Automatic system and energetic efficiency optimization algorithm for solar panels on mobile systems

The system described in this paper is aiming to solve the non-optimal energy conversion in solar panels due to the angle bias of the panel surface orientation related with radiation source. Because the device is intended to function on a mobile system with unpredictable moves, the orientation algorithm works in an adaptive manner. The mathematical background of the algorithm use geometric 3D vector objects and the goal is to maximize the light energy incident on the solar panel surface (which is equivalent with maximizing the scalar product of a pair of normal vectors). The geometric problem of orienting a plane surface in space has two degrees of freedom, so it can be mechanically resolved by two motors. These motors will individually make a rotation of the device around the two central axes of the square panel. In this regard, the orientation system receive at its input minimum three signals representing information about the spatial angle position of the power panel relative to light source and outputs two signals which controls the mechanical movement made by the motors. For simplicity reasons, the sensors used to detect the angle position are actually small solar cells identical with the cells that form the power panel, disposed beside the four sides of it and with a fixed zenith angle. This angle determines a different illumination (influenced by the position of the light source) which leads to the desired positional information. Due to the symmetry of the system and the alignment of the sensors with the rotational axes of the motors, the orientation algorithm can be made simply and independently on the two motors. With a fixed number of motor steps per algorithm cycle, the only decision that must be made is the sense of rotation. This decision is computed immediately by comparing the signals produced with the corresponding pair of sensors.