KR20190051333A - Photovoltaic module - Google Patents

Abstract

The present invention relates to a photovoltaic module. According to an embodiment of the present invention, the photovoltaic module comprises: a solar cell module having a plurality of solar cells; a converter converting a level of direct current (DC) power inputted from the solar cell module; a DC terminal capacitor storing the DC power outputted from the converter; and an inverter converting the DC power from the DC terminal capacitor into alternating current power. The converter includes: a full bridge switching unit performing switching for the DC power; a transformer having an input side connected to an output terminal of the full bridge switching unit; a resonant capacitor and a resonant inductor arranged between the full bridge switching unit and the transformer; and a synchronous rectification unit connected to an output side of the transformer. To this end, ripples of input current can be reduced.

Description

{PHOTOVOLTAIC MODULE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar module, and more particularly, to a solar module capable of reducing a ripple of an input current.

With the recent depletion of existing energy sources such as oil and coal, interest in alternative energy to replace them is increasing. Among them, solar cells are attracting attention as a next-generation battery that converts solar energy directly into electrical energy using semiconductor devices.

Meanwhile, the photovoltaic module means that the solar cells for solar power generation are connected in series or in parallel.

On the other hand, the converter of the solar module performs the maximum power point follow-up control, and it is necessary to reduce the ripple of the input current input to the converter. To this end, various approaches have been studied.

An object of the present invention is to provide a solar module capable of reducing ripples of an input current.

Another object of the present invention is to provide a solar module capable of downsizing the converter.

According to an aspect of the present invention, there is provided a solar module including: a solar cell module having a plurality of solar cells; a converter for converting a level of a DC power input from the solar cell module; A full bridge switching unit for performing switching to a direct current power source; and a full bridge switching unit for switching the output of the full bridge switching unit, A resonance capacitor and a resonance inductor disposed between the full bridge switching unit and the transformer; and a synchronous rectifier connected to the output side of the transformer. The inverter includes a plurality of switching elements.

According to another aspect of the present invention, there is provided a solar module including: a solar cell module having a plurality of solar cells; a converter for converting a level of a DC power input from the solar cell module; And a converter for converting the direct current power from the dc short capacitor to the alternating current power. The converter includes a half bridge switching unit for performing switching to the direct current power source, A resonance capacitor and a resonance inductor disposed between the half bridge switching unit and the transformer; and a synchronous rectifier connected to the output side of the transformer. The inverter includes a plurality of switching elements do.

A solar module according to an embodiment of the present invention includes a solar cell module having a plurality of solar cells, a converter for converting the level of the DC power input from the solar cell module, DC converter according to claim 1, wherein the converter includes a full bridge switching unit for performing switching to a direct current power source, and a full bridge switching unit for connecting the input side to the output terminal of the full bridge switching unit A transformer, a resonance capacitor and a resonance inductor disposed between the full bridge switching unit and the transformer, and a synchronous rectifier connected to the output side of the transformer, thereby reducing the ripple of the input current.

Especially. The resonance of the resonance capacitor, the resonance inductor, and the transformer enables the ripple of the input current to be reduced.

On the other hand, when the variation of the input voltage is large, the ripple of the input current can be reduced by delaying the driving phase of the full bridge switching section.

Thus, since the ripple of the input current input to the converter is reduced, the dc-stage capacitor can use the film capacitor instead of the electrolytic capacitor. Therefore, the dc-stage capacitor can be miniaturized.

Furthermore, since the ripple of the input current to be input to the converter is reduced, the turn ratio of the transformer can be reduced, and therefore, the transformer can be downsized. As a result, the converter used in the solar module can be miniaturized.

On the other hand, the inverter includes a plurality of switching elements, and at least a part of the plurality of switching elements may include a gallium nitride (GaN) transistor or a silicon carbide (SiC) transistor, The recovery loss can be reduced.

According to another aspect of the present invention, there is provided a solar module including: a solar cell module having a plurality of solar cells; a converter for converting a level of the DC power input from the solar cell module; The converter includes a half bridge switching unit for performing switching to a direct current power source, and a half bridge switching unit for switching the input side to the output side of the half bridge switching unit. The resonance capacitor and the resonance inductor disposed between the half bridge switching unit and the transformer, and the synchronous rectification unit connected to the output side of the transformer, the ripple of the input current can be reduced.

Especially. The resonance of the resonance capacitor, the resonance inductor, and the transformer enables the ripple of the input current to be reduced.

FIG. 1A is a diagram illustrating an example of a solar light system including a solar module according to an embodiment of the present invention.
1B is a view showing another example of a solar optical system including a solar module according to an embodiment of the present invention.
2 is a front view of a solar module according to an embodiment of the present invention.
3 is a rear view of the solar module of Fig. 2;
Fig. 4 is a circuit diagram showing the interior of the junction box in the solar module of Fig. 2. Fig.
5 is a circuit diagram of a power conversion device in a solar module according to an embodiment of the present invention.
6 to 7 are diagrams referred to in the description of the power conversion apparatus of FIG.
8 is a circuit diagram of a power conversion device in a solar module according to another embodiment of the present invention.
9 is a circuit diagram of a power conversion device in a solar module according to another embodiment of the present invention.
10 is a diagram referred to the description of the power conversion apparatus of FIG.
11 is a circuit diagram of a power conversion device in a solar module according to another embodiment of the present invention.
12 is a circuit diagram of a power conversion device in a solar module according to another embodiment of the present invention.
13 is an exploded perspective view of the solar cell module of FIG.

In this specification, a method of reducing the ripple of the input current input to the converter in the solar module is proposed.

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

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.

FIG. 1A is a diagram illustrating an example of a solar light system including a solar module according to an embodiment of the present invention.

Referring to the drawings, a solar light system 10a according to an embodiment of the present invention may include a solar module 50 and a gateway 80. [

The solar module 50 may include a solar cell module 100 and a junction box 200 including a power conversion device 500 (see FIG. 5) for converting and outputting DC power from the solar cell module have.

In the drawing, the junction box 200 is shown attached to the back surface of the solar cell module 100, but is not limited thereto. It is also possible that the junction box 200 is provided separately from the solar cell module 100.

On the other hand, a cable oln for supplying the AC power outputted from the junction box 200 to the grid can be electrically connected to the output terminal of the junction box 200. [

Meanwhile, a gateway 80 may be located between the junction box 200 and the grid 90.

On the other hand, the gateway 80 can detect the alternating current io and the alternating voltage vo outputted from the solar module 50 flowing through the cable oln.

On the other hand, the gateway 80 can output a power factor adjustment signal for power factor adjustment based on the phase difference between the alternating current io and the alternating voltage vo output from the solar module 50. [

For this purpose, the gateway 80 and the solar module 50 can perform power line communication (PLC communication) using the cable 323.

On the other hand, the power conversion device (500 in FIG. 5) in the solar module 50 can convert the DC power output from the solar cell module 100 into AC power and output it.

To this end, a converter (530 of FIG. 5) and an inverter (540 of FIG. 5) may be provided in the power conversion device (500 of FIG. 5) in the solar module 50.

In the present invention, the level of the DC power from the solar cell module 100 is converted through the converter 530 in the power conversion apparatus (500 of FIG. 5), and thereafter, Stage power conversion apparatus that performs a conversion of a power source to a power source.

On the other hand, the present invention proposes a method of reducing the ripple of the input current input to the converter 530 in a two stage stage power conversion apparatus.

The solar module 50 according to an embodiment of the present invention may include a solar cell module 100, a converter 530, an inverter 540, and a controller 550.

The converter 530 in the power conversion apparatus 500 according to the embodiment of the present invention includes a full bridge switching unit 532, a transformer 536 to which the input side is connected to the output terminal of the full bridge switching unit 532, A resonance capacitor Cr and a resonance inductor Lr disposed between the bridge switching unit 532 and the transformer 536 and a synchronous rectification unit 538 connected to the output side of the transformer 536. [

Particularly, by disposing the true capacitor Cr and the resonant inductor Lr at the front end of the transformer 536, the resonance of the true capacitor Cr, the resonant inductor Lr and the transformer 536 changes the input voltage The ripple of the input current can be reduced. Furthermore, the ripple of the DC power output to the converter 530 can be reduced.

Therefore, it is not necessary to use a large-capacity electrolytic capacitor as the dc-short capacitor, for example, a small-capacity film capacitor may be used. The use of such a small-capacity film capacitor may be referred to as a capacitorless technique.

Further, since the ripple of the input current to be input to the converter 530 is reduced, the turn ratio of the transformer 536 can be reduced, and the transformer 536 can be downsized. As a result, the converter 530 used in the solar module 50 can be downsized.

The inverter 570 includes a plurality of switching elements Q5 to Q8 and at least a part of the plurality of switching elements Q5 to Q8 may be a gallium nitride Thus, it is possible to reduce the reverse recovery loss at the time of high-speed switching.

1B is a view showing another example of a solar optical system including a solar module according to an embodiment of the present invention.

Referring to the drawings, a solar light system 10b according to an embodiment of the present invention may include a plurality of solar modules 50a, 50b, ..., 50n and a gateway 80. [

The solar cell system 10b of Fig. 1b differs from the solar cell system 10a of Fig. 1a in that a plurality of solar modules 50a, 50b, ..., 50n are connected in parallel with each other.

Each of the plurality of solar modules 50a, 50b, ..., 50n includes a solar cell module 100a, 100b, ..., 100n and a circuit for converting and outputting DC power from the solar cell module And junction boxes 200a, 200b, ..., 200n including devices.

In the drawing, the junction boxes 200a, 200b, ..., 200n are attached to the back surfaces of the solar cell modules 100a, 100b, ..., 100n, but the present invention is not limited thereto. It is also possible that the junction boxes 200a, 200b, ..., 200n are provided separately from the respective solar cell modules 100a, 100b, ..., 100n.

On the other hand, cables 31a, 31b, ..., oln for supplying AC power outputted from the junction boxes 200a, 200b, ..., 200n to the grid are connected to the junction boxes 200a, 200b, ..., ..., 200n, respectively.

The converter 630 in each power conversion device 500 in the plurality of photovoltaic modules 50a, 50b, ..., 50n in FIG. 1b is, as described in the description of FIG. 1a, A transformer 536 connected to the output end of the full bridge switching unit 532 and connected to the input end of the full bridge switching unit 532 and a resonant capacitor Cr disposed between the full bridge switching unit 532 and the transformer 536, And a synchronous rectification section 538 connected to the output side of the transformer 536. [

Particularly, by disposing the true capacitor Cr and the resonant inductor Lr at the front end of the transformer 536, the resonance of the true capacitor Cr, the resonant inductor Lr and the transformer 536 changes the input voltage The ripple of the input current can be reduced. Furthermore, the ripple of the DC power output to the converter 530 can be reduced. In addition, miniaturization of the dc-stage capacitor and downsizing of the transformer are also possible.

FIG. 2 is a front view of a solar module according to an embodiment of the present invention, and FIG. 3 is a rear view of the solar module of FIG. 2.

Referring to the drawings, a solar module 50 according to an embodiment of the present invention may include a solar cell module 100 and a junction box 200 located on the back surface of the solar cell module 100.

The junction box 200 may include at least one bypass diode that is bypassed to prevent hot spots in the case of shadow generation or the like.

4 and the like, three bypass diodes (Da, Db, and Dc in FIG. 4) are provided corresponding to the four solar cell strings in FIG.

On the other hand, the junction box 200 can convert DC power supplied from the solar cell module 100. This will be described with reference to FIG. 4 and subsequent figures.

On the other hand, the solar cell module 100 may include a plurality of solar cells.

In the figure, a plurality of sinker cells are connected in series by ribbons (133 in FIG. 12) to form a solar cell string 140. By this, 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. 2 is a sectional view showing the first solar cell string 140a and the second solar cell string 140b by the bus ribbons 145a, 145c and 145e disposed at the lower part of the solar cell module 100, 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.

2 shows the second solar cell string 140b and the third solar cell string 140c respectively by the bus ribbons 145b and 145d disposed on the upper part of the solar cell module 100, And 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 (not shown) 4 conductive lines (not shown) are connected to the bypass diode (Da, Db, and Dc in FIG. 4) in the junction box 200 disposed on the back surface of the solar cell module 100 through openings formed in the solar cell module 100 ).

At this time, the opening formed in the solar cell module 100 may be formed corresponding to the region where the junction box 200 is located.

Fig. 4 is a circuit diagram showing the interior of the junction box in the solar module of Fig. 2. Fig.

Referring to the drawings, the junction box 200 can convert DC power from the solar cell module 100 and output the converted power.

In particular, in connection with the present invention, the junction box 200 may include a power conversion device (500 of FIG. 5) for outputting an AC power source.

To this end, the junction box 200 may include a converter 530, an inverter 540, and a control unit 550 for controlling the converter 530 and the junction 530.

The junction box 200 may further include a bypass diode 510 for bypassing, a capacitor 520 for storing DC power, and a filter 570 for filtering the AC power have.

The junction box 200 may further include a communication unit 580 for communication with an external gateway 80.

On the other hand, the junction box 200 includes an input current detection unit A, an input voltage detection unit B, a converter output current detection unit C, a converter output voltage detection unit D, an inverter output current detection unit E, And may further include a detection unit F.

On the other hand, the control unit 550 can control the converter 530, the inverter 540, and the communication unit 580.

The bypass diode 510 may include bypass diodes Dc, Db, and Da disposed between the first through fourth conductive lines (not shown) of the solar cell module 100, respectively . At this time, it is preferable that the number of the bypass diodes is one or more and smaller than the number of the conductive lines by one.

The bypass diodes Dc, Db and Da receive the solar direct current power from the solar cell module 100, particularly from the first to fourth conductive lines (not shown) in the solar cell module 100. The bypass diodes Dc, Db, and Da can be bypassed when a reverse voltage is generated in the DC power supply from at least one of the first to fourth conductive lines (not shown).

On the other hand, the DC power source through the bypass diode 510 can be input to the capacitor 520.

The capacitor unit 520 may store an input DC power input through the solar cell module 100 and the bypass diode unit 510. [

In the figure, the capacitor unit 520 includes a plurality of capacitors Ca, Cb, and Cc connected in parallel to each other. Alternatively, a plurality of capacitors may be connected in series- It is also possible to connect to the terminal. Alternatively, it is also possible that the capacitor unit 520 includes only one capacitor.

The converter 530 can convert the level of the input voltage from the solar cell module 100 via the bypass diode unit 510 and the capacitor unit 520. [

In particular, the converter 530 can perform power conversion using a DC power source stored in the capacitor unit 520.

Meanwhile, the converter 530 according to the embodiment of the present invention will be described in more detail with reference to FIG.

On the other hand, the switching elements in the converter 530 can be turned on / off based on the converter switching control signal from the controller 550. [ Thereby, the level-converted DC power can be outputted.

The inverter 540 can convert the DC power converted by the converter 530 into AC power.

In the drawing, a full-bridge inverter is illustrated. That is, the upper and lower arm switching elements Q5 and Q7 and the lower arm switching elements Q6 and Q8 are connected in series and the two pairs of upper and lower arm switching elements are connected in parallel to each other (Q5, Q6, Q7 and Q8) Lt; / RTI > Diodes may be connected in anti-parallel to each switching element Q5 to Q8.

The switching elements Q5 to Q8 in the inverter 540 can be turned on / off based on the inverter switching control signal from the controller 550. [ As a result, an AC power source having a predetermined frequency can be output. Preferably, it has a frequency (approximately 60 Hz or 50 Hz) that is equal to the alternating frequency of the grid.

On the other hand, the capacitor C may be disposed between the converter 530 and the inverter 540.

The capacitor C may store the level-converted DC power of the converter 530. On the other hand, both ends of the capacitor C may be referred to as a dc stage, and accordingly, the capacitor C may be called a dc-stage capacitor.

The input current detection unit A may sense the input current ic1 supplied from the solar cell module 100 to the capacitor unit 520. [

The input voltage detecting unit B may sense the input voltage Vc1 supplied from the solar cell module 100 to the capacitor unit 520. [ Here, the input voltage Vc1 may be equal to the voltage stored across the capacitor unit 520. [

The sensed input current ic1 and the input voltage vc1 may be input to the control unit 550. [

The converter output current detection unit C senses the output current ic2 output from the converter 530 or the dc step current and the converter output voltage detection unit D detects the output current ic2 output from the converter 530, (vc2), i.e., the dc voltage. The sensed output current ic2 and the output voltage vc2 may be input to the control unit 550. [

The inverter output current detector E detects the current ic3 output from the inverter 540 and the inverter output voltage detector F detects the voltage vc3 output from the inverter 540. [ The detected current ic3 and the voltage vc3 are input to the control unit 550. [

Meanwhile, the control unit 550 may output a control signal for controlling the switching elements of the converter 530. In particular, the control unit 550 controls the control unit 550 so that at least one of the detected input current ic1, the input voltage vc1, the output current ic2, the output voltage vc2, the output current ic3, or the output voltage vc3 On timing signals of the switching elements in the converter 530 can be output.

On the other hand, the control unit 550 can output an inverter control signal for controlling each of the switching elements Q5 to Q8 of the inverter 540. [ In particular, the control unit 550 controls the control unit 550 so that at least one of the detected input current ic1, the input voltage vc1, the output current ic2, the output voltage vc2, the output current ic3, or the output voltage vc3 On timing signals of the switching elements Q5 to Q8 of the inverter 540 can be output on the basis of the above signals.

On the other hand, the control unit 550 can control the converter 530 to calculate the maximum power point for the solar cell module 100 and accordingly output the DC power corresponding to the maximum power.

On the other hand, the communication unit 580 can perform communication with the gateway 80. [

For example, the communication unit 580 can exchange data with the gateway 80 by power line communication.

On the other hand, the communication unit 580 may transmit current information, voltage information, power information, and the like of the solar module 50 to the gateway 80. [

On the other hand, the filter unit 570 may be disposed at the output terminal of the inverter 540.

The filter unit 570 includes a plurality of passive elements and generates a phase difference between the AC current io output from the inverter 540 and the AC voltage vo based on at least a part of the plurality of passive elements Can be adjusted.

FIG. 5 is a circuit diagram of a power conversion apparatus in a solar module according to an embodiment of the present invention, and FIGS. 6 to 7 are views referred to the description of the power conversion apparatus of FIG.

The power conversion device 500 in the solar module 100 according to the embodiment of the present invention includes the converter 530 and the inverter 540 shown in the figure, A converter output voltage detecting unit D, a converter output voltage detecting unit C, a converter output voltage detecting unit C, a converter output voltage detecting unit D, a control unit 550, a communication unit 580, an input current detecting unit A, An inverter output current detection unit E, and an inverter output voltage detection unit F.

A filter unit 570 for reducing electromagnetic noise may further be disposed at an output terminal of the inverter 540. The filter unit 570 at this time includes first and second inductors L1 and L2 disposed at both ends of the inverter 530 and a capacitor C4 between the first inductor L1 and the second inductor 12 .

Hereinafter, the converter 530 and the inverter 540 shown in Fig. 5 will be mainly described.

The power conversion apparatus 500 in the solar module 100 according to the embodiment of the present invention includes a converter 530 for converting the level of the DC power input from the solar cell module 100, And an inverter 570 for converting a DC power source from the dc short capacitor C to an AC power source.

The converter 530 includes a full bridge switching unit 532 for switching the DC power source, a transformer 536 to which the input side is connected to the output terminal of the full bridge switching unit 532, a full bridge switching unit 532, A resonant capacitor Cr and a resonant inductor Lr disposed between the transformer 536 and the transformer 536 and a synchronous rectifier 538 connected to the output side of the transformer 536. [

Especially. The resonance of the resonance capacitor Cr and the resonance inductor Lr and the resonance of the transformer 536 can reduce the ripple of the input current.

On the other hand, each of the switching elements Q1 to Q4 in the full bridge switching unit 532 performs the zero voltage switching (ZVS) and the zero current switching (ZCS) by the resonance capacitor Cr and the resonance inductor Lr .

As shown in the drawing, the full bridge switching unit 532 includes first to second switching elements Q1 and Q2 connected in parallel with each other, and a full-bridge switching unit Q1 and Q2 connected in series to the first and second switching elements Q1 and Q2. 3 to the fourth switching elements Q3 and Q4.

The first node n1 between the first switching device Q1 and the second switching device Q2 and the second node n1 between the third switching device Q3 and the fourth switching device Q4 n2, the input side na, nb of the transformer 536 can be connected.

As shown in the drawing, the synchronous rectification section 538 includes a first diode element D1 and a second diode element D2 connected in series to each other, a first capacitor C1 and a second capacitor C1 connected in series with each other, (C2).

At this time, the first diode D1 and the second diode D2, and the first capacitor C1 and the second capacitor C2 may be connected in parallel with each other.

 Between a third node n3 between the first diode D1 and the second diode D2 and a fourth node n4 between the first capacitor C1 and the second capacitor C2, The output side of the transformer 536 can be connected.

Meanwhile, the inverter 570 may include fifth and sixth switching elements Q5 and Q6 connected in series with each other and seventh and eighth switching elements Q7 and Q8 connected in series with each other.

A fifth node n5 between the fifth switching element Q5 and the sixth switching element Q6 and a sixth node n6 between the seventh switching element Q7 and the eighth switching element Q8 , AC power can be output.

On the other hand, the control unit 550 can control the converter 530 and the inverter 570 together.

In particular, the control unit 550 may output the control signal Sfb to the full bridge switching unit 532 in the converter 530 for maximum power point tracking control.

Particularly, when the variation of the input voltage Vc1 input to the converter 530 is large, the control unit 550 reduces the ripple of the input current ic1 by delaying the driving phase of the full bridge switching unit 532 .

As described above, since the ripple of the input current ic1 input to the converter 530 is reduced, the dc short-circuit capacitor C can use the film capacitor instead of the electrolytic capacitor. Therefore, the dc short-circuit capacitor C can be miniaturized.

Further, since the ripple of the input current ic1 input to the converter 530 is reduced, the turn ratio of the transformer 536 can be reduced, and accordingly, the transformer 536 can be downsized. As a result, the converter 530 used in the solar module 50 can be downsized.

On the other hand, the control unit 550 can output the control signal Sic to the inverter 570 for AC power output corresponding to the system frequency.

It is preferable that the switching frequency of the inverter 570 is higher than the switching frequency of the first to fourth switching elements Q1 to Q4 in the full bridge switching unit 532 in the converter 530. [

On the other hand, when performing high-speed switching, switching loss may occur.

Therefore, it is preferable that all of the plurality of switching elements Q5 to Q8 in the inverter 570 include a gallium nitride (GaN) transistor or a silicon carbide (SiC) transistor as shown in the figure. Thus, the reverse recovery loss at the time of high-speed switching can be reduced.

Meanwhile, the first to fourth switching devices Q1 to Q4 in the full bridge switching unit 532 in FIG. 5 may include a metal oxide semiconductor field effect transistor (MOSFET).

Meanwhile, the control unit 550 may perform frequency control and phase control on the full bridge switching unit 532.

On the other hand, the control unit 550 can control the switching elements Q1 to Q4 in the full bridge switching unit 532 to perform switching with a duty of 50%, respectively. In this case, each of the switching elements Q1 to Q4 in the full bridge switching unit 532 has a phase difference of about 180 degrees and can perform switching.

On the other hand, when the variation of the input voltage Vc1 is large, the control unit 550 can increase the range of the output voltage by changing the switching frequency.

More specifically, when the variation of the input voltage Vc1 is large, the control unit 550 can extend the range of the output voltage by delaying the driving phase of the full bridge switching unit 532. [

FIG. 6 is a diagram showing voltage waveforms, current waveforms, and the like in the power conversion device 500 of FIG.

Vpv represents the voltage waveform supplied from the solar cell module 100 of FIG. 5, VQ1 and VQ4 represent the voltage waveforms across the first and fourth switching elements, IQ1 and IQ4 represent the voltage waveforms of the first and fourth switching elements It shows current waveforms flowing at both ends.

VQ2 and VQ3 represent voltage waveforms across the second and third switching elements, IQ2 and IQ3 represent current waveforms flowing across both the second and third switching elements, and Ilr represents a current flowing through the resonant inductor element Lr VD2 and ID2 denote voltage and current waveforms across the second diode element D2, respectively, and Vdc denotes a voltage waveform across the first diode element D1, Indicates the voltage waveform across the capacitor.

7 is a waveform showing the dc voltage (Vdc) outputted from the converter 530 and the AC power (Vac) outputted from the inverter 540.

According to the power converter 500 of FIG. 5, since the maximum power point tracking (MPPT) control in the converter 530 is performed, a constant dc voltage with little fluctuation of the dc short voltage Vdc can be outputted have.

Then, the inverter 540 performs high-speed switching to output a stable AC power (Vac).

8 is a circuit diagram of a power conversion device in a solar module according to another embodiment of the present invention.

Referring to the drawings, a power conversion device 500b in a solar module according to another embodiment of the present invention is similar to the power conversion device 500 of FIG. 5, except that the first and second diodes There is a difference in that the elements D1 and D2 are the ninth and tenth switching elements Q9 and Q10.

Hereinafter, differences from FIG. 5 will be mainly described.

Since the synchronous rectification unit 538 in the power conversion apparatus 500b includes the ninth and tenth switching elements Q9 and Q10, it may be called a half bridge switching unit.

The synchronous rectification section 538 may include a ninth switching element Q9 and a tenth switching element Q10 connected in series with each other and a first capacitor C1 and a second capacitor C2 connected in series with each other have.

Here, a third node n3 between the ninth switching element Q9 and the tenth switching element Q10 and a fourth node n4 between the first and second capacitors C1 and C2, The output side of the transformer 536 can be connected.

The ninth switching element Q9 and the tenth switching element Q10 can perform switching by the control signal of the control part 550 and can perform switching such as zero voltage switching and zero current switching So that the power consumption can be reduced. Therefore, the converter 500 of FIG. 8 can perform high-efficiency power conversion.

On the other hand, the ninth switching element Q9 and the tenth switching element Q10 may include a metal oxide semiconductor field effect transistor (MOSFET).

FIG. 9 is a circuit diagram of a power conversion device in a solar module according to another embodiment of the present invention, and FIG. 10 is a diagram referred to the description of the power conversion device of FIG.

Referring to the drawings, a power conversion device 500c in a solar module according to another embodiment of the present invention is similar to the power conversion device 500 of FIG. 5, except that the first and second There is a difference in that the diode elements D1 and D2 are the ninth and tenth switching elements Q9 and Q10 and some switching elements in the inverter 550 are formed of a gallium nitride (GaN) transistor or a silicon carbide ) Transistors, while the other part includes a metal oxide semiconductor field effect transistor (MOSFET).

Hereinafter, differences from FIG. 5 will be mainly described.

The synchronous rectification section 538 may include a ninth switching element Q9 and a tenth switching element Q10 connected in series with each other and a first capacitor C1 and a second capacitor C2 connected in series with each other have.

Here, a third node n3 between the ninth switching element Q9 and the tenth switching element Q10 and a fourth node n4 between the first and second capacitors C1 and C2, The output side of the transformer 536 can be connected.

A portion Q5 and Q6 of the plurality of switching elements Q5 through Q8 in the inverter 570 includes a gallium nitride (GaN) transistor or a silicon carbide (SiC) transistor, and the other portions Q7 and Q8 comprise a metal Oxide semiconductor field effect transistors (MOSFETs).

At this time, some Q5 and Q6 of the plurality of switching elements Q5 and Q8 perform high-speed switching and the other portions Q7 and Q8 perform low-speed switching corresponding to the system frequency.

10 shows a case where the duty of the signals Sg5 and Sg6 applied to the gate terminals of the portions Q5 and Q6 of the plurality of switching elements Q5 to Q8 gradually increases or decreases during the Ta and Tb periods in the systematic period .

10 shows an example in which the duty ratio of the signals Sg7 and Sg8 applied to the gate terminals of the portions Q7 and Q8 of the plurality of switching elements Q5 to Q8 is turned on and off during Ta and Tb periods, respectively do.

Thus, by configuring the switching elements in the hybrid type, the manufacturing cost of the inverter 570 can be reduced.

11 is a circuit diagram of a power conversion device in a solar module according to another embodiment of the present invention.

Referring to the drawings, a power conversion device 500d in a solar module according to another embodiment of the present invention is similar to the power conversion device 500 of FIG. 5, except that the first and second There is a difference in that the diode elements D1 and D2 are the ninth and tenth switching elements Q9 and Q10.

Hereinafter, differences from FIG. 5 will be mainly described.

The synchronous rectification section 538 may include a ninth switching element Q9 and a tenth switching element Q10 connected in series with each other and a first capacitor C1 and a second capacitor C2 connected in series with each other have.

Here, a third node n3 between the ninth switching element Q9 and the tenth switching element Q10 and a fourth node n4 between the first and second capacitors C1 and C2, The output side of the transformer 536 can be connected.

On the other hand, the ninth switching element Q9 and the tenth switching element Q10 may include a gallium nitride (GaN) transistor or a silicon carbide (SiC) transistor.

12 is a circuit diagram of a power conversion device in a solar module according to another embodiment of the present invention.

Referring to the drawings, a power conversion device 500e in a solar module according to another embodiment of the present invention is similar to the power conversion device 500 of FIG. 5, except that the first and second There is a difference in that the diode elements D1 and D2 are the ninth and tenth switching elements Q9 and Q10 and the half bridge switching unit 532b is used instead of the full bridge switching unit 532. [

Hereinafter, differences from FIG. 5 will be mainly described.

The converter 530 in the power conversion apparatus 500e includes a half bridge switching unit 532b for performing switching to the DC power source, a transformer 536 connected to the input side of the output terminal of the half bridge switching unit 532b, A resonant capacitor Cr and a resonant inductor Lr disposed between the half bridge switching unit 532b and the transformer 536 and a synchronous rectification unit 538 connected to the output side of the transformer 536. [ The ripple of the input current ic1 can be reduced by providing the synchronous rectification section connected to the output side of the transformer.

Especially. The resonance of the resonance capacitor Cr and the resonance inductor Lr and the resonance of the transformer 536 can reduce the ripple of the input current.

On the other hand, when the variation of the input voltage is large, the ripple of the input current can be reduced by delaying the driving phase of the half bridge switching unit 532b.

As described above, since the ripple of the input current input to the converter 530 is reduced, the dc short-circuit capacitor C can use the film capacitor instead of the electrolytic capacitor. Therefore, the dc short-circuit capacitor C can be miniaturized.

Further, since the ripple of the input current to be input to the converter 530 is reduced, the turn ratio of the transformer 536 can be reduced, and the transformer 536 can be downsized. As a result, the converter 530 used in the solar module 50 can be downsized.

Meanwhile, the half bridge switching unit 532b may include first and second switching devices Q1 and Q2 connected in parallel with each other.

 The input side of the transformer 536 may be connected to the first node n1 between the first switching device Q1 and the second switching device Q2.

The synchronous rectification unit 538 includes a ninth switching element Q9 and a tenth switching element Q10 connected in series with each other and a first capacitor C1 and a second capacitor C2 connected in series with each other can do.

Here, a third node n3 between the ninth switching element Q9 and the tenth switching element Q10 and a fourth node n4 between the first and second capacitors C1 and C2, The output side of the transformer 536 can be connected.

On the other hand, the ninth switching element Q9 and the tenth switching element Q10 may include a metal oxide semiconductor field effect transistor (MOSFET).

The inverter 570 includes a plurality of switching elements Q5 to Q8 and at least a part of the plurality of switching elements Q5 to Q8 may be a gallium nitride . Thus, the reverse recovery loss at the time of high-speed switching can be reduced.

13 is an exploded perspective view of the solar cell module of FIG.

Referring to FIG. 13, the solar cell module 100 of FIG. 2 may include a plurality of solar cells 130. The first sealing material 120 and the second sealing material 150 located on the lower surface and the upper surface of the plurality of solar cells 130 and the rear substrate 110 and the second sealing material 120 located on the lower surfaces of the first sealing material 120, And may further include a front substrate 160 positioned on the top surface of the sealing member 150.

The solar cell 130 is a semiconductor device that converts solar energy into electrical energy. The solar cell 130 may be a silicon solar cell, a compound semiconductor solar cell, a tandem solar cell, Dye-sensitized or CdTe, CIGS type solar cells, thin film solar cells, and the like.

The solar cell 130 is formed of a light receiving surface on which solar light is incident and a rear surface opposite to the light receiving surface. For example, the solar cell 130 includes a silicon substrate of a first conductivity type, a second conductivity type semiconductor layer formed on the silicon substrate and having a conductivity type opposite to that of the first conductivity type, An antireflection film formed on the second conductive type semiconductor layer and having at least one opening exposing a part of the surface of the second conductive type semiconductor layer; And a rear electrode formed on the rear surface of the silicon substrate.

Each solar cell 130 may be electrically connected in series, parallel, or series-parallel. Specifically, a plurality of solar cells 130 can be electrically connected by a 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 collecting electrode formed on the rear surface of another adjacent solar cell 130. [

In the figure, it is illustrated that the ribbon 133 is formed in two lines, and the solar cell 130 is connected in series by the ribbon 133 to form the solar cell string 140.

Thus, as described with reference to FIG. 2, six strings 140a, 140b, 140c, 140d, 140e, and 140f are formed, and each string may include ten solar cells.

The back substrate 110 may be, but is not limited to, a TPT (Tedlar / PET / Tedlar) type having a waterproof, insulating and ultraviolet shielding function as a back sheet. Although the rear substrate 110 is shown as a rectangular shape in FIG. 4, the rear substrate 110 may be formed in various shapes such as a circular shape and a semicircular shape according to the environment in which the solar cell module 100 is installed.

The first sealing member 120 may be attached to the rear substrate 110 to have the same size as the rear substrate 110 and a plurality of solar cells 130 may be formed on the first sealing member 120 And can be positioned adjacent to each other so as to achieve the same.

The second sealing member 150 may be positioned on the solar cell 130 and may be laminated to the first sealing member 120.

Here, the first sealant 120 and the second sealant 150 allow each element of the solar cell to chemically bond. The first sealing material 120 and the second sealing material 150 can be various examples such as an ethylene vinyl acetate (EVA) film.

On the other hand, the front substrate 160 is preferably placed on the second sealing material 150 so as to transmit sunlight, and is preferably made of tempered glass in order to protect the solar cell 130 from an external impact or the like. Further, it is more preferable to use a low-iron-content tempered glass containing a small amount of iron in order to prevent the reflection of sunlight and increase the transmittance of sunlight.

It is to be understood that the invention is not to be limited in its application to the details of construction and the manner in which the above described embodiments of the invention are put into practice, .

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 (15)

A solar cell module comprising a plurality of solar cells;
A converter for converting a level of a DC power input from the solar cell module;
A dc capacitor that stores the DC power output from the converter;
And an inverter for converting the direct current power from the dc short capacitor to an alternating current power,
The converter includes:
A full bridge switching unit for switching the DC power supply;
A transformer having an input connected to an output terminal of the full bridge switching unit;
A resonant capacitor and a resonant inductor disposed between the full bridge switching unit and the transformer;
And a synchronous rectifier connected to the output side of the transformer. The method according to claim 1,
The inverter includes:
Wherein at least a portion of the plurality of switching elements comprises a gallium nitride (GaN) transistor or a silicon carbide (SiC) transistor. The method according to claim 1,
The full-
First and second switching elements connected in parallel to each other;
And third to fourth switching elements serially connected to the first and second switching elements, respectively,
The input side of the transformer is connected between a first node between the first switching device and the second switching device and a second node between the third switching device and the fourth switching device Solar modules. The method of claim 3,
Wherein the first to fourth switching elements comprise:
And a metal oxide semiconductor field effect transistor (MOSFET). The method according to claim 1,
The synchronous rectification unit includes:
A first diode element and a second diode element connected in series to each other;
And a first capacitor and a second capacitor connected in series to each other,
The output side of the transformer is connected between a third node between the first diode element and the second diode element and a fourth node between the first capacitor and the second capacitor. . The method according to claim 1,
Wherein the dc-only capacitor comprises a film capacitor. The method according to claim 1,
And a controller for controlling the converter and the inverter. The method according to claim 1,
The inverter includes:
Fifth and sixth switching elements connected in series to each other;
And seventh and eighth switching elements connected in series to each other,
Wherein the AC power is output through a fifth node between the fifth switching device and the sixth switching device and a sixth node between the seventh switching device and the eighth switching device. . The method according to claim 1,
The synchronous rectification unit includes:
A ninth switching element and a tenth switching element connected in series to each other;
And a first capacitor and a second capacitor connected in series to each other,
And an output side of the transformer is connected between a third node between the ninth switching element and the tenth switching element and a fourth node between the first capacitor and the second capacitor. module. 10. The method of claim 9,
Wherein the ninth switching element and the tenth switching element in the synchronous rectification part include a gallium nitride (GaN) transistor or a silicon carbide (SiC) transistor. The method according to claim 1,
Wherein all of said plurality of switching elements in said inverter comprise a gallium nitride (GaN) transistor or a silicon carbide (SiC) transistor. The method according to claim 1,
Characterized in that a part of the plurality of switching elements in the inverter comprises a gallium nitride (GaN) transistor or a silicon carbide (SiC) transistor and the other part comprises a metal oxide semiconductor field effect transistor Optical module. A solar cell module comprising a plurality of solar cells;
A converter for converting a level of a DC power input from the solar cell module;
A dc capacitor that stores the DC power output from the converter;
And an inverter for converting the direct current power from the dc short capacitor to an alternating current power,
The converter includes:
A half bridge switching unit for performing switching to the DC power source;
A transformer having an input connected to an output terminal of the half bridge switching unit;
A resonant capacitor and a resonant inductor disposed between the half bridge switching unit and the transformer;
And a synchronous rectifier connected to the output side of the transformer. 14. The method of claim 13,
The inverter includes:
Wherein at least a portion of the plurality of switching elements comprises a gallium nitride (GaN) transistor or a silicon carbide (SiC) transistor. 14. The method of claim 13,
The half bridge switching unit includes:
And first and second switching elements connected in parallel to each other,
And an input side of the transformer is connected to a first node between the first switching device and the second switching device.

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