CLOSED LOOP TRACKING SYSTEM USING SIGNAL BEAM

摘要

The invention is a system and method for heliostat mirror control. Here, each heliostat mirror generates a low intensity “signal beam”, directed at an angle off from the heliostat mirror's high intensity and sensor blinding “main beam” of reflected solar energy. The low intensity signal beams may be created by reflecting a small portion of the incident solar light at an angle from the main beam, by reflected artificial light, or from lasers shinning onto mirrors from known locations. The signal beams are detected by optical sensors mounted way from the main heliostat receiver focus, and can be used in a closed loop control system to efficiently ensure that individual heliostat mirrors in a heliostat array accurately track sunlight and direct the sunlight to a central receiver. Because heliostat mirrors need not be taken “off sun” for positioning, the system allows heliostat arrays to be run at high efficiency.

主权项

1. A closed-loop tracking system comprising:
a plurality of heliostats, wherein each of the plurality of heliostats comprises a mirror configured to generate a main beam and an optical element configured to generate a signal beam at an angular offset from said main beam, wherein each signal beam is spread over a range of angles; a receiver configured to concurrently receive the main beam from each one of the plurality of heliostat mirrors; and a signal beam target to concurrently receive the signal beam from each one of the plurality of optical elements, wherein the signal beams from the plurality of optical elements are concurrently transmitted to and received by the signal beam target.