Embodiments of the claimed invention relate to tracking in general, and more particularly trackers and systems for tracking the sun and/or other astronomical objects based on two general axes of rotation.
In the emerging industry of solar power, dual axis sun tracking has been the favored approach over single axis tracking owing to its known reputation as a more effective additional facility to provide accurate positioning thus significantly improving solar panel overall output. Primarily formed with means for tracking the motion of the sun, dual axis trackers are often used to provide tracking movements for a plurality of linked solar panels, such linking thereby necessitates the plurality of panels to be mounted on considerably large and complex frame or fixtures. These frames are typically sustained by a single vertical support post and equipped with numerous components to provide dual axis movements in addition to ensuring the panels move in alignment based on two axes. In many occasions, an insubstantial structure would face instability complications particularly due to weight imbalance and wind load effects on solar panels.
However, the overall handling of dual axis trackers and systems and its installation are often associated with complexity and being prohibitively expensive due to the considerably large number of operational components compared to that of single axis trackers. Perceptibly, increased complexity and number of components introduces additional possibilities for malfunctions and overall failures. Another major barrier for installation of solar tracking systems is portability and construction, whereby for highly complex systems having a large number of moving parts, portability and construction would be correspondingly difficult and in some cases, would involve relatively high cost.
In an effort to alleviate or partially address the current drawbacks of dual axis sun trackers and systems, the idea of central actuating structures or members adapted to provide synchronized movements for a plurality of solar panels have been introduced in the market, although a great majority of these structures suffers from one or more flaws such as complexity in installation, ineffective wind loading features, weight imbalances which could gradually affect the tracking accuracy and thus become uneconomical.
One of the helpful attempts to resolve issues linked to weigh imbalance in sustaining large amount of solar arrays; is as disclosed in U.S. Pat. No. 4,968,355 (Johnson), whereby this patent teaches a counterbalanced solar tracking system including a plurality of truss structures, polar driving means and a plurality of wheel segments to move arrays of panels. From here it is apparent that although the disclosed structure may be expedient for providing a counterbalanced sun tracking system there appears to be a large number of moving components involved in order to achieve the desired results. Therefore, installation for this system can be a complicated task.
In another disclosure, United States Application Number 2011/0041834 (Liao, Henry H) teaches a dual axis solar tracker system and apparatus which comprises dual linear actuators mounted adjacent to a ground post which is a vertical post, a rotatable or rotating head being connected to the top end of the ground post for providing or actuating dual axis movements of two panels mounted to a horizontal beam. The rotating head is essential to permit rotation of the panels. Based on the moving parts disclosed, this tracker system can be regarded as cost effective, however the number of solar panel that can be mounted to each horizontal beam is limited, otherwise the stability of the tracker system may be compromised. Therefore, this tracker may not be effectively fit for supporting a large array of solar panels or providing synchronized movements for a large number of solar panels.
In another exemplary of the prior art, European Patent Number 1998122 A1 has suggested a rotating head or an additional device that enables the rotation or at least causes rotation of the supported PV module. It can be seen from this particular disclosure that the rotation of module is heavily dependent on a spherical tower affixed to a base structure. The tower is adapted to be able to tilt and track the sun. The weight of the photovoltaic module is entirely supported by a spherical tower adapted to provide movements to said module in tracking the sun. From here it can be recognized that the structure, more particularly the tower may succumb to failure after a period of time owing to the mechanical stress and strain from the large number of panels to be supported on a single point.
Accordingly, there remains a considerable need for solar trackers systems and methods that can expediently resolve the drawbacks associated to providing a counterbalanced and stable dual axis solar tracking structure to provide synchronized movements for a plurality of solar panels with minimum number of moving components thus substantially reducing the overall cost and time required for installation.
Various objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawings in which like numerals represent like components or members.
In one aspect of the claimed invention, there is disclosed a dual axis solar tracking system (200) comprising: a support structure (300) for supporting at least one solar device (1) comprising at least two horizontal members (301,302), at least one transverse post (308) secured at a central region of the support structure (300) and a movable carriage frame (353) pivotally coupled to the horizontal members (301, 302);
In a further aspect of the claimed invention, there is at least one carrier arm (351) pivotally coupled to at least one of the horizontal members (301, 302) and to the movable carriage frame (353); said carrier arm (351) for holding at least one solar device (1); a motion assembly (352) pivotally coupled to the carriage frame (353) for providing movements to the carriage frame (353) and the carrier arm (351).
In another aspect of the claimed invention, the motion assembly (352) comprises at least one telescopic member (352a) and a track assembly (352b); said track assembly (352b) comprising at least one sliding member (40) being slidably connected to a sliding track (41).
In a further aspect of the claimed invention, the telescopic member (352a) is pivotally and slidably coupled to the motion assembly (352) and in a manner such that a lower section of the telescopic member (352a) is slidable on the sliding member (40); and that the lower section of the telescopic member (352a) is movable laterally or forward and backward.
It is another aspect of the claimed invention at which the solar device (1) varying orientations or movements are in response to the motions provided by the motion assembly (352) in cooperation with the carriage frame (353) and the carrier arm (351).
These and further objects and advantages will be apparent to those skilled in the art in connection with the drawings and then detailed description of the embodiments set forth below.
Features of the claimed invention will be apparent from the following description when read with reference to the accompanying drawings:
a) illustrates the overall view of the solar tracking system in accordance with the preferred embodiments of the claimed invention;
b) illustrates a perspective view of the support structure (300) for the system (200) in accordance with a preferred embodiment of the claimed invention;
a) shows a perspective and elevated view of the motion assembly in accordance with the preferred embodiments of the claimed invention;
b) shows another perspective and elevated view of the motion assembly in accordance with the preferred embodiments of the claimed invention;
c) shows a view of a mounting member in accordance with the preferred embodiments of claimed invention;
a) illustrates the carrier arm without the solar device in accordance with the preferred embodiments of the claimed invention;
b) illustrates the carrier arm having two solar panels and reflective means mounted thereon in accordance with the preferred embodiments of the claimed invention;
c) illustrates a connector for providing pivotal connection of the carrier arm to the horizontal post in accordance with the preferred embodiments of the claimed invention;
a)-
In the following description, reference is made to the accompanying drawings where, by way of illustration, specific embodiments of the invention are shown. It is to be understood that other embodiments may be used as structural and other changes may be made without departing from the scope of the claimed invention. Also, the various embodiments and aspects from each of the various embodiments may be used in any suitable combinations. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.
Embodiments of the claimed invention are directed to a solar tracker having the object of solving the previously discussed drawbacks in a cost effective manner.
Relative terms such as “upper”, “lower”, “below”, “above” and the likes may be used for ease of description in elucidating the subject matter of the present invention, particularly for describing an element or member's relationship to another member or element.
To that end the tracking system in accordance with the preferred embodiments of the claimed invention provides orientations in tracking the sun for an array of solar-based devices; based on two different axes. It is contemplated that the tracking system can be used for tracking other astronomical objects of the solar system. Examples of solar devices include solar panels and additional solar reflector/concentrator members; whereby these devices are linked within the system in a manner such that the synchronized movements can be provided with minimum number of moving components.
a) generally illustrate dual axis tracking system (200) for supporting and moving a plurality of solar devices (1,2), module or an array of solar based devices in tracking the sun in one embodiment, comprising a plurality of solar devices (1,2); support structure (300), at least one carrier arm (351) (inserted in amended drawings), a carriage assembly for holding and providing movement of solar devices (1, 2) and a motion transfer or motion assembly (352).
Support Structure
b) shows a perspective view of the support structure (300) for the system (200) in accordance with a preferred embodiment of the claimed invention.
Now referring to
As shown in
In one aspect of the claimed invention, the horizontal members (301, 302) are in the form of square hollow posts. As briefly discussed in the preceding paragraph, each end of the horizontal members (301, 302) is rotatably connected to at least two mutually opposing vertical support posts (303, 304, 305,306). The vertical posts (303, 304, 305,306) may be constructed from suitable materials with sufficient strength to support the overall structure including the plurality of solar devices (1,2).
Accordingly in order to achieve a rotatable connection or attachment with the horizontal members (301, 302), the vertical posts (303, 304, 305, 306) may include a cross tube thus forming a T-shaped post as shown
As seen in
The purpose of the transverse post (308) will be described herein below in conjunction with the carriage assembly.
The support structure (300) further comprises a plurality of concrete blocks (80, 81, 82, 83) or anchoring means of the likes to serve as foundations for the tracking system (200).
Carriage Assembly
In this embodiment, the carriage frame (353) generally comprises of at least four horizontal posts interlocked together in a manner such that they form a H-shaped frame. For this configuration, two of the said posts being spaced apart at a predetermined distance, referred herein as the middle posts (19,20) are perpendicularly connected in between two other posts (17, 18), which are referred herein as lateral posts. At least two horizontal posts of the carriage frame (353), particularly the lateral posts (17, 18), are in parallel position with that of the horizontal posts (301, 302) of the support structure when assembled, and are pivotally connected to at least one carrier arm (351) (overall illustration of carrier arm is shown in
Motion Assembly
a) shows a perspective and elevated view of the motion assembly (352) in accordance with the preferred embodiments of the claimed invention.
Now referring to
Now referring to
Still referring to
Accordingly, the first concentric rings connector (70a, 70b) is positioned at the top portion of the telescopic unit (352a), whereby for this portion, the outer ring (70b) is secured or may be formed with the transverse post (308). The second set of concentric rings (71a, 71b) is positioned approximately at the middle portion or section of the telescopic member (352a) whereby the telescopic member (352a) slides through the inner ring (71a) of the second concentric ring (71a, 71b) and terminates at the first concentric ring (70a, 70b). In this arrangement, the outer ring (71b) is secured to the middle region of the carriage frame (353). The third concentric rings set (72a, 72b) is positioned at the lower portion of the telescopic unit (352a), and connected to the track assembly (352b). It should be noted that in this embodiment, in order to allow the telescopic member (352a) to be extensible or compressible, as to perform a telescopic effect, the inner ring (71b) of the second concentric rings (71a, 71b) is not secured or mounted to the telescopic member (352a). The inner rings (70a, 72a) of the first and third concentric rings (70a, 70b, 72a, 72b) however are mounted to the respective sections of the telescopic member (352a).
c) shows the mounting or connecting member (25) of the motion assembly (352) in accordance with the preferred embodiments of the claimed invention. The mounting member (25) is generally a flange type connector, which includes a tubular body having a pair of peripheral disc shape members (25a, 25b) (note: no 25a or 25b (shown in
Track Assembly/Unit
With reference to
The sliding member (40) comprises two elongated members (40a, 40b) being horizontally positioned and held in position by an inverted U shaped structure or member (40c) whereby each end of said elongated members is provided with at least one roller means (52,53,54,55) so as to enable these elongated members to be slidably connected to the sliding tracks (41) as shown in
Still referring to
As mentioned earlier, the third concentric rings connector (72a, 72b) is secured to the sliding member (40) in a manner such that it is slidable along the length of the sliding member (40). In this connection, the third concentric rings connector (72a, 72b) at which the outer ring (72b) in this preferred embodiment is formed with two mutually opposing T-shape connectors (38, 39); which serves mainly to provide slidable attachment to the sliding member (40). In this position, the third concentric rings connector (72a, 72b) therefore serves as a movable base for the motion assembly (352). The connector (72a, 72b) therefore moves perpendicular to that of the sliding member (40) movement.
The second motor unit (352d) comprises a conventional geared motor connected to a shaft, said shaft having a moveable piece is disposed on the U-shaped member (40c) of the sliding member (40) in manner such that it is able to provide forward and backward motion for the third concentric rings connector (72a, 72b).
Proceeding from the above, the sliding member (40) in accordance with the preferred embodiments of the claimed invention comprises two horizontal posts (40a, 40b) having equal or uniform dimension. The third concentric rings connector (72a, 72b) is disposed perpendicularly in between said two posts (40a, 40b) thus keeping these posts apart at a predetermined distance. The third concentric rings connector (72a, 72b) is connected in a manner such that it can slide effortlessly on said horizontal posts (40a, 40b) of the sliding member (40) with the aid of the second motor unit (352d). As discussed earlier, on each end of the horizontal posts (40a, 40b) of the sliding member (40) there is provided at least one roller or slide elements so as to allow the linear motion of the sliding member (40) along the sliding track (41). The depicted means or methods of attaching the roller(s) to the respective horizontal posts as shown in the drawings are by way of example and one of skill in the art will appreciate that other methods are available and are included within the scope of the invention.
Carrier Arm/Solar Device Holder
a) illustrates the carrier arm (351) without the solar device (1) in accordance with the preferred embodiments of the claimed invention. The carrier arm (351) may be constructed from alloy based material, or suitably rigid material capable of holding at least a pair of solar devices (1,2). It can be coated or non-coated. The carrier arm (351) comprises two sections, the first section being the upper end or section of the arm (351a) is adapted to carry the desired solar devices, for instance, at least a pair of solar panels (1) or solar module (1), and another end (351b), which is the lower end or lower section, is pivotally coupled to the carriage frame (353). The carrier arm (351) generally resembles a T-shape structure thus comprising a cross bar being the upper section and a vertical bar being the lower section.
The upper section (351a) of the carrier arm (351) being the solar panel holder may include, for example, at least one panel frame for one solar panel or a pair of holder bars (351c, 351d) disposed a right angle with respect to the top section of the carrier arm (351). Each bar is secured at a predetermined distance from each other on the top section of the carrier arm (351a) as suitably shown in
Now referring to
In an alternative embodiment, at least two solar panels (1) and at least one reflecting means or a concentrator means (2) can be secured to the carrier arm (351) to increase or optimize solar radiation towards the panels (1). It is contemplated that the attachment of solar panels or modules on the carrier arm (351) may include standard mountings, which are known in the art.
Still referring to
A rod-like fastening means or simply a bolt can be extended through the mounting hole (65) formed on each projection (90,91), into the corresponding mounting hole on the lateral post (17, 18) thus safely securing the lower section (351b) of the carrier arm (351) thereto.
Operational Assemblage
In accordance with the preferred embodiments of the claimed invention, when assembled, there can be a plurality of solar devices such as solar panels (1) mounted on each carrier arm (351). The carriage frame (353) is connected to the carrier arm (351) by way of the lateral posts (17, 18), in which there can be, for example two carrier arms (351) secured to each lateral post (17,18) of the carriage frame (353). Accordingly, there can be eight solar panels (1), each of which having two reflecting means secured adjacent to it, thus a total of 24 solar devices can be secured one carriage frame (353). The motion assembly (352) is disposed proximate to the central region of the carriage frame (353) whereby the telescopic member (352a) is pivotally connected within the overall structure of the solar tracker (200). The transverse post (308) is horizontally connected at the central region of the solar tracker (200).
Dual Axis Sun-Tracking
In accordance with the preferred embodiments of the claimed invention, the sun-tracking motion of the subject solar tracker (200) is based on dual axis tracking, whereby the motion assembly moves the solar devices uniformly about the respective pivotal axes, depending on the motion of the attached motor units, which in turn depends on the position of the sun or celestial object.
The first motion of the solar tracker (200) is the movement of the carrier arm (351) carrying the solar device (s) in this context being solar panels (1) and reflecting means; is based on a vertical axis or day motion of the sun, thus moving based on the east to the west plane, and vice versa. The first motion of the solar tracker (200) aims to keep the panels perpendicular to the position of the sun. The second motion provided by the solar tracker (200) is basically in contrast to that of the vertical axis, whereby the second motion is based on a horizontal axis or lateral motion for tracking the seasonal positions of the sun.
The first motion therefore is accomplished based on the movement of the sliding member (40) along the length of the posts of the sliding track (41). The second motion is accomplished based on the movement of the lower section of the telescopic member (352a) along the sliding member (40). Generally, the telescopic member (352) plays a major role in a manner such that the lower section can be moved laterally and forward and backward owing to the slidable and pivotal attachment to the sliding member (40); which is being moved by the first and second motor units (352c, 352d).
Understandably, the solar tracking overall operation is dependent on the positions of the sun, which is by and large, based on geographical locations. Tracking parameters may include current time, date and seasonal changes. As an example, the tracking information for countries included in the Southern and Northern hemisphere is shown in
From the above disclosure it is seen that the dual axis tracking system of the claimed invention is of simple construction with minimal moving parts, but capable of providing synchronized orientations to possibly an unlimited number of solar panels or solar array in tracking the sun. Perceptibly, with minimal components, the overall costing can be significantly reduced than that of existing dual axis trackers, hence potential cost savings. Further, the claimed invention potentially addresses land constraint issues as the structure of the tracker as disclosed herein can support and control or maneuver arrays of panels with minimal amount of components.
It is further contemplated, and as briefly disclosed in earlier paragraphs, the dual axis tracking system can be used for tracking other astronomical or celestial objects, whereby for such purpose, the astronomical tools can be mounted on the carrier arms (351) in a manner such that the tools or devices can move in alignment or synchronously during tracking
Another apparent advantage is using the tracking system as disclosed herein in applications when reflectors and concentrators are used. Sunlight can be efficiently reflected towards the panels based on more varied or flexible angles considering the dual axis movements compared to that of a single axis movements. Examples of the reflection angles for each mirror or sunray reflective means can be seen in
Thus, specific arrangements and combinations of a dual axis tracker have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the disclosure. Moreover, in interpreting the disclosure, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced.