JP2020115747A - Power supply, distribution system, and power converter - Google Patents

Abstract

To facilitate the electrical work and secures the total amount of a solar cell module by effectively utilizing a limited installation area without waste in a power supply device that receives the output of the solar cell module by multiple DC/DC converters.SOLUTION: A power supply device according to the present invention that receives the output of a solar cell module by multiple DC/DC converters includes an output line unit that collectively pulls out the output for a solar cell assembly in which the voltage value at the maximum power point is approximate, from among solar cell modules, and an input line unit that distributes and delivers power carried by the output line unit so that the power is within the range of the input power capacity of each of the DC/DC converters.SELECTED DRAWING: Figure 8

Description

The present invention relates to a power supply device that constitutes a solar power generation system.

Photovoltaic power generation systems are becoming widely used for homes, businesses, large-scale power plants, and the like. For example, for home use, a solar cell module is installed on the roof of a house. In addition, a power conditioner is installed indoors and connected to the solar cell module. The power conditioner is equipped with a DC/DC converter and an inverter. The DC/DC converter needs an input power capacity corresponding to the maximum output power of the solar cell module.

The power conditioner includes a typical single input type in which only one DC/DC converter is mounted, and a multi-input type in which, for example, three DC/DC converters are mounted (for example, FIG. See 1.). The input power capacity of one DC/DC converter in the multi-input type power conditioner is, for example, 2 kW for home use, and is 2 kW×3, which can correspond to a 6 kW solar cell module.

Japanese Patent No. 4205071

FIG. 12: is a figure which shows an example of the domestic power supply device (photovoltaic power generation system) which mounted 3 strings of solar cell modules of maximum output electric power 2 kW on the gabled roof. Each of the solar cell modules M21, M22, M23 is connected to the power conditioner 150 by, for example, two single-core cables C21, C22, C23. The power conditioner 150 incorporates three DC/DC converters 151, 152, 153 corresponding to the solar cell modules M21, M22, M23. The input power capacity of each DC/DC converter is 2 kW. In this case, electrical work is required to connect a total of 6 cables.

FIG. 13: is a figure which shows the other example of the domestic power supply device which mounted 3 strings of solar cell modules of maximum output electric power 2 kW on the hipped roof. Each of the solar cell modules M24, M25, M26 is connected to the power conditioner 150 by, for example, two single-core cables C24, C25, C26. The power conditioner 150 incorporates three DC/DC converters 151, 152, 153 corresponding to the solar cell modules M24, M25, M26. The input power capacity of each DC/DC converter is 2 kW. In this case as well, electrical work for connecting a total of 6 cables is required.

As described above, in the conventional power supply device, the number of cables that connect the solar cell module and the power conditioner to each other is large, so that it takes time to carry out electrical work, and the cost of the cables increases the cost of the entire device. To contribute to. Although the number of cables can be reduced by reducing the installation location of the solar cell module, the reduction of the installation location does not meet the user's needs because the roof area is to be used effectively in order to obtain as much power generation as possible.
Further, in the conventional power supply device, when the output of one string exceeds 2 kW, it is necessary to suppress the value of one string to 2 kW or less even if the roof area has a margin.

In view of such conventional problems, the present invention makes it possible to easily perform electrical work and effectively use a limited installation area in a power supply device that receives the output of a solar cell module by a plurality of DC/DC converters. Then, it aims at securing the whole quantity of a solar cell module.

The present invention is a power supply device that receives the output of a solar cell module by a plurality of DC/DC converters, and the output is output for a solar cell assembly of the solar cell modules having similar voltage values at the maximum power point. An output line unit that collectively pulls out and an input line unit that distributes and distributes the power carried by the output line unit so as to be within the range of the input power capacity of each DC/DC converter.

ADVANTAGE OF THE INVENTION According to the power supply device of this invention, electric construction can be performed easily, the limited installation area can be used more effectively, and the total amount of solar cell modules can be secured.

It is a figure which shows the outline of the power supply device which uses the solar cell module installed in the roof of the house as a power generation element. It is a circuit diagram of a power supply device as a reference example. It is a figure which shows the outline of the power supply device which concerns on 1st Embodiment of this invention. It is a circuit diagram of the power supply device of FIG. It is a figure which shows the outline of the power supply device which concerns on 2nd Embodiment. It is a circuit diagram of the power supply device of FIG. It is a figure which shows the outline of the power supply device which concerns on 3rd Embodiment. It is a circuit diagram of the power supply device of FIG. It is a figure which shows the outline of the power supply device which concerns on 4th Embodiment. It is a figure which shows the outline of the power supply device which concerns on 5th Embodiment. It is a figure which shows the outline of the power supply device which concerns on 6th Embodiment. It is a figure which shows an example of the power supply device which mounted 3 strings of solar cell modules on the gabled roof. It is a figure which shows the other example of the power supply device which mounted 3 strings of solar cell modules on the roof of a ridge type.

[Summary of Embodiment]
The gist of the embodiment of the present invention includes at least the following.

(1) This is a power supply device that receives the output of the solar cell module by a plurality of DC/DC converters, and among the solar cell modules, the aggregate of solar cells whose voltage value at the maximum power point is similar to An output line unit that collectively draws out the output and an input line unit that distributes and distributes the power carried by the output line unit so as to be within the range of the input power capacity of each DC/DC converter There is.
The maximum power point (Maximum Power Point) is a target point in maximum power point tracking control (MPPT (Maximum Power Point Tracking) control).

In the power supply device configured as described above, the output line unit pulls out the outputs of the aggregate of solar cells whose voltage values at the maximum power point approximate each other. Therefore, it is not necessary to provide separate output line portions (for example, cables) for the solar cell assemblies having similar voltage values at the maximum power point and wire them to the DC/DC converter. Therefore, the minimum number of output line parts is sufficient, which facilitates the electrical work of the power supply device. Further, since power can be distributed by being distributed in the input line section, the electric power carried by the output line section may exceed the input power capacity of each DC/DC converter. This eliminates the need to reduce the installation area of the solar cell module due to the restriction of the input power capacity. That is, it is possible to more effectively use the limited installation area and secure the entire amount of the solar cell module.

In operation of the DC/DC converter, it is not always necessary to reduce the installation area of the solar cell module according to the input power capacity of the DC/DC converter.
However, when a solar cell module that exceeds the input power capacity of the DC/DC converter is installed, the amount of power generated by the solar cell module cannot be maximized, and the extra installed solar cell module is wasted. Therefore, a solar cell module having an input power capacity of the DC/DC converter is often connected.

(2) Further, in the power supply device of (1), it is preferable that the plurality of DC/DC converters that receive power distribution input by power distribution by the input line section perform maximum power point tracking control in synchronization with each other.
In this case, with respect to the electric power merged into the common output line portion and conveyed, a plurality of DC/DC converters in a parallel relationship perform maximum power point tracking control in synchronization with each other to collect the solar cells. Maximum power at that time can be drawn from the entire body.

(3) Further, in the power supply device according to (1) or (2), the installation location is a roof of a house, and the objects whose output is integrated by the output line portion are installed on one plane and a parallel surface thereof. It is the assembly of the said solar cell currently used.
In this case, not only one plane of the roof but also a plane parallel to the roof is approximate to the solar radiation condition, and thus the voltage value at the maximum power point is approximate. Therefore, the aggregates of solar cells on these surfaces are treated as one group and distributed as needed at the time of input to the DC/DC converter to maximize the area of the roof with a complicated shape. It is possible to install solar cells.

(4) Further, the power supply device according to any one of (1) to (3) includes a storage battery, and at least one of the plurality of DC/DC converters is bidirectional, and the storage battery is connected. The configuration may be different.
In this case, a solar battery and a storage battery can be used together as a DC power supply. In addition, the storage battery can be charged from the commercial power system by night power or the surplus power of solar power generation.

(5) Further, the power supply device according to any one of (1) to (3) includes a storage battery, the plurality of DC/DC converters are bidirectional, and the input line unit includes the plurality of DC/DC converters. A switch that connects each of the DC converters to one of the output line portion and the storage battery may be provided.
The power supply device in this case includes power supply from the solar cell module to the DC/DC converter, power supply from the storage battery to the DC/DC converter, charging of the storage battery with night power from the commercial power system, and surplus power of solar power generation. The storage battery can be charged by any of the above.

[Details of Embodiment]
Hereinafter, description will be given with reference to the drawings. First, a reference example as a basis of a power supply device according to an embodiment of the present invention will be described.

《Reference example》
FIG. 1 is a diagram schematically showing a power supply device having a solar cell module installed on a roof of a house as a power generating element. This roof has a ridged shape, and three of the four surfaces have good sunlight, and are suitable for installation of solar cell modules (solar power generation panels). Therefore, for example, three strings of solar cell modules M1, M2, M3 are provided on three surfaces.

The maximum outputs of the solar cell modules M1, M2, M3 are the same, and are, for example, 2 kW. However, from the viewpoint of installation location (position, angle, etc.), the solar radiation conditions for the solar cell modules M1, M2, M3 installed on the three surfaces cannot always be said to be close to each other. Each of the solar cell modules M1, M2, M3 is connected to the power conditioner 50 via, for example, two single-core cables C1, C2, C3. In this case, the total number of cables is six. The power conditioner 50 is provided outdoors or indoors.

FIG. 2 is a circuit diagram of the power supply device 100 as a reference example. The solar cell modules M1, M2, M3 are respectively connected to the power conditioner 50 via the output line portion C (corresponding to the cables C1, C2, C3). The power conditioner 50 integrates the DC outputs of the solar cell modules M1, M2, and M3, converts the DC outputs into AC, and outputs the AC to provide system interconnection with the commercial power system 20 or power supply to the house. be able to.

The power conditioner 50 is a multi-input type and includes three DC/DC converters 3, 5 and 7 corresponding to the solar cell modules M1, M2 and M3. That is, the solar cell modules M1, M2, M3 correspond one-to-one with the three DC/DC converters 3, 5, 7. Here, the input power capacities of the DC/DC converters 3, 5, and 7 are values capable of inputting the maximum outputs of the solar cell modules M1, M2, and M3, and are, for example, 2 kW.

The output of the solar cell module M1 is input to the DC/DC converter 3 via the input line portion 1 and the capacitor 2 in the power conditioner 50. The DC/DC converter 3 is a step-up chopper circuit formed by connecting a DC reactor Lb, a switching element Qb, and a diode Db as shown in the figure. The switching element Qb is, for example, a FET (Field Effect Transistor), and is turned on/off by the control unit 12. The DC/DC converter 3 controlled by the control unit 12 performs maximum power point tracking control (MPPT (Maximum Power Point Tracking) control) by adjusting the voltage/current input from the solar cell module M1. ..

The control unit 12 may include, for example, a CPU, a memory, and the like and operate mainly by software, or may be configured by only hardware without depending on software.

Similarly, the output of the solar cell module M2 is input to the DC/DC converter 5 via the input line portion 1 and the capacitor 4 in the power conditioner 50. The DC/DC converter 5 has the same configuration as the DC/DC converter 3, and is on/off controlled by the control unit 12. The DC/DC converter 5 controlled by the control unit 12 performs MPPT control by adjusting the voltage/current input from the solar cell module M2.

Similarly, the output of the solar cell module M3 is input to the DC/DC converter 7 via the input line section 1 and the capacitor 6 in the power conditioner 50. The DC/DC converter 7 has the same configuration as the DC/DC converter 3, and is on/off controlled by the controller 12. The DC/DC converter 7 controlled by the control unit 12 performs MPPT control by adjusting the voltage/current input from the solar cell module M3.

In this way, the DC/DC converters 3, 5, and 7 perform MPPT control on the solar cell modules M1, M2, and M3 at different installation locations, thereby performing optimum control according to the solar radiation conditions. Maximum power at the time can be drawn.

The outputs of the three DC/DC converters 3, 5 and 7 are connected to a common DC bus 8 and integrated. The DC output of the DC bus 8 is converted into an AC output by the inverter 10 via the capacitor 9. The inverter 10 includes switching elements Q1, Q2, Q3, Q4 connected in a full bridge shape as shown in the drawing. The switching elements Q1, Q2, Q3, Q4 are on/off controlled by the controller 12. The filter 11 including the AC reactors Lf1 and Lf2 and the capacitor Cf removes a high frequency component included in the output of the inverter 10. In this way, the AC voltage/current capable of system interconnection with the commercial power system 20 is output from the power conditioner 50.

The control unit 12 is also a part of the DC/DC converters 3, 5, 7 and a part of the inverter 10.

<<1st Embodiment>>
FIG. 3 is a diagram showing an outline of the power supply device according to the first embodiment of the present invention. This roof has a ridged shape, and for example, two of the four surfaces have a good sun exposure, and are suitable for installation of solar cell modules. Therefore, two strings of solar cell modules M4 and M5 are provided on two surfaces.

Here, for example, the maximum output of the solar cell module M4 is 4 kW, and the maximum output of the solar cell module M5 is 2 kW. From the viewpoint of the installation location (position, angle, etc.), the solar radiation conditions for the solar cell modules M4, M5 installed on the two surfaces are not always close to each other. Therefore, it cannot be said that the voltage values at the maximum power points of the solar cell modules M4 and M5 are similar. However, even if the solar cell module M4 is divided into a plurality of solar cell modules M4, their maximum power point voltage values are similar. The same applies to the solar cell module M5.
The solar cell modules M4 and M5 are connected to the power conditioner 50 via, for example, two single-core cables C4 and C5. In this case, the total number of cables is four. The power conditioner 50 is usually installed indoors. The electric path that has entered the power conditioner 50 from the cable C4 is divided into two.

FIG. 4 is a circuit diagram of the power supply device 100. The difference from FIG. 2 is the string configuration of the solar cell module and the input line section 1, and the other points are the same as in FIG. 2.
Each of the solar cell modules M4 and M5 is connected to the power conditioner 50 via the output line portion C (corresponding to the cables C4 and C5). The input from the solar cell module M4 is distributed in the input line section 1 and is distributed to the DC/DC converters 3 and 5 via the capacitors 2 and 4, respectively. Therefore, 4 kW is divided into 2 kW each, and can be accepted as the input power capacity of each of the DC/DC converters 3 and 5.

The DC/DC converters 3 and 5 are on/off controlled by the control unit 12 and controlled in synchronization with each other. The DC/DC converters 3 and 5 controlled by the control unit 12 perform MPPT control by adjusting the voltage/current input from the solar cell module M4. In this way, the MPPT control can be executed synchronously by the two DC/DC converters 3 and 5 with respect to the output of the solar cell module M4 of 4 kW which exceeds the input power capacity of each DC/DC converter.

On the other hand, the output of the solar cell module M5 is input to the DC/DC converter 7 via the input line section 1 and the capacitor 6 in the power conditioner 50. The DC/DC converter 7 is on/off controlled by the controller 12. The DC/DC converter 7 controlled by the control unit 12 performs MPPT control by adjusting the voltage/current input from the solar cell module M5.

In this manner, the DC/DC converters 3, 5 and 7 perform MPPT control on the solar cell modules M4 and M5 having different installation locations and outputs, thereby performing optimum control according to the solar radiation conditions. Maximum power at the time can be drawn.

The outputs of the three DC/DC converters 3, 5 and 7 are connected to a common DC bus 8 and integrated. The DC output of the DC bus 8 is converted into an AC output by the inverter 10 via the capacitor 9. The filter 11 including the AC reactors Lf1 and Lf2 and the capacitor Cf removes a high frequency component included in the output of the inverter 10. In this way, the AC voltage/current capable of system interconnection with the commercial power system 20 is output from the power conditioner 50.

<<Second Embodiment>>
FIG. 5: is a figure which shows the outline of the power supply device which concerns on 2nd Embodiment. This roof has a gabled shape, and one of the two surfaces has a good sun exposure and is suitable for installing a solar cell module. Therefore, the solar cell module M6 is provided in one string on one surface. In this case, since the solar cell module M6 is one string, the voltage value at the maximum power point is one. However, even if the solar cell module M6 is divided into a plurality of solar cell modules M6, the voltage values at their maximum power points are similar.

Here, for example, the maximum output of the solar cell module M6 is 6 kW. The solar cell module M6 is connected to the power conditioner 50 via, for example, two single-core cables C6. In this case, the total number of cables is two. The power conditioner 50 is usually installed indoors. The electric line that has entered the power conditioner 50 from the cable C6 is divided into three.

FIG. 6 is a circuit diagram of the power supply device 100. The difference from FIG. 2 is the string configuration of the solar cell module and the input line section 1, and the other points are the same as in FIG. 2.
The solar cell module M6 is connected to the power conditioner 50 via the output line portion C (corresponding to the cable C6). The input from the solar cell module M6 is divided into three in the input line portion 1, and is distributed to the DC/DC converters 3, 5, and 7 via the capacitors 2, 4 and 6, respectively. Therefore, 6 kW is divided into 2 kW each, and can be accepted as the input power capacity of each of the DC/DC converters 3, 5, 7.

The DC/DC converters 3, 5 and 7 are on/off controlled by the control unit 12 and are controlled in synchronization with each other. The DC/DC converters 3, 5, and 7 controlled by the control unit 12 perform MPPT control by adjusting the voltage/current input from the solar cell module M6. In this way, the MPPT control can be executed synchronously by the three DC/DC converters 3, 5, and 7 with respect to the output of the solar cell module M6 of 6 kW, which exceeds the input power capacity of each DC/DC converter.

As described above, the three DC/DC converters 3, 5, and 7 perform MPPT control in synchronization with the solar cell module M6, thereby performing optimal control according to the solar radiation condition and maximizing the maximum power at that time. Can be pulled out.

The outputs of the three DC/DC converters 3, 5 and 7 are connected to a common DC bus 8 and integrated. The DC output of the DC bus 8 is converted into an AC output by the inverter 10 via the capacitor 9. The filter 11 including the AC reactors Lf1 and Lf2 and the capacitor Cf removes a high frequency component included in the output of the inverter 10. In this way, the AC voltage/current capable of system interconnection with the commercial power system 20 is output from the power conditioner 50.

<<Third Embodiment>>
FIG. 7 is a diagram showing an outline of the power supply device according to the third embodiment. This roof is a dormitory-shaped composite type, and for example, 3 out of 6 surfaces have good sunlight, and are suitable for installation of solar cell modules. Therefore, three strings of solar cell modules M7, M8, M9 are provided on three surfaces. The solar cell modules M7 and M8 have different surfaces, but are parallel to each other. Therefore, the solar cell modules M7 and M8 have similar solar radiation conditions.

Here, for example, the maximum output of the solar cell module M7 is 3 kW, the maximum output of the solar cell module M8 is 1 kW, and the maximum output of the solar cell module M9 is 2 kW. From the standpoint of installation location (position, angle, etc.), the solar cell module M9 and the solar cell modules M7 and M8 cannot be said to have solar radiation conditions that are always close to each other. However, the solar cell modules M7 and M8 are always close to each other in solar radiation conditions. Therefore, regarding the solar cell modules M7 and M8, the voltage values of their maximum power points are close to each other.
Therefore, the outputs of the solar cell modules M7 and M8 are combined. As a means for putting them together, for example, a current collecting cable that joins the electric paths at the junction J is used, or a junction box is used at the junction J.

Thus, the solar cell modules M7 and M8 are connected to the power conditioner 50 via, for example, two single-core current collecting cables C7, and the solar cell module M9 is connected to, for example, two single-core cables C9. Connected. In this case, the total number of cables is four. The power conditioner 50 is usually installed indoors. The electric path that has entered the power conditioner 50 from the power collection cable C7 is divided into two.

FIG. 8 is a circuit diagram of the power supply device 100. The difference from FIG. 2 is the string configuration of the solar cell module, the output line section C, and the input line section 1, and the other points are the same as in FIG. 2.
The solar cell modules M7 and M8 are connected to the power conditioner 50 via the output line portion C (corresponding to the current collecting cable C7). The solar cell module M9 is connected to the power conditioner 50 via the output line portion C (corresponding to the cable C9). Inputs from the solar cell modules M7 and M8 are distributed in the input line unit 1 and are distributed to the DC/DC converters 3 and 5 via the capacitors 2 and 4, respectively. Therefore, 4 kW (3 kW+1 kW) is divided into 2 kW each, and can be accepted as the input power capacity of each of the DC/DC converters 3 and 5.

The DC/DC converters 3 and 5 are on/off controlled by the control unit 12 and controlled in synchronization with each other. The DC/DC converters 3 and 5 controlled by the control unit 12 perform MPPT control by adjusting the voltage/current input from the solar cell modules M7 and M8. In this way, the MPPT control can be executed in synchronization by the two DC/DC converters 3 and 5 with respect to the outputs of the solar cell modules M7 and M8 having a total of 4 kW that exceed the input power capacity of each DC/DC converter.

On the other hand, the output of the solar cell module M9 is input to the DC/DC converter 7 via the input line section 1 and the capacitor 6 in the power conditioner 50, and is on/off controlled by the control section 12. The DC/DC converter 7 controlled by the control unit 12 performs MPPT control by adjusting the voltage/current input from the solar cell module M9.

In this way, the DC/DC converters 3, 5 and 7 perform MPPT control on the solar cell modules M7, M8 and M9 having different installation locations and outputs, thereby performing optimum control according to the solar radiation conditions. , Maximum power at that time can be extracted.

The outputs of the three DC/DC converters 3, 5 and 7 are connected to a common DC bus 8 and integrated. The DC output of the DC bus 8 is converted into an AC output by the inverter 10 via the capacitor 9. The filter 11 including the AC reactors Lf1 and Lf2 and the capacitor Cf removes a high frequency component included in the output of the inverter 10. In this way, the AC voltage/current capable of system interconnection with the commercial power system 20 is output from the power conditioner 50.

<<Summary of First to Third Embodiments>>
As described above in detail, in the power supply device 100 shown in FIG. 4, FIG. 6, and FIG. 8, the output line portion C is an assembly of solar cells whose solar radiation conditions approximate to each other by being on the same plane or parallel planes. For (solar cell module), the outputs are collected together and extracted. To be more precise and universally speaking, with respect to an aggregate of solar cells having similar voltage values at the maximum power point, the outputs are collectively extracted. Therefore, it is not necessary to provide separate output line portions C for the solar cell assemblies having similar voltage values at the maximum power point and to wire the DC/DC converters 3, 5, and 7. Therefore, the minimum number of output line portions C (the number of cables) is sufficient, and the electric work of the power supply device 100 can be easily performed.

Further, since power can be distributed by being distributed in the input line section 1, the power carried by the output line section C may exceed the input power capacity of each DC/DC converter 3, 5, 7. This eliminates the need to reduce the installation area of the solar cell module due to the restriction of the input power capacity. That is, it is possible to more effectively use the limited installation area and secure the entire amount of the solar cell module.

Further, as described above, the plurality of DC/DC converters that receive the power distribution input by the power distribution by the input line unit 1 perform the maximum power point tracking control in synchronization with each other. In this case, regarding the electric power that is merged into the common output line section and is conveyed, a plurality of DC/DC converters in a parallel relationship perform maximum power point tracking control in synchronization with each other, so that Power can be drawn.

The target whose output is integrated by the output line portion C is an aggregate of solar cells installed on one plane and its parallel plane. In other words, not only one plane of the roof, but also the plane parallel to it, the solar radiation conditions are similar, and the voltage value at the maximum power point is similar, so it is handled as a whole and is necessary when inputting to the DC/DC converter. By distributing power accordingly, it is possible to install solar cells that maximize the area of the roof with a complicated shape.

In addition, when performing MPPT control using three DC/DC converters 3, 5, and 7 according to the input connection pattern (mode of the output line part C) of a solar cell, including the above-mentioned example, it is as follows. become.

In Table 1, in the case of “3 inputs” shown in FIGS. 1 and 2 (reference example), the three DC/DC converters 3, 5, and 7 perform MPPT control, respectively. Assuming that the patterns shown in FIGS. 3, 4 or 7 and 8 are “2 inputs-1”, in this case, the two DC/DC converters 3 and 5 perform the synchronized MPPT control and perform one DC/DC. The converter 7 independently performs MPPT control. Further, as “2 inputs-2”, two DC/DC converters 5 and 7 may perform synchronized MPPT control, and one DC/DC converter 3 may perform MPPT control independently. Furthermore, as “2 inputs-3”, two DC/DC converters 3 and 7 may perform synchronized MPPT control, and one DC/DC converter 5 may perform MPPT control independently.

If the input power capacities of the three DC/DC converters 3, 5, and 7 are the same as each other, it is meaningless to divide the two inputs into three patterns, but if the input power capacities are different, depending on the output from the solar cell module. It is meaningful to consider the combination of the DC/DC converters 3, 5, 7 on the receiving side.
In the case of "1 input" shown in FIGS. 5 and 6, the three DC/DC converters 3, 5 and 7 perform MPPT control in synchronization with each other.
By providing the power conditioner 50 with a setting function capable of easily switching such MPPT control patterns, it is possible to easily set a pattern suitable for the arrangement of the solar cell modules at the time of construction. ..

<<4th Embodiment>>
Next, a power supply device using a storage battery in addition to the solar cell will be described.
FIG. 9 is a diagram showing an outline of the power supply device according to the fourth embodiment. This roof is a composite type of a ridge type similar to that shown in FIG. 7. For example, two of the six sides have good sunlight and are suitable for installation of solar cell modules. Therefore, two strings of solar cell modules M11 (1 kW) and M12 (3 kW) are provided on two surfaces. The solar cell modules M11 and M12 have different surfaces, but are parallel to each other. Therefore, the solar cell modules M11 and M12 have similar solar radiation conditions.

Therefore, similar to the third embodiment, for the solar cell modules M11 and M12, for example, a current collecting cable C11 is used to collect the outputs. Then, the combined output is divided into two in the power conditioner 50 and input to the DC/DC converters 3 and 5. The other DC/DC converter 7A is bidirectional, and the storage battery 30 is connected thereto via a cable C30. In order to make it bidirectional, for example, the diode Db in the DC/DC converter 7 in FIG. 8 may be replaced with a switching element (hereinafter, the same applies to bidirectionality).

The outputs of the three DC/DC converters 3, 5, 7 are converted into AC output by the inverter 10, and AC voltage/current that can be system-interconnected with the commercial power system 20 is output from the power conditioner 50. The AC output also serves as electric power used in the house. Each unit in the power conditioner 50 is controlled by the control unit 12. The inverter 10 can also be used in the opposite direction as an AC/DC converter.

In such a power supply device, two kinds of DC power supplies (solar battery, storage battery) can be connected to one power conditioner 50 and used together. For example, when the generated electric power of the solar cell modules M11 and M12 is used in the load inside the house, the surplus electric power can be charged into the storage battery 30. Further, it is possible to charge the storage battery 30 with the nighttime power from the commercial power system 20 and supply the power from the storage battery 30 to the load during the daytime. When the storage battery 30 is charged with the nighttime power, the inverter 10 serves as a rectifier circuit and the DC/DC converter 7A serves as a step-down circuit.

<<Fifth Embodiment>>
FIG. 10 is a diagram showing an outline of the power supply device according to the fifth embodiment. The arrangement of the roof and the solar cell modules M7, M8, M9 is the same as in FIG. 7 (third embodiment). Therefore, similar to the third embodiment, for the solar cell modules M7 and M8, for example, a current collecting cable C7 is used to collect the outputs. Then, the combined output is divided into two in the power conditioner 50 via the switch SW1 and input to the bidirectional DC/DC converters 3A and 5A. The other DC/DC converter 7A is also bidirectional, and the output of the solar cell module M9 is given from the cable C9 via the switch SW2. The input voltage from the solar cell modules M7 to M9 to the power conditioner 50 is detected by the voltage sensors 13 and 14. A current sensor may be used instead of the voltage sensor.

A storage battery 30 is connected to the input sides of the DC/DC converters 3, 5 and 7 via switches SW3, SW4 and SW5, respectively.
The outputs of the three DC/DC converters 3, 5, 7 are converted into AC output by the inverter 10, and AC voltage/current that can be system-interconnected with the commercial power system 20 is output from the power conditioner 50. The AC output also serves as electric power used in the house. Each unit (including the switches SW1 to SW5) in the power conditioner 50 is controlled by the control unit 12. The output signals of the voltage sensors 13 and 14 are provided to the control unit 12. The switches SW1 to SW5 form the input line section 1. The inverter 10 can also be used in the opposite direction as an AC/DC converter.

In such a power supply device, the switches SW3 to SW5 are opened and the switches SW1 and SW2 are closed during the daytime. As a result, the solar cell modules M7 to M9 and the power conditioner 50 can be connected in the state where the storage battery 30 is disconnected, and system interconnection can be performed. On the contrary, at night, the switches SW1 and SW2 are opened, the switches SW3 to SW5 are closed, the solar cell modules M7 to M9 are disconnected, and night power can be stored in the storage battery 30.

When the solar cell modules M7 to M9 do not generate power due to rain or the like, this is detected by the voltage sensors 13 and 14. The control unit 12 receiving the output signals of the voltage sensors 13 and 14 opens the switches SW1 and SW2, closes the switches SW3 to SW5, disconnects the solar cell modules M7 to M9, and supplies power to the load by discharging the storage battery 30. To do. Note that this control can be performed for each of the cables C7 and C9. For example, when the voltage of the cable C9, that is, when the solar cell module M9 is not generating power, only the input of the DC/DC converter 7A can be switched from the solar cell module M9 to the storage battery 30. However, when electric power is provided by discharging the storage battery 30, grid interconnection is not performed, and only electric power is supplied to the load inside the house.

<<6th Embodiment>>
FIG. 11: is a figure which shows the outline of the power supply device which concerns on 6th Embodiment. The difference from FIG. 10 is that three modules of storage batteries 31, 32, 33 are provided corresponding to the DC/DC converters 3, 5, 7 respectively, and the other points are the same as in FIG. 10. The operation is also similar to that of the fifth embodiment, and therefore the description thereof is omitted here.

《Others》
In each of the above-described embodiments, the power conditioner 50 including three DC/DC converters is shown as an example of multi-input. , Which are summarized by the output line portion C, can be applied.

In addition, although each of the above-described embodiments describes the case where the solar cell module is installed on the roof of a house of a general household, the solar cell module is also installed in a small-scale solar power generation for business or a large-scale solar power generation (mega solar) Similar differences in solar radiation conditions may occur depending on the location. Even in such a case, similarly to the above-described power supply device, for an aggregate of solar cells whose solar radiation conditions are similar, an output line portion is provided to collectively pull out the output, and the electric power carried by the output line portion is individually supplied. It is possible to provide an input line section that distributes and distributes power so as to be within the range of the input power capacity of the DC/DC converter.

In each of the above-described embodiments, one example in which the solar radiation conditions are approximate is given, but as described above, more accurately and universally speaking, regarding the aggregate of solar cells in which the voltage value of the maximum power point is approximate. It means that the output is collected. In other words, for a group of solar cells that can perform common MPPT control, the outputs should be combined and, if necessary, distributed on the power conditioner side, and power conversion should be performed by multiple DC/DC converters. You can

Further, although the multi-input type power conditioner 50 including a plurality of DC/DC converters is shown in each of the above-described embodiments, it is possible to arrange a plurality of single-input type power conditioners and perform similar control. However, in this case, in order to perform synchronous control between the DC/DC converters that receive the input distributed and distributed, a common control unit that exceeds the frame of one power conditioner is required.

It should be understood that the embodiments disclosed this time are exemplifications in all points and not restrictive. The scope of the present invention is defined by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

1 Input Line 2 Capacitor 3,3A DC/DC Converter 4 Capacitor 5,5A DC/DC Converter 6 Capacitor 7,7A DC/DC Converter 8 DC Bus 9 Capacitor 10 Inverter 11 Filter 12 Control 13/14 Voltage Sensor 20 Commercial Power system 30,31-33 Storage battery 50 Power conditioner 100 Power supply device 150 Power conditioner 151-153 DC/DC converter C Output line section C1-C6, C9, C21-C26, C30 Cable C7, C11 Current collecting cable Cf Capacitor Db diode J confluence point Lb DC reactor Lf1, Lf2 AC reactor M1 to M9, M11, M12, M21 to M26 solar cell module Q1 to Q4, Qb switching element SW1 to SW5 switch

The present invention relates to a power supply device , a distribution system, and a power conversion device that constitute a solar power generation system.

Claims (5)

A power supply device for receiving the output of a solar cell module by a plurality of DC/DC converters,
Among the solar cell modules, for the solar cell assembly in which the voltage value at the maximum power point is approximate, an output line section that collectively pulls out the output,
An input line unit that distributes the electric power carried by the output line unit so that the electric power is distributed within the range of the input power capacity of each DC/DC converter. The power supply device according to claim 1, wherein the plurality of DC/DC converters that receive power distribution input by power distribution by the input line unit perform maximum power point tracking control in synchronization with each other. 3. The installation place is a roof of a house, and an object whose output is integrated by the output line portion is an assembly of the solar cells installed on a plane and a plane parallel to the plane. The power supply device according to. Equipped with a storage battery,
The power supply device according to any one of claims 1 to 3, wherein at least one of the plurality of DC/DC converters is bidirectional and the storage battery is connected. Equipped with a storage battery,
The plurality of DC/DC converters are bidirectional,
The said input line part is equipped with the switch which connects each of these DC/DC converters to any one of the said output line part and the said storage battery. Power supply.

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