KR20160025933A - Transformer and power converting apparatus icnluing the same - Google Patents

Abstract

The present invention relates to a transformer and a power converting apparatus including the same. The power converting apparatus according to the embodiment of the present invention includes a converter part which converts DC power of a solar cell module and includes interleaving converters, and a control part which controls the converter part. The control part changes the switching cycles of the interleaving converters, corresponds to a variation of the switching cycle, and changes a phase difference for the operation range between the interleaving converters. Thereby, high-efficiency power conversion can be carried out in a power conversion process.

Description

TRANSFORMER AND POWER CONVERSION APPARATUS WITH THE SAME

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer and a power conversion apparatus having the same, and more particularly, to a transformer and a power conversion apparatus having the transformer capable of high efficiency power conversion at the time of power conversion.

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.

On the other hand, the photovoltaic module means that solar cells for solar power generation are connected in series or parallel, and the photovoltaic module can include a junction box for collecting the electricity produced by the solar cell.

An object of the present invention is to provide a transformer capable of high-efficiency power conversion at the time of power conversion and a power conversion device having the transformer.

According to an aspect of the present invention, there is provided a transformer including: a bobbin having a hollow portion and including a winding guide portion guiding a winding wound on a side surface; a first protrusion inserted into the hollow; A first core having first and second side portions spaced apart, a second projection inserted into the hollow, and third and fourth side portions spaced apart from each other surrounding the bobbin, the first and second side portions being coupled to the bobbin A second core, and a winding wound around the winding guide portion in the bobbin.

According to another aspect of the present invention, there is provided a power conversion apparatus including a converter unit for converting DC power from a solar cell module, a controller for controlling the converter unit, and a capacitor for storing a voltage output from the converter unit. Wherein the converter section includes a switching element, a transformer for performing power conversion by a switching operation of the switching element, and a diode element disposed at an output terminal of the transformer, wherein the transformer is formed of a hollow, A first protrusion which is inserted into the hollow, a first protrusion which is inserted into the hollow, and a second protrusion which is inserted into the hollow, A second core coupled to the bobbin and having third and fourth side surfaces spaced apart from each other and spaced apart from each other, In comprises a winding wound around the winding guide portion.

According to an embodiment of the present invention, a transformer includes: a bobbin including a winding guide portion for forming a hollow and guiding a winding wound on a side surface; a first protrusion inserted into the hollow; and first and second protrusions surrounding the bobbin, A second core coupled to the bobbin and having a first core having a second side portion, a second projection inserted into the hollow, and third and fourth side portions spaced apart from each other and surrounding the bobbin, By providing a winding wound around the winding guide portion in the bobbin, it is possible to perform high-efficiency power conversion at the time of power conversion.

1 is an example of a configuration diagram of a solar photovoltaic system 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;
4 is an exploded perspective view of the solar cell module of FIG.
5 is an example of a bypass diode configuration of the solar module of FIG.
FIG. 6 is an example of a block diagram of the power conversion module in the junction box of FIG. 2. FIG.
7A is an example of an internal circuit diagram of the power conversion module of FIG.
7A is an example of an internal circuit diagram of the power conversion module of FIG.
7B is another example of the internal circuit diagram of the power conversion module of FIG.
8A and 8B are diagrams illustrating an operation method of the power conversion module of FIG.
9A to 9B are diagrams for explaining the operation of the tap inductor boost converter of FIG. 7A.
FIGS. 10A and 10B are diagrams for explaining output of a pseudo direct current power source using an input power source in the converter unit of FIG. 6;
11 is a diagram showing an example of a converter section.
12 is a perspective view of a bobbin in a transformer in accordance with an embodiment of the present invention.
13 to 17 are views referred to in the description of Fig.

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.

1 is an example of a configuration diagram of a solar photovoltaic system according to an embodiment of the present invention.

Referring to the drawings, the solar photovoltaic system 10 of FIG. 1 may include a plurality of solar modules 50a, 50b, ..., 50n.

Each of the solar cell modules 50a, 50b, ..., 50n includes a plurality of solar cells, and each of the solar cell modules 100a, 1000b, ..., 100n that generates a DC power, The junction box 200a (100a, 1000b, ..., 100n) is attached to the back surface of the modules 100a, 1000b, ..., 100n and converts direct current power from each of the solar cell modules 100a, , 200b, ..., 200n.

At this time, the junction boxes 200a, 200b, ..., 200n include a power conversion module (see FIG. 6 (a)) for converting DC power from each of the solar cell modules 100a, 1000b, Of 700).

The power conversion module (700 of FIG. 6) may include bypass diodes (Da, Db, Dc), a converter section (530 of FIG. 6), and an inverter section (540 of FIG. 6) have. Such a power conversion module (700 of FIG. 6) may be called a microinverter.

The solar cell modules 100a, 1000b, ..., 100n and the junction boxes 200a, 200b, ..., 100n are connected to the plurality of solar modules 50a, 50b, ..., 50n in the embodiment of the present invention, , ..., 200n), it can be called a solar photovoltaic module.

According to this configuration, by attaching a micro inverter for outputting AC power to each of the solar cell modules 100a, 1000b, ..., 100n, even if the output of any one of the solar cell modules is lowered, The photovoltaic modules 50a, 50b, ..., 50n are connected in parallel to each other to supply AC power generated by the grid (grid).

Unlike the string type in which a plurality of solar modules 50a, 50b, ..., 50n are connected in series, AC power is generated and output independently of each other, and is connected in parallel. Therefore, The AC power can be output to the system stably regardless of the output.

Meanwhile, in the embodiment of the present invention, the transformers of the plurality of interleaving converters in the power conversion module (700 of FIG. 6) include a bobbin including a winding guide portion for forming a hollow and guiding a winding wound on a side surface, A first protrusion formed on the bobbin and having first and second side portions spaced apart from each other and surrounding the bobbin; a second protrusion inserted into the hollow; and third and fourth side portions surrounding the bobbin and spaced from each other A second core coupled to the bobbin together with the first core, and a winding wound around the winding guide portion in the bobbin. As a result, it is possible to perform high-efficiency power conversion at the time of power conversion. This will be described later with reference to FIG.

FIG. 2 is a front view of the solar module according to the embodiment of the present invention, FIG. 3 is a rear view of the solar module of FIG. 2, and FIG. 4 is an exploded perspective view of the solar module of FIG.

2 to 4, a solar module 50 according to an embodiment of the present invention includes a solar cell module 100 and a junction box 200 located on one side of the solar cell module 100 . The solar module 50 may further include a heat dissipating member (not shown) disposed between the solar cell module 100 and the junction box 200.

First, the solar cell module 100 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.

First, the solar cell 130 is a semiconductor device that converts solar energy into electrical energy. The solar cell 130 includes a silicon solar cell, a compound semiconductor solar cell, A tandem solar cell, a dye-sensitized solar cell, or a CdTe or CIGS type solar cell.

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. 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 through fourth conductive lines 135a, 135b, 135c, and 135d, respectively The first to fourth conductive lines 135a, 135b, 135c and 135d are connected to bypass diodes (Da, Db and Dc in Fig. 6) in the junction box 200 arranged on the back surface of the solar cell module 100, Respectively. In the drawing, the first through fourth conductive lines 135a, 135b, 135c, and 135d extend through the openings formed on the solar cell module 100 to the back surface of the solar cell module 100. FIG.

It is preferable that the junction box 200 is disposed closer to an end of the solar cell module 100 where the conductive lines extend.

2 and 3, since the first to fourth conductive lines 135a, 135b, 135c, and 135d extend from the top of the solar cell module 100 to the back surface of the solar cell module 100, ) Is located at the upper part of the back surface of the solar cell module 100. FIG. Thereby, the length of the conductive line can be reduced, and the power loss can be reduced.

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.

The junction box 200 is mounted on the back surface of the solar cell module 100 and can be power-converted using the DC power supplied from the solar cell module 100. Specifically, the junction box 200 may include a power conversion module 700 that converts a DC power source to an AC power source and outputs the AC power.

The power conversion module 700 may include bypass diodes Da, Db, and Dc, a converter unit 530, and an inverter unit 540 on one circuit board. The power conversion module 700 may be called a microinverter.

On the other hand, in order to prevent moisture penetration of the circuit elements in the junction box 200, a coating for preventing moisture permeation may be performed using silicon or the like inside the junction box.

An opening (not shown) is formed in the junction box 200 so that the first to fourth conductive lines 135a, 135b, 135c and 135d are connected to bypass diodes (Da, Db, Dc).

On the other hand, an AC output cable 38 for outputting a power-converted AC power to the outside may be connected to one side of the junction box 200.

Meanwhile, the solar module 50 may include a frame 105 for fixing the outer frame of the solar cell module 10. It is preferable that the thickness h2 of the junction box 200 is smaller than the thickness h1 of the frame 105 so that the junction box 200 does not protrude from the backside.

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

Referring to the drawings, bypass diodes Da, Db, and Dc may be connected corresponding to 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, and is connected to the first solar cell string 140a or the second solar cell string 140b 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 0.6 V generated in a normal solar cell is generated, the potential of the cathode electrode is approximately 12 V (= 0.6 V * 20), as compared with the potential of the anode electrode of the first bypass diode Da Lt; / RTI > That is, the first bypass diode Da operates normally, not bypass.

On the other hand, when a hot spot occurs due to shading or foreign matter adhering to any solar cell of the first solar cell string 140a, the voltage generated in any one solar cell is approximately 0.6V (About -15 V), rather than a voltage of about < / RTI > Accordingly, the potential of the anode electrode of the first bypass diode Da becomes higher by about 15 V than that of the cathode electrode, and the first bypass diode Da performs the bypass operation. Therefore, the voltage generated in the solar cell in the first solar cell string 140a and the second solar cell string 140b is not supplied to the junction box 200. [ In this way, when a reverse voltage generated in some solar cells is generated, it is possible to prevent destruction of the solar cell or the like by bypassing. In addition, except for the hotspot area, it is possible to supply the generated DC power.

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

On the other hand, unlike FIG. 5, six bypass diodes can be connected corresponding to six solar cell strings, and various other modifications are possible.

FIG. 6 is an example of a block diagram of the power conversion module in the junction box of FIG. 2. FIG.

Referring to the drawing, a power conversion module 700 in a junction box may include a bypass diode 510, a converter 530, a capacitor C1, an inverter 540, and a controller 550 have.

The bypass diode unit 510 includes bypass diodes Dc, Db, Da disposed between the first to fourth conductive lines 135a, 135b, 135c, and 135d of the solar cell module 100, . 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 are connected to the first to fourth conductive lines 135a, 135b, 135c and 135d in the solar cell module 50, Power is input. The bypass diodes Dc, Db, and Da can be bypassed when a reverse voltage is generated from a DC power source from at least one of the first through fourth conductive lines 135a, 135b, 135c, and 135d have.

On the other hand, the input power supply Vpv via the bypass diode 510 is input to the converter unit 530.

The converter unit 530 converts the input power supply Vpv output from the bypass diode unit 510. Meanwhile, the converter unit 530 may be called a first power conversion unit.

For example, the converter unit 530 can be converted into a pseudo DC voltage with the DC input power supply Vpv as shown in FIG. 8A. Accordingly, the pseudo DC power can be stored in the capacitor C1. Both ends of the dc short capacitor C1 may be referred to as a dc stage, and the capacitor C1 may be referred to as a dc short capacitor.

As another example, the converter unit 530 can boost the DC input power supply Vpv and convert it to DC power as shown in FIG. 8A. Accordingly, the boosted DC power can be stored in the dc-stage capacitor C1.

The inverter unit 540 can convert the DC power stored in the dc-stage capacitor C1 into the AC power. On the other hand, the inverter unit 540 may be called a second power conversion unit.

For example, the inverter unit 540 can convert the pseudo dc voltage converted in the converter unit 530 to AC power.

As another example, the inverter unit 540 can convert the DC power boosted by the converter unit 530 to AC power.

On the other hand, the converter unit 530 preferably includes a plurality of interleaving converters for pseudo DC voltage conversion or step-up DC power supply conversion.

In particular, in the embodiment of the present invention, it is assumed that the converter section 530 includes three or more interleaving converters.

In the figure, n converters 610a, 610b, ... 610n are connected in parallel to each other. the energy conversion capacities of the n converters 610a, 610b, ... 610n may be the same.

The current by the DC input power supply Vpv becomes 1 / N in the n converters 610a, 610b, ... 610n, and at the output terminals of the n converters 610a, 610b, ... 610n, The output currents of the respective converters are combined into one.

The current phase of each of the n converters 610a, 610b, ... 610n is interleaved with a reference phase contrast of + 360 ° / N (610a, 610b, ... 610n) ), - (360 [deg.] / N) or close to the phase delay.

As described above, when the n converters are interleaved, the ripple of the input current and the output current of the converter section 530 is reduced, and accordingly, the capacity and size of the circuit elements in the power conversion module 700 are reduced There are advantages. Accordingly, the thickness of the junction box can be made smaller than the thickness of the frame 105 of the solar cell module.

On the other hand, as the interleaving converter, a tap inductor boost converter, a flyback converter, or the like can be used.

7A is an example of an internal circuit diagram of the power conversion module of FIG.

The power conversion module 700 includes a bypass diode 510, a converter 530, a dc capacitor C1, an inverter 540, a controller 550, and a filter 560 ).

Figure 7A illustrates a tapped-inductor boost converter with an interleaved converter. In the figure, the converter section 530 includes a first tap inductor boost converter to third tap inductor boost converters 611a, 611b, ..., 611c.

The bypass diode section 510 is connected to the first to fourth conductive lines 135a, 135b, 135c and 135d arranged between the respective angles of the a-node, b-node, c- And third bypass diodes Da, Db, and Dc.

The converter unit 530 can perform power conversion using the DC power supply Vpv output from the bypass diode unit 510. [

In particular, the first tap inductor boost converter to the third tap inductor boost converters 611a, 611b, ..., 611c output the converted DC power to the dc-stage capacitor C1 by the interleaving operation.

The first tap inductor boost converter 611a includes a tap inductor T1, a switching element S1 connected between the tap inductor T1 and the ground terminal, and a switching element S1 connected between the output terminal of the tap inductor and conducting one- And a diode D1. On the other hand, a dc short capacitor C1 is connected between the output terminal of the diode D1, that is, between the cathode and the ground terminal.

Specifically, the switching element S1 can be connected between the taps of the tap inductor T and the ground terminal. The output terminal (secondary side) of the tap inductor T is connected to the anode of the diode D1 and the dc-side capacitor C1 is connected between the cathode of the diode D1 and the ground terminal do.

On the other hand, the primary side and the secondary side of the tap inductor T have opposite polarities. On the other hand, the tap inductor T may be referred to as a switching transformer.

On the other hand, the primary side and the secondary side of the tap inductor T are connected to each other as shown in the drawing. Thereby, the tap inductor boost converter can be a non-insulated type converter.

On the other hand, when the three tap inductor boost converters 611a, 611b and 611c are connected in parallel to each other and driven by an interleaving method, the input current components are branched in parallel. Therefore, each tap inductor boost converter 611a, 611b, and 611c are reduced.

On the other hand, each of the tap inductor boost converters 611a, 611b, and 611c can adaptively operate in response to the power required value of the output AC power.

For example, when only the first converter 611a operates, or when the power required value is approximately 190W to 230W, only the first and second converters 611a and 611b operate or the power If the required value is approximately 290 W to 330 W, both of the first to third interleaved converters 611a, 611b, and 611c may operate. That is, each of the tap inductor boost converters 611a, 611b, and 611c can selectively operate. This optional operation can be controlled by the control unit 550. [

The inverter unit 540 converts the level-converted DC power from the converter unit 530 into AC power. In the drawing, a full-bridge inverter is illustrated. Namely, the upper and lower arm switching elements Sa and Sb connected in series to each other and the lower arm switching elements S'a and S'b are paired, and two pairs of upper and lower arm switching elements are connected in parallel to each other (Sa & Sb & S'b). Diodes are connected in anti-parallel to each switching element Sa, S'a, Sb, S'b.

The switching elements in the inverter unit 540 perform a turn-on / off operation based on an inverter switching control signal from the control unit 550. [ As a result, AC power having a predetermined frequency is output. Preferably, it has a frequency (approximately 60 Hz or 50 Hz) that is equal to the alternating frequency of the grid.

The filter unit 560 performs smooth understanding of the AC power output from the inverter unit 540 and performs low pass filtering. To this end, in the figure, the inductors Lf1 and Lf2 are exemplified, but various examples are possible.

The converter input current sensing unit A senses the input current ic1 input to the converter unit 530 and the converter input voltage sensing unit B senses the input voltage ic1 input to the converter unit 530 vc1. The sensed input current ic1 and the input voltage vc1 may be input to the control unit 550. [

Meanwhile, the converter output current sensing unit C senses the output current ic2 output from the converter unit 530, that is, the dc step current, and the converter output voltage sensing unit D receives the output current ic2 from the converter unit 530 And detects the output voltage 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 sensing unit E senses the current ic3 output from the inverter unit 540 and the inverter output voltage sensing unit F outputs the voltage vc3 output from the inverter unit 540, Lt; / RTI > The detected current ic3 and the voltage vc3 are input to the control unit 550. [

On the other hand, the control unit 550 can output a control signal for controlling the switching element S1 of the converter unit 530 in Fig. In particular, the control unit 550 controls the control unit 550 so that the output voltage vc2 is 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, On timing signal of the switching element S1 in the converter unit 530 can be output.

The control unit 550 may also output an inverter control signal for controlling each of the switching elements Sa, S'a, Sb, S'b of the inverter unit 540. In particular, the control unit 550 controls the control unit 550 so that the output voltage vc2 is 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, On timing signals of the respective switching elements Sa, S'a, Sb, S'b of the inverter unit 540 can be outputted based on the above-described signals.

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

7B is another example of the internal circuit diagram of the power conversion module of FIG.

The power conversion module 700 of FIG. 7B includes a bypass diode 510, a converter 530, a dc capacitor C1, an inverter 540, A control unit 550, and a filter unit 560.

However, FIG. 7B illustrates a flyback converter as an interleaving converter in the converter unit 530. FIG. In the figure, it is exemplified that the converter section 530 includes first to third flyback converters 612a, 612b, ..., 612c.

In particular, the first flyback converter to the third flyback converters 612a, 612b, ..., 612c are of an insulation type, unlike the non-insulation type tap inductor boost converter, To the dc-stage capacitor C1.

The first flyback converter 612a includes a transformer T11, a switching element S11 connected between the primary side and the ground terminal of the transformer T11, and a secondary side connected to the secondary side of the transformer T11, And a diode D11 for performing the operation. On the other hand, the dc short capacitor C1 is connected between the output terminal of the diode D11, that is, between the cathode and the ground terminal. On the other hand, the primary side and the secondary side of the transformer T11 have opposite polarities.

8A and 8B are diagrams illustrating an operation method of the power conversion module of FIG.

8A, the converter unit 530 of the power conversion module 700 according to the embodiment of the present invention converts a DC power from the solar cell module 100 into a pseudo DC voltage Can be converted.

7A, when the converter section 530 is a tap inductor boost converter or when the converter section 530 is a flyback converter as shown in FIG. 7B, by switching on / off of the switching element S1 or S11, And can be converted into a pseudo dc voltage having an envelope such as a direct current power source. Accordingly, the pseudo DC power can be stored in the capacitor C1.

Meanwhile, the inverter 540 receives a pseudo DC voltage, performs a switching operation, and outputs the AC power. Specifically, a pseudo DC voltage having an envelope such as a full-wave rectified DC power can be converted into an AC power having + and -, and output. In particular, it can be converted into AC power corresponding to the grid frequency and output.

8B, the converter unit 530 of the power conversion module 700 according to the embodiment of the present invention level-converts the DC power from the solar cell module 100, specifically boosts the DC power, It can be converted into a boosted DC power source.

7A, when the converter section 530 is a tap inductor boost converter or when the converter section 530 is a flyback converter as shown in FIG. 7B, by switching on / off of the switching element S1 or S11, (Vp) can be converted to the boosted DC power. Accordingly, the boosted DC power can be stored in the capacitor C1.

The inverter 540 receives the boosted DC power, performs a switching operation, and outputs the AC power. In particular, it can be converted into AC power corresponding to the grid frequency and output.

9A to 9B are diagrams for explaining the operation of the tap inductor boost converter of FIG. 7A.

The operation of the first tap inductor boost converter 611a will be briefly described. When the switching element S1 is turned on, the input voltage Vpv, the primary side of the tap inductor T1, And a closed loop through the switching element S1 are formed, and the first current I1 flows on the closed loop. At this time, since the secondary side of the tap inductor T1 has a polarity opposite to that of the primary side, the diode D1 can not be turned on and is turned off. As a result, the energy due to the input voltage Ppv is stored in the primary side of the tapped inductor T1.

Next, when the switching element S1 is turned off, the input voltage Vpv, the primary side, the secondary side, and the diode D1 of the tap inductor T1, and the capacitor C1, And a second current I2 flows on the closed loop. That is, since the secondary side of the tap inductor T1 has the opposite polarity to the primary side, the diode D1 becomes conductive. Accordingly, the input voltage Ppv, the energy stored in the primary side and the secondary side of the tap inductor T1 can be stored in the capacitor C1 via the diode D1.

As described above, the converter section 530 can output a pseudo direct current power source or a high efficiency and high voltage direct current power source by using the input voltage Ppv and the energy stored in the primary side and the secondary side of the tapped inductor Tl .

FIGS. 10A and 10B are diagrams for explaining output of a pseudo direct current power source using an input power source in the converter unit of FIG. 6;

6 and 10A, the first to third interleaved converters 610a, 610b, and 610c in the converter unit 530 output a pseudo DC power source using a DC input power source Vpv.

Specifically, the converter unit 530 outputs a pseudo direct current power source having a peak value of approximately 330 V by using a direct current power source of approximately 32 V to 36 V from the solar cell module 100.

The control unit 550 controls the duty ratio of the switching elements of the first to third interleaved converters 610a, 610b, and 610c based on the detected input power supply Vpv and the detected output power supply Vdc .

In particular, the lower the input voltage Vpv, the greater the duty of the switching elements of the first through third interleaved converters 610a, 610b, 610c, and the higher the input voltage Vpv, the smaller the duty of the switching element .

On the other hand, the lower the target output power supply Vdc, the smaller the duty of the switching elements of the first to third interleaved converters 610a, 610b, and 610c, and the higher the target output power supply Vdc, . For example, when the target output power supply Vdc is about 330 V, which is the peak value, the duty of the switching element can be greatest.

In Fig. 10A, the pseudo DC power supply waveform Vslv to be outputted is exemplified by such a duty variable, and this pseudo DC power supply waveform exemplifies that it follows the target sine waveform Vsin.

On the other hand, in the present invention, the switching frequency of the converter section 530 is varied so that the pseudo DC power supply waveform Vslo more accurately follows the full-wave rectified waveform Vsin.

The error DELTA E2 between the pseudo direct current power source waveform Vslf and the target sine waveform Vsin when the switching frequency of the converter section 530 is fixed is smaller than the error DELTA E2 between the pseudo direct current power source waveform Vslf and the target sine waveform Vsin, Becomes larger than the error DELTA E1 between the pseudo direct current power supply waveform Vslv and the target sine waveform Vsin when the switching frequency of the pseudo direct current power supply Vslv is varied.

In the present invention, in order to reduce such an error, the switching frequency of the converter section 530 is varied. That is, the switching frequency of the switching elements of the first to third interleaved converters 610a, 610b, and 610c is varied.

The control unit 550 sets the switching frequency of the converter unit 530 to be larger as the rate of change of the target sinusoidal waveform Vsin becomes larger, that is, the switching period becomes shorter as the rate of change of the target sinusoidal waveform Vsin becomes smaller So that the switching frequency of the converter unit 530 is reduced, that is, the switching period is increased.

10A, the switching period is set to Ta in the rising section of the target sinusoidal waveform Vsin, and the switching period is set to be Tb, which is larger than Ta, in the peak section of the target sinusoidal waveform Vsin . That is, it is illustrated that the switching frequency corresponding to the switching period Ta is higher than the switching frequency corresponding to the switching period Tb. This makes it possible to reduce the error DELTA E1 between the pseudo DC power supply waveform Vslv and the target sine waveform Vsin.

On the other hand, for the switching frequency variable of FIG. 10A, it is also possible to describe the switching mode technique of the switching device.

11 is a diagram showing an example of a converter section.

Referring to the drawing, the converter section includes a transformer 1110 for converting the input voltage 1100 according to the switching operation of the switching element S by the ratio of the primary winding and the secondary winding, and a transformer 1110 connected to the secondary winding And a capacitor C for storing the converted power source.

 The transformer 1110 of FIG. 11 may be a transformer in the tap inductor boost converter of FIG. 7A, or a transformer in the flyback converter of FIG. 7B.

At this time, the turns ratio of the primary side and the secondary side of the transformer 1110 may be 1: 4, and the number of turns may be 4 times and 20 times, respectively. Depending on the winding ratio and the number of windings, the secondary side voltage is boosted to about four times that of the primary side voltage. Accordingly, the tap inductor boost converter operates as a boost converter capable of voltage boosting.

FIG. 12 is a perspective view of a bobbin in a transformer according to an embodiment of the present invention, and FIGS. 13 to 17 are views referred to the explanation of FIG.

12, the bobbin of the transformer may include a winding guide portion 1317 for forming a hollow and guiding a winding 1610 wound on a side surface thereof.

The bobbin 1310 includes at least one first connection terminal 1359 disposed in the output direction of the primary winding 1610 and electrically connected to the circuit board and a second connection terminal 1359 disposed in the output direction of the secondary winding 1610 And at least one second connection terminal 1349 electrically connected to the circuit board.

The bobbin 1310 has an elliptical upper frame 1314 having a hollow shape and an elliptical lower frame 1315 spaced apart from the upper frame and having a hollow shape. The upper frame 1314 and the lower frame 1315, The winding guide portion 1317 can be disposed.

The bobbin 1310 may further include first and second projections 1316 and 1318 for guiding the winding 1610 on the upper frame 1314.

At this time, the first and second projections 1316 and 1318 may be disposed at positions corresponding to the connection terminals 1349 and 1359. I. E., On the upper frame 1314, at the location of the smallest radius of curvature. As a result, the winding can be guided when the winding is wound.

15, on the other hand, the winding 1610 includes a primary winding C01 and a secondary winding CO2. At this time, the primary winding C01 and the secondary winding CO 2 are insulated from each other, and an insulating layer can be disposed therebetween.

In the figure, the output direction of the primary winding C01 wound around the winding guide portion 1317 and the output direction of the secondary winding 1610 are different from each other. As a result, they can be connected to circuit elements, respectively.

On the other hand, it is preferable that the thickness of the primary winding 1610 is thicker than the thickness of the secondary winding (CO 2) according to the winding ratio.

13 to 14, the length between the hollow center Po and the first connection terminal 1359, the center of the hollow Po and the second connection terminal 1349 May be designed to have different lengths.

On the other hand, the winding ratio of the primary winding C01 and the secondary winding CO 2 is 1: 4, and the number of windings is 4 and 20, respectively. Depending on the winding ratio and the number of windings, the secondary side voltage is boosted to about four times that of the primary side voltage. Accordingly, the tap inductor boost converter operates as a boost converter capable of voltage boosting.

Next, referring to Figs. 13 to 14, the length (le1) between the hollow center Po and the first connection terminal 1359, the length between the center Po of the hollow and the second connection terminal 1349 (le2) is longer.

For example, the length le1 between the hollow center Po and the first connection terminal 1359 may be approximately 20 to 21 mm, and the length between the hollow center Po and the second connection terminal 1349 The length le2 may be approximately 25 to 22 mm.

On the other hand, the length (Le3) between the hollow center Po and the side of the bobbin in the direction of the first connection terminal 1359 is larger than the length Le3 between the center of the hollow Po and the side of the bobbin in the direction of the second connection terminal 1349 It is preferable that the length le4 is longer.

For example, the length le3 between the hollow center Po and the side surface of the bobbin in the direction of the first connection terminal 1359 may be approximately 19 to 20 mm, and the center of the hollow Po and the second connection The length le4 between the sides of the bobbin in the direction of the terminal 1349 may be approximately 20 to 21 mm.

The height of the transformer can be lowered due to the structure of the bobbin. Therefore, in consideration of the thickness h1 of the frame 105 of the photovoltaic module shown in Fig. 3, the power converter, that is, the junction box 200 Can be designed to be smaller.

Figure 16 illustrates a first core 1710 having first protrusions 1705 inserted into the hollow and first and second side portions 1707, 1708 surrounding and spaced from each other. Here, the first core 1710 may be a lower core coupled with the bobbin 1310.

The first side portion 1707 may include bent portions 1707a and 1707c that are bent at both sides of the straight portion 1707b and the straight portion 1707b and the second side portion 1708 may include a straight portion 1708b And bent portions 1708a and 1708c bent at both sides of the straight portion 1708b.

Figure 17 illustrates a transformer 1800 in which a second core 1720 corresponding to a first core 1710 is coupled to a bobbin 1310 together with a first core 170. [

The second core 1720 has a structure corresponding to the first core 1710 as an upper core.

A second projection to be inserted into the hollow, and third and fourth side portions surrounding the bobbin 1310 and spaced apart from each other.

On the other hand, the first connection terminals 1349 and 1347 are electrically connected to the circuit board 1900, and the second connection terminals (not shown) are also electrically connected to the circuit board 1900.

According to the structure of the transformer 1800, the height, that is, the thickness can be designed to be about 15 mm or less, while the power conversion efficiency can be 96% or more, as compared with the conventional structure. This enables high-efficiency power conversion.

And the primary inductance may be approximately 10 to 20 uH and the secondary inductance may be approximately 350 to 400 uH.

The transformer according to the present invention and the power conversion apparatus having the transformer according to the present invention are not limited to the configuration and the method of the embodiments described above but the embodiments can be applied to all or some of the embodiments Some of which may be selectively 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 details may be made therein without departing from the spirit and scope of the present invention.

Claims (17)

A bobbin having a hollow portion and including a winding guide portion for guiding a winding wound on a side surface;
A first core having first projections inserted into the hollow and first and second side portions surrounding the bobbin and spaced apart from each other;
A second core coupled to the bobbin with the first core and having a second projection inserted into the hollow, and third and fourth side portions surrounding the bobbin and spaced apart from each other; And
And a winding wound around the winding guide portion in the bobbin. The method according to claim 1,
Wherein a winding ratio of the primary winding and the secondary winding in the winding is 1: 4, and each winding is 4 times and 20 times. The method according to claim 1,
Wherein the height of the transformer is 15 mm or less. The method according to claim 1,
The winding,
A primary side winding, and a secondary side winding,
And the output direction of the primary winding wound on the winding guide portion is different from the output direction of the secondary winding. 5. The method of claim 4,
The bobbin
At least one first connection terminal disposed in the output direction of the primary winding and electrically connected to the circuit board; And
And at least one second connection terminal disposed in the output direction of the secondary winding and electrically connected to the circuit board. 6. The method of claim 5,
Wherein a length between the center of the hollow and the second connection terminal is longer than a length between the center of the hollow and the first connection terminal. 7. The method according to any one of claims 4 to 6,
Wherein a thickness of the primary winding is larger than a thickness of the secondary winding. The method according to claim 1,
The bobbin
Further comprising first and second elliptically shaped frames formed with hollows,
And the winding guide portion is disposed between the first and second frames. The method according to claim 1,
The bobbin
Further comprising first and second projections formed on the first frame for guiding the windings. A converter unit for converting DC power from the solar cell module;
A control unit for controlling the converter unit; And
And a capacitor for storing a voltage output from the converter unit,
The converter unit includes:
A switching element, a transformer for performing power conversion by switching operation of the switching element, and a diode element disposed at an output terminal of the transformer,
Wherein the transformer comprises:
A bobbin having a hollow portion and including a winding guide portion for guiding a winding wound on a side surface;
A first core having first projections inserted into the hollow and first and second side portions surrounding the bobbin and spaced apart from each other;
A second core coupled to the bobbin with the first core and having a second projection inserted into the hollow, and third and fourth side portions surrounding the bobbin and spaced apart from each other; And
And a winding wound around the winding guide portion in the bobbin. 11. The method of claim 10,
Wherein the turns ratio of the primary winding and the secondary winding in the winding is 1: 4, and each turn is 4 times and 20 times. 11. The method of claim 10,
And the height of the transformer is 15 mm or less. 11. The method of claim 10,
Wherein the converter section includes a tap inductor boost converter including the transformer. 14. The method according to claim 10 or 13,
The converter unit includes:
A plurality of interleaving converters,
And each of the interleaving converters includes the transformer. 11. The method of claim 10,
An inverter unit for outputting an AC power using a voltage stored in the capacitor; And
And a filter unit for filtering and outputting the AC power from the inverter unit. 11. The method of claim 10,
The winding includes a primary winding and a secondary winding,
The bobbin
At least one first connection terminal disposed in the output direction of the primary winding and electrically connected to the circuit board; And
And at least one second connection terminal disposed in an output direction of the secondary winding and electrically connected to the circuit board. 17. The method of claim 16,
Wherein a length between the center of the hollow and the second connection terminal is longer than a length between the center of the hollow and the first connection terminal.

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