KR20120129112A - Combined photovoltaic and photovoltaic thermal system - Google Patents

Abstract

PURPOSE: A sunlight and photovoltaic complex system are provided to output the maximum power by controlling the level of a DC power supply outputted from each module. CONSTITUTION: A first dc/dc converter of a sunlight part(55) converts the level of a DC power supply supplied from solar cell modules(50a, 50b) and outputs a transformed power source. A second dc/dc converter of a photovoltaic unit(75) is electrically connected with the first dc/dc converter. The second dc/dc converter converts the level of the DC power supply supplied from the photovoltaic complex modules(70a, 70b) and outputs the transformed power source. [Reference numerals] (300a,300b,300(n-1),300n) dc/dc converter

Description

Combined photovoltaic and photovoltaic thermal system

The present invention relates to a photovoltaic and solar thermal composite system, and more particularly, to a photovoltaic and solar thermal composite system having a solar cell module and a solar thermal composite module.

Recently, with the anticipation of depletion of existing energy sources such as oil and coal, there is increasing interest in alternative energy to replace them. Among them, solar cells are in the spotlight as next generation cells that directly convert solar energy into electrical energy using semiconductor devices.

An object of the present invention is to provide a solar and solar thermal composite system capable of improving the output power output from the solar and solar thermal composite system having a solar cell module and a solar thermal composite module.

The solar and solar thermal composite system according to an embodiment of the present invention for achieving the above object, at least one solar cell module and a first dc / dc converter for outputting the level conversion of the DC power supplied from the solar cell module A second dc / dc converter electrically connected to at least one solar unit and at least one solar thermal module and a first dc / dc converter, which converts and outputs DC power supplied from the solar thermal module; It includes a photovoltaic unit provided, the second dc / dc converter, based on at least one of the DC power input to the first dc / dc converter or the DC power output from the first dc / dc converter, the level of the DC power Outputs the variable.

In addition, the solar and solar thermal composite system according to an embodiment of the present invention for achieving the above object, the first dc / dc level conversion of the DC power supplied from the at least one solar cell module and solar cell module and outputs A second dc / dc electrically connected to the solar unit including the converter, the at least one solar thermal composite module, and the first dc / dc converter, and level converting and outputting the DC power supplied from the solar thermal composite module; A solar power unit including a converter, wherein the first dc / dc converter, based on at least one of the DC power input to the second dc / dc converter or the DC power output from the second dc / dc converter, DC power supply Variable level is output.

According to an embodiment of the present invention, in a composite photovoltaic and photovoltaic composite system having a solar cell module and a solar thermal composite module, the level of the DC power output from each module based on the DC power output from each module or the like. Can be adjusted. This makes it possible to output the maximum power under the entire system.

In addition, by using the solar thermal composite module, it is possible to perform heat exchange, it is possible to supply hot water.

On the other hand, by forming a junction box having a dc / dc converter integrally formed in each module for adjusting the DC power level of each module, by minimizing the loss of the DC power generated in the solar cell module or the solar thermal composite module efficiently Can be managed by.

1 is a block diagram of a solar and solar thermal composite system according to an embodiment of the present invention.
2 is a block diagram of a solar and solar thermal composite system according to another embodiment of the present invention.
3 is a front view of a solar module according to an embodiment of the present invention.
4 is a rear view of the solar module of FIG. 3.
5 is an exploded perspective view of the solar cell module of FIG. 3.
6 is an example of a bypass diode configuration of the solar module of FIG. 3.
7 is an exploded perspective view of a solar thermal composite module according to an embodiment of the present invention.
FIG. 8 illustrates a voltage versus current curve of the solar cell module of FIG. 3.
9 illustrates a voltage versus power curve of the solar cell module of FIG. 3.
FIG. 10 is an example of an internal circuit diagram of a junction box of the solar module of FIG. 3.
FIG. 11 is another example of an internal circuit diagram of the junction box of the solar module of FIG. 3.
12 to 13 are views for explaining the power optimization of the solar and solar thermal composite system according to an embodiment of the present invention.

Hereinafter, with reference to the drawings will be described the present invention in more detail.

The suffix "module" and " part "for components used in the following description are given merely for convenience of description, and do not give special significance or role in themselves. Accordingly, the terms "module" and "part" may be used interchangeably.

1 is a block diagram of a solar and solar thermal composite system according to an embodiment of the present invention.

Referring to the drawings, the solar and solar thermal composite system 10 of FIG. 1 may include a solar unit 55 and a solar unit 75.

The solar unit 55 may include at least one solar cell module and a dc / dc converter for level converting and outputting a DC power output from the solar cell module.

The photovoltaic unit 75 may include at least one solar thermal composite module and a dc / dc converter for level converting and outputting a DC power output from the solar thermal composite module.

In the drawing, the solar cell unit 55 is a dc / dc converter electrically connected to the plurality of solar cell modules 50a, 50b, ..., and each of the solar cell modules 50a, 50b, ... 300a, 300b, ...), and the solar cell unit 75 includes a plurality of solar thermal composite modules 70a and 70b, and the solar thermal composite modules 70a and 70b, respectively. An example includes an dc / dc converter 300 (n-1) and 300n electrically connected thereto, but various examples are possible without being limited thereto.

For example, the solar cell unit 55 includes one solar cell module 50a and a dc / dc converter 300a electrically connected to the solar cell module, and the solar cell unit 75 includes one solar cell. The composite module 70a and the dc / dc converter 300n electrically connected to the solar thermal composite module 70a may be included.

As another example, a dc / dc converter 300a in which the solar unit 55 is electrically connected to the plurality of solar cell modules 50a, 50b, ..., and each of the solar cell modules 50a, 50b, ..., respectively. And a dc / dc converter 300n including a photovoltaic portion 75 electrically connected to one solar thermal composite module 70a and the solar thermal composite module 70a. It may include.

In another example, the solar cell unit 55 includes one solar cell module 50a and a dc / dc converter 300a electrically connected to the solar cell module, and the solar cell unit 75 includes a plurality of solar cell units. The solar thermal composite modules 70a and 70b and the dc / dc converters 300 (n-1) and 300n electrically connected to the respective solar thermal composite modules 70a and 70b may be included.

As another example, when the solar cell unit 55 includes a plurality of solar cell modules 50a, 50b, ..., the solar cell unit 55 includes a plurality of solar cell modules 50a, 50b, ... Each solar cell string in the array may have a dc / dc converter connected to each other.

As another example, when the solar heat unit 75 includes a plurality of solar thermal composite modules 70a and 70b, the solar heat unit 75 may be formed in the plurality of solar thermal composite modules 70a and 70b. Each solar cell string may have a dc / dc converter connected to each other.

As another example, when the solar cell unit 55 includes a plurality of solar cell modules 50a, 50b, ..., the solar cell unit 55 includes a plurality of solar cell modules 50a, 50b, ... It may be provided with a dc / dc converter commonly connected to).

In addition, as another example, when the solar unit 75 includes a plurality of solar thermal composite modules 70a and 70b, the solar thermal unit 75 is connected to the plurality of solar thermal composite modules 70a and 70b. It may have a dc / dc converter connected in common.

As a result, according to the exemplary embodiment of the present invention, the solar unit 55 and the solar unit 75 may include different dc / dc converters.

Hereinafter, the solar system 10 of FIG. 1 will be described based on the above-described various solar systems.

The DC power output from the solar cell modules 50a, 50b, ... may be different from the DC power output from the solar thermal composite modules 70a and 70b.

For example, among the solar cell modules 50a, 50b, ... and the solar thermal composite modules 70a, 70b of the same capacity, heat transfer by cold water circulation in the solar thermal composite modules 70a, 70b When performed, the power output from the solar thermal composite modules 70a and 70b may be greater than that of the solar cell modules 50a, 50b,...

As another example, heat transfer by liquid circulation in the solar thermal composite module 70a, 70b of the solar cell modules 50a, 50b, ... and the solar thermal composite module 70a, 70b of the same capacity. This is not performed smoothly, if the temperature of the solar thermal composite module (70a, 70b) rises higher than the solar cell module (50a, 50b, ...), in the solar thermal composite module (70a, 70b) The output power may be smaller than that of the solar cell modules 50a, 50b,...

In the embodiment of the present invention, the solar cell modules 50a, 50b, ... and the solar thermal composite module 70a, 70b, under the solar and solar thermal composite system having a solar cell module and a solar thermal composite module ) Supplies different direct current power sources, ensuring maximum power output over the entire system.

To this end, the dc / dc converter provided in the solar unit 55 and the dc / dc converter provided in the solar unit 75, can perform power optimizing (output optimizing) to efficiently output the DC power have. Such a dc / dc converter may be referred to as a power optimizer.

On the other hand, the difference in the output DC power source may occur between the solar cell modules (50a, 50b, ...), may also occur between the solar thermal composite module (70a, 70b). Therefore, the embodiment of the present invention also takes this case into consideration, so that the maximum power is output over the entire system.

That is, dc / dc converters are connected to the plurality of solar cell modules 50a, 50b, ..., respectively, to perform power optimization, and dc / dc to the plurality of solar thermal composite modules 70a, 70b, respectively. The dc converter can be connected to perform power optimization.

The power optimizing function will be described later with reference to FIGS. 12 to 13.

On the other hand, each of the dc / dc converter (300a, 300b, ..., 300 (n-1), 300n), as shown in the figure, the solar cell module (50a, 50b, ...) or solar heat It may be provided separately from the composite module (70a, 70b).

For example, when the junction box 115 (FIGS. 4 and 10) is formed integrally with each of the solar cell modules 50a, 50b, ... or the solar thermal composite module 70a, 70b, the junction box ( 115 may include only the bypass diode unit 510 and the capacitor unit 520. Each of the dc / dc converters 300a, 300b,..., 300 (n-1) and 300 n may be provided as a circuit module separately from the junction box 115.

On the other hand, as another example, each dc / dc converter (300a, 300b, ..., 300 (n-1), 300n) may be provided in the junction box 115, as shown in FIG. In this case, it is possible to efficiently manage by minimizing the loss of the DC power generated by each solar cell module (50a, 50b, ...) or the solar thermal composite module (70a, 70b). Meanwhile, the junction box 115 formed integrally may be referred to as a module integrated converter (MIC) circuit.

On the other hand, although not shown in the drawings, the DC power level converted by the output in each dc / dc converter can be added to the energy storage unit (not shown) as a sum of the DC power and stored. To this end, the energy storage unit may include a plurality of capacitors.

On the other hand, although not shown in the figure, the solar and solar thermal composite system 10 may further include an inverter (not shown) for converting the DC power output by level conversion in each dc / dc converter into an AC power source. . For example, an inverter may be electrically connected to each dc / dc converter, and in another example, one inverter may be commonly connected to all dc / dc converters.

AC power output from the inverter may be supplied to the grid. An example of the inverter 400 will be described later with reference to the inverter 640 of FIG. 11.

Figure 2 is another example of the configuration of the solar and solar thermal complex system according to an embodiment of the present invention.

Referring to the drawings, the photovoltaic and photovoltaic composite system 20 of FIG. 2 is similar to the photovoltaic and photovoltaic composite system 10 of FIG. 1, but is not a dc / dc converter of FIG. There is a difference in that it includes 400a, 400b, ... 400n). Only the differences are described below.

Each micro inverter 400a, 400b, ... 400n performs the functions of a dc / dc converter and an inverter together. That is, the DC power supplied from each solar cell module 50a, 50b, ... or the solar thermal composite module 70a, 70b is level-converted, and the level-converted DC power is converted into AC power and output. The output AC power may be supplied to the grid.

On the other hand, similar to Figure 1, the DC power output from the solar cell modules (50a, 50b, ...), the level may be different from the DC power output from the solar thermal composite module (70a, 70b).

To this end, the micro inverter provided in the solar unit 55 and the micro inverter provided in the solar unit 75 may perform power optimizing to efficiently output DC power.

On the other hand, the difference in the output DC power source may occur between the solar cell modules (50a, 50b, ...), may also occur between the solar thermal composite module (70a, 70b). Therefore, the embodiment of the present invention also takes this case into consideration, so that the maximum power is output over the entire system.

That is, micro inverters are connected to the plurality of solar cell modules 50a, 50b, ..., respectively, and power optimization can be performed, and micro inverters are respectively connected to the plurality of solar thermal composite modules 70a, 70b. To perform power optimization.

The power optimization function will be described later with reference to FIGS. 12 to 13. In addition, an example of the micro inverters 400a, 400b, ... 400n will be described later with reference to FIG.

3 is a front view of the solar module according to an embodiment of the present invention, FIG. 4 is a rear view of the solar module of FIG. 3, and FIG. 5 is an exploded perspective view of the solar cell module of FIG. 3.

3 to 5, the solar module 100 according to the embodiment of the present invention may include a solar cell module 50 and a junction box 115 positioned on one surface of the solar cell module 50. Can be. In addition, the solar module 100 may further include a heat dissipation member (not shown) disposed between the solar cell module 50 and the junction box 115.

First, the solar cell module 50 may include a plurality of solar cells 130. In addition, the first sealing member 120 and the second sealing member 140 positioned on the lower surface and the upper surface of the plurality of solar cells 130, the rear substrate 110 and the second positioned on the lower surface of the first sealing member 120. It may further include a front substrate 160 located on the upper surface of the sealing material 140.

First, the solar cell 130, the solar cell 130 is a semiconductor device that converts solar energy into electrical energy, such as silicon solar cells, compound semiconductor solar cells, and stacked solar cells. It may be a tandem solar cell, dye-sensitized or CdTe, CIGS-type solar cell and the like.

The solar cell 130 is formed of a light receiving surface on which sunlight is incident and a rear surface opposite to the light receiving surface. For example, the solar cell 130 includes a first conductive silicon substrate, a second conductive semiconductor layer formed on the silicon substrate and having a conductivity type opposite to that of the first conductive type;

An anti-reflection film formed on the second conductive semiconductor layer, a front electrode penetrating the anti-reflection film and contacting a portion of the second conductive semiconductor layer, and a rear electrode formed on the rear surface of the silicon substrate; Can be.

Each solar cell 130 may be electrically connected in series or in parallel or in parallel. Specifically, the plurality of solar cells 130 may be electrically connected by the ribbon 133. The ribbon 133 may be bonded to the front electrode formed on the light receiving surface of the solar cell 130 and the rear electrode current collecting electrode formed on the back surface of another adjacent solar cell 130.

In the figure, the ribbon 133 is formed in two lines, by the ribbon 133, the solar cells 130 are connected in a row, illustrating that the solar cell string 140 is formed. As a result, six strings 140a, 140b, 140c, 140d, 140e, and 140f are formed, and each string includes ten solar cells. Unlike the drawings, various modifications are possible.

On the other hand, each solar cell string can be electrically connected by a bus ribbon. FIG. 3 shows that the first solar cell string 140a and the second solar cell string 140b are formed by the bus ribbons 145a, 145c, and 145e disposed under the solar cell module 50, respectively. The battery string 140c and the fourth solar cell string 140d illustrate that the fifth solar cell string 140e and the sixth solar cell string 140f are electrically connected. 3, the 2nd solar cell string 140b and the 3rd solar cell string 140c are respectively comprised by the bus ribbon 145b, 145d arrange | positioned on the upper part of the solar cell module 50, The 4th aspect It illustrates that the battery string 140d and the fifth solar cell string 140e are electrically connected.

On the other hand, the ribbon connected to the first string, the bus ribbons 145b and 145d, and the ribbon connected to the fourth string are electrically connected to the first to fourth conductive lines 135a, 135b, 135c, and 135d, respectively. And the first to fourth conductive lines 135a, 135b, 135c, and 135d are connected to the bypass diodes Da, Db, Dc, and Dd in the junction box 115 disposed on the rear surface of the solar cell module 50. do. In the drawings, the first to fourth conductive lines 135a, 135b, 135c, and 135d extend to the rear surface of the solar cell module 50 through openings formed on the solar cell module 50.

On the other hand, it is preferable that the junction box 115 is further disposed adjacent to an end portion of which the conductive line extends from both ends of the solar cell module 50.

3 and 4, since the first to fourth conductive lines 135a, 135b, 135c, and 135d extend from the top of the solar cell module 50 to the rear surface of the solar cell module 50, the junction box 115 may be used. ) Illustrates that the solar cell module 50 is located above the back of the solar cell module 50. As a result, the length of the conductive line can be reduced, and power loss can be reduced.

Unlike FIGS. 3 and 4, when the first to fourth conductive lines 135a, 135b, 135c, and 135d extend from the bottom of the solar cell module 50 to the rear surface of the solar cell module 50, the junction box 115 may be located at the bottom of the back of the solar cell module 50.

The back substrate 110 is a back sheet, and functions as a waterproof, insulation, and UV protection, and may be a TPT (Tedlar / PET / Tedlar) type, but is not limited thereto. In addition, although the rear substrate 110 is illustrated in a rectangular shape in FIG. 5, the rear substrate 110 may be manufactured in various shapes such as a circle and a semi-circle according to the environment in which the solar cell module 50 is installed.

On the other hand, the first sealing material 120 may be attached to the same size as the rear substrate 110 on the rear substrate 110, the plurality of solar cells 130 on the first sealing material 120 is a few rows. Can be located next to each other to achieve.

The second sealing member 140 may be positioned on the solar cell 130 to be bonded to the first sealing member 120 by lamination.

Here, the first sealant 120 and the second sealant 140 allow each element of the solar cell to chemically bond. The first sealant 120 and the second sealant 140 may be various examples such as an ethylene vinyl acetate (EVA) film.

On the other hand, the front substrate 160 is located on the second sealing material 140 so as to transmit sunlight, it is preferable that the tempered glass in order to protect the solar cell 130 from an external impact. In addition, it is more preferable that it is a low iron tempered glass containing less iron in order to prevent reflection of sunlight and increase the transmittance of sunlight.

The junction box 115 is attached to the rear surface of the solar cell module 50, and may convert power using a DC power supplied from the solar cell module 50. Specifically, the capacitor unit 520 of FIG. 10 may be provided. In addition, the junction box 115 may further include a dc / dc converter (530 of FIG. 10) for level converting and outputting the DC power. In addition, the junction box 115 may further include bypass diodes Da, Db, and Dc that prevent current from flowing back between the strings of the solar cells. In addition, an inverter (640 of FIG. 11) for converting DC power into AC power may be further provided. This will be described later with reference to FIGS. 10 and 11.

As described above, the junction box 115 according to the embodiment of the present invention includes at least bypass diodes Da, Db, and Dc, a capacitor unit 520 of FIG. 10 that stores a DC power supply, and a dc / dc converter. 10 (530) may be provided.

On the other hand, in the junction box 115, in order to prevent moisture penetration of circuit elements, the inside of the junction box may be coated with a moisture barrier, using silicon or the like.

On the other hand, an opening (not shown) is formed in the junction box 115 so that the first to fourth conductive lines 135a, 135b, 135c, and 135d described above are bypass diodes Da, Db, Dc, and Dd in the junction box. ) Can be connected.

On the other hand, during operation of the junction box 115, high heat is generated from the bypass diodes Da, Db, Dc, Dd, etc., and the generated heat is a specific solar cell arranged at the position where the junction box 115 is attached. The efficiency of 130 can be reduced.

To prevent this, the solar module 100 according to the embodiment of the present invention may further include a heat dissipation member (not shown) disposed between the solar cell module 50 and the junction box 115. In order to disperse the heat generated by the junction box 115, the cross-sectional area of the heat dissipation member 400 is preferably larger than the cross-sectional area of the plate 300. For example, it may be formed on all of the rear surface of the solar cell module 50. On the other hand, the heat radiation member (not shown) is preferably formed of a metal material such as gold (Au), silver (Ag), copper (Cu), aluminum (Al), tungsten (W) having a good thermal conductivity.

On the other hand, on one side of the junction box 160, an external connection terminal (not shown) for outputting the power-converted DC power or AC power to the outside may be formed.

6 is an example of a bypass diode configuration of the solar module of FIG. 3.

Referring to the drawings, the bypass diodes Da, Db, and Dc may be connected to the six solar cell strings 140a, 140b, 140c, 140d, 140e, and 140f. Specifically, the first bypass diode Da is connected between the first solar cell string and the first bus ribbon 145a, so that the first solar cell string 140a or the second solar cell string 140b is connected. When the reverse voltage is generated, the first solar cell string 140a and the second solar cell string 140b are bypassed.

For example, when a voltage of approximately 0.6V generated in a normal solar cell occurs, the potential of the cathode electrode is about 12V (= 0.6V * 20) relative to the potential of the anode electrode of the first bypass diode Da. Becomes higher. That is, the first bypass diode Da performs normal operation instead of bypass.

On the other hand, in one solar cell of the first solar cell string 140a, when a hot spot occurs due to shading or foreign matter adheres, the voltage generated in one solar cell is approximately 0.6V. The reverse voltage (approximately -15V) is generated rather than the voltage of. Accordingly, the potential of the anode electrode of the first bypass diode Da becomes about 15V higher than that of the cathode electrode. Accordingly, the first bypass diode Da performs the bypass operation. Therefore, the voltage generated by the solar cells in the first solar cell string 140a and the second solar cell string 140b is not supplied to the junction box 115. As described above, when a reverse voltage generated in some solar cells is generated, bypassing can prevent destruction of the solar cell. In addition, it is possible to supply the generated DC power, except for the hot spot area.

Next, the second bypass diode Db is connected between the first bus ribbon 145a and the second bus ribbon 145b to connect the third solar cell string 140c or the fourth solar cell string 140d. When the reverse voltage is generated, the third solar cell string 140c and the fourth solar cell string 140d are bypassed.

Next, the third bypass diode Dc is connected between the first solar cell string and the first bus ribbon 145a to reverse the first solar cell string 140a or the second solar cell string 140b. When voltage is generated, the first solar cell string and the second solar cell string are bypassed.

Meanwhile, unlike FIG. 6, six bypass diodes may be connected to six solar cell strings, and various other modifications are possible.

7 is an exploded perspective view of a solar thermal composite module according to an embodiment of the present invention.

Referring to the drawings, the solar thermal composite module 70 according to the embodiment of the present invention, similar to the solar cell module 50 of FIG. 5, may include a plurality of solar cells 230. Through such a solar cell, it is possible to convert solar energy into electrical energy.

Meanwhile, in order to convert solar energy into thermal energy, the solar thermal composite module 70 may include a heat transfer part 220. In addition, it may further include a heat absorbing plate 225, and a heat insulator 215 for preventing a rise in temperature of the entire module 70, to efficiently perform heat exchange.

The photovoltaic-thermal module 70 may be broadly classified into an air-collecting module and a liquid module. The air collecting type uses air (natural convection or forced convection) as the heat transfer medium, and the liquid type uses liquid as the heat transfer medium.

7 illustrates an example of the liquid module among them. Accordingly, the solar thermal composite module 70 includes a heat absorbing plate 225 on the bottom surface of the plurality of solar cells 230 in addition to the sealing material 220 on the upper surface of the plurality of solar cells 230 and the front substrate 160 on the sealing material. ), A heat insulator 215 on the rear substrate 210, and a heat transfer part 220 disposed between the heat absorption plate 225 and the heat insulator 215. In addition, disposed on each side of the module 70, it may further include a frame 280 including a suction port 270, the discharge port 275 for the suction or discharge of the liquid.

That is, the solar energy absorbed by the heat absorption plate 225 raises the temperature of the liquid in the heat transfer unit 220, and the temperature rises the liquid through the outlet 275 to a later heat exchanger (not shown). Delivered. A heat exchanger (not shown) may perform heat exchange using the elevated liquid temperature. In this manner, hot water supply or the like can be performed by heat exchange.

As described above, the DC power output from the solar thermal composite module 70 may be different from the DC power output from the solar cell module 50.

For example, in the case of performing heat transfer by circulating cold water in the solar thermal composite module 70 among the solar thermal composite module 70 and the solar cell module 50 having the same capacity, the solar thermal composite module 70 Power by the DC power output from the power supply may be greater than that of the solar cell module 50. In spite of such a power difference, when the solar thermal composite module 70 and the solar cell module 50 are connected in series, the power output from the solar thermal composite module 70 may be lowered. . In an embodiment of the present invention, in order to prevent this, power optimization is performed through a dc / dc converter connected to each of the modules 50 and 70.

For example, the level of the direct current output from the solar cell module 50 and the solar thermal composite module 70 is raised relative to the solar thermal composite module 70, which enables higher power output. This allows the solar thermal composite module 70 to output higher power than the solar cell module 50.

On the other hand, in another example, in the solar thermal composite module 70 and the solar cell module 50 of the same capacity, when the heat transfer by the liquid circulation is not performed to the solar thermal composite module 70, the solar thermal composite module The temperature of 70 may rise higher than that of the solar cell module 50, and according to the elevated temperature, power by the output DC power may be smaller than that of the solar cell module 50. In spite of such a power difference, when the solar thermal composite module 70 and the solar cell module 50 are connected to each other in series, a phenomenon in which the power output from the solar cell module 50 is lowered may occur. In an embodiment of the present invention, in order to prevent this, power optimization is performed through a dc / dc converter connected to each of the modules 50 and 70.

For example, the level of the direct current output from the solar cell module 50 and the solar thermal composite module 70 is raised relative to the solar cell module 50, which enables higher power output. This allows the solar cell module 50 to output higher power than the solar thermal composite module 70.

In addition, in the case where the photovoltaic and solar thermal composite system according to the embodiment of the present invention includes a plurality of solar thermal composite modules 70, the solar thermal composite modules 70, as described above, Similarly, power optimization may be performed for maximum power output.

8 illustrates a voltage versus current curve of the solar cell module of FIG. 3, and FIG. 9 illustrates a voltage versus power curve of the solar cell module of FIG. 3.

First, referring to FIG. 8, as the open voltage Voc supplied from the solar cell module 50 increases, the short current supplied from the solar cell module 50 decreases. According to the voltage current curve L, the corresponding voltage Voc is stored in the capacitor unit 520 provided in the junction box 115.

Meanwhile, referring to FIG. 9, the maximum power Pmpp supplied from the solar cell module 50 may be calculated by a maximum power point tracking algorithm (MPPT). For example, while reducing the open voltage Voc from the maximum voltage V1, power is calculated for each voltage, and it is determined whether the calculated power is the maximum power. Since the power increases from the voltage V1 to the voltage Vmpp, the calculated power is updated and stored. In addition, since the power decreases from the Vmpp voltage to the V2 voltage, eventually, Pmpp corresponding to the Vmpp voltage is determined as the maximum power.

Meanwhile, the maximum power determination algorithm MPPT of FIGS. 8 and 9 may be similarly applied to the solar thermal composite module 70 of FIG. 7.

Meanwhile, the voltage current curve L and the voltage power curve of FIG. 8 vary according to the temperature of the solar cell module 50 or the solar thermal composite module 70.

Therefore, according to another embodiment of the present invention, each of the solar cell module 50 or the solar thermal composite module 70 may further include a temperature sensing unit (not shown). Then, according to the sensed temperature, the above-described maximum power determination algorithm (MPPT) may be performed.

Of course, the maximum power determination algorithm (MPPT) may be performed in consideration of the characteristics (input power or output power) of another module, as in the embodiment of the present invention. That is, power optimization may be performed in consideration of characteristics with other modules.

FIG. 10 is an example of an internal circuit diagram of a junction box of the solar module of FIG. 3.

Referring to FIG. 10, the junction box 115 according to an embodiment of the present invention may include a bypass diode unit 510, a capacitor unit 520, a dc / dc converter 530, and a controller 550. Can be.

The junction box 115 outputs AC power. Such a junction box 115 may be referred to as a micro inverter.

The bypass diode unit 510 includes the first to fourth nodes disposed between the a, b, c, and d nodes corresponding to the first to fourth conductive lines 135a, 135b, 135c, and 135d, respectively. Third bypass diodes Da, Db, and Dc are included.

The capacitor unit 520 stores the DC power supplied from the solar cell module 50. In the figure, the three capacitors Ca, Cb, and Cc are illustrated in parallel connection, but may be connected in series or in series-parallel mixed connection.

 The dc / dc converter 530 performs level conversion using a DC power source stored in the capacitor unit 520. In the figure, a flyback converter using the turn-on timing of the switching element S1 and the turns ratio of the transformer T is illustrated. Thereby, the boosting of the dc level can be performed. Meanwhile, a converter controller (not shown) may be further provided for controlling the turn-on timing of the switching element S1.

Meanwhile, the dc / dc converter 530 may be a boost converter, a buck converter, a forward converter, or the like, in addition to the flyback converter of the drawing, and a combination thereof (for example, , Cascaded Buck-Boost Converter, etc.) is also available.

On the other hand, the input current sensing unit A detects the current ic1 supplied to the dc / dc converter 520, and the input voltage sensing unit B is input to the dc / dc converter 520, that is, The voltage vc1 stored in the capacitor unit 520 is sensed. The sensed current ic1 and voltage vc1 are input to the controller 550.

In addition, the output current detector C detects a current ic2 output from the dc / dc converter 520, and the output voltage detector D outputs a voltage (outputted from the dc / dc converter 520). detect vc2). The sensed current ic2 and voltage vc2 are input to the controller 550.

The controller 550 may calculate the input power using the sensed input power source ic1 or vc1. Since the input power source ic1 or vc1 is a direct current, the input power can be calculated by multiplying the input current and the input voltage.

In addition, the controller 550 may calculate the input power by using the sensed input power source ic2 or vc2. Since the input power source ic2 or vc2 is a direct current, the input power can be calculated by multiplying the input current and the input voltage.

The controller 550 may receive output power information Sin of another module 100 or 200. In addition, the output power information Sout of the corresponding module may be output to the other module 100 or 200.

The controller 550 may control the output power of the corresponding module, specifically, the output power in consideration of the output power of another module. That is, power optimization may be performed in consideration of output power of other modules.

For example, when the output power output from the solar thermal composite module is set to be larger than other solar cell modules 50 (see FIG. 12), the control unit 550 of the solar thermal composite module 70. The switching element of the dc / dc converter 530 connected to the solar thermal composite module 70 based on the input power or output power input to the dc / dc converter connected to the other solar cell module 50 ( the turn-on timing of the S _S1), it can be controlled to be longer than the turn-on timing of the other solar cell module 50, the switching element (S _S1), the dc / dc converter 530 is connected to. As a result, the dc / dc converter 530 connected to the solar thermal composite module 70 can supply more output power.

As another example, when the output power output from the solar thermal composite module is set to be smaller than the other solar cell module 50 (see FIG. 13), the control unit 550 of the solar thermal composite module 70 The switching element S _S1 of the dc / dc converter 530 connected to the solar thermal composite module 70 based on an input power or an output power input to the dc / dc converter of another solar cell module 50. The turn on timing of may be controlled to be shorter than the turn on timing of the switching element S _S1 of the dc / dc converter 530 connected to the other solar cell module 50. As a result, the dc / dc converter 530 connected to the solar thermal composite module 70 can supply smaller output power.

The power optimizing control of the controller 550 may be performed between heterogeneous modules (solar composite module and solar cell module) as well as between homogeneous modules (between solar composite modules or solar cell modules).

FIG. 11 is another example of an internal circuit diagram of the junction box of the solar module of FIG. 3.

Referring to FIG. 11, the junction box 115 according to the embodiment of the present invention is similar to FIG. 10, except that the dc / dc converter 630 further includes an inverter 640.

That is, the junction box 115 of FIG. 10 may correspond to the solar and solar thermal system of FIG. 1, and the junction box 115 of FIG. 11 may correspond to the solar and solar thermal system of FIG. 2.

The inverter 640 converts the level-converted DC power supply into AC power. In the figure, a full-bridge inverter is illustrated. That is, the upper arm switching elements Sa and Sb and the lower arm switching elements S'a and S'b, which are connected in series with each other, become a pair, and a total of two pairs of upper and lower arm switching elements are parallel to each other (Sa & S'a, Sb & S'b). Diodes are connected in anti-parallel to each of the switching elements Sa, S'a, Sb, and S'b.

The switching elements in the inverter 640 are turned on / off based on an inverter switching control signal from an inverter controller (not shown). As a result, an AC power supply having a predetermined frequency is output. Preferably, it is preferable to have the same frequency (approximately 60 Hz) as the alternating frequency of the grid.

Meanwhile, a capacitor unit (not shown) for storing the level-converted dc power may be further included between the dc / dc converter 630 and the inverter 640. The capacitor unit (not shown) may include a plurality of capacitors, similar to the capacitor unit 620 described above.

The controller 650 may perform the power optimization control as described above, similarly to the controller 550 of FIG. 10.

12 to 13 are views for explaining the power optimization of the solar and solar thermal composite system according to an embodiment of the present invention.

Referring to FIG. 12, first, when power optimization is not applied, the dc / dc converters 300a, 300b ... connected to the solar cell modules 50a, 50b, ... output 100W of power, respectively. In addition, the dc / dc converter 300c connected to the solar thermal composite module 70a exemplifies outputting 100W of power.

At this time, the output possible power of the dc / dc converters 300a, 300b ... connected to the solar cell modules 50a, 50b, ... is 100W based on a current of 10A and a voltage of 10V, Assuming that the output power of the dc / dc converter 300c connected to the composite module 70a is 120W based on a current of 12A and a voltage of 10V, the dc / dc converters 300a, 300b, and 300c connected in series with each other. Due to this, the output current output from the dc / dc converter 300c connected to the solar thermal composite module 70a is lowered to 10A, so, as shown in the drawing, the power of 100W based on the current of 10A and the voltage of 10V Will be output. That is, the power lower than the actual power supply can be output.

To solve this, the current output from the dc / dc converter (300c) connected to the solar thermal composite module 70a is set to 10A, it can be controlled to increase the output voltage to 12V. That is, the controller 550 of the solar thermal composite module 70a may control the switching element S1 of the dc / dc converter 300c to output the increased voltage. Therefore, as shown in the drawing, the solar thermal composite module 70a can output power of 120W, unlike 100W power of other solar cell modules 50a, 50b, .... Accordingly, the output power efficiency of the entire photovoltaic and solar thermal composite system is improved.

Referring to FIG. 13, first, when power optimization is not applied, the dc / dc converters 300a, 300b, ... connected to the solar cell modules 50a, 50b, ... output 80W of power, respectively. In addition, the dc / dc converter 300c connected to the solar thermal composite module 70a exemplifies outputting power of 80W.

At this time, the output possible power of the dc / dc converters 300a, 300b ... connected to the solar cell modules 50a, 50b, ... is 100W based on a current of 10A and a voltage of 10V, Assuming that the output power of the dc / dc converter 300c connected to the composite module 70a is 800W based on a current of 8A and a voltage of 10V, the dc / dc converters 300a, 300b, and 300c connected in series with each other. Therefore, the output current output from the dc / dc converter (300a, 300b ...) connected to the solar cell module (50a, 50b, ...) is lowered to 8A, so, as shown in the figure, the current of 8A And 80 W of power based on a voltage of 10 V. That is, the power lower than the actual power supply can be output.

In order to solve this, the current output from the dc / dc converter 300c connected to the solar thermal composite module 70a is set to 10A, but the output voltage can be controlled to be lowered to 8V. That is, the controller 550 of the solar thermal composite module 70a may control the switching element S1 of the dc / dc converter 300c to output the lowered voltage. Therefore, as shown in the figure, the solar thermal composite module 70a can output power of 80W.

On the other hand, the current output from the dc / dc converter (300a, 300b ...) connected to the solar cell module (50a, 50b, ...) is set to 10A, the output voltage is set to 10V. That is, the controller 550 of the solar cell modules 50a, 50b, ... may control the switching element S1 of the dc / dc converters 300a, 300b ... to output the set current and voltage. have. Therefore, as shown in the drawing, the solar cell modules 50a, 50b, ... can output 100W of electric power. Accordingly, the output power efficiency of the entire photovoltaic and solar thermal composite system is improved.

 The photovoltaic and solar thermal composite system according to the present invention is not limited to the configuration and method of the embodiments described as described above, but the embodiments are all or part of each embodiment so that various modifications can be made May be optionally combined.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention.

Claims (20)

A solar unit including at least one solar cell module and a first dc / dc converter for level converting and outputting DC power supplied from the solar cell module; And
At least one solar thermal composite module, and a second dc / dc converter electrically connected to the first dc / dc converter and configured to level convert and output a DC power supplied from the solar thermal composite module. It includes;
The second dc / dc converter,
And based on at least one of a DC power input to the first dc / dc converter or a DC power output from the first dc / dc converter, varying and outputting the level of the DC power. Solar and solar combined system. The method of claim 1,
The photovoltaic unit is a solar and solar thermal composite system, characterized in that it comprises a plurality of solar cell modules. The method of claim 1,
The solar unit,
A plurality of solar cell modules,
And a dc / dc converter connected to each of the solar cell modules. The method of claim 1,
The solar unit,
A plurality of solar cell modules,
And a dc / dc converter connected to each of the strings of solar cells in the plurality of solar cell modules. The method of claim 1,
The photovoltaic unit, a photovoltaic and solar thermal composite system characterized in that it comprises a plurality of solar thermal composite module. The method of claim 1,
The solar heat unit,
A plurality of solar thermal composite modules,
And a dc / dc converter connected to each of the solar thermal composite modules. The method of claim 1,
The solar heat unit,
A plurality of solar thermal composite modules
And a dc / dc converter connected to each of the strings of solar cells in the plurality of solar thermal composite modules. The method of claim 1,
The first dc / dc converter,
And varying the level of the DC power based on at least one of a DC power input to the second dc / dc converter or an output power output from the second dc / dc converter. Photovoltaic and solar thermal composite system. The method of claim 1,
A second solar thermal composite module; And
And a third dc / dc converter for level converting and outputting DC power supplied from the solar thermal composite module.
The second dc / dc converter,
DC power input to the first dc / dc converter, DC power output from the first dc / dc converter, DC power input to the third dc / dc converter, or output from the third dc / dc converter Based on at least one of the direct current power source, characterized in that for varying the level of the direct current power source and characterized in that the solar and solar thermal composite system. The method of claim 1,
Among the first dc / dc converter for level-changing and outputting the DC power supplied from the solar cell module, and the DC power input to the second dc / dc converter or the output power output from the second dc / dc converter Based on at least one, the first junction box having a first control unit for controlling the first dc / dc converter to vary the level of the DC power supply; and further comprising a solar and solar thermal system . The method of claim 10,
The first junction box,
Photovoltaic and solar thermal composite system, characterized in that attached to the back of the solar cell module. The method of claim 1,
The second dc / dc converter for level converting and outputting the direct current power supplied from the solar thermal composite module, and the output from the direct current power input to the first dc / dc converter or the first dc / dc converter And a second junction box having a second control unit for controlling the second dc / dc converter to vary the level of the DC power source based on at least one of the power sources. Composite system. The method of claim 12,
The second junction box,
Photovoltaic and solar thermal composite system, characterized in that attached to the back of the solar thermal composite module. The method of claim 10,
The first junction box,
An input current detector configured to sense a current input to the first dc / dc converter;
An input voltage detector configured to sense a voltage input to the first dc / dc converter;
An output current detector configured to sense a current output to the first dc / dc converter; And
And a combined output voltage detector for sensing a voltage output to the first dc / dc converter. The method of claim 10,
The first junction box,
And a inverter converting the DC power level converted by the first dc / dc converter into an AC power and outputting the AC power. The method of claim 12,
The second junction box,
An input current detector configured to sense a current input to the second dc / dc converter;
An input voltage detector configured to detect a voltage input to the second dc / dc converter;
An output current detector for sensing a current output to the second dc / dc converter; And
And a combined output voltage detector for sensing a voltage output to the second dc / dc converter. The method of claim 12,
The second junction box,
And a inverter for converting and outputting the DC power level converted by the second dc / dc converter into an AC power source. The method of claim 1,
In the solar cell module,
A plurality of solar cells;
A first sealant and a second sealant formed on lower and upper surfaces of the plurality of solar cells;
A rear substrate formed on a bottom surface of the first sealing material; And
And a front substrate formed on an upper surface of the second sealing material. The method of claim 1,
The solar thermal composite module,
A plurality of solar cells;
Sealing materials formed on upper surfaces of the plurality of solar cells;
A front substrate formed on an upper surface of the sealing material;
A heat absorption plate formed on the bottom surface of the plurality of solar cells;
A heat transfer part formed on the bottom surface of the heat absorption plate;
A thermal insulator formed on a lower surface of the heat transfer part; And
And a rear substrate formed on the bottom surface of the thermal insulator. A solar unit including at least one solar cell module and a first dc / dc converter for level converting and outputting DC power supplied from the solar cell module; And
At least one solar thermal composite module, and a second dc / dc converter electrically connected to the first dc / dc converter and configured to level convert and output a DC power supplied from the solar thermal composite module. It includes;
The first dc / dc converter,
And based on at least one of a DC power input to the second dc / dc converter or a DC power output from the second dc / dc converter, varying and outputting the level of the DC power. Solar and solar combined system.

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