Array positioning system with out-of-focus solar cells

• US 4,367,403 A
• Filed: 08/11/1981
• Issued: 01/04/1983
• Est. Priority Date: 01/21/1980
• Status: Expired due to Fees

• Current Assignee: RCA Corporation
• Original Assignee: RCA Corporation
• Inventors: Miller, Arthur
• Primary Examiner(s): Nelms, David C.
• Assistant Examiner(s): Hostetter, Darwin R.
• Application Number:
  US06/292,017
• Time in Patent Office: 511 Days
• Field of Search: 250/203 R, 250/202, 126/425, 126/424, 356/141, 356/152
• US Class Current: 250/203.4
• CPC Class Codes: F24S 2030/136 for moving several solar collectors by common transmission elements
• CPC Class Codes: F24S 30/458 with inclined primary axis
• CPC Class Codes: F24S 50/20 for tracking
• CPC Class Codes: G01S 3/7861 Solar tracking systems
• CPC Class Codes: H01L 31/0543 comprising light concentrating means of the refractive type, e.g. lenses
• CPC Class Codes: H02S 20/32 specially adapted for solar tracking
• CPC Class Codes: Y02E 10/47 Mountings or tracking
• CPC Class Codes: Y02E 10/52 PV systems with concentrators
• CPC Class Codes: Y10S 136/291 Applications

Abstract

A solar array positioning system includes first light sensor means facing the same direction as the solar array and second light sensor means facing the opposite direction. A third sensor, this one responsive to gravity, is employed to indicate the direction about a diurnal slew axis that the array is tilted. These sensors are employed to determine the initial array slewing direction to insure that during slewing and subsequent tracking, the array never is rotated through more than a given angle, less than 360°, between two fixed limits. This permits connection to the array by hard wiring rather than slip rings. The system includes also fourth sensor means for providing fine tracking signals which assume control of the array position during tracking. A vane structure reduces the sensitivity of various of the sensors to obscuration by foreign particles. A low cost uncorrected lens may be used with the fourth.

Claims

1. In a solar tracking system including means responsive to a first signal applied as an input thereto for moving the system about a polar oriented axis and means responsive to a second signal applied as an input thereto for moving the system about a second axis orthogonal to said polar oriented axis,

means for producing said first and second signals, said means for producing said first and second signals including lens means for concentrating solar energy in a given area and a plurality of solar sensor means responsive to the concentrated energy in said given area for producing said first and second signals, said lens means comprising a lens which when partially obscured tends to produce asymmetrically eclipsed concentrated energy in said area to thereby produce an error in said first and second signals, said lens means having a given focal length, the improvement therewith comprising:

said plurality of solar sensor means being spaced at a plane other than at said given focal length, said plane being located between said lens and its focal point so as to receive an image from said lens which compensates for said eclipsed energy to effectively symmetrically concentrate the energy in said given area.

2. The lens means of claim 1 wherein said lens means comprises a double convex, spherical lens.

3. The lens means of claim 2 wherein said lens is corrected only at a central portion thereof.