Performance Feedback & Control of Solar Concentrators Using Wave Front Sensing Techniques (Preprint)
Abstract
The major requirement for using concentrating Solar Thermal devices is the proper placement of the focal spot on the absorber to provide heating of the working fluid to produce thrust or to generate electricity. Without proper placement of the focal spot, either in a spacecraft or ground unit, solar energy is not transferred to the propellant or working fluid or at best case, a significantly smaller proportion of the incident energy is transferred to the fluid. A control system is needed for ground units to track the Sun across the sky or to track the Sun as the spacecraft maneuvers. The control system would use a fine focus controller after acquiring a general location for the Sun. Optimal focus was defined for a space-based system as 0.1 degree and 0.1 inch in x, y, and z. The research problem is to: (1) develop a sensor that provides information about the location of the focus beam from the concentrator that also can tolerate the extreme temperatures involved in providing solar heating, and (2) develop the mathematics of a control system that will focus the concentrator in an optimal fashion based on the sensor measurements. The sensor developed in this dissertation solves the temperature issues by using the absorber as a wave front Sensor and imaging that device with a Charge Coupled Device (CCD) to determine the location of the focal beam.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 07, 2007
- Accession Number
- ADA480829
Entities
People
- Jason N. Beasley
Organizations
- Air Force Research Laboratory