Heliostat control employing direct current motor

Abstract

An improvement in a system and method of controlling a body to maximize the amount of solar energy received by a collector by moving the body in azimuth and elevation by respective DC motors having connected therewith ring magnets and Hall Effect Devices for signalling the degrees, or steps of rotation. The at least one body may be a collector, per se, or a plurality of heliostats in an array reflecting onto a central collector. A central computer calculates a commanded position for particular time of particular day for the particular location of the body. A microprocessor incorporating respective software and hardware then calculates the position for the heliostat to be in terms of the number of signals from the Hall Effect Device, compares the number of signals from the Hall Effect Device once the motors are energized in, respectively, azimuth and elevation and runs to the commanded position. The software and hardware incorporate means for appropriately starting and stopping the motors at a desired point, such as the zero position of a cycle of alternating current to minimize noise; incorporates means for determining when there is a power failure and shutting down the system to prevent damage upon reapplication of power or the like. By this technique, the body is kept correctly oriented throughout the day using only the time of the day without requiring the usual sensors and feedback apparatus.