Solar cell apparatus

Provided is a solar cell apparatus. The solar cell apparatus includes: a substrate; a first cell group on the substrate; a second cell group on the substrate; a first diode connected in parallel to the first cell group; and a second diode connected in parallel to the second cell group.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. national stage application of International Patent Application No. PCT/KR2010/006706, filed Sep. 30, 2010, which claims priority to Korean Application No. 10-2009-0093636, filed Sep. 30, 2009 and Korean Application No. 10-2009-0093622, filed Sep. 30, 2009, the disclosures of each of which are incorporated herein by reference in their entirety.

TECHNICAL FIELD

The present disclosure relates to a solar cell apparatus.

BACKGROUND ART

A solar battery generates photoelectro-motive force using a plurality of P-N junction cells. The plurality of P-N junction cells are connected in the form of a module according to capacity and a plurality of modules having a predetermined capacity are connected in series or parallel in a circuit to constitute an array.

A solar cell system requires almost no more future maintenance costs once the initial investment costs are collected and also has no moving parts so that energy is supplied with less mechanical defects.

In general, in order to supply electricity generated from a solar battery module to a system, the minimum group of a plurality of battery cells in series is electrically connected to a junction box through a bus bar.

However, if a solar battery panel is shaded by an external object or is covered by impurity or foreign substance, a shaded or covered cell becomes overloaded and overheated.

DISCLOSURE

Technical Problem

Embodiments provide a solar cell apparatus having improved efficiency of electricity generation.

Technical Solution

In one embodiment, a solar cell apparatus includes:

a substrate;

a first cell group on the substrate;

a second cell group on the substrate;

a first diode connected in parallel to the first cell group; and

a second diode connected in parallel to the second cell group.

In another embodiment, a solar cell apparatus includes:

a substrate;

a first cell group on the substrate;

a second cell group on the substrate; and

an error detection unit detecting at least one error from the first cell group and the second cell group.

In further another embodiment, a solar cell apparatus includes:

a substrate;

a first cell group on the substrate;

a second cell group on the substrate;

a junction box attached to the substrate;

a first bus bar connected to the first cell group and extending to the junction box;

a connection electrode connected to the first cell group and the second cell group and extending to the junction box; and

a second bus bar connected to the second cell group and extending to the junction box.

Advantageous Effects

In a solar cell apparatus according to an embodiment, a plurality of cell groups are disposed on a substrate. Additionally, in relation to a solar cell apparatus according to an embodiment, bus bars and connection electrodes are connected to cell groups, respectively, so that the cell groups may be separately driven.

That is, in relation to a solar cell apparatus according to an embodiment, a diode is connected in parallel to each of cell groups, so that each of the cell groups may generate power separately. That is, when a first cell group cannot generate power due to shadow, a current formed by a second cell group may flow through a first diode. That is, the disabled first cell group may not affect the second cell group.

Additionally, a solar cell apparatus according to an embodiment may include an error detection unit for detecting errors of cell groups. Especially, a solar cell apparatus according to an embodiment may detect an error in each cell group.

Like this, in relation to a solar cell apparatus according to an embodiment, each cell group is separately driven and an error thereof may be easily detected. Accordingly, in relation to a solar cell apparatus according to an embodiment, even when there are some disabled cell groups, the entire cell groups may not be disabled and some of the cell groups are still driven. Additionally, a solar cell apparatus according to an embodiment may easily detect cell groups having detected errors and its situation may be resolved promptly.

Accordingly, a solar cell apparatus according to an embodiment prevents the deterioration of photoelectric conversion efficiency and thus improves the photoelectric conversion efficiency.

Additionally, a solar cell apparatus according to an embodiment may include a power supply unit to provide power to an error detection unit by itself. Additionally, a solar cell apparatus according to an embodiment may easily transmit signals detected through a signal output unit to external.

BEST MODEL

In the description of embodiments, it will be understood that when a substrate, layer, film, or electrode is referred to as being ‘on’ or ‘under’ another substrate, layer, film, or electrode, the terminology of ‘on’ and ‘under’ includes both the meanings of ‘directly’ and ‘indirectly’. Further, the reference about ‘on’ and ‘under’ each component will be made on the basis of drawings. In addition, the sizes of elements and the relative sizes between elements may be exaggerated for further understanding of the present disclosure.

FIG. 1is a plan view of a solar battery module according to a first embodiment.FIG. 2is a sectional view taken along the line0-0′ ofFIG. 1.FIG. 3is a sectional view taken along the line I-I′ ofFIG. 1.FIG. 4is a view of a current path when a second cell group does not operate.FIG. 5is a plan view illustrating the rear side of a solar battery module according to a first embodiment.

Referring toFIGS. 1 to 5, the solar battery module according to the first embodiment includes a substrate100, a plurality of cell groups CU1, CU2, and CU3, a plurality of connection electrodes810,710,720,730,740,750, and820, a plurality of diodes D1, D2, and D3, and a junction box800.

The substrate100supports the plurality of cell groups CU1, CU2, and CU3, the plurality of connection electrodes810,710,720,730,740,750, and820, the plurality of diodes D1, D2, and D3, and the junction box800. The substrate100may have a plate shape. The substrate100may be an electrical insulator. The substrate100may be a glass substrate, a plastic substrate, or a stainless steel substrate. In more detail, the substrate100may be a soda lime glass substrate.

The cell groups CU1, CU2, and CU3are disposed on the substrate100. The cell groups CU1, CU2, and CU3may be connected in series to each other. Additionally, each of the cell groups CU1, CU2, and CU3may include a plurality of cells connected in series to each other. For example, the cell groups may include a first cell group CU1, a second cell group CU2, and a third cell group CU3.

The first cell group CU1includes first cells A11and second cells A22.

The number of the first cells A11may be N. The first cells A11are connected in series to each other. Additionally, the first cells A11may be disposed in a first column. A current generated in the first cells A11may flow in a first direction.

The number of the second cells A22may be N. The second cells A22are connected in series to each other. Additionally, the second cells A22may be disposed in a second column. At this point, a current generated in the second cells A22may flow in a second direction opposite to the first direction.

Additionally, the first cells A11may be connected in series to the second cells A22. That is, the first cells A11and the second cells A22are connected in series to each other.

The second cell group CU2includes third cells A33and fourth cells A44.

The number of the third cells A33may be N. The third cells A33are connected in series to each other. Additionally, the third cells A33may be disposed in a third column. A current generated in the third cells A33may flow in the first direction.

The number of the fourth cells A44may be N. The fourth cells A44are connected in series to each other. Additionally, the fourth cells A44may be disposed in a fourth column. At this point, a current generated in the fourth cells A44may flow in the second direction opposite to the first direction.

Additionally, the third cells A33may be connected in series to the fourth cells A44. That is, the third cells A33and the fourth cells A44are connected in series to each other.

The third cell group CU3includes fifth cells A55and sixth cells A66.

The number of the fifth cells A55may be N. The fifth cells A55are connected in series to each other. Additionally, the fifth cells A55may be disposed in a fifth column. A current generated in the fifth cells A55may flow in the first direction.

The number of the sixth cells A66may be N. The sixth cells A66are connected in series to each other. Additionally, the sixth cells A66may be disposed in a sixth column. At this point, a current generated in the sixth cells A66may flow in the second direction opposite to the first direction.

Additionally, the fifth cells A55may be connected in series to the sixth cells A66. That is, the fifth cells A55and the sixth cells A66are connected in series to each other.

The connection electrodes810,710,720,730,740,750, and820are conductors. The connection electrodes810,710,720,730,740,750, and820may be formed of a material (for example, a metal having low resistance such as copper or silver).

The connection electrodes810,710,720,730,740,750, and820connect the cell groups CU1, CU2, and CU3. Additionally, the connection electrodes810,710,720,730,740,750, and820may connect the cells A11to A66in each column. Additionally, the connection electrodes810,710,720,730,740,750, and820may connect the cell groups CU1, CU2, and CU3to wirings connected to an external charging device or an adjacent solar battery module.

The connection electrodes may be a first bus bar810, a first connection electrode710, a second connection electrode720, a third connection electrode730, a fourth connection electrode740, a fifth connection electrode750, and a second bus bar820.

The first bus bar810is connected to the first cells A11. In more detail, the first bus bar810may directly contact the last cell101of the first cells A11. The first bus bar810may be connected to a wiring connected to an external device.

The first bus bar810extends from the last cell101of the first cells A11to the junction box800. That is, the first bus bar810extends from the top side of the substrate100to the rear side.

The first connection electrode710connects the first cells A11and the second cells A22. In more detail, the first connection electrode710connects the first cell102of the first cells A11and the first cell103of the second cells A22.

Additionally, as shown inFIGS. 2 and 3, the first cells A11may have a symmetric structure to the second cells A22. That is, the first connection electrode710is connected to the front electrode of the first cell102of the first cells A11and is connected to the back electrode of the first cell103of the second cells A22. That is, the first connection electrode710connects the respectively different electrodes of the first cell102of the first cells A11and the first cell103of the second cells A22.

In the same manner, the first bus bar810may be connected to the back electrode of the last cell101of the first cells A11and may be connected to the front electrode of the last cell104of the second cells A22.

The second connection electrode720connects the first cell group CU1and the second cell group CU2. In more detail, the second connection electrode720connects the second cells A22and the third cells A33. In more detail, the second connection electrode720connects the last cell104of the second cells A22and the last cell of the third cells A33.

The second connection electrode720extends from the top side of the substrate100to the rear side. That is, the second connection electrode720extends from the second cells A22and the third cells A33to the junction box800.

The third connection electrode730connects the third cells A33and the fourth cells A44. In more detail, the third connection electrode730connects the first cell of the third cells A33and the first cell of the fourth cells A44. That is, the third connection electrode730contacts the first cell of the third cells A33and the first cell of the fourth cells A44.

The fourth connection electrode740connects the second cell group CU2and the third cell group CU3. In more detail, the fourth connection electrode740connects the fourth cells A44and the fifth cells A55. In more detail, the second connection electrode740connects the last cell of the fourth cells A44and the last cell of the fifth cells A55.

The fourth connection electrode740extends from the top side of the substrate100to the rear side. That is, the fourth connection electrode740extends from the fourth cells A44and the fifth cells A55to the junction box800.

The fifth connection electrode750connects the fifth cells A55and the sixth cells A66. In more detail, the fifth connection electrode750connects the first cell of the fifth cells A55and the first cell of the sixth cells A66. That is, the fifth connection electrode750contacts the first cell of the fifth cells A55and the first cell of the sixth cells A66.

The second bus bar820is connected to the sixth cells A66. In more detail, the second bus bar820may directly contact the top side of the last cell of the sixth cells A66. The second bus bar820may be connected to a wiring connected to an external device.

The second bus bar820extends from the last cell of the sixth cells A66to the junction box800. That is, the second bus bar820extends from the top side of the substrate100to the rear side. At this point, the first bus bar810may be connected to a (+) output terminal and the second bus bar820may be connected to a (−) output terminal.

The diodes D1, D2, and D3are separately connected to the connection electrodes810,710,720,730,740,750, and820. The diodes D1, D2, and D3are disposed on the rear side of the substrate100. The diodes D1, D2, and D3are disposed in the junction box800.

The diodes D1, D2, and D3may be a first diode D1, a second diode D2, and a third diode D3.

The first diode D1is connected in parallel to the first cell group CU1. In more detail, the first diode D1is connected to the first bus bar810and the second connection electrode720. That is, one terminal of the first diode D1is connected to the first bus bar810and the other terminal is connected to the second connection electrode720.

When the first cell group CU1is disabled, a current generated in the second group CU2and the third cell group CU3may detour via the first diode D1.

The second diode D2is connected in parallel to the second cell group CU2. In more detail, the second diode D2is connected to the second connection electrode720and the third connection electrode730. That is, one terminal of the second diode D2is connected to the second connection electrode720and the other terminal is connected to the third connection electrode730.

When the second cell group CU2is disabled, a current generated in the first group CU1and the third cell group CU3may detour via the second diode D2.

The third diode D3is connected in parallel to the third cell group CU3. In more detail, the third diode D3is connected to the third connection electrode730and the second bus bar820. That is, one terminal of the third diode D3is connected to the third connection electrode730and the other terminal is connected to the second bus bar820.

When the third cell group CU3is disabled, a current generated in the first group CU1and the second cell group CU2may detour via the third diode D3.

As shown inFIG. 5, the junction box800is attached to the substrate100. In more detail, the junction box800may be attached to the rear side of the substrate100. The junction box800receives the diodes D1, D2, and D3. The junction box800may receive a circuit substrate100that the diodes D1, D2, and D3, the first bus bar810, the second connection electrode720, the fourth connection electrode740, and/or the second bus bar820contact.

A solar battery module according to an embodiment may operate overall even when some of the cell groups CU1, CU2, and CU3are disabled. For example, as shown inFIG. 5, when a part or all of the third cells A33are disabled or defective due to shadow or foreign substance, the second cell group CU2may not generate power.

At this point, a current generated in the first group CU1and the third cell group CU3may detour via the second diode D2. That is, a current generated in the first group CU1and the third cell group CU3may flow through the second bus bar820, the third cell group CU3, the second diode D2, the third cell group CU1, and the first bus bar810.

Accordingly, the solar battery module may separately drive each of the cell groups CU1, CU2, and CU3and overall performance deterioration caused when some cell groups are disabled may be prevented.

Accordingly, the solar battery module according to an embodiment may have improved photoelectric conversion efficiency.

FIGS. 6 to 18are views illustrating manufacturing processes of a solar battery module according to a first embodiment.FIGS. 7 to 18are sectional views taken along the lines0-0′ and I-I′ ofFIG. 6. Description for this manufacturing method will refer to that for the above-mentioned solar battery module. That is, the description for the above solar battery module may be substantially combined to that for this manufacturing method.

Referring toFIG. 6, provided is a substrate100including a first area A1, a second area A2, a third area A3, a fourth area A4, a fifth area A5, and a sixth area6.

The substrate100is formed of glass and may include a ceramic (such as alumina) substrate100, a stainless steel or titanium substrate100, or a polymer substrate100.

The glass substrate100may be formed of soda lime glass and the polymer substrate100may be formed of polyimide.

Additionally, the substrate100may be rigid or flexible.

The N number of cells may be formed in each of the first area A1, the second area A2, the third area A3, the fourth area A4, the fifth area A5, and the sixth area6.

FIGS. 7 to 18are sectional views taken along the lines0-0′ and I-I′ ofFIG. 6. The first area A1, the third area A3, and the fifth area A5are formed with the same shape and the second area A2, the fourth area A4, and the sixth area A6are formed with the same shape. Therefore, only the sectional view of the first area A1and the second area A2will be shown.

As shown inFIGS. 7 and 8, a back electrode pattern200is formed on the substrate100. The back electrode pattern200includes a plurality of back electrodes. The back electrode pattern200is formed after a back electrode layer is formed on the substrate100and a photo-lithography process is performed to pattern the back electrode layer.

Or, after a mask is disposed on the substrate100, the back electrode pattern200may be formed in each area. The back electrode pattern200may be formed of a conductor such as metal.

For example, the back electrode pattern200may be formed using a Mo target through a sputtering process. This is because Mo has high electrical conductivity, ohmic contact with a light absorbing layer, and high temperature stability under Se atmosphere.

Additionally, although not shown in the drawings, the back electrode pattern200may be formed with at least one layer. When the back electrode pattern200is formed with a plurality of layers, layers constituting the back electrode pattern200may be formed of respectively different materials.

Additionally, the back electrode pattern200may be disposed with a stripe shape or a matrix shape and may correspond to each cell. However, the back electrode pattern200is not limited to the above shape and may be formed with various shapes.

Later, referring toFIGS. 9 and 10, a light absorbing layer300and a buffer layer400are formed on the back electrode pattern200.

The light absorbing layer300includes a Group I-III-VI based compound. In more detail, the light absorbing layer300includes a Cu(In, Ga)Se2based (CIGS based) compound.

For example, in order to form the light absorbing layer300, a CIG based metal precursor layer is formed on the back electrode pattern200by using a Cu target, an In target, and a Ga target. Later, after a reaction of the metal precursor layer and Se is completed through a selenization process, a CIGS based light absorbing layer is formed.

Additionally, during the metal precursor layer forming process and the selenization process, an alkali element in the substrate100is diffused into the metal precursor layer and the light absorbing layer300through the back electrode pattern200. The alkali element improves the grain size and crystallization of the light absorbing layer300.

Additionally, the light absorbing layer300may be formed using Cu, In, Ga, and Se through co-evaporation.

The light absorbing layer300receives external incident light and converts it to electric energy. The light absorbing layer300generates photoelectron-motive force through photoelectric effect.

The buffer layer400may be formed of at leas one layer and may be formed by stacking at least one of CdS, ITO, ZnO, and i-ZnO on the substrate100having the light absorbing layer300.

At this point, the buffer layer400is an n-type semiconductor layer and the light absorbing layer300is a p-type semiconductor layer. Accordingly, the light absorbing layer300and the buffer layer400form a pn junction.

The buffer layer400is disposed between the light absorbing layer300and a front electrode formed later. That is, since the light absorbing layer300and the front electrode layer500have a large difference in lattice constant and energy band gap, the buffer layer400having an intermediate band gap of the layers300and500is inserted therebetween to form an excellent junction.

According to this embodiment, although one buffer layer is formed on the light absorbing layer300, the present invention is not limited thereto and thus the buffer layer400may be formed of a plurality of layers.

Later, referring toFIGS. 11 and 12, a contact pattern310penetrating the light absorbing layer300and the buffer layer400is formed. The contact pattern310may be formed through a mechanical method and a portion of the back electrode pattern200is exposed.

Referring toFIGS. 13 and 14, a front electrode500and a connection line700are formed by stacking a transparent conductive material on the buffer layer400.

When the transparent conductive material is stacked on the buffer layer400, it may be inserted in the contact pattern310to form the connection line700.

The back electrode pattern200and the front electrode500are electrically connected to each other through the connection line700.

The front electrode500is formed of a ZnO doped with Al through a sputtering process on the substrate100.

The front electrode500is a window layer forming a pn junction with the light absorbing layer300. Since the front electrode500serves as a transparent electrode at the front side of the solar battery, it is formed of a ZnO having high light transmittance and excellent electrical conductivity.

At this point, an electrode having low resistance may be formed by doping the ZnO with Al.

A ZnO thin film, i.e., the front electrode500, may be formed through an RF sputtering method using a ZnO target, a reactive sputtering method using a Zn target, and a metal organic chemical vapor deposition method.

Additionally, a double structure, in which an Indium Tin Oxide (ITO) thin film having excellent electro-optical property is deposited on the ZnO thin film, may be formed.

As shown inFIGS. 15 and 16, a separation pattern320penetrating the light absorbing layer300, the buffer layer400, and the front electrode500is formed.

The separation pattern320may be formed through a mechanical method and a portion of the back electrode pattern200is exposed.

The buffer layer400and the front electrode500may be separated by the separation pattern320and also each cell is separated by the separation pattern320.

The front electrode500, the buffer layer400, and the light absorbing layer300may be disposed with a stripe shape or a matrix shape by the separation pattern320. However, the separation pattern320is not limited to the above shape and may be formed with various shapes.

A plurality of cells are formed on the substrate100by the separation pattern320. The plurality of cells may include a first cell group CU1, a second cell group CU2, and a third cell group CU3.

As shown inFIGS. 17 and 18, a first bus bar810, a first connection electrode710, and a second connection electrode720are formed to be connected to the back electrode pattern200.

The first bus bar810, the first connection electrode710, and the second connection electrode720may be formed by removing portions of the front electrode500, the buffer layer400, and the light absorbing layer300at the both ends of the substrate100and then exposing the front electrode pattern200.

In this embodiment, although the first bus bar810, the first connection electrode710, and the second connection electrode720are connected to the back electrode pattern200, they are not limited thereto. That is, the first bus bar810, the first connection electrode710, and the second connection electrode720may be formed on the front electrode500.

In order to form the first bus bar810, the first connection electrode710, the second connection electrode720, the third connection electrode730, the fourth connection electrode740, the fifth connection electrode750, and the second bus bar820, a conductive paste is printed on the exposed back electrode pattern200. The printed conductive paste is sintered, and then the first bus bar810, the first connection electrode710, the second connection electrode720, the third connection electrode730, the fourth connection electrode740, the fifth connection electrode750, and the second bus bar820are formed.

Additionally, first cells A11in the first area A1and second cells A22in the second area A2are formed symmetrical to each other.

That is, the first cells A11may be formed with a structure in which the first bus bar810is connected to a (+) electrode and the first connection electrode710is connected to a (−) electrode. Additionally, the second cells A22may be formed with a structure in which the first connection electrode710is connected to a (+) electrode and the second connection electrode720is connected to a (−) electrode.

At this point, the back electrode pattern200in the first area A1and the back electrode pattern200in the second area A2may be connected to each other through the first connection electrode710. Accordingly, the first cells A11and the second cells A22may be connected in series to each other.

Later, a first diode D1is disposed between the first bus bar810and the second connection electrode720, a second diode D2is disposed between the second connection electrode720and the fourth connection electrode740, and a third diode D3is disposed between the fourth connection electrode740and the second bus bar820.

In this manner, each of the cell groups CU1, CU2, and CU3is separately driven, so that a solar battery module having improved photoelectric conversion efficiency may be provided.

FIG. 19is a plan view illustrating the front side of a thin film solar battery module according to a second embodiment.FIG. 20is a plan view illustrating the front side of a bulk type thin film solar battery module according to a second embodiment.FIG. 21is a plan view of a junction box at the rear side of a substrate.FIG. 22is a plan view illustrating the inner structure of a junction box.FIG. 23is a view of a comparator.FIGS. 24 and 25are views of a display means. Description for this embodiment refers to that for the above-mentioned embodiments. That is, except for the modified portions, the description for the above embodiments may be substantially combined to that for this embodiment.

Referring toFIGS. 19 to 25, the solar battery module according to the second embodiment includes a solar battery panel having a plurality of cell groups CU1, CU2, and CU3disposed on a substrate100, and a junction box800.

The substrate100is formed of glass and may include a ceramic (such as alumina) substrate, a stainless steel or titanium substrate, or a polymer substrate.

Each of the cell groups CU1, CU2, and CU3includes a plurality of cells. The plurality of cells may be formed of a Cu(In, Ga)Se2, (CIGS based) compound, a CuInSe2, (CIS based) compound, or a CuGaSe2(CGS based) compound.

A bus bar810is connected to the first cells A11and a second bus bar820is connected to the sixth cells A66. The first cells A11, the second cells A22, the third cells A33, the fourth cells A44, the fifth cells A55, and the sixth cell A66may be connected in series to each other through the connection electrodes710,720,730,740, and750.

The first diode D1, the second diode D2, and the third diode D3detour current when one of the cell groups CU1, CU2, and CU3is disabled. For example, when a shadow is casted on or a defect occurs in the second cell group CU2, the resistance of the second cell group CU2is increased. At this point, a current generated in the first group CU1and the third cell group CU3may detour via the second diode D2.

The first diode D1the second diode D2, and the third diode D3are disposed in the junction box800at the rear side of the substrate100. Additionally, the first bus bar810, the second connection electrode720, the fourth connection electrode740, and the second bus bar820extend to the junction box800.

Additionally, a solar battery module according to an embodiment is not limited to the thin film solar battery module ofFIG. 19, and thus may be a bulk solar battery module ofFIG. 20.

As shown inFIG. 20, bulk solar batteries105, where an n-type layer is formed on a p-type Si substrate to from a PN junction, are connected in series, so that a solar battery module may be formed.

Additionally, the solar batteries105are connected to each other in the bulk solar battery module through the connection electrodes710,720,730,740, and750. Additionally, the first bus bar810and the second bus bar820may be connected to the solar batteries at the both ends of the bulk solar battery module.

Referring toFIGS. 21 to 25, the solar battery module according to the this embodiment includes the first diode D1, the second diode D2, the third diode D3, a first output terminal910, a second output terminal920, a power supply unit950, an error detection unit930, and a signal output unit940.

The first diode D1, the second diode D2, the third diode D3, the first output terminal910, the second output terminal920, the power supply unit950, the error detection unit930, and the signal output unit940may be received in the junction box800.

The first output terminal910is connected to the first bus bar810. Unlike this, the first bus bar810may extend to form the first output terminal910. The second output terminal920is connected to the second bus bar820. Unlike this, the second bus bar820may extend to form the second output terminal920.

The first output terminal910and the second output terminal920may be connected to a power conversion system converting DC power into AC power having a predetermined frequency.

The power supply unit950includes a coil850. The coil850is disposed at the second output terminal920. When a current generated by the cells in the cell groups CU1, CU2, and CU3flows in the second output terminal920, a magnetic field is changed and an included current flows in the coil850. The power supply unit950may generate a power source by using a current generated through the electromagnetic induction phenomenon.

Additionally, the power supply unit950may supply the generated power to the error detection unit930and the signal output unit940. Especially, when some of the cell groups CU1, CU2, and CU3are disabled, a current flowing through the second output terminal920is changed. At this point, the power supply unit950may supply power through an induction current generated by the changed current.

The error detection unit930detects errors of the cell groups CU1, CU2, and CU3. In more detail, the error detection unit930may detect disabled ones from the cell groups CU1, CU2, and CU3.

The error detection unit930includes a comparator931. The error detection unit930receives a voltage from the both ends of the first diode D1, the both ends of the second diode D2, and the both ends of the third diode D3. Additionally, The error detection unit930detects errors of the cell groups CU1, CU2, and CU3by comparing the inputted voltage with a reference voltage.

That is, signals such as the voltage inputted in the error detection unit930may be applied to a circuit having the comparator931. Additionally, which cell groups are shaded or have defects may be detected through the signals.

The signal output unit940receives the signals generated from the error detection unit930and transmits them to external. That is, the signal output unit940outputs the signals from the error detection unit930to the external display means960.

As shown inFIG. 23, the comparator931may include an operational amplifier (OP). The comparator931compares a reference voltage VRefwith an input VInputand outputs an output voltage VOut. At this point, the reference voltage VRefmay be more than or equal to about 0.7V, i.e., a voltage of the diode, and the input voltage VInputmay be signals of the both ends of each of the diodes D1, D2, and D3.

Accordingly, the comparator931may vary according to the number of the diodes D1, D2and D3and according to this embodiment, at least three comparators may be included in the error detection unit930.

If there is no showdown on or no defect in the cell groups CU1, CU2, and CU3, a voltage of each of the cell groups CU1, CU2, and CU3is measured at the both ends of each of the diodes D1, D2, and D3.

However, if there is a shadow on or a defect in a part of the solar battery cell, a voltage at the both ends of each of the diodes D1, D2, and D3may be measured at about 0.7V, i.e., a voltage of the diode.

Accordingly, when the comparator931sets about 1V as the reference voltage VRefand applies the voltage at the both ends of each of the diodes D1. D2, and D3as the input voltage VInputand a signal less than the reference voltage VRefoccurs, the error detection unit930may be designed to output the output voltage VOut.

For example, if there is a shadow on or a defect in the second cell group CU2, the voltage of the second connection electrode720and the fourth connection electrode740at the both ends of the second diode D2are measured at about 0.7V.

When about 0.7V, i.e., the voltage at the both ends of the second diode D2, is inputted as the input voltage VInput, since the input voltage VInputis less than about 1V, i.e., the reference voltage VRef, the output voltage VOutis generated by the comparators931and200. The output voltage VOutgenerated by the comparator931is transmitted to the signal output unit940.

Referring toFIGS. 24 and 25, the signal output unit940outputs a signal to the external display means960in response to the signals from the error detection unit930. The display means960may be a flasher961such as an LED lamp or an image means962such as a monitor. At this point, the flasher961or the image means962may be connected to the signal output unit940through the connection line830.

Additionally, the signal output unit940may include a Radio Frequency (RF) module850. When the RF module850is included in the signal output unit940, a signal may be transmitted to the display means960without the connection line830.

According to the solar battery module and the method of detecting an error thereof, the power supply unit950, the error detection unit930, the signal output unit940are included in the junction box to determine whether there is a shadow on or a defect in an entire solar battery module.

Additionally, the solar battery module according to this embodiment may determine which cell has a shadow or a defect by using the error detection unit930.

Additionally, the power supply unit950may drive the error detection unit930and the signal output unit940without additional power because a coil is disposed in the power supply unit950.

As mentioned above, the solar battery module is described and may correspond to a solar cell apparatus in a broad sense. Accordingly, the above-mentioned embodiments may be applied to various solar cell apparatuses.

Additionally, the features, structures, and effects described in the above embodiments are included in at least one embodiment, but the present invention is not limited thereto. Furthermore, the features, structures, and effects in each embodiment may be combined or modified for other embodiments by those skilled in the art Accordingly, contents regarding the combination and modification should be construed as being in the scope of the present invention.

INDUSTRIAL APPLICABILITY

A solar cell apparatus according to an embodiment is used for photovoltaic power generation fields.