Bidirectional solar tracker

Abstract

The tracker is formed by a structure ( 3 ) bearing a platform ( 1 ) carrying the solar panels ( 2 ) that varies both the azimuth and elevation orientation thereof in order to track the sun. This movement is achieved by means of two actuators ( 4 ) connected respectively to fixed points (P 1 o , P 2 o ) on the ground and other vertices (P 1 , P 2 ) of the platform ( 1 ), thereby causing the platform to rotate around a central support point “O” of the same. The distances (D 1 , D 2 ) between the points which join the actuators ( 4 ) have a one-to-one relation with the rotation angles (β, α) of the platform ( 1 ) around both perpendicular axes: an oblique fixed axis (O-Cl) and another axis ( 0 -Az) that angularly varies the inclination thereof with respect to the first.

1 . BIDIRECTIONAL SOLAR TRACKER, of the type formed by a support structure ( 3  or  3 ′) bearing a platform ( 1 ) carrying the solar panels ( 2 ) which convert solar energy into electrical energy, varying the orientation of the platform ( 1 ) in both azimuth and elevation in order to constantly offer its surface in a direction perpendicular to the solar rays, characterized in that the movement for varying the orientation of the platform ( 1 ) is achieved by means of two actuators ( 4  or  4 ′) connected respectively to fixed points (P 1   o , P 2   o ) on the ground and other vertices (P 1 , P 2 ) of the platform ( 1 ), causing the latter to be able to rotate around a central support point “O” of the same, from an initial position to another final position, with two degrees of freedom due to said two vertices (P 1 , P 2 ) of the platform ( 1 ) being related with two angles α, β of rotation thereof: one of them β around an oblique fixed axis (O-G 1 ) fixed to the ground and forming an angle Φ with the coordinate axis (OY) parallel to the surface of the ground and the other angle α around an axis (O-Az) perpendicular to the previous one, contained in the plane of the platform  1  and which angularly varies its inclination when the latter does so around the oblique fixed axis (O-G 1 ). 
   
   
       2 . BIDIRECTIONAL SOLAR TRACKER, according to  claim 1 , characterized in that the distances (D 1 , D 2 ) of the vertices (P 1 , P 2 ) to the respective fixed points (P 1   o , P 2   o ) of the ground maintain a one-to-one relation with the angles (α, β) of rotation of the platform ( 1 ) around its perpendicular axes (O-C 1 , O-Az), which determines that, for each pair of angles (α, β), there exists just one pair of said distances (D 1 , D 2 ) and vice versa. 
   
   
       3 . BIDIRECTIONAL SOLAR TRACKER, according to  claim 1 , characterized in that the distances (D 1 , D 2 ) are calculated and determined by the two desired angles (α, β), according to the coordinates of the place, time of year and moment of the day, adjusting and varying them with the actuators ( 4 ). 
   
   
       4 . BIDIRECTIONAL SOLAR TRACKER, according to  claim 3 , characterized in that the actuators ( 4 ) are hydraulic cylinders, spindles, or any other mechanical element that can fix the distances (D 1 , D 2 ). 
   
   
       5 . BIDIRECTIONAL SOLAR TRACKER, according to  claim 3 , characterized in that the actuators are tracking devices with light-point feedback, with which the angle (β) around the fixed axis (O-G 1 ) manages to be varied with increments of signs opposite to the distances (D 1 , D 2 ), with a small variation in the other angle (α), and with equal increments of the same sign for variation of the angle (α) around the axis (O-G 1 ), orientable in its angle, perpendicular to the above and which is carried out with a minor variation of the other angle (β) for small movements, which causes the platform ( 1 ) to be centered on the light point in a few reiterated alternative movements. 
   
   
       6 . BIDIRECTIONAL SOLAR TRACKER, according to  claim 1 , characterized in that the platform is constituted on the basis of a frame ( 5 ) that is mounted in tilting fashion on a support ( 10 ), the actuators ( 4 ′) being connected to separate points of the actual frame ( 5 ), establishing a rotation of said frame ( 5 ) and therefore of the platform around a central point, rotating with two degrees of freedom, with the particular feature that the orientation of the corresponding platform in the manner of a swivel joint is effected via the “T” support ( 10 ), the cross-member ( 10 ′) of which is traversed by a transverse axis ( 9 ) belonging to the frame ( 5 ), being able to rotate with a degree of freedom around it; provision having been made for the vertical core or section ( 12 ) of said “T” support ( 10 ) to be traversed longitudinally by an axis ( 11 ) secured between two struts ( 13 ,  14 ) of the respective fixed structure ( 3 ′) for supporting the platform, rotating with the second degree of freedom. 
   
   
       7 . BIDIRECTIONAL SOLAR TRACKER, according to  claim 1 , characterized in that the corresponding hydraulic system for operating the actuators ( 4  or  4 ′) incorporates a device for prevention of damage by the wind, the device consisting of one or more pressure switches ( 19 ) mounted in the hydraulic fluid line or lines ( 20 ), in which participates a cylinder ( 22 ) with its piston ( 23 ), said pressure switch or switches ( 19 ) being fitted in order to provide a signal indicating the exact moment when the movement of the platform carrying the solar panels has to be carried out automatically to the horizontal position of minimum resistance to the strong wind of said platform with the solar panels. 
   
   
       8 . BIDIRECTIONAL SOLAR TRACKER, according to  claim 1 , characterized in that the corresponding hydraulic system for operating the actuators ( 4  or  4 ′) incorporates a pressure regulation device consisting of a pair of oleo-pneumatic dampers ( 25 ) with the ability to regulate the sudden loads to which the fixed structure ( 3  or  3 ′) of the solar tracker is subjected due to the effect of outside agents; with the particular feature that said oleo-pneumatic dampers ( 25 ) are connected in parallel with the fluid lines ( 19 ′) corresponding to the hydraulic system ( 22 ′- 23 ′). 
   
   
       9 . BIDIRECTIONAL SOLAR TRACKER, according to  claim 8 , characterized in that the oleo-pneumatic dampers ( 25 ) preferably consist of respective oleo-pneumatic expansion tanks. 
   
   
       10 . BIDIRECTIONAL SOLAR TRACKER, according to  claim 8 , characterized in that each expansion tank constituting the respective oleo-pneumatic damper ( 25 ) includes an internal membrane ( 28 ) as a regulating element of the pressure inside the tank, the latter having a calibrated hole ( 28 ) for the discharge of the fluid. 
   
   
       11 . BIDIRECTIONAL SOLAR TRACKER, according to  claim 8 , characterized in that mounted in the hydraulic fluid lines ( 19 ′), to which the oleo-pneumatic dampers ( 25 ) are connected, are respective controlled non-return valves ( 30 ). 
   
   
       12 . BIDIRECTIONAL SOLAR TRACKER, according to  claim 2 , characterized in that the distances (D 1 , D 2 ) are calculated and determined by the two desired angles (α, β), according to the coordinates of the place, time of year and moment of the day, adjusting and varying them with the actuators ( 4 ). 
   
   
       13 . BIDIRECTIONAL SOLAR TRACKER, according to  claim 4 , characterized in that the corresponding hydraulic system for operating the actuators ( 4  or  4 ′) incorporates a device for prevention of damage by the wind, the device consisting of one or more pressure switches ( 19 ) mounted in the hydraulic fluid line or lines ( 20 ), in which participates a cylinder ( 22 ) with its piston ( 23 ), said pressure switch or switches ( 19 ) being fitted in order to provide a signal indicating the exact moment when the movement of the platform carrying the solar panels has to be carried out automatically to the horizontal position of minimum resistance to the strong wind of said platform with the solar panels. 
   
   
       14 . BIDIRECTIONAL SOLAR TRACKER, according to  claim 4 , characterized in that the corresponding hydraulic system for operating the actuators ( 4  or  4 ′) incorporates a pressure regulation device consisting of a pair of oleo-pneumatic dampers ( 25 ) with the ability to regulate the sudden loads to which the fixed structure ( 3  or  3 ′) of the solar tracker is subjected due to the effect of outside agents; with the particular feature that said oleo-pneumatic dampers ( 25 ) are connected in parallel with the fluid lines ( 19 ′) corresponding to the hydraulic system ( 22 ′- 23 ′). 
   
   
       15 . BIDIRECTIONAL SOLAR TRACKER, according to  claim 9 , characterized in that each expansion tank constituting the respective oleo-pneumatic damper ( 25 ) includes an internal membrane ( 28 ) as a regulating element of the pressure inside the tank, the latter having a calibrated hole ( 28 ) for the discharge of the fluid. 
   
   
       16 . BIDIRECTIONAL SOLAR TRACKER, according to  claim 9 , characterized in that mounted in the hydraulic fluid lines ( 19 ′), to which the oleo-pneumatic dampers ( 25 ) are connected, are respective controlled non-return valves ( 30 ). 
   
   
       17 . BIDIRECTIONAL SOLAR TRACKER, according to  claim 10 , characterized in that mounted in the hydraulic fluid lines ( 19 ′), to which the oleo-pneumatic dampers ( 25 ) are connected, are respective controlled non-return valves ( 30 ).