PROTECTION OF SPACE SOLAR CELLS IN AN ARRANGEMENT IN THE FORM OF A STRING

Abstract

A protection of space solar cells in an arrangement in the form of a string that extends in an X direction. In each case two space solar cells directly neighboring in the X direction are electrically connected to one another in series via a metallic connector of a first type. The string has a first end and a second end opposite from the first end, and a protection arrangement is provided directly at one of the two ends along a y direction. The protection arrangement includes a first string protection diode arrangement, a metal strip, and a second string protection diode arrangement provided in the Y direction. The protection arrangement is electrically connected to one of the two ends of the string via two spaced-apart metal strips, and each string protection diode arrangement includes multiple unhoused string protection diodes.

Claims

1. A protection of an arrangement comprising space solar cells arranged in the form of a string, wherein: at least a portion of the arrangement of space solar cells being arranged in succession in the form of the string, which extends in an X direction, the string includes at least two space solar cells, in each case two space solar cells directly neighboring in the X direction are electrically connected to one another in series via one or more metallic connectors, the space solar cells each have a receiving surface that is situated in an X direction and in a Y direction, the string has a front side and a rear side, the receiving surfaces of the space solar cells being provided on the front side of the string, the string has a first end and a second end, the two ends each extending in the y direction along a side of the space solar cell arranged at the ends of the string, each space solar cell has a bypass diode that is connected to the respective space solar cell, the space solar cells each have a thickness between 30 m and 300 m or a thickness between 50 m and 160 m in a Z direction, on the front side a protection arrangement is provided at at least one of the two ends along the y direction, and the protection arrangement is electrically connected to the space solar cell of the string, situated at the end, via one of the metallic connectors, the protection arrangement including a first string protection diode arrangement, a metal strip, and a second string protection diode arrangement, the metal strip has a first head-side end, a spacer, and a second head-side end, the first string protection diode arrangement is connected in series to the first head-side end of the metal strip in the y direction via one of the metallic connectors, and the second string protection diode arrangement is connected in series to the second head-side end of the metal strip via one of the metallic connectors, the connectors each have two contact surfaces that are spaced apart by a connecting piece, the string protection diode arrangements have multiple string protection diodes that are designed as part of a DIE, the DIE having a top side and a bottom side, the string protection diodes situated on the DIE are arranged in rows and/or in columns, on the top side of the DIE, two directly neighboring string protection diodes are separated by a scribe line region, and have electrically separated front side contacts, and the rear side of the DIE is metal-plated, so that multiple or all string protection diodes have a shared rear side contact, the shared rear side contact is connected to the metal strip or to the space solar cell arranged at the ends of the string, and one of the front side contacts of the string protection diodes is connected to one of the space solar cells situated at the ends of the string or to the metal strip, each DIE is unhoused, and on the top side has its own cover, the cover being adhesively bonded to the top side of the DIE, the protective arrangement as a whole has a flat design, and has a thickness less than 1 mm in a Z direction, and an extension of the overall protection arrangement in the Y direction is greater than an extension in the X direction by at least a factor of five.

2. The protection of an arrangement of space solar cells according to claim 1, wherein the connectors have a first contact surface and a second contact surface, one of the two contact surfaces being connected to the metal contact at the bottom side, or to one of the metal contacts at the top side, of one of the string protection diodes, and the other of the two contact surfaces being connected to the metal strip.

3. The protection of an arrangement of space solar cells according to claim 1, wherein for the connectors, the two contact surfaces have the same or different designs.

4. The protection of an arrangement of space solar cells according to claim 1, wherein, for the connectors, at least one of the two contact surfaces or both contact surfaces has/have a contact tab or multiple contact tabs, respectively.

5. The protection of an arrangement of space solar cells according to claim 1, wherein, for the connectors, the connecting piece between the two contact surfaces has a meandering design in order to mechanically decouple the two contact surfaces from one another.

6. The protection of an arrangement of space solar cells according to claim 1, wherein the two contact surfaces of the connectors each have a flat design, and each have a thickness between 0.01 mm and 0.7 mm in the Z direction.

7. The protection of an arrangement of space solar cells according to claim 1, wherein the connectors have a rectangular area, and a long side of the rectangular area has an extension that is larger than a short side by at least a factor of 5.

8. The protection of an arrangement of space solar cells according to claim 1, wherein all space solar cells of the string each have a bypass diode, and the bypass diode is directly connected to the particular space solar cell.

9. The protection of an arrangement of space solar cells according to claim 1, wherein one of the two contacted string protection diode arrangements is directly connected to the bypass diode of the space solar cell arranged at one of the two ends.

10. The protection of an arrangement of space solar cells according to claim 1, wherein the protection arrangement is provided at both ends of the string.

11. The protection of an arrangement of space solar cells according to claim 1, wherein, when light strikes the front side of the space solar cells, a current flows exclusively through the respective contacted string protection diode and the metal strip to a connection line.

12. The protection of an arrangement of space solar cells according to claim 4, wherein the contact tabs have a thickness between 0.01 mm and 0.5 mm or between 0.02 mm and 0.2 mm.

13. The protection of an arrangement of space solar cells according to claim 1, wherein the cover of the DIE is transparent in the infrared range in order to reflect the solar radiation, and/or the cover is designed as a cover glass.

14. The protection of an arrangement of space solar cells according to claim 1, wherein the protection arrangement is provided directly at one of the two ends, and the distance in the X direction between the protection arrangement and the space solar cell that is connected to the protection arrangement is in a range between 10 m and 10 mm or in a range between 100 m and 2 mm.

15. The protection of an arrangement of space solar cells according to claim 1, wherein cooling for the string protection diodes is provided by the metal strip and/or a metal-plated bottom side of the DIEs.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0114] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0115] FIGS. 1a and 1b show various designs of a string of space solar cells with a protection arrangement, provided at both ends, which is connected in each case to one of the space solar cells situated at the respective end,

[0116] FIGS. 2a to 2e illustrate detailed views of, among other things, the front side, the lateral side, and the rear side of the protection arrangement which is connected to a space solar cell,

[0117] FIGS. 3a to 3f show various detailed views of the protection arrangement and of the connectors together with a string protection diode arrangement,

[0118] FIG. 4 shows a top view of the top side of a DIE with multiple string protection diodes that are electrically separated by means of a scribe line, and

[0119] FIG. 5 shows a top view of one discrete example of string protection diodes on the rear side of a panel according to the conventional art.

DETAILED DESCRIPTION

[0120] The illustrations in FIGS. 1a and 1b show various designs of a string STRA of space solar cells WSZ with a protection arrangement SA that is provided at both ends, the particular protection arrangement SA being connected to one of the space solar cells WSZ situated at the respective end.

[0121] The protection arrangement SA has a flat design overall, and has a thickness less than 1 mm in a Z direction.

[0122] The extension of the overall protection arrangement SA in the Y direction is greater than the extension in the X direction by at least a factor of five.

[0123] One of the two ends of the protection arrangement SA is designed as a positive voltage pole (+), and the other end is designed as a negative voltage pole ().

[0124] However, it should be understood that only one protection arrangement SA can be provided, either at the end with the positive voltage pole (+) or at the end with the negative voltage pole ().

[0125] In the present case, the space solar cells WSZ are arranged in succession in the form of the string STRA extending in an X direction, the string STRA including a total of five space solar cells WSZ. Each of the five space solar cells WSZ is protected by its own cover glass DGS on a top side.

[0126] In each case, two space solar cells WSZ directly neighboring one another in the X direction are electrically connected to one another in series via exactly two metallic connectors VB1.

[0127] The space solar cells WSZ have a receiving surface situated in each case in an X direction and in a Y direction.

[0128] The string STRA has a front side and a rear side, the front side being illustrated in the depicted top view.

[0129] In the present case, the receiving surfaces of the space solar cells WSZ are provided on the front side of the string STRA.

[0130] The string STRA has a first end and a second end opposite the first end, the two ends each extending in the y direction along one side of the space solar cell WSZ situated at the ends of the string.

[0131] In the present case, each of the space solar cells WSZ has a bypass diode SD that is connected to the particular space solar cell WSZ. The bypass diodes SD are each situated in a corner of the associated space solar cell WSZ, and via two connectors VB1, VB2 are connected to the space solar cell WSZ directly neighboring in the X direction and to the space solar cell WSZ directly neighboring in the Y direction.

[0132] It is understood that the bypass diode SD and the associated space solar cell WSZ in the X direction can be covered by a single cover glass DGS.

[0133] The space solar cells WSZ each have a thickness between 30 m and 300 m or a thickness between 50 m and 160 m in a Z direction.

[0134] The protection arrangements SA situated on the front side of the string STRA are in each case provided along the y direction.

[0135] The protection arrangements SA are electrically connected to the space solar cells WSZ of the string STRA, situated at the two ends, via multiple metallic connectors.

[0136] The protection arrangement SA includes a first string protection diode arrangement DGDS, a metal strip BUB, and a second string protection diode arrangement DGDS. In addition, contact tabs with contact surfaces K1 are preferably formed at the metal strip; the contact tabs and the metal strip generally have a one-piece design.

[0137] The metal strip BUB has a first head-side end, a spacer, and a second head-side end.

[0138] In the example illustrated in FIG. 1a, also referred to as the first alternative, in the y direction the first string protection diode arrangement DGDS is connected in series to the first head-side end of the metal strip BUB via one of the metallic connectors VB1.

[0139] Furthermore, the second string protection diode arrangement DGDS is connected in series, likewise in the y direction, to the second head-side end of the metal strip BUB via one of the metallic connectors VB1.

[0140] Each of the two string protection diode arrangements DGDS has a first string protection diode DS1, a second string protection diode DS2, and a third string protection diode DS3. The string protection diodes DS1 through DS3 are arranged together on a DIE D, in each case two directly neighboring string protection diodes DS1 through DS3 being electrically separated from one another on the top side of the DIE D by a scribe line RR. In the present case, the string protection diodes DS1 through DS3 are arranged in a row in each case.

[0141] The connectors VB1 each have two contact surfaces that are spaced apart from one another by a connecting piece.

[0142] In the protection arrangement SA, connected to the end at which the positive potential (+) is present, the two string protection diode arrangements DGDS are each connected to the space solar cell WSZ via one of the connectors VB1 provided in the X direction. In other words, the two branches of the string protection diode arrangements DGDS are parallel to one another and thus create redundancy.

[0143] The metal strip BUB has two contact tabs K1, one each for connecting a flexible cable.

[0144] It is noted that for each of the two branches, the flexible cable is connected in series, via the contact tabs K1, to the metal strip BUB, to the string protection diode arrangements DGDS, and to the space solar cell WSZ.

[0145] In the protection arrangement SA, connected to the end at which the negative potential () is present, the two electrically contacted string protection diodes DS1 through DS3 of the string protection diode arrangements DGDS are each connected in the negative X direction, via one of the connectors VB1, to a flexible cable by means of one of the respective contact tabs K1.

[0146] In addition, one of the string protection diodes DS1 through DS3 of the DIE D from one of the string protection diode arrangements DGDS is connected to the bypass diode of the space solar cell WSZ via one of the connectors VB1. In the present case, the metal strip BUB is connected, via two other of the connectors VB1, to the space solar cell WSZ provided at the end of the string STRA.

[0147] In addition, the contacted string protection diode DS1 through DS3 of the first string protection diode arrangement DGDS and the contacted string protection diode DS1 through DS3 of the second string protection diode arrangement DGDS are connected in series, likewise in the y direction, to the first or to the second head-side end of the metal strip BUB via one of the metallic connectors VB1.

[0148] Here as well, the two branches of the string protection diode arrangements DGDS are connected to one another in parallel, thus creating redundancy.

[0149] It is noted that for each of the two branches, the space solar cells WSZ are connected in series, via the metal strip BUB, to the string protection diode arrangements DGDS and to the flexible connecting cables.

[0150] In the embodiment illustrated in FIG. 1b, also referred to as the second alternative, only the differences from the embodiment stated in conjunction with the drawing of FIG. 1a are explained.

[0151] At the first head-side end, at which the positive potential (+) is present, the first string protection diode arrangement DGDS is situated directly on the metal strip BUB without a connector VB1. Two connectors VB1 may thus be saved, compared to the embodiment illustrated in FIG. 1a.

[0152] Furthermore, at the second head-side end the second string protection diode arrangement DGDS is situated directly on the metal strip BUB.

[0153] In the two alternatives illustrated in FIG. 1a or FIG. 1b, in the X direction the two string protection diode arrangements DGDS are each electrically connected in series, via one of the metallic connectors VB1, to the space solar cell WSZ situated at the end of the string STRA.

[0154] It is noted that in the present case, the string protection diode arrangements DGDS each have their own cover in the form of a cover glass. It is understood that the cover can be in each case adhesively bonded to the individual string protection diode arrangements DGDS.

[0155] The illustrations in FIGS. 2a through 2e show detailed views of, among other things, the front side, the lateral side, and the rear side of the protection arrangement SA which is connected to a space solar cell WSZ.

[0156] In particular, FIG. 2b shows a side view, FIG. 2c shows a top view of the rear side, and FIG. 2c shows a perspective view of the arrangement in FIG. 2a.

[0157] FIG. 2e shows a portion of a detailed side view of a string protection diode arrangement DGDS.

[0158] Only the differences from the preceding embodiments are explained below.

[0159] FIG. 2a shows the top view of the front side of one of the space solar cells WSZ, which is covered by a cover glass DGS. At one of the two ends, which are an edge of the space solar cell WSZ formed in the Y direction for the serial connection to an adjacent space solar cell WSZ, the contact tabs of a total of three of the connectors VB1 are visible.

[0160] The connectors VB1 have a first contact surface and a second contact surface. In each case, one of the two contact surfaces of the three connectors is welded to the top side of the space solar cell WSZ. The other contact surface is provided for connection to a further space solar cell WSZ. In the present case the two contact surfaces have an identical design.

[0161] Both contact surfaces have multiple contact tabs. The respective connecting pieces between each of the two contact surfaces of the connectors VB1 have a meandering design in order to mechanically decouple the respective two contact surfaces from one another.

[0162] At the opposite, long edge of the space solar cell WSZ, the protection arrangement SA is provided in each case with the two string protection diode arrangements DGDS, protected in each case by a cover glass designed as a cover layer, and the metal strip BUB. It is understood that the cover glass can be transparent in the infrared range in order to emit heat radiation into space.

[0163] A total of three contact tabs K1 are provided at the metal strip BUB for connection of the flexible cables.

[0164] The side view in FIG. 2b shows the small thickness of the string STRA, which is less than one millimeter. In addition, a step is formed between the metal strip BUB and the contact tabs K1.

[0165] It is apparent from the rear side view in FIG. 2c that the bypass diode SD is connected to the bottom side of the space solar cell WSZ via a wide connector VB2. Furthermore, the protection arrangements SA are connected to the opposite edge via the contact surfaces of the connectors VB1. In addition, the DIE D with the three string protection diodes DS1 through DS3 is illustrated at both ends of the metal strip. In each case, only the first string protection diode DS1 is connected to the string STRA.

[0166] It is apparent from the illustration in FIG. 2e that one of the two contact surfaces of the connector VB1 is connected to the top side of the DIE D and is covered by the cover glass. In addition, the connector VB1 has a step between the two contact surfaces.

[0167] FIGS. 3a through 3f illustrate detailed views of the protection arrangement SA, the connectors VB1, and the design of the string protection diodes DGDS. Only the differences from the preceding figures are explained below.

[0168] It is shown that the contact surfaces of the connectors VB1 each have exactly three contact tabs. In addition, in the side view in FIG. 3b it is shown that the protection arrangement SA has a very thin design in the Z direction, and preferably has a thickness less than 1 mm.

[0169] The enlarged detail in FIG. 3d shows that on one side of the string protection diode DGDS, a cover glass DG is situated on the top side of the DIE D by use of an adhesive KL.

[0170] The illustration in FIG. 4 shows a top view of the top side of a DIE D with multiple string protection diodes DS1 through DS6, which are electrically separated by means of the scribe line RR.

[0171] In contrast to the preceding arrangements, the DIE D now contains a total of six string protection diodes DS1 through DS6, the string protection diodes DS1 through DS6 being arranged in two rows. The DIE has a rectangular shape.

[0172] The bottom side may be metal-plated over the entire surface and is contacted via one of the connectors VB1. At the top side, only the second string protection diode DS2 is contacted via one of the connectors VB1.

[0173] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.