Patent Publication Number: US-2023164943-A1

Title: Electronic power converter

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of International Patent Application Number PCT/EP2021/070025, filed on Jul. 16, 2021, which claims priority to German Patent Application number 10 2020 119 040.9, filed on Jul. 17, 2020, and is hereby incorporated by reference in its entirety. 
    
    
     FIELD 
     The disclosure relates to an electronic power converter having a housing. 
     BACKGROUND 
     A power converter is an electrical power handling device that exchanges electrical power with other electrical units through its connections and manipulates it by electronic means. For example, power converters include inverters, DC voltage converters, frequency converters, battery converters, power supplies for AC or DC loads, and the like. 
     DE 10 2014 105 985 discloses an inverter which has a plurality of converter modules, wherein each converter module has its own housing. The converter modules can comprise various functions, for example, converting electrical power, e.g. converting direct current to direct current or direct current to alternating current or vice versa. The converter modules can be electrically connected via plug connectors and thus combined in different ways, wherein such a combination always results in an electronic power converter. 
     WO2016/012541 describes accommodating an inverter, as used, for example, in photovoltaic systems for converting direct current into alternating current, in a housing which can be fixed to a wall by means of a wall bracket. 
     The size of the housing of a power converter is basically dependent on the rated power of the power converter. With a rated power in the range of about one kilowatt to one megawatt, a common power converter regularly exchanges currents of several dozen amperes at voltages of a few hundred volts. The connections of the power converters are dimensioned accordingly. In addition, there are regularly high requirements for electromagnetic compatibility and protection class of a power converter. By contrast, a low weight and a low volume of the power converter or at least of the converter modules of a power converter are desirable, especially to allow assembly and, where necessary, repair. 
     SUMMARY 
     The disclosure addresses the problem of further simplifying the assembly of a power converter at a place of use. 
     In one embodiment, an electronic power converter is of modular design and has a first housing, a second housing and a coupling element arranged between the housings. The coupling element is connectable to at least one of the housings via a detent connection. Such a power converter can be, for example, a power electronic inverter for a photovoltaic system. Due to the modular structure of the housing of the power converter, it is possible to easily provide different configurations of the power converter. This allows the power converter to be easily and efficiently matched to the intended use, e.g., the type and application of the photovoltaic system with which the power converter is to interact. Different components of the power converter can be accommodated here in different configurations in different housings and can easily be suitably assembled and mounted due to the modular structure. Due to the provided coupling element, which can be latched to at least one housing, the versatility of the structure can be further increased and the assembly can be further simplified. In particular, coupling elements can be provided in various embodiments, e.g. sealing and/or with passages for, for example, cables and the like. 
     In one embodiment of the power converter, the housings each have a rear side and a peripheral frame. The frame of the first and/or the second housing has at least one slot on a first frame side and/or a second frame side. In one embodiment, the slot runs transversely to the long edge of the frame side, for example, transversely to the perimeter of the frame. The slot is configured to latch with the coupling element to allow a secure detent connection. In embodiments, the first and/or the second frame side comprises one or more further slots to allow an even more secure latching with the coupling element. In yet a further embodiment, both the first and second frame sides comprise the slot or slots. This may provide further expandability of the power converter. In one embodiment, it is advantageous if the first and second frame sides face each other. In one embodiment, the first and/or the second frame side have, in addition to the slot or slots, further through-recesses through which connections, e.g. in the form of electrical cables, can run between the two housings. 
     In one embodiment, the coupling element is plate-like and has a base plate with at least one through-recess, wherein the coupling element is arranged in a planar manner between the first and the second housing. In one embodiment, the coupling element is elongate and has, for example, comparable proportions to the cross-section of the first and/or the second housing. Due to the plate-like design of the coupling element, a secure, planar coupling of the first and second housings can be achieved. The through-recess is suitable for accommodating connection elements, for example, electrical connections, in order to connect components of the power converter accommodated in the first housing to components of the power converter accommodated in the second housing. In one embodiment, the coupling element has a plurality of, in particular two, through-recesses. 
     In one embodiment, the base plate has at least one first detent projection running transversely, for example, perpendicularly, to the base plate and having a first detent lug. In one embodiment, the detent projection extends parallel to the surface normal of the detent projection and runs transversely, for example, perpendicularly, to the longitudinal direction of the base plate. The detent projection is intended to be inserted into one of the slots of the housing and is elongate in one embodiment. The detent projection can then be latched in the slot of the first or the second housing via the detent lug. In one embodiment, the detent lug points towards the edge of the base plate of the coupling element. In further embodiments, the coupling element may have further detent projections with further detent lugs. 
     In one embodiment, the coupling element has a second detent projection with a second detent lug on the side of the base plate opposite the first detent projection, for example, perpendicular to the base plate. In one embodiment, the second detent projection with the second detent lug is symmetrical to the first detent projection and first detent lug. In such a case, the base surface of the base plate is substantially the plane of symmetry of the first and second detent projections. 
     In a further embodiment, the frame of the first housing and the frame of the second housing each comprise at least one slot. The slots of the housings are arranged such that the housings can be arranged relative to the coupling element such that the first detent projection of the coupling element can be latched into the slot of the first housing, and such that the second detent projection of the coupling element can be latched into the slot of the second housing. Thus, the first and second housings are connected to each other by the coupling element, in that the coupling element is arranged between the frames of the housings. 
     In one embodiment, the base plate of the coupling element is made of solid material, for example, plastic. This allows further stabilization of the power converter. 
     In one embodiment, the at least one through-recess of the coupling element has a peripheral protrusion, which is arranged centrally in the through-recess. Via the peripheral protrusion it is possible, for example, to lock inlays or inserts in the through-recess. In one embodiment, the coupling element has an elastic insert that has a peripheral groove. The insert can be arranged in the through-recess of the coupling element in such a way that the peripheral protrusion engages in the groove so that the insert seals the through-recess, in particular against moisture, air and/or dust. 
     For example, the elastic insert has at least one recess, which is formed as a blind recess or through-recess. The through-recess is configured to serve as a feedthrough for current-carrying lines of the power converter. This makes it possible to form the power converter in a modular manner and to establish electrical connections between the components accommodated in the housings, in particular by the frames of the housings also having through-holes at positions which correlate with the through-recesses of the coupling element or the insert in the assembled state. 
     In one embodiment, the power converter comprises a wall bracket. The first housing and/or the second housing each have a peg on opposite third and fourth frame sides oriented substantially perpendicular to the first frame side and/or the second frame side. The wall bracket has a substantially U-shaped profile with a base side attachable to a wall and two edge sides, wherein the edge sides each have a T-shaped recess. In the assembled state, the edge sides of the wall bracket rest against the opposite third and fourth frame sides of the first or the second housing in such a way that the pegs each engage in a respective one of the T-shaped recesses. In one embodiment, the foot of the T-shape serves here to guide the peg at the beginning of the assembly process, while the end points of the roof of the T-shape serve as a receptacle in the assembled state. 
     In one embodiment, the T-shaped recesses of the wall bracket with the roof of the T-shape run substantially parallel to the base side and parallel to the third and fourth frame sides. This allows the roof of the T-shape to serve as a receptacle for a peg in the assembled state. In one embodiment, the pegs have a circular cross-section for this purpose. 
     In one embodiment, the first housing and/or the second housing has two elongate rear projections running parallel to each other in their longitudinal direction and parallel to the third and fourth frame sides, wherein the pegs arranged on the sides of the rear projections facing each other. This allows the pegs to be received in the T-shapes on an inner side, so that the appearance need not be impaired when viewed from outside the housings. 
     In one embodiment, the edge sides of the wall bracket are formed as a V-profile with a first leg and a second leg, wherein the first leg of each edge side adjoins the base side and the second leg of each edge side adjoins the first leg. The vertices of the V-shape are each directed outwards. In the assembled state, the rear projections lie flat on the outer sides of the respective second legs of the wall bracket. In one embodiment, the inner surfaces of the rear projections are inclined correspondingly to the second leg of the wall bracket so that, in the assembled state, the rear projections can lie flat against the second legs. In one embodiment, the rear projections lie on the outside of the wall bracket. 
     In one embodiment, the T-shaped recesses of the wall bracket are opposite each other and are centered in the respective second legs of the edge side. The foot points of the T-shaped recesses are closed or open. Even when the foot points of the T-shaped recesses are closed, the pegs of the housing can engage the foot of the T-shaped recess because the second leg of the wall bracket is inclined inwardly. The pegs are, in one embodiment, located on the inside of the rear projections. The distance between the pegs is thus greater than the distance between the front edges of the second legs and insertion is possible even when the foot of the T-shape is closed. 
     To increase stability, at least one of the housings can be additionally fixed to the wall bracket, for example, by means of a screw that can be screwed to an upper end of the second leg of the wall bracket. 
     In one embodiment, the first housing is connected to a first wall bracket and the second housing is connected to a second wall bracket, wherein, in an assembled state of the power converter, the pegs of the first housing are arranged at respective lower end points of the roof of the T-shaped recesses of the first wall bracket and the pegs of the second housing are arranged at respective upper end points of the roof of the T-shaped recesses of the second wall bracket. This embodiment allows a particularly simple assembly, in which first the first housing is mounted on the first wall bracket and then the second housing is mounted on the second wall bracket by guiding the pegs of the second housing in the T-shaped recess of the second wall bracket in such a way that the second housing can be pushed from below in the direction of the first housing and against the coupling element arranged below the first housing. The second housing is then at least temporarily held by the first housing by the latching of the coupling element, in particular until it is otherwise fixedly connected to the first housing, for example, via a separate screw connection, and/or until the second housing itself is fastened to the wall bracket or the wall. 
     In one embodiment, the coupling element may comprise a display unit configured to display operational data of the power converter. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       In the following, the disclosure is further explained and described with reference to exemplary embodiments shown in the figures. 
         FIG.  1    schematically shows a power converter with a first housing and a wall bracket, 
         FIG.  2    schematically shows a wall bracket from the side, 
         FIG.  3    schematically shows a power converter with the first housing and the attached wall bracket, 
         FIG.  4    schematically shows a plan view of two wall brackets, 
         FIG.  5    schematically shows a power converter with two wall brackets as well as the first and a second housing, 
         FIG.  6    schematically shows two coupling elements, 
         FIG.  7    schematically shows a longitudinal section through each of the two coupling elements, 
         FIG.  8    schematically shows a longitudinal section through the first and second housings and through the two coupling elements, 
         FIG.  9    schematically shows the first housing and one of the coupling elements, 
         FIG.  10    schematically shows the first housing, the coupling element and the second housing. 
     
    
    
     DETAILED DESCRIPTION 
       FIG.  1    shows schematically from an oblique bottom view a power converter with a first housing  10 . The first housing  10  has a rear side  16  and a peripheral frame  24 . Cooling fins  14  are arranged on the rear side  16  of the housing  10 . To the side of the cooling fins  14 , there are located on the rear side  16  two rear projections  12 , each of which has a peg  18  on its inner side. The two rear projections  12  frame the cooling fins  14  from two opposite sides. The pegs  18  of the two rear projections  12  are opposite each other. 
       FIG.  1    further schematically illustrates a wall bracket  20 . The wall bracket  20  has a substantially U-shaped profile with a base side  26  and two edge sides  28 . The base side  26  has two guides  27  for receiving one wall rail  62  each (cf.  FIG.  4   ). The edge sides  28  in turn have a V-profile with a first leg  56  and a second leg  58 . The V-profile of the two edge sides  28  is directed outwardly here, wherein the first leg  56  is inclined outwardly and the second leg  58  is inclined inwardly. The wall bracket  20  is configured to be attached to a wall or the like by its base side  26 . 
     A T-shaped recess  22  is formed centrally in each of the second legs  58  of the two edge sides  28 , the T-shaped recesses being formed as retaining grooves for holding the first housing  10  or the second housing  30  (cf.  FIG.  5   ). The T-shaped recess  22  comprises a foot and a roof resembling a T-shape, wherein the roof is arranged perpendicular to the foot (see e.g.  FIG.  5   ). The T-shaped recess  22  is arranged such that the roof of the T-shape  22  is arranged parallel to the edge of the second leg  58  and hence parallel to the base side  26 . The foot of the T-shaped recess  22  runs perpendicularly towards the edge of the second leg  58 . The foot of the T-shaped recess  22  can be closed at its footpoint or open at the edge of the second leg  58 . 
       FIG.  2    shows a schematic view from the side of the wall bracket  20 . The base side  26  has two guides  27  for receiving wall rails  62  (cf.  FIG.  4   ). The edge sides  28  have a V-profile, wherein the first leg  56  of the V-profile is inclined outwardly and the second leg  58  of the V-profile is inclined inwardly. 
       FIG.  3    schematically shows a power converter with the first housing  10  and the wall bracket  20 . The wall bracket  20  is plugged onto the housing  10  so that the pegs  18  engage in the T-shaped recess  22 . In this case, the pegs  18  are located at one end of the roof of the T-shaped recess  22 . When plugged on, the peg  18  is inserted at the foot end into the T-shaped recess  22 , is guided over the foot of the T-shaped recess  22  to the roof of the T-shaped recess  22 , and from there to one end of the roof of the T-shaped recess  22 . By means of one or more screws  19 , the housing  10  can be fixed to the wall bracket  20 , for example, to an upper end of the second leg  58 . 
       FIG.  4    schematically shows a front view of two wall brackets  20  attached to a wall or the like. Each of the wall brackets  20  has two wall rails  62  received in its guides  27 . The wall rails  62  allow for easy mounting of the wall brackets  20  with the correct spacing. Also shown are the T-shaped recesses  22 , into the foot of which the pegs  18  or the pegs  31  (cf.  FIG.  5   ) can be inserted for mounting. 
       FIG.  5    schematically shows a power converter with two wall brackets  20  as well as the first housing  10  and a second housing  30 . The second housing  30  has a rear side  49  and a peripheral frame  50 . In the right part of the figure, the first housing has already been fitted onto the upper wall bracket  20  and, where necessary, fixed in place. 
     The left side of  FIG.  5    shows how the second housing  30  can be fitted onto the lower wall bracket  20 . The second housing  30  has rear projections in the same manner as the first housing, the inner sides of the rear projections having the pegs  31 . First, a peg  31  of the second housing  30  is inserted into the foot of the T-shaped recess  22 . After the peg reaches the roof of the T-shaped recess  22 , the second housing  30  is pushed upwards so that the pegs are guided to the upper end of the roof of the T-shaped recess  22 . By latching using a coupling element  32  or  64  (cf.  FIG.  6   ), the second housing  30  can then be locked to and held against the first housing  10  via the coupling device or element  32 ,  64 . 
       FIG.  6    schematically shows two coupling devices or elements  32 ,  64 . Both have a plate-like elongate basic form. 
     The first coupling element  32  has a base plate  34  with two through-recesses  36 . Each of the through-recesses  36  has an inner peripheral protrusion  46  that is centered in the through-recess  36 . The first coupling element  32  has four detent protrusions  38 ,  40 ,  42 ,  44 . As shown in  FIG.  7   , the detent protrusion or projection  38  has a detent lug  37 , the detent projection  40  has a detent lug  39 , the detent projection  42  has a detent lug  41 , and the detent projection  44  has a detent lug  43 . The detent projections  38  and  42  are opposite each other on opposite sides of the base plate  34  and point away from each other, wherein their detent lugs  37  and  41  point in parallel in the same direction. The detent projections  40  and  44  lie opposite each other on opposite sides of the base plate  34  and point away from each other, wherein their detent lugs  39  and  43  point in parallel in the same direction. 
     The second coupling element  64  has a base plate  52  with two through-recesses  74  and optionally a display element  63 . The display element  63 , which can have a touch-sensitive surface, can be used, for example, to display status information or operational data of the power converter and to implement a user interface for user interaction with the power converter. The second coupling element  64  includes four detent protrusions  66 ,  68 ,  70 ,  72 . The detent projections  66 ,  68 ,  70 ,  72  each have a detent lug  65 ,  67 ,  69 ,  71 , shown in  FIG.  7   . The detent projections  66  and  70  are located opposite each other on opposite sides of the base plate  52  and point away from each other. Their detent lugs  65  and  69  point in parallel in the same direction. The detent projections  68  and  72  lie opposite each other on opposite sides of the base plate  52  and point away from each other. Their detent lugs  67  and  69  point in parallel in the same direction. 
     The coupling element has inserts  48  for closing the through-recesses  36 ,  74 . The inserts  48  are plate-like and have through-recesses  54 . The inserts  48  are, for example, made of rigid elastic material such as solid plastic and can be inserted into the through-recesses  36 ,  74  of the coupling elements  32  and  64 . Electrical lines, for example, can then run through the through-recesses  54  of the inserts  48  to interconnect components of the power converter located in different housings  10 ,  30 . The inserts  48  seal the through-recesses  36 ,  74  and thus the entire power converter (hermetically) from the particular environment and, by their through-recesses  54 , provide a suitable guide for the electrical lines. 
     Furthermore, elastic inserts can be provided for the through-recesses  36 ,  74  of the coupling elements  32 ,  64 . The elastic inserts can seal the relevant housing, to which they can be attached, from the environment and, for example, have a groove in which the protrusion  46  can engage. Sealing elastic inserts have, for example, no recesses or blind recesses. The sealing is performed, for example, against moisture, air and/or dust. The elastic inserts can, for example, be formed as a gel pad. The elastic inserts can also optionally have through-recesses through which electrical lines can be routed, in particular such powers which (in sum) can transport electrical powers of the order of magnitude of the rated power of the power converter. For both types of insert, elastic or rigid, it is advantageous if coupling elements  32 ,  64 , which are arranged between housings, have through-recesses  54 . Coupling elements  32 ,  64  that are connected to only one housing  10 ,  30 , for example, are provided with inserts without through-recesses so that they can seal the housing  10 ,  30 . 
       FIG.  7    schematically shows longitudinal sections through the coupling elements  32  and  64 . 
     The coupling element  64  has the two through-recesses  74 . In coupling element  64 , the detent projections  66  and  70  are arranged opposite each other and point in opposite directions. The detent projections  68  and  72  are arranged opposite each other and point in opposite directions. The detent projections  66  and  68  point in the same direction and are arranged on the same side of the base plate  52 . The detent projections  70  and  72  point in the same direction and are arranged on the same side of the base plate  52 . 
     The coupling element  32  has the two through-recesses  36  with the protrusion  46  peripherally therein. In coupling element  32 , detent projections  38  and  42  are arranged opposite each other and point in opposite directions. The detent projections  40  and  44  are arranged opposite each other and point in opposite directions. The detent projections  38  and  40  point in the same direction and are arranged on the same side of the base plate  34 . The detent projections  42  and  44  point in the same direction and are arranged on the same side of the base plate  34 . 
       FIG.  8    schematically shows a longitudinal section through the first and second housings  10 ,  30  and through the two coupling elements  32 ,  64 . In the housings  10 ,  30  there are arranged slots  25  in which the detent projections  38 ,  40 ,  42 ,  44 ,  66 ,  68 ,  70 ,  72  can be latched. 
       FIG.  9    schematically shows the first housing  10  and the coupling element  64 . The coupling element  64  can be arranged on the first housing  10  by inserting the detent projections  70 ,  72  of the coupling element  64  into the slots  25  on the corresponding frame side and latching them by means of the detent lugs  69 ,  71 . The frame  24  of the first housing  10  has through-recesses  60  which correspond to the through-recesses  74  of the coupling element  64  and through which, for example, electrical lines can be passed. 
       FIG.  10    shows how the coupling element  64  is arranged on the second housing  30 . Here, the detent projections  66 ,  68  are inserted into slots  25  of the second housing and latched in the slots  25  of the second housing  30  by the detent lugs  65 ,  67 . The free detent projections  70 ,  72  of the coupling element  64  may be inserted into slots of the first housing  10  and latched therein by means of the detent lugs  69 ,  72 . The housings  10 ,  30  can thus be connected and positioned. 
     In one embodiment, in the case of a wall bracketing according to  FIG.  5   , a coupling element  32 ,  64  can be positioned between the first and second housings  10 ,  30  and latched to the housings  10 ,  30  as described. In one embodiment, the second housing  30  can be held here at least temporarily by the first housing  10 . Subsequently, the housings  10 ,  30  connected in this way can optionally be screwed together. Optionally, further housings can be mounted, for example a third housing to the second housing  30  opposite the first housing  10  or to the first housing  10  opposite the second housing  30 . Such further housings can be fastened by means of further wall brackets  20 , which are spaced apart from the wall brackets  20  of the first or the second housing  10 ,  30  via further wall rails  62 . Optionally, further housings mountable in a horizontal direction are also conceivable. Connecting electrical lines can be routed through the through-recesses  60  in the frame  24  of the first housing  10  and in the frame  50  of the second housing  30 , as well as the through-recesses  74  of the coupling element  64 .