EP2577185A1

EP2577185A1 - Mounting rack for a photovoltaic module and tracking device for a photovoltaic installation

Info

Publication number: EP2577185A1
Application number: EP10774129.0A
Authority: EP
Inventors: Hans-Peter Fischer
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-05-25
Filing date: 2010-10-05
Publication date: 2013-04-10
Also published as: US20130075545A1

Abstract

In order to allow reliable and safe vertical tracking with a simple design at the same time for a photovoltaic installation having a multiplicity of photovoltaic modules (4) which are arranged on mounting racks (2), the invention provides for mounting rack (2) to in each case have a driver element (18) which, in particular, is cylindrical and has a common drive means (20) looping around it in the installed state. In order to prevent slip between the drive means (20) and the driver element (18), a friction braking device is provided which, in particular, is formed by a guide slot (24) in the driver element (18).

Description

description

Supporting frame for a photovoltaic module and tracking device for a

photovoltaic system

The invention relates to a support frame for a photovoltaic module having the features of the preamble of patent claim 1 and a tracking device for a photovoltaic system with a plurality of such support frames.

From EP 1 710 651 B1 a biaxial tracking device can be seen, in which both a vertical and a horizontal tracking is provided.

In photovoltaic systems, the achievable energy output depends on the angle of incidence of the sun relative to the photovoltaic module, so that it is expedient to increase the energy yield to use facilities that track the photovoltaic modules of the system depending on the year or time changing sun position. Here, on the one hand, the vertical tracking should be mentioned, in which the photovoltaic module is tracked by a rotation of the module supporting support structure about an axis which is substantially vertical to the earth's surface, the sun's run. In addition, in a two-axis tracking addition, a horizontal tracking is possible in such a way that the photovoltaic module is pivoted or inclined in a horizontal axis, so that ideally a right angle to the sun is guaranteed.

In the tracking device to be taken from EP 1 710 651 B1, a plurality of support frames for a respective photovoltaic module are provided via a common drive means, in particular a cable, for transmitting an actuating movement of a drive motor jointly assigned to the support frames. The rope is in each case around a driver element, which is designed as an approximately cylindrical drum, guided around and wraps around this. The advantage of this drive assembly with the one common motor for a variety of

CONFIRMATION COPY Support frames is that even with a variety of installed photovoltaic modules only one or a few motors are required.

Proceeding from this, the present invention seeks to provide a support frame and a tracking device, so that a reliable transmission of the actuating movement is ensured.

The object is achieved by a support frame with the features of claim 1, which in the assembled state is part of a tracking device for a photovoltaic system with a plurality of photovoltaic modules, which are preferably only vertically tracked the sun. The support frame is designed for automatic vertical tracking of the photovoltaic module mounted in operation on the support frame. It comprises a support pole and a rotatably connected to the support pole and this surrounding, preferably cylindrical driver element. In the assembled state this is wrapped by a particular flexible drive means for transmitting a driving force. In order to ensure a possible slip-free connection between the drive means and the driver element is provided between the drive means and the driver element Reibbremseinrichtung effective. In the assembled state, a plurality of supporting frames are connected for vertical tracking via the common drive means.

In view of a simple installation, the drive means is usually only loose, that is connected without fixed and positive connection with the driver element. When using a rope this is led around the driver element. Preferably, the entrainment element is in this case looped around by the cable in the manner of a loop, ie the cable is guided around the entrainment element at least one or more times. The transmission of the driving force takes place here via the associated friction between the drive means and the driver element, without a positive connection is formed. Depending on the size of the photovoltaic system, preferably several 10 to, for example, 30 or 40 supporting frames are connected to one another via a common drive motor and via the common drive means. U.N- Investigations have now shown that in this case the problem may arise that due to slippage between the driver element and the drive the different support frames undergo a different vertical tracking, ie in a field with a variety of such support frames there is a risk that these with respect to their Drehorientierung are aligned differently, which is to be avoided in terms of the most efficient solar yield.

In order to avoid this and at the same time to maintain the simplest possible installation by simply looping around the driver element, the friction brake device is provided which increases the friction between the driver element and the drive means so that slip between the two elements is avoided.

Conveniently, the driver element for this purpose has a lateral surface which has structuring as a friction brake device. For example, this is the lateral surface with elevations and depressions, so for example provided radially projecting webs to increase the friction.

In a preferred embodiment, the lateral surface has at least one guide slot extending in the circumferential direction. In the assembled state, the driver element is located in this guide slot. Due to the incorporation of the guide slot, the cable is therefore no longer smooth in this area on the mantle surface, but instead extends straight over the length of the guide slot away. At the entrance and exit ends of the guide slot, the rope rests against edges, so that the friction is significantly increased and slippage is avoided. The guide slot extends over an angle of rotation of more than 20 °, for example, and preferably more than 30 ° over the circumference of the driver element. The guide slot therefore covers a comparatively large circumferential angle, which has a positive effect on the desired high frictional force between the cable and the guide slot edges. In order to ensure a reliable guidance of the drive means around the driver element and in particular to ensure that the drive means runs through the guide slot, a guide element for guiding the drive means is provided in an expedient development. This is formed in particular by radially protruding from the lateral surface elements, such as guide webs, knobs or the like. By the guide element is therefore prevented that the driver element slides in the vertical direction along the lateral surface.

This is particularly advantageous in the installation of photovoltaic systems in the open field with bumps in which the individual support frames are not arranged on an identical horizontal height. The drive means may therefore possibly run obliquely to the vertical axis and guided to the driver element.

Conveniently, the guide element in this case has a guide region converging to the friction brake device, so that the drive means is also supplied in an oblique course to the friction brake device, in particular the guide slot. This is achieved for example by two opposing, converging or wedge-shaped and projecting radially from the lateral surface guide webs.

Two-axis tracking devices, which in addition to the vertical tracking about a vertical axis and a horizontal tracking is provided about a horizontal axis, usually require a high design effort and / or separate servo motors for the two Nachführbewegungen. In the case of the mechanical positive coupling between the vertical and the horizontal tracking to be taken from EP 1 170 651 B1, a high frictional force must be overcome by the drive. In order to achieve a cost-effective design of both the support frame and in view of the possibility of using less powerful engines is provided in an expedient embodiment that the support frame is designed exclusively for automatic vertical tracking. An automatic horizontal tracking, in which the angle of inclination during the course of the day takes account of the position of the sun by a varying horizontal inclination is not provided.

To additionally ensure at the same time the highest possible solar yield depending on the installation of the photovoltaic system is additionally provided that a fixing device for manual adjustment of a horizontal angle of inclination is provided. For this purpose, the support frame has a support frame on which the respective photovoltaic module rests in the mounted state. This support frame is movably mounted about a horizontal pivot axis.

At the same time, a defined horizontal angle of inclination can be fixed manually via the fixing device. Thus, for example, depending on the installation location (latitude) as optimal as possible horizontal inclination angle is set, preferably once during installation or commissioning of the system.

Conveniently, the fixing device in this case comprises a plurality of discrete locking settings for setting defined horizontal angles of inclination. This is achieved in particular by the fact that the fixing device comprises a linkage, which is arranged between the support mast and the support frame, and which has a variable attachment end, which can preferably be locked or fastened to the support mast at different positions in order to be able to adjust the different angles of inclination , In particular, this is arranged on the support mast a perforated plate.

Preferably, the support frame comprises an adjusting device, via which the rotational orientation of different portions of the support mast are mutually adjustable, ie mutually reversible to each other can be fixed. This adjustment is used to simplify the assembly or for easy readjustment in the course of operation. In a photovoltaic system with a plurality of interconnected support frames, the vertical tracking is done via a common drive motor, there is the problem that due to tolerances and play in the drive train, the individual photovoltaic modules occupy a different azimuth angle after installation of the common drive means, ie a different angle of rotation around the vertical axis. By the division of the support structure in two sections, which are rotatable against each other, the advantage is achieved that after installation of the system, if due to such play and tolerance effects, the vertical orientation between different support frames is not completely in sync, the vertical rotational position of individual support frames in a simple Way is adjustable without the support frame must be rotated in total with respect to an anchoring element.

The two sections of the support mast are preferably interconnected at the separation point via flanges. At least one of the flanges has a slot guide, preferably curved along a circular path, for a fastening element such as a screw. The flanges ensure easy assembly and high mechanical stability. Usually, it is provided that the drive for the vertical tracking on one of the two subregions, in particular the lower portion attacks.

According to a preferred embodiment, the flange of the lower portion of the support mast forms an upper termination for the driver element, i. the separation point is arranged at the upper end of the driver element. In the case of the hollow cylindrical design of the driver element, this flange preferably forms a cover, so that a closed assembly is formed. A storage area of the support mast on the footplate is thereby better protected.

The object is further achieved according to the invention by a tracking device for a Photovoitaikanlage in which a plurality of such support frames are connected to each other via a common drive means, in particular rope. The drive means is driven by a common drive for the exercise of an actuating movement for the support frames for vertical tracking. The drive means is in this case frictionally guided around the driver elements, preferably these are fully or repeatedly wrapped by the drive means. Embodiments of the invention will be explained in more detail below with reference to FIGS. It shows in simplified representations

1 is a support frame with photovoltaic module mounted thereon in a perspective view,

2 shows the support frame according to FIG. 1 in a side view, FIG.

Fig. 3 is a rough simplified representation of a tracking device with several connected via a common drive means and driven by a common drive motor supporting frames.

4 is a perspective enlarged view of the bottom-side portion of the support frame with a cylindrical, arranged around a support mast entrainment,

5 shows the elements according to FIG. 3 in a side view, FIG.

Fig. 6 is a simplified side view of a driver with guide slot and guide elements and

7 is a sectional view in the region of the driver for illustrating the adjusting device,

In the figures, like-acting parts are provided with the same reference numerals.

1 shows a support frame 2 with a photovoltaic module 4 mounted thereon. In this case, the photovoltaic module 4 can again be composed of individual sub-modules which are electrically interconnected with one another.

The support frame 2 - as shown again in Fig. 2 - comprises a vertically extending support pole 6, which carries at its upper end a support frame 8, on which the photovoltaic module 4 is fixed. The support frame 8 is in this case adjustable about a horizontal pivot axis 10 in its inclination. Spaced from the pivot axis 10, a strut 12 of the support frame 8 is arranged, on which a rod consisting of a rod 14 is rotatably mounted. The linkage 14 is fixed with its lower end to the support pole 6. For this purpose, a perforated plate 16 is attached to the support pole 6 in the embodiment. The linkage 14 is in this perforated plate 16 by means of a fastener in unobstructed attachable different vertical positions. The linkage 14 with the perforated plate 16 therefore forms a fixing device for manual adjustment of a horizontal angle of inclination of the support frame eighth

The support frame 2 has at its lower, bottom-side end a mounting foot 17, with which it is to be anchored to the ground. In the embodiment, a flange-like plate is provided for this purpose, which can be anchored via screws in the ground. In the exemplary embodiment, a driver element 18 is provided immediately above the mounting foot 17. An adjusting movement, namely a rotational movement about the vertical axis of the support mast 6, is exerted on the support mast 6 by means of a drive means 20 (see FIG. As a result, a vertical tracking of the photovoltaic module 4, so a tracking in east-west direction allows. Due to the immediate arrangement near the bottom, the tilting moments exerted on the support frame 2 via the drive means 20 (with respect to the vertical) are kept low.

In a photovoltaic system usually a plurality of such support frames 2 with photovoltaic modules 4 is arranged in one or more rows. By way of example and in simple terms, FIG. 3 shows a single-row arrangement with a total of five support frames 2, which are symbolized by the driver element 18. As can be seen from this, the individual supporting frames 2 are connected to one another via the common drive means 20, in particular a cable (wire rope) and to carry out the vertical tracking, the rotational movement is synchronously transmitted to all driver elements 18 via the drive means 20. The drive means 20 is in this case wrapped around each of the driver elements 18, ie, each driver element 18 rotates completely at least once. Furthermore, a common drive 22, in particular electric motor is arranged, via which the actuating force is transmitted to the drive means. The support frames 2 together with the drive means 20 and the drive 22 forms a tracking device for a vertical tracking of the individual photovoltaic modules. The tracking is controlled according to the time of day. In order to ensure a synchronous rotational adjustment of the individual support frames 2, a friction brake device is provided, which is formed in the embodiment as a circumferentially extending guide slot 24 which is introduced in a lateral surface 26 of the driver element designed as a hollow cylinder 18. The configuration of the driver element 18 with the guide slot 24 can best be seen from FIGS. 3 to 5. The guide slot 24 has, for example, a width of 5 to 10 mm and preferably extends over a rotational angle, for example in the range of 20 ° to 60 ° in the circumferential direction.

As a result of this friction brake device designed in this way, the frictional force acting between the drive means 20 (cable) and the driver element 18 is significantly increased compared to a design without a guide slot 24, so that slip between the drive means 20 and the driver element 18 is avoided. When tensioning the rope during commissioning, this applies to the edge-side edges (viewed in the circumferential direction) of the guide slot 24, so that these edges form a friction brake acting in both directions with little design effort. As a result, a synchronous vertical tracking of all supporting frames 2 is ensured.

Fig. 5 shows a variant embodiment, wherein in addition to the guide slot 24 still guide elements 28 are arranged on the lateral surface 26. In the exemplary embodiment, these are arranged in the circumferential direction on both sides of the guide slot 24. The respective guide element 28 is in this case formed by two opposite guide webs which protrude radially on the lateral surface 26 and define a guide region 30 between them. In the exemplary embodiment, this guide region 30 converges towards the guide slot. By means of these guide elements 28, a reliable and secure guidance of the drive means 20 in the desired desired position is achieved even in the case of a deployment in the open field, in which the various supporting frames 2 are fastened at different height levels. Slipping in the vertical direction is avoided. As is apparent from Fig. 7, the support mast 6 is rotatably arranged together with the driver element 18 on the mounting foot 17. For this purpose, in the exemplary embodiment, the fastening foot 17 has a support tube 34 which extends in the vertical direction and over which the hollow-cylindrical support mast 6 is slipped. The support mast 6 itself is subdivided into two subregions 36A, 36B, which are connected to one another via a flange connection. For this purpose, a fastening flange 38A, B is disposed on each of the subregions 36A, B, which in the exemplary embodiment are designed as radially projecting and, in particular, annular plates. The two mounting flanges 38A, B and thus the two portions 36A, B are fastened to each other at different rotational positions. For this purpose, in particular a slot guide and fasteners are provided. As a result, an adjusting device for the rotational adjustment of the two partial areas 36A, B is formed with each other. This adjustment device is used to simplify installation, at startup after the construction and the looping of the individual

Driver elements 18 with the drive means 20, the individual photovoltaic modules 4 to align exactly in the same east-west angular position. In this way, a synchronous alignment of all photovoltaic modules 4 is made possible in a simple manner during commissioning. About the separation point is generally defined a decoupling possibility between the drive train and the upper portion.

As can be seen from Fig. 7, the driver element 18 is formed in the manner of a hollow cylinder, which is non-rotatably connected via struts with the lower portion 36A. In the exemplary embodiment, the flange 38A of the lower portion 36A at the same time forms an upper cover of the hollow cylindrical driver element 18. Overall, a largely closed inner cavity is thereby created, in which in particular the bearing point of the support mast 6 rests protected.

In order to avoid sluggishness sliding elements are provided in the embodiment of the type of bearing sleeves. These are each arranged in the lower and upper regions of the support tube 34. Preferably, both bearing sleeves a kind of ring flange. The support mast 6 is supported with its lower end, on which it also forms an annular flange, on this annular flange of the bearing sleeve, so that a rather flat contact is formed. The bearing sleeves consist for example of an abrasion-resistant plastic or of a suitable metal.

Furthermore, a storm protection 40 is provided for the support mast 6 such that the support mast is secured in particular against an axial lifting of the mounting foot 17 with simultaneous rotatability. In the embodiment, this is an acting in the axial direction positive engagement between the mounting bracket 17 and the support mast 6, in particular its bottom-side flange is formed. The storm protection 40 is in this case formed in a simple manner by a bent tab, which is fastened with its one end to the mounting bracket 17 and protrudes with its other end on the flange, in particular with a small axial distance.

The support frame 2 described here, as well as the tracking device described with reference to FIG. 3, are characterized overall by a simple structure and high operational reliability. The simple structure is decisively coined, in particular, by the support frame 2, which is designed only for a single-axis, vertical automatic tracking system. It is also of particular advantage that a manual adjustment of the horizontal angle of inclination can be made via the fixing device, in order to ensure the highest possible solar yield despite the simplified structure. For the simple and inexpensive construction is also of particular importance the design with the driver element 18 and the common drive 22 and the common drive means 20 for a plurality of supporting frames 2. By Reibbremseinrichtung a reliable operation with synchronous vertical tracking is guaranteed. With regard to the ease of installation is still emphasize the adjustment, which allows an exact synchronous adjustment of the individual photovoltaic modules 4 in the same orientation after installation of the drive means 20. These three aspects, namely the fixing device with the manual adjustment of the horizontal inclination, the Reibbremseinrichtung and the Adjustment are in principle independently feasible. The fixing device and the adjusting device can therefore also be realized independently of the embodiment with the Reibbremseinrichtung. The submission of divisional applications to these aspects, irrespective of the configuration with the friction brake device, is reserved.

Bezugszetchenliste

2 support frame

4 photovoltaic module

6 support pole

8 supporting frame

10 horizontal pivot axis

12 strut

14 linkages

16 perforated sheet

17 mounting foot

18 driver element

20 drive means

22 drive

24 guide slot

26 lateral surface

28 guide element

30 leadership area

34 support tube

36A.B subarea

38A.B mounting flange

40 tab

Claims

claims

1. supporting frame (2) for a photovoltaic module (4) to be tracked for the sun, which is designed for vertical tracking of the photovoltaic module (4) and a support mast (6) and a driver element (18) connected to and rotatably connected to the support mast (6) comprises, in the mounted state by a drive means (20) for transmitting a driving force is looped, characterized in that a Reibbremseinrichtung (24) for preventing slippage between the driver element (18) and the drive means (20) is provided.

Second support frame (2) according to claim 1, characterized in that the driver element (18) has a lateral surface (26) which has a structuring as a friction brake device (24).

3. supporting frame (2) according to claim 2, characterized in that the lateral surface (26) has at least one extending in the circumferential direction guide slot (24) in which rests the drive means (20) in the assembled state.

4. Supporting frame (2) according to one of the preceding claims, characterized in that on the driver element (18) is provided a guide element (28) for guiding the drive means (20).

5. Supporting frame (2) according to claim 4, characterized in that the guide element (28) forms a friction brake device (24) converging guide region (30).

6. Supporting frame (2) according to one of the preceding claims, characterized in that a support frame (8) is provided, on which the photovoltaic module (4) rests in the mounted state, wherein a fixing device (14, 16) for manual adjustment of a horizontal inclination angle is provided.

7. Supporting frame (2) according to claim 6, characterized in that the fixing device (14, 16) has a plurality of discrete locking positions for setting defined horizontal angles of inclination.

8. Support frame (2) according to claim 7, characterized in that the fixing device comprises a linkage (14) which is connected on the one hand to the support mast (6) and on the other hand to the support frame (8), wherein a variable attachment end of the linkage (14 ) can be locked at different positions to set the horizontal angle of inclination.

9. Supporting frame (2) according to claim 8, characterized in that the fixing device has a support mast (6) fixed perforated plate (16) via which the variable attachment end can be locked at different positions.

10. Supporting frame (2) according to one of the preceding claims, characterized in that for the bottom-side attachment of the support frame (2) a mounting foot (17) and an adjusting device for rotational adjustment of partial areas (36A.B) of the support mast (6) is provided with each other.

11. tracking device for a photovoltaic system with a plurality of supporting frames (2) according to any one of the preceding claims, with a common drive (22) and a common drive means (20) for transmitting an actuating movement for vertical tracking on the individual support frames (2), wherein the drive means is guided around the driver elements (18).