The present invention relates to a linearly-arranged solar array comprising at least two tracking support systems for solar panels, and to a solar field integrating at least two linearly-arranged solar arrays in parallel.
The object of the invention relates to the field of tracking support systems, also called solar trackers, and specifically, to tracking support systems that can be oriented according to one single main axis of rotation, in order to follow the Sun as it rises and goes down from East to West. For information, such a main axis of rotation extends substantially parallel to the ground to which the tracking support system is anchored.
Such tracking support systems are often combined in line (extending from North to South) within linearly-arranged solar arrays, and these linearly-arranged solar arrays are, in turn, duplicated so as to form a solar field which may integrate several tens, and even several thousands, of tracking support systems.
In solar fields that integrate several linearly-arranged solar arrays, it is known, in particular from documents ES 2 368402, US 2008/308091 and EP 2 317 247, to mount several movable platforms, side-by-side, in order to form lines which are driven in rotation by means of a cross transmission system. Thus, all movable platforms are rotatably coupled perpendicular to the main axis of rotation.
Furthermore, these documents describe a rotational coupling between parallel linearly-arranged arrays by setting up connecting bars which extend perpendicular to the lines in order to connect together the movable platforms, and which extend across and in the middle of the alleys bordered by the linearly-arranged arrays. These connecting bars are positioned between two platforms, in particular at the middle of horizontal beams, and consequently across the alleys, so that the torque that is exerted by the connecting bars on the beams is sufficient for rotating each beam from end to end. Such connecting bars constitute a real inconvenience for the traffic of vehicles in these alleys, such as for example vehicles intended for cleaning the solar panels, for transport of personnel and maintenance and repair equipment, etc.
The present invention aims to solve these drawbacks by providing a linearly-arranged solar array which exhibits a simple design and which offers the possibility of traffic of vehicles in the alleys bordered by such arrays.
To this end, it provides a linearly-arranged solar array comprising at least two tracking support systems for solar panels, wherein each tracking support system can be oriented according to one single main axis of rotation, wherein the tracking support systems are aligned on the same line with their main axes of rotation being substantially coincident, said solar array being characterized in that each tracking support system comprises:
and in that the array further comprises an actuation system which is common to said tracking support systems, said actuation system being coupled to their mechanical drive systems via a mechanical transmission device extending parallel to the main axis of rotation, said transmission device being coupled to the movable devices of the mechanical drive systems of each tracking support system, so that the platforms are driven in rotation concomitantly by said actuation system by means of the transmission device and the mechanical drive systems.
Thus, the array is realized from several tracking support systems each having its own fixed structure, its own movable structure with the platform, and its own mechanical system for driving the movable structure in rotation; the synchronous rotation of the platforms being achieved by an actuation system which is common to the linearly-arranged array, this common actuation system being coupled to different mechanical drive systems by a transmission device which is distinct from the movable structure and mounted in an offset manner with respect to the main axis of rotation, thereby facilitating the mounting and maintenance of the array. This transmission device extends parallel to the main axis of rotation in order not to disturb the traffic of vehicles in the adjacent alleys.
The platform of the movable structure of a tracking support system may comprise one or several beams, each beam being parallel to the main axis of rotation. As a non-limiting example, the platform may optionally comprise several cross-members perpendicular to the axis of rotation and secured on each beam. Of course, the solar panels may be directly secured on the beam(s).
Of course, in a solar field which integrates several lines of solar panels, it is possible to have several linearly-arranged solar arrays in accordance with the invention, on the same line. In fact, with lines of solar panels extending over several hundreds of meters, with several tens of tracking support systems per each line, it is advantageous, for mechanical reasons, to have several linearly-arranged solar arrays disposed side-by-side and aligned on the same line, and hence, have several actuation systems per each line, always with one single actuation system per each linearly-arranged solar array which would be common to several tracking support systems. As will be described next, it is also possible to have one single actuation system that is common to two linearly-arranged solar arrays which are placed on two parallel and adjacent lines.
Moreover, it should be noted that the main axes of rotation are substantially parallel to the ground to which the array is anchored, and that, for the same linearly-arranged array, these main axes of rotation are substantially coincident, in the sense that they may be completely coincident in the case where all tracking support systems have been anchored to a flat even ground, but theses main axes of rotation may be substantially tilted with respect to each other in the case where the tracking support systems of the same array are anchored to a slightly hilly ground.
According to the invention, the platforms of the tracking support systems are not directly connected to each other and they are spaced apart by a predetermined distance along the main axis of rotation.
According to one feature, the actuation system is secured on the fixed structure or on the mechanical drive system of either one of the tracking support systems, in particular on a central tracking support system.
According to another feature, the movable device of the mechanical drive system of each tracking support system is disposed below the corresponding platform, and the transmission device extends below the platforms of the tracking support systems.
According to another feature, the platform of each tracking support system comprises a central beam rotatably mounted on the fixed structure about the main axis of rotation, and the connecting element of each mechanical drive system is fixedly mounted on said central beam, preferably in the proximity of a rotation bearing of the central beam on the fixed structure.
According to another feature, the transmission device comprises either one of the devices that are listed below:
In a first embodiment, the mechanical drive system of each tracking support system is of the type comprising a ring gear sector meshing with a gearwheel, in particular a worm screw, said gearwheel being rotatably coupled to the transmission device and rotatably mounted on a bearing secured on the fixed structure, and the ring gear sector is secured to the platform, the ring gear sector and the gearwheel respectively forming the connecting element and the movable device of the mechanical drive system.
Such a solution is particularly advantageous in terms of robustness and reliability of the rotation of the platforms. In one embodiment with one single beam per each tracking support system, the ring gear sector may be directly secured to the beam. In another embodiment with two beams or more per each tracking support system, the ring gear sector may be secured to a cross-member which is, in turn, secured to the beams.
In a second embodiment, the mechanical drive system of each tracking support system is of the type comprising a parallel link mechanism comprising:
wherein the transmission device is connected to the central hinges formed between the lower and upper arms in order to displace said central hinges toward and away from each other, the transmission arm and the assembly (so-called, the parallel link assembly) that integrates the lower and upper arms respectively forming the connecting element and the movable device of the mechanical drive system.
Such a solution is particularly advantageous in terms of robustness and cost, and it has the benefit of a particularly reduced wear of the parts that constitute the parallel link mechanism. Moreover, it is advantageously possible to consider such a mechanical drive system on an independent tracking support system which has its own actuation system.
Advantageously, according to this second embodiment, the actuation system consists of an actuating cylinder and it includes a body secured on either one of the lower and upper arms at the first central hinge of a mechanical drive system of either one of the tracking support systems, and a rod movable inside the body and exhibiting an end secured to the second central hinge of said mechanical drive system.
Still advantageously, according to this second embodiment, the transmission device consists of a cable type transmission and it includes two cables respectively fastened to the first and second central hinges of the mechanical drive systems of each tracking support system.
In a third embodiment, the mechanical drive system of each tracking support system is of the type comprising a nut in which a threaded rod is engaged, said nut being pivotally mounted on the fixed structure via an axle perpendicular to the threaded rod, and said threaded rod exhibiting a lower end rotatably coupled to the transmission device and an upper end coupled to a first end of a transmission arm via a ball joint connection, said transmission arm exhibiting an opposite second end rotatably secured to the platform, the transmission arm and the threaded rod respectively forming the connecting element and the movable device of the mechanical drive system.
Such a solution is particularly advantageous in terms of robustness and durability.
Advantageously, the actuation system consists of a rotary motor or an actuating cylinder.
The invention also relates to a solar field of the type comprising at least two linearly-arranged solar arrays, each linearly-arranged solar array comprising at least two tracking support systems for solar panels, wherein each tracking support system can be oriented according to one single main axis of rotation and comprises:
wherein said linearly-arranged solar arrays extend substantially parallel to each other and at least one of the solar arrays is in accordance with the invention.
According to a first possibility, the two solar arrays are in accordance with the invention. Thus, the rotational motions of the two arrays are independent, therefore, there is no material obstacle which can disturb the traffic in the alley bordered by these two arrays.
According to a second possibility:
and the field further comprises at least one connection between the transmission device of the first array and the transmission device of the second array, so that the platforms of the second array are driven in rotation by the actuation system of the first array, concomitantly with the platforms of the first array, by means of the connection(s) between the two arrays.
Thus, the rotational motions of the two arrays are dependent of each other, with the actuation system of the first array ensuring the rotation of the platforms of the two arrays. Thus, the arrays are referred to as a pair of coupled arrays. The rotation of the platforms of the first array is transmitted to those of the second array thanks to the connection(s). Thus, a vehicle can circulate between two pairs of coupled arrays, therefore at least between two rows, along the entire length of the alley which separates two such pairs of coupled arrays, without any restriction. The connection is advantageously, but not necessarily, disposed at the extremities of the arrays in order to limit the inconvenience.
Other features and advantages of the present invention will appear upon reading the following detailed description, of three non-limiting embodiments, with reference to the appended figures in which:
Referring to
Within the same solar array 1, the tracking support systems 2 are aligned on the same line with their main axes of rotation 20 substantially coincident, while considering the clearances due to mounting and on-site installation and the defects of the ground (irregularities of the terrain, defective planarity, etc.).
This tracking support system 2 comprises:
In the embodiments that are illustrated in the figures, the fixed structure 21 comprises two bases spaced apart along the main axis of rotation 20 and each including two ground anchor feet. Each of the two bases of the fixed structure 21 supports an upper bearing 210, the beam 23 being rotatably mounted in these two bearings 210. Anchoring the fixed structure 21 to the ground may be achieved by means of anchor piles, preferably one pile per each foot, and/or by means of counterweights. Of course, the fixed structure 21 may be realized in other forms, in particular in the form of a pylon or a post.
The platforms 22, and hence the beams 23, are not connected to each other, and the beams 23 of two adjacent tracking support systems 2 are spaced apart by a predetermined distance. Of course, it is possible to have at least two parallel beams 23, instead of one single beam 23.
In the first embodiment illustrated in
In the second embodiment illustrated in
From a functional point of view, by displacing the central hinges 253 formed between the lower arms 250 and the upper arms 251 horizontally away from each other, the first end of the transmission arm 252 is pulled downward, and therefore, the beam 23, and hence the platform 22, are rotated in one direction, whereas by displacing these central hinges 253 horizontally toward each other, the first end of the transmission arm 252 is pushed upward, and therefore, the platform 22 is rotated in the opposite direction.
In the third embodiment illustrated in
From a functional point of view, by rotating the threaded rod 261 in either direction, the threaded rod 261 is raised or lowered in the nut 260 which pivots on the axle 264 in order to follow the motion, so that the first end of the transmission arm 262 is pushed upward or pulled downward, and therefore, the beam 23, and hence the platform 22, are rotated in either direction.
In accordance with the invention, the array 1 further comprises an actuation system 3 which is common to all tracking support systems 2, in order to rotate their respective platforms 22 in a synchronous manner.
This actuation system 3, which consists of a power actuator, is coupled to mechanical drive systems 24, 25, 26 of all these tracking support systems 2, via a mechanical transmission device 4 extending parallel to the beams 23. Thus, this actuation system acts on all mechanical drive systems 24, 25, 26 in order to rotate all platforms 22 of the same array 1, at the same time. Of course, as has been described before, it is possible to have several linearly-arranged solar arrays in accordance with the invention which are placed on the same line, and which are then aligned and disposed successively side-by-side.
In the first embodiment and as is illustrated in
As can be seen in
In order to convert the rotation of the rotary motor 3 into a displacement of the mechanical drive systems 24, 25, 26, several transmission devices 4 may be considered.
In a first variant of the first embodiment which is illustrated in
It is also possible to provide a belt and pulley transmission (by replacing each cable 40 by a belt) or a chain and sprocket transmission (by replacing each cable 40 by a chain and the pulleys by sprockets).
In a second variant of the first embodiment which is illustrated in
In the second embodiment of
In this second embodiment, the transmission device 4 consists of a cable type transmission 44. As can be seen in
In the variant of
Thus, by displacing the central hinges 253 toward or away from each other, the two cables 44 pull the hinges of the other parallel link mechanisms, and therefore, all platforms 22 pivot in a synchronous manner.
Of course, in this second embodiment, it is possible to consider replacing the actuating cylinder by a rotary motor which pulls the cables 44 horizontally in order to displace the central hinges 253 of all parallel link mechanisms toward and away from each other.
In the third embodiment illustrated in
The transmission device 4 of the first array 1 is connected to the transmission device 4 of the second array 10 by a connection 5, in particular a connecting rotary driveshaft exhibiting a first end rotatably coupled to a pulley 41 of the transmission device 4 of the first array 1, and a second end rotatably coupled to a pulley 41 of the transmission device 4 of the second array 10. This connection 5 is advantageously, but not necessarily, disposed at the extremities of the arrays 1, 10.
Thus, the rotation of the rotary motor 3 of the first array 1 is transmitted to the platforms 22 of the second array 10 via the connection 5 and via the transmission device 4 of the second array 10.
Thus, it is possible to circulate freely in the alleys A bordered by the two arrays 1, 10 which are paired together by a connection 5.
Of course, the above-mentioned embodiment is by no way limitative and other improvements and details may be brought to the solar array of the invention, without departing from the scope of the invention where other forms of the mechanical drive systems and/or the transmission device may, for example, be considered.
Number | Date | Country | Kind |
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1350975 | Feb 2013 | FR | national |
Filing Document | Filing Date | Country | Kind |
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PCT/FR2014/050203 | 2/4/2014 | WO | 00 |