. The control unit 128 receives instructions from the control unit 122 and controls each switching element of the DC / DC converter 108 to realize the power conversion function of the DC / DC converter 108. The control unit 128 also functions as a BMS (Battery Management System). Specifically, the control unit 128 has functions to prevent overcharging and over-discharging of the battery 110, to calculate the remaining battery capacity of the battery 110, and to balance the voltages of the multiple cells that make up the battery 110. The BMS may be provided separately from the control unit 128, for example, within the housing 150.

[0041] As described above, connectors 160, 164, and 168 are of the same type (e.g., plugs), while connectors 162, 166, and 170 are connectors that can be connected to each other (e.g., receptacles). Furthermore, the arrangement of terminals for connecting DC / DC converters 104, 106, and 108 is the same from connector 160 to connector 170. That is, each wire connected to the positive terminal of DC / DC converters 104, 106, and 108 is connected to the terminal at the same position in connectors 160, 164, and 168, respectively. Each wire connected to the negative terminal of DC / DC converters 104, 106, and 108 is connected to the terminal at the same position in connectors 160, 164, and 168, respectively. As a result, by stacking enclosure 142 to enclosure 150 as described above, the output section of DC / DC converter 104, the second input / output section of DC / DC converter 106, and the second input / output section of DC / DC converter 108 are connected to the DC bus wiring 120. That is, the DC bus wiring 120 is extended by connector 160 to connector 170 (see dashed line). Similarly, the signal lines connected to each control unit from connector 160 to connector 174 are also connected to the same terminals at each connector. As a result, by stacking multiple enclosures as described above, the converters inside each enclosure can be connected to the DC bus, the control units can be interconnected, and the power supply system can be installed in a small space on the ground. Therefore, external wiring is unnecessary, the power supply system can be installed quickly without wiring errors, and the converters and wiring do not need to be placed on the building walls, thus not detracting from the building's aesthetics. In addition, since the wiring is housed within a conductive material enclosure such as metal, the noise filter can be simplified. For example, instead of using a high-performance, expensive noise filter, you can use an inexpensive noise filter with a simple circuit configuration.

[0042] As described above, the DC / AC converter and each of the multiple DC / DC converters, along with the control unit that controls the converters, are housed in the same enclosure. The enclosure housing the DC / AC converters has a connector on its bottom, while the other enclosures have connectors on their top and bottom. This allows for easy connection between the control unit that controls the DC / AC converters and the control unit that controls the DC / DC converters, simply by stacking multiple enclosures.

[0043] As described above, by placing the enclosure 150 housing the battery 110 at the bottom of the multiple enclosures, the heavy battery is positioned at the very bottom, allowing the power supply system 100 to be installed stably.

[0044] In a housing different from housing 148, which includes a DC / DC converter for the battery, housings 144 and 146, which are adjacent to each other vertically, each have connectors on their top and bottom surfaces that connect to the DC bus (wiring 120) when stacked. This makes it easy to add a new housing, configured similarly to the existing housing, to expand the functionality of the power supply system, by housing a new DC / DC converter. In other words, by stacking the existing housing and the new housing, a new DC / DC converter can be connected to the DC bus.

[0045] As described above, the power supply system 100 includes DC / DC converters 104, 106, and 108. This makes it easy to install a power supply system that includes three DC / DC converters with different functions (for example, a DC / DC converter for solar power generation, a DC / DC converter for EVs, and a DC / DC converter for storage batteries).

[0046] Furthermore, even if enclosure 144 and enclosure 146 are swapped, the same functionality as a power supply system can be maintained. In addition, additional enclosures with the same internal configuration and connection configuration can be added, allowing for easy expansion of functionality.

[0047] Furthermore, the enclosure 148 is mounted on top of the enclosure 150, and no other enclosure is placed between the enclosure 148 and the enclosure 150. Therefore, connector 172 may be the same type of connector as connectors 160, 164, and 168, or it may be a different type of connector. Connector 174 may be any connector that can connect to connector 172.

[0048] Preferably, each enclosure included in the power supply system 100 has an alignment mechanism (hereinafter referred to as a guide mechanism) to streamline stacking operations. Figure 3 shows the external shape of enclosure 144 as an example of the shape of each enclosure. Enclosure 144 has a rectangular top surface 180 and a bottom surface 182, and has protrusions 184 and 186 at at least two diagonally opposite corners of the four corners of the top surface 180. Enclosure 144 also has recesses 188 and 190 on the bottom surface 182 at positions corresponding to the protrusions 184 and 186, respectively. The protrusions 184 and 188 are shaped to fit together, and the protrusions 186 and 190 are shaped to fit together. The protrusions 184 and 186, and the recesses 188 and 190, function as a guide mechanism. The housing 144 has a connector 162 on its top surface 180 and another connector 164 on its bottom surface 182. Connectors 162 and 164 are positioned in the same location on each surface. Connector 162 protrudes slightly from the top surface 180, and connector 164 is slightly recessed from the bottom surface 182 to match the protrusion of connector 162, so that connectors 162 and 164 can be fitted together. Housings 146 and 148 also have protrusions and recesses, similar to housing 144, and connectors are positioned on them. Housing 142 only needs to have a recess on its bottom surface that can be fitted together with protrusions 184 and 186, respectively. Housing 150 only needs to have a protrusion on its top surface that can be fitted together with recesses 188 and 190, respectively. As described above, when stacking multiple enclosures, arranging them so that the corresponding protrusions and recesses fit together allows for easy and accurate connection of the corresponding connectors, making the installation of the power system easier. Furthermore, damage to the connectors and their terminals during installation can be avoided. Since the connectors connecting the enclosures are not exposed externally when stacked, connector degradation can be prevented.

[0049] The housing's guide mechanism is not limited to the one shown in Figure 3, but is arbitrary. A protrusion of a predetermined size and shape can be provided on the upper surface 180, and a recess of a shape that engages with the protrusion can be provided on the lower surface 182 at a position corresponding to the protrusion.

[0050] (First variation) A portion of the configuration of the power supply system 100 shown in Figure 2 may be installed. Referring to Figure 4, the power supply system 200 according to the first modified example includes a DC / AC converter 102, a DC / DC converter 104, and control units 122 and 124. The power supply system 200 is a single-function system that has only the function of a photovoltaic power generation system. The DC / AC converter 102 and control unit 122 are housed in a housing 142. The DC / DC converter 104 and control unit 124 are housed in a housing 144. The housing 144 is fixed to a base 140 installed on the ground via anchor bolts or the like. The power supply system 200 is the same as the power supply system 100 shown in Figure 2, but with housings 146, 148 and 150 removed. In Figure 4, elements with the same reference numerals as in Figure 2 have the same function as in Figure 2. Therefore, redundant explanations will not be repeated. The power supply system 200 is connected to a PV module 112 and functions as a photovoltaic power generation system. Furthermore, when installed as a single-function system, the housing 144 shown in Figure 4 does not necessarily need to have the connector 164.

[0051] In the power supply system 200, the converters and control units can be connected simply by stacking the enclosures 142 and 144 during installation, eliminating the need for wiring between enclosures. Therefore, installation is easy, and the power supply system can be installed in a small space on the ground.

[0052] (Second variation) Some of the components shown in Figure 2 that are installed may differ from those in Figure 4. Referring to Figure 5, the power supply system 202 according to the second modification includes a DC / AC converter 102, a DC / DC converter 108, control units 122 and 128, and a battery 110. The power supply system 202 is a single-function system that has only the function of an energy storage system. The DC / AC converter 102 and control unit 122 are housed in a housing 142. The DC / DC converter 108 and control unit 128 are housed in a housing 148. The battery 110 is housed in a housing 150. The housing 150 is fixed to a base 140 installed on the ground via anchor bolts or the like. The power supply system 202 is the power supply system 100 shown in Figure 2, with housings 144 and 146 removed. In Figure 5, elements with the same reference numerals as in Figure 2 have the same functions as in Figure 2. Therefore, redundant explanations will not be repeated. The power supply system 202 functions as an energy storage system by charging and discharging the battery 110.

[0053] In the power supply system 202, the converters and control units can be connected simply by stacking the enclosures 142, 148, and 150 during installation, eliminating the need for inter-enclosure wiring. Therefore, installation is easy, and the power supply system can be installed in a small space on the ground.

[0054] Similarly, a single-function system that only functions as an EV charging and discharging system can be installed. In that case, in the power supply system 100 shown in Figure 2, housings 144, 148, and 150 can be removed, and housings 142 and 146 can be stacked and installed. Therefore, wiring work between housings is unnecessary, installation work is easy, and the power supply system can be installed in a small space on the ground.

[0055] (Third variation) Some of the components shown in Figure 2 that are installed may differ from those in Figures 4 and 5. Referring to Figure 6, the power supply system 204 according to the third modified example includes a DC / AC converter 102, a DC / DC converter 104, a DC / DC converter 108, control units 122, 124, and 128, and a battery 110. The DC / AC converter 102 and control unit 122 are housed in a casing 142. The DC / DC converter 104 and control unit 124 are housed in a casing 144. The DC / DC converter 108 and control unit 128 are housed in a casing 148. The battery 110 is housed in a casing 150. The casing 150 is fixed to a base 140 installed on the ground via anchor bolts or the like. The power supply system 204 is the same as the power supply system 100 shown in Figure 2, but with the casing 146 removed. In Figure 6, elements with the same reference numerals as in Figure 2 have the same functions as in Figure 2. Therefore, redundant explanations will not be repeated. The power system 204 functions as a solar power generation system and an energy storage system.

[0056] In the power supply system 204, the converters and control units can be connected simply by stacking the enclosures 142, 144, 148, and 150 during installation, eliminating the need for inter-enclosure wiring. Therefore, installation is easy, and the power supply system can be installed in a small space on the ground.

[0057] When initially installing a power supply system, a single-function power supply system with the configuration shown in Figure 4 or Figure 5 can be installed, and functions can be added later. For example, if power supply system 200 (Figure 4) is already installed, the function of an energy storage system can be added by adding (expanding) enclosures 148 and 150. In the expansion work, enclosures 148 and 150 can be placed below enclosure 144, and they can be easily installed by stacking them, realizing power supply system 204 shown in Figure 6. For example, if power supply system 202 (Figure 5) is already installed, the function of a solar power generation system can be added by installing PV modules 112 on the roof and adding (expanding) enclosure 144. In the expansion work, enclosure 144 can be placed between enclosures 142 and 148, and they can be easily installed by stacking them, realizing power supply system 204 shown in Figure 6. Furthermore, by adding enclosure 146 to power supply system 204 shown in Figure 6, the function of an EV charging and discharging system can be added. For expansion work, it is sufficient to place enclosure 144 between enclosure 144 and enclosure 148 (or between enclosure 142 and enclosure 144), and by stacking them, installation is easy, realizing the power supply system 100 shown in Figure 2. In either case, installation can be done without wiring between devices, and the installation area does not increase from the existing power supply system.

[0058] (Fourth variation) In the above, the functional expandability of the power supply system was described in the case of adding new functions to an existing power supply system, but it is not limited to this. In the power supply system according to the fourth modified example, the existing functions are improved (enhanced). Referring to Figure 7, the power supply system 206 according to the fourth modified example includes a DC / AC converter 102, a DC / DC converter 104, a DC / DC converter 210 and a DC / DC converter 108, a control unit 122, a control unit 124, a control unit 212 and a control unit 128 and a storage battery 110. The DC / AC converter 102 and the control unit 122 are housed in a housing 142. The DC / DC converter 104 and the control unit 124 are housed in a housing 144. The DC / DC converter 210 and the control unit 212 are housed in a housing 214. The DC / DC converter 108 and the control unit 128 are housed in a housing 148. The storage battery 110 is housed in a housing 150. The housing 150 is fixed to a base 140 installed on the ground via anchor bolts or the like. The power supply system 206 is the same as the power supply system 204 shown in Figure 6, with the addition of a housing 214 (which houses the DC / DC converter 210 and the control unit 212). In Figure 7, elements with the same reference numerals as in Figure 2 have the same functions as in Figure 2. Therefore, to avoid repeating explanations, we will mainly explain the differences.

[0059] The DC / DC converter 210 and the control unit 212 function similarly to the DC / DC converter 104 and the control unit 124, respectively. That is, the DC / DC converter 210, under the control of the control unit 212, converts (e.g., boosts) the input DC voltage to a predetermined DC voltage and outputs it. The input section of the DC / DC converter 210 is connected to the PV module 220, and the output section of the DC / DC converter 210 is connected to the terminals of the connector 216. The PV module 220 is configured similarly to the PV module 112 and is installed, for example, on a roof. The connector 216 includes terminals connected to the DC power output section of the DC / DC converter 210 and terminals connected to the control unit 212. Each terminal of the connector 216 is also connected to the corresponding terminal on the connector 218. The DC / DC converter 210 converts the voltage of the generated power (DC power) input from the PV module 220 to a predetermined DC voltage and outputs it to the terminals of the connector 216. As a result, the output power of the DC / DC converter 210 is input to the DC / AC converter 102 via connectors 216, 164, 162, and 160, and is converted to AC power by the DC / AC converter 102 as described above. That is, the power generated by the PV module 220 is supplied to the load 132 and the grid 134 via the distribution board 130. The DC / DC converter 210 is implemented, for example, by a bridge circuit using multiple semiconductor switching elements. The control unit 212 receives instructions from the control unit 122 and controls each switching element of the DC / DC converter 210 to realize the power conversion function of the DC / DC converter 210.

[0060] In the expansion work from power supply system 204 (see Figure 6), it is sufficient to install housing 214 between housings 144 and 148 (or between housings 142 and 144), and installation can be easily done by simply stacking them without wiring between devices, realizing power supply system 208 shown in Figure 7. When PV module 220 is added to the existing PV module 112, power supply system 206 functions as a power supply system with increased power generation capacity compared to power supply system 204 shown in Figure 6. In other words, power supply system 206 is a power supply system with improved functionality as a solar power generation system compared to power supply system 204 shown in Figure 6.

[0061] Furthermore, in a power supply system that also functions as an energy storage system (for example, the power supply system 204 shown in Figure 6), if the function of the energy storage system is to be improved (increased energy storage capacity), the housing 150 can be replaced with a housing that includes a battery with a larger capacity than the battery 110. If the DC / DC converter 108 housed in housing 148 cannot match the performance of the battery included in the replacement housing, housing 148 can be replaced with a new housing that includes a DC / DC converter.

[0062] Similar to power supply system 100 (see Figure 2), in both power supply system 204 (see Figure 6) and power supply system 206 (see Figure 7), the housing 150 containing the battery 110 is positioned at the bottom, so that the heavy battery 110 is placed at the very bottom. Therefore, the power supply system can be installed stably.

[0063] (Fifth variation) The above describes a case where the battery 110 and the DC / DC converter 108 for the battery are housed in separate enclosures, but is not limited to this. The battery 110 and the DC / DC converter 108 for the battery may be housed in a single enclosure. Referring to Figure 8, the power supply system 208 according to the fifth modified example includes a DC / AC converter 102, a DC / DC converter 104, a DC / DC converter 106, and a DC / DC converter 108, a control unit 122, a control unit 124, a control unit 126, and a control unit 128, and a battery 110. The DC / AC converter 102 and the control unit 122 are housed in enclosure 142. The DC / DC converter 104 and the control unit 124 are housed in enclosure 144. The DC / DC converter 106 and the control unit 126 are housed in enclosure 146. The DC / DC converter 108, the control unit 128, and the battery 110 are housed in enclosure 230. The enclosure 230 is fixed to the base 140, which is installed on the ground, via anchor bolts or the like. The power supply system 208 is the same as the power supply system 100 shown in Figure 2, but with the enclosure 230 replacing the enclosures 148 and 150. The enclosure 230 can be said to be the integrated form of the enclosures 148 and 150. In Figure 8, elements with the same reference numerals as in Figure 2 have the same functions as in Figure 2. Therefore, redundant explanations will not be repeated.

[0064] The enclosure 230 houses the DC / DC converter 108, the control unit 128, and the battery 110. Unlike the enclosures 148 and 150 shown in Figure 2, it does not include connectors 172 and 174. Within the enclosure 230, the DC / DC converter 108 and the control unit 128 are directly connected to the battery 110. In the power supply system 202 shown in Figure 5, the power supply system 204 shown in Figure 6, and the power supply system 206 shown in Figure 7, the enclosures 148 and 150 may also be replaced with the enclosure 230 shown in Figure 8. In any case, when installing the elements that function as an energy storage system, only the enclosure 230 needs to be installed, which is more efficient and easier to install than when installing two enclosures (enclosures 148 and 150).

[0065] (Sixth variation) In the fifth modification, a case was described in which the battery 110 and the DC / DC converter 108 for the battery are housed in a single enclosure, but the system is not limited to this. The DC / AC converter 102 and the DC / DC converter may be housed in a single enclosure. Referring to Figure 9, the power supply system 240 according to the sixth modification includes DC / AC converters 102, DC / DC converters 104, DC / DC converters 106 and 108, control units 122, 124, 126 and 128, and the battery 110. The DC / AC converters 102 and 104, control units 122 and 124 are housed in enclosure 242. The DC / DC converters 106 and 126 are housed in enclosure 146. The DC / DC converters 108 and 128 are housed in enclosure 148. The battery 110 is housed in enclosure 150. The power supply system 240 is the same as the power supply system 100 shown in Figure 2, but with housing 242 replacing housings 142 and 144. Housing 242 can be described as housings 142 and 144 being formed as a single unit. In Figure 9, elements with the same reference numerals as in Figure 2 have the same functions as in Figure 2. Therefore, redundant explanations will not be repeated.

[0066] Unlike housings 142 and 144 shown in Figure 2, housing 242 does not include connectors 160 and 162. Within housing 242, the DC / AC converter 102 and control unit 122 are directly connected to the DC / DC converter 104 and control unit 124, respectively. In the power supply systems shown in Figures 4 to 8, housing 142 and the housing located below it may be integrally formed. For example, in the power supply system 202 shown in Figure 5, housing 142 and housing 148 may be integrally formed. In any case, since only one housing containing the DC / AC converter and DC / DC converter needs to be installed, it is more efficient and easier to install than installing two separate housings containing the DC / AC converter and DC / DC converter.

[0067] The above describes a case where connector 160 is located on the bottom surface of housing 142, connector 162 is located on the top surface of housing 144, and housing 142 is placed on top of housing 144, thereby connecting connector 160 and connector 162. However, the description is not limited to this. Connector 160 may be located inside housing 142, and connector 162 may be located inside housing 144. In that case, with housing 142 placed on top of housing 144, the corresponding terminals of connector 160 and connector 162 can be connected inside the housing by wiring or busbars. This eliminates the need for wiring between housings on the outside, simplifies installation, and allows the power system to be installed in a small space on the ground. Therefore, since the converters and the wiring connecting them do not need to be placed on the building walls, the aesthetics of the building are not compromised. Note that when connectors 160 and connector 162 are located inside the housing, they are not limited to combinable combinations such as plugs and receptacles, but are arbitrary. For example, connectors 160 and connector 162 may be terminal blocks. Similarly, connectors 164 to 174 may also be located inside the enclosure, and may be connected inside the enclosure by wiring or busbars when the enclosures are stacked. When connectors 164 to 174 are located inside the enclosure, they are not limited to plugs and receptacles, but are arbitrary and may be terminal blocks.

[0068] The present disclosure has been described above by describing embodiments, but the embodiments described above are illustrative and the present disclosure is not limited to the embodiments described above. The scope of the present disclosure is as indicated by each claim of the claims, with reference to the description of the detailed description of the invention, and includes all modifications within the meaning and scope equivalent to the wording contained herein. [Explanation of symbols]

[0069] 100, 200, 202, 204, 206, 208, 240, 900 Power Systems 102, 902 DC / AC converter 104, 106, 108, 210, 904, 906, 908 DC / DC converters 110, 910 storage batteries 112, 220, 912 PV modules 114,914 electric vehicles 116, 916 Power Switch 118 Current Measurement Unit 120 Wiring 122, 124, 126, 128, 212 Control Unit 130, 920 distribution board 132,922 load 134, 924 lines 140 base 142, 144, 146, 148, 150, 214, 230, 242 cabinets 160, 162, 164, 166, 168, 170, 172, 174, 216, 218 connectors 180 Top 182 Bottom surface 184, 186 Convex part 188, 190 recess

Claims

1. DC / AC converter and First DC / DC converter, A first housing that houses the DC / AC converter, The system includes a second housing that houses the first DC / DC converter, The DC / AC converter and the first DC / DC converter are electrically connected via a DC bus. The first housing has a first connection portion, The second housing has a second connection portion, The second connection part is connected to the first connection part when the first housing is placed on top of the second housing. The first DC / DC converter is a power supply system connected to the DC bus by the second connection being connected to the first connection.

2. The first connection part is located on the lower surface of the first housing, The second connection part is located on the upper surface of the second housing, The power supply system according to claim 1, wherein the second connection portion is connected to the first connection portion by the first housing being placed on top of the second housing.

3. Storage batteries and The present invention further includes a third housing that houses the aforementioned storage battery, The third enclosure is positioned below the second enclosure. The first DC / DC converter is The power generated by converting the discharge power of the aforementioned battery is output to the DC bus, and, The power supply system according to claim 1 or claim 2, which converts power supplied from the DC bus to generate charging power for the storage battery.

4. The power supply system according to claim 3, wherein the second housing and the third housing are formed integrally.

5. The power supply system according to claim 3, wherein the first housing and the second housing are formed integrally.

6. The power supply system according to claim 1 or 2, wherein the second housing further has a third connection portion connected to the DC bus.

7. The second DC / DC converter, The present invention further includes a third housing that houses the second DC / DC converter, The third housing has a fourth connection part, The power supply system according to claim 6, wherein the second DC / DC converter is connected to the DC bus via the third connection and the fourth connection when the second housing is positioned above the third housing.

8. The third connection portion is located on the lower surface of the second housing, The fourth connection part is located on the upper surface of the third housing, The power supply system according to claim 7, wherein the second DC / DC converter is connected to the DC bus via the third and fourth connection portions, with the second housing positioned above the third housing.

9. Storage batteries and The present invention further includes a fourth enclosure housing the aforementioned battery, The fourth enclosure is positioned below the third enclosure. The second DC / DC converter is The power output from the aforementioned battery is converted and output to the DC bus, and, The power supply system according to claim 7, which converts the power supplied from the DC bus to generate charging power for the storage battery.

10. The power supply system according to claim 9, wherein the third housing and the fourth housing are formed integrally.

11. The power supply system according to claim 9, wherein the first housing and the second housing are formed integrally.

12. Third DC / DC converter, The present invention further includes a fifth housing that houses the third DC / DC converter, The fifth housing has a fifth connection part and a sixth connection part, The third connection part is connected to the fifth connection part when the second housing is placed on top of the fifth housing. The fourth connection is connected to the sixth connection when the fifth housing is placed on top of the third housing. The third DC / DC converter is connected to the DC bus by connecting the third connection part and the fifth connection part. The power supply system according to claim 7, wherein the second DC / DC converter is connected to the DC bus by connecting the fourth connection part and the sixth connection part.

13. The fifth connection part is located on the upper surface of the fifth housing, The sixth connection part is located on the lower surface of the fifth housing, The third connection portion is connected to the fifth connection portion when the second housing is placed on top of the fifth housing. The power supply system according to claim 12, wherein the fourth connection is connected to the sixth connection by the fifth housing being placed on top of the third housing.

14. The first housing contains a first control unit that controls the DC / AC converter, The second housing houses a second control unit that controls the first DC / DC converter, A first signal line housed in the first housing and connected to the first control unit, It further includes a second signal line housed in the second housing and connected to the second control unit, The power supply system according to claim 1 or claim 2, wherein the first signal line and the second signal line are connected by the connection of the first connection and the second connection.

15. The first housing has a first guide mechanism located on the lower surface of the first housing, The second housing has a second guide mechanism located on the upper surface of the second housing, The power supply system according to claim 1 or 2, wherein the first housing is positioned on the second housing such that the first guide mechanism and the second guide mechanism are interlocked.

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