The present invention relates to a solar power plant having a solar tracking apparatus, and more particularly to a solar power plant having a solar tracking apparatus which can increase the collection efficiency of photovoltaic modules.
Solar power generation technology is different from solar heat generation technology in which radiant heat energy transmitted from the sun is utilized. The solar power generation technology utilizing limitless clean energy has several advantages, including no necessity of additional energy or driving source, simple construction whether it is a small system or a large system, and no strain on the environmental limitation.
On the other hand, the solar power generation technology is disadvantageous in that the amount of energy generated may vary by the sunshine duration. In addition, a large number of photovoltaic modules are required to yield a relatively large amount of power, and the power generated based on the solar power generation technology is expensive compared to commercial power. Further, DC power is first obtained. The photovoltaic modules are classified into a tracking type in which the sun is tracked in a power-driven manner or by device manipulation to allow direct rays of sunlight to enter the front surface of the photovoltaic modules in a vertical direction all the time in order to maximize the generation efficiency; a semi-fixed type in which the photovoltaic modules are vertically adjustable in positions by season or month; and a fixed type in which positions of the photovoltaic modules are fixed regardless of the altitude with respect to the sun.
The solar tracking apparatus moves a solar collector or lens in order to increase collection efficiency while tracking the sun on the move. Solar tracking methods are largely classified into programmed tracking and sensor-based tracking. In the former tracking method, the movement of the sun based on the rotation of the earth on its axis and the revolution of the earth round the sun is preprogrammed and photovoltaic modules are rotated. In the latter tracking method, the movement of the sunlight is sensed and directions of photovoltaic modules are controlled. Along with the technological advance of the related art in various applications, a variety of improvements are being made. The solar tracking apparatus employs various techniques including sun position detection, use of tracking members, tracking driving system, and so on.
Korea Patent No. 044021 discloses a solar tracking method using a solar tracking apparatus. In the disclosed solar tracking method, the solar tracking apparatus is constructed such that when the normal azimuth of a photovoltaic module lags behind the sun's azimuth by a first angle, the normal azimuth of the photovoltaic module photovoltaic module may precede the sun's azimuth by a second angle.
Korea Patent No. 0483291 discloses a sun position tracking method for a solar heat system. Korea Patent No. 0369897 discloses a combined solar tracking controller for a focusing type solar heat collector.
As described above, the conventional solar tracking apparatus has several disadvantages in view of its relative complex structure, inaccurate positioning, and so on. In particular, it is quite difficult to simultaneously drive various photovoltaic modules along the sun.
To solve the above problems, it is an object of the present invention to provide a solar power plant having a solar tracking apparatus, which can increase the focusing efficiency of photovoltaic modules, by simultaneously tracking the sun using the photovoltaic modules westwards and facilitating the altitude adjustment northwards.
It is another object of the present invention to provide a solar power plant having a solar tracking apparatus, which can reduce leeway resistance by separating photovoltaic modules and can simultaneously track photovoltaic modules along the sun westwards.
It is still another object of the present invention to provide a solar power plant having a solar tracking apparatus, which can adjust the tilt direction of a track photovoltaic module northwards.
According to an aspect of the present invention, there is provided a solar power plant including a plurality of first support members positioned in the front end of the solar power plant, main frames hinged to the respective first support members, a plurality of second support members positioned in the rear ends of the main frames, a plurality of sub frames rotatably installed on the main frames and arranged in parallel with one another, photovoltaic modules installed on the respective sub frames, and rotating means simultaneously rotating the sub frames with respect to the main frames by a predetermined angle in forward and reverse directions.
In the present invention, the solar power plant may further comprise elevating means installed on at least one of the plurality of second support members, for moving the main frames up and down. The elevating means may include first links rotatably supported on the second support members and having both ends protruding from the second support members, second links each having both ends hinged to one end of each of the first links and the rear end of each of the main frames, and an each installed at the second support members and hinged to the other ends of the second links to rotate the first links.
The rotating means comprises rotatable links capable of simultaneously rotating sub frames installed on the main frames with respect to the main frames, the rotatable links installed on the rotation shafts of the respective sub frames or the sub frames; connection links connecting ends of the respective rotatable links; and an actuator installed on the first support member to be connected to one of the sub frames or the connection links for rotating the rotation shafts in forward and reverse directions or reciprocating the connection links back and forth.
Alternatively, according to another aspect of the present invention, there is provided a solar power plant comprising: a plurality of first support members positioned at front ends; a plurality of second support members main frames hinged to rear ends of the main frames; a plurality of sub frames rotatably installed on the main frames and arranged to be parallel with one another; photovoltaic modules installed on the respective sub frames; and rotating means rotating the rotation shafts or one of the sub frames, and including extension brackets extending downwardly from the bottom surface of the respective sub frames, linking brackets interconnecting the extension brackets, and an actuator installed on the main frames or the sub frames.
Here, the solar power plant may further comprise elevating means installed between the second members and the main frames and elevating the main frames up and down.
The solar power plant according to the present invention tracks the diurnal motion of the sun from the east to the west and adjusts its altitude with respect to the sun, thereby generating the electricity. The solar power plant according to an embodiment of the present invention is shown in
Referring to
When installing the sub frames 15 for the main frames 13 and 14, first and second pillow blocks 31 and 32 are installed on the main frames 13 and 14 corresponding to the first and second support members 11 and 12, respectively, and first and second rotation shafts 33 and 34 are rotatably installed on the first and second pillow blocks 31 and 32 installed on opposite sides on the sub frames 15 northwards, respectively. One or a plurality of photovoltaic modules 100 are installed on the sub frames 15. The main frames 13 and 14 are supported by the first and second support members 11 and 12, respectively, and arranged in parallel with each other. However, the arrangement of the main frames 13 and 14 is not limited to the illustrated example but rectangular arrangement may be possible. In other words, heights of the first and second support members 13 and 14 may vary according to their positions installed, that is, the latitudes. In the celestial equator region, for example, the sub frames 15 for installing the respective photovoltaic modules 100 having substantially the same height are preferably maintained at a horizontal position. A height difference between the first and second support members 11 and 12 is preferably made to be larger to make a tilt angle of the sub frames 15, i.e., the photovoltaic modules 100 installed on the sub frames 15 as the positions shift from the celestial equator region to the southern pole or the northern pole.
The rotating means 20 performs tracking by simultaneously rotating the respective sub frames 15 with respect to the main frames 13 and 14 along the sun westwards. As shown in
In addition, an actuator 23 for reciprocating the connection link 22 back and forth is installed at an end of the connection link 22. The actuator 23 may be comprised of, but not limited to, a screw jack having a structure capable of transmitting the driving force of a motor to a screw by means of a decelerator, as shown in
As shown in
Alternatively, as shown in
Referring to
Hinge coupling between the first support members 51 and the main frames 52 may be made by installing first and second brackets 54a and 54b at corresponding portions of the first support members 51 and the main frames 52 and coupling the same by means of hinge pins 54c.
The elevating means 60 includes drive shafts 61 supported by the second support members 53, first links 62 connected to the drive shafts 61, and second links 63 connecting ends of the respective first links 62 with rear ends of the main frames. Thirds links 64 are installed at the drive shafts 61, and the third links 64 are rotated by a rotatable actuator 65 installed on the second support members 53 by a predetermined angle. Here, the rotatable actuator 65 may be comprised of a jack screw having a lead screw reciprocating back and forth by being rotated in forward and reverse directions by means of a cylinder or a motor.
The elevating means is not limited to the illustrated example and any structure can be used as long as it can rotate the main frames 52 about the first support members 51.
As described above, the solar power plant 50 includes a plurality of sub frames 15 rotatably installed on the main frames 52 and arranged to be parallel with one another, and photovoltaic modules 100 installed on the respective sub frames 15, and rotating means 20 for rotating the sub frames 15 with respect to the main frames 52 by a predetermined angle in forward and reverse directions. The rotating means 20 are substantially the same as in the previous embodiments and an explanation thereof will not be given. As a matter of course, there is no interference while rotating the sub frames 15.
Meanwhile, damping means for preventing the main frames 52 from abruptly elevating or lowering with respect to the second support members 53 may be separately provided in the second support members 53 having the elevating means 60. For example, the damping means is preferably a shock absorber.
Referring to
The hinge portions 72 may be universal joints or ball joints capable of adjusting rotation of the main frames 73 at a predetermined angle.
The first angle adjusting means 80 may include a first driver 84 having a first rotation shaft 81 rotatably installed at either side of the main support member 71, a first rotatable link 82 installed at the first rotation shaft 81, and a second rotatable link 83 connecting the first rotatable link 82 and the main frame 83. Here, the second rotatable link 83 and the main frame 73 are coupled to each other by hinge coupling. As described above, the hinge coupling can be made by means of universal joints or ball joints. In addition, the first driver 84 may be provided at ends of the first rotation shafts 81.
The first driver 84 may include a jack screw 84b connected to the first rotation shaft 81 by a link 84a.
The second angle adjusting means 90 may have substantially the same structure as the first angle adjusting means. The second angle adjusting means 90 may include second driver 94 having a second rotation shaft 91 rotatably installed at the other side of the main support member 71, a third rotatable link 92 installed at the second rotation shaft 91, and a fourth rotatable link 93 connecting the third rotatable link 92 and the main frame 73, the second driver 94 provided at ends of the second rotation shaft 91 for rotating the second rotation shaft by a predetermined angle. Here, each of the second driver 94 may include a jack screw 94b connected to the second rotation shaft 91 by a link 94a.
The first and second angle adjusting means are not limited to the illustrated examples, and any structures can be used as long as they are capable of independently elevating the main frames 73 supported by the main support member 71.
The aforementioned solar power plant operates as follows. At sunrise, the solar power plant 10 operates such that the elevating means 60 is driven to rotate the photovoltaic modules 100 installed on the sub frames 15 so as to be aligned with the sun. Here, if the photovoltaic modules 100 installed on the sub frames 15 are aligned with the sun, they are maximally exposed to the sun, suggesting that a large amount of sunlight is irradiated.
In such a state, the sun's azimuth varies as the sun follows the ecliptic over time. The azimuth of a photovoltaic module and the sun's azimuth are sensed by a sensor (not shown), and the actuator (23 or 40) is driven based on the information obtained by the sensor, thereby rotating the respective sub frames 15 by a predetermined angle.
Accordingly, the photovoltaic modules 100 can track the sun all day, thereby maximizing generation efficiency.
Meanwhile, due to the seasonal change of the altitude, heights of the elevating means 60 installed on the main frames 51 can be adjusted in a south-north direction, that is, in a direction in which the sun follows the ecliptic.
In other words, the rotatable actuator 65 is driven to rotate the first links 62, thereby rotating the second links 63 to rotate the second links 63 connecting the same with rear ends of the main frames 52, and adjusting the heights of the main frames 52 by elevating rear ends of the main frames 52.
The solar tracking system can maximize the efficiency of the photovoltaic modules 100 according to the present invention while simplifying the structures of the photovoltaic modules 100, compared to the conventional solar tracking system using the sun's azimuth altitude.
In particular, as shown in
Referring to
As described above, the solar power plant according to the present invention can increase the collection efficiency by rotating the main frames in a south-north direction and tracking the sun along the course of the ecliptic, i.e., westwards, while maximizing generation efficiency by manually or automatically adjusting the angles of the photovoltaic modules depending on their altitudes over time of month or season. In addition, since the solar tracking according to the present invention is simple, a high degree of design freedom can be achieved. Further, the simplified configuration can reduce the manufacturing cost associated with the solar power plant according to the present invention.
Since the solar power plant according to the present invention can adjust the altitude by elevating sub frames in the south-north directions and can track the sun by rotating the sub frames in the east-west directions, it can increase the collection efficiency of sunlight. In addition, angles of photovoltaic modules can be adjusted according to the sun's altitude by the season or month of the year, thereby maximizing generation efficiency.
While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.
It is therefore desired that the present embodiments be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than the foregoing description to indicate the scope of the invention.
Since the solar power plant according to the present invention can be designed and constructed on any installation site, e.g., the slant land, the mountainous area, or a building, without space restriction, it can be widely utilized to a variety of photovoltaic power generation fields.
Number | Date | Country | Kind |
---|---|---|---|
10-2007-0094941 | Sep 2007 | KR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/KR08/05102 | 8/29/2008 | WO | 00 | 3/17/2010 |