High-precision shadow-cast solar tracking

Abstract

High-precision shadow-based solar tracking system. The invention relates to a high-precision solar tracker that locates the sun in the sky and tracks its movement by continuously measuring an alignment deviation orthogonal to the direction of incidence of the sun's rays. This is achieved using a shadow-projecting mechanism (2) that, by default, keeps light sensors (1) in shadow and detects the alignment deviation in the form of a Gaussian brightness curve (3). An algorithm analyzing the signals measured by the brightness sensors, satellite geopositioning information, and the capture of a solar optical focus allows for the determination of a correction command for solar-powered machines. The invention will improve the performance of solar-powered machines in many different environments and will contribute to optimizing the use of solar energy in industry.Figure for abbreviation [Fig 1].

Description

Title of the invention: High-precision shadow-cast solar tracking

[0001] The present invention relates to a high-precision solar tracker for controlling a solar machine in order to find the sun in the sky and follow its movement.

[0002] Solar energy is gaining importance in the industrial world due to the scarcity of non-renewable energies and the increase in pollution caused by greenhouse gases when using fossil fuels. But to increase the energy efficiency of solar machines (photovoltaic, concentrated solar thermal) and promote their use in industry, it is necessary to obtain high precision of alignment with the sun and to maintain orthogonality to the direction of incidence of the sun's rays.

[0003] The energy efficiency of a solar-powered machine is optimal when the part receiving the sun's rays (for example: solar panel, lens, mirror) is oriented orthogonally to the direction of incidence of the solar rays. Solar tracking is traditionally carried out using directional cross sensors for photoelectric panel type applications, and are not sensitive to a small deviation in the angle of incidence of alignment with the sun.

[0004] The device according to the invention makes it possible to overcome this drawback. The objective of this invention is to propose a solar tracking system that is simple to use, economical, and has high sun alignment performance.

[0005] The device consists of three information input modules that measure the alignment to the sun.

[0006] The main module is the shadow solar tracking module. This module consists of a first part composed of a ring of brightness sensors, such as photoresistors, arranged concentrically around a central tube. The number of brightness sensors has an influence on the accuracy of the shadow solar tracking module. A second part which acts as a shade in the form of a disc concentric with the light sensor crown and of the same diameter. When the module is orthogonal to the direction of incidence of the sun's rays, the disk casts a shadow on all the light sensors. When the module is misaligned with the sun, the cast shadow moves so that some of the light sensors come out of the cast shadow and receive sunlight on their surface. The expected signal from this sensor module will be in the form of a centered Gaussian type curve. The position of the centered average of the signal curve of the light sensors indicates the direction of the correction to bring to the machine to ensure that there is orthogonality between the module and the direction of the sun's rays.

[0007] The second module is a satellite geopositioning module. It is used to compare the theoretical position of the sun in the sky with the data obtained by the first module.

[0008] The third module is a real-time camera-based image analysis module that analyzes the image of the optical focus of a solar concentrator. Misalignment with the sun shifts the position of the optical focus. Real-time image processing indicates what corrections need to be made to the machine to best align with the sun.

[0009] These three information inputs are then processed by an algorithm which, at the output, sends control commands to the motors of the solar machine to which these modules are associated.

[0010] [Fig. 1] represents the first high-precision solar tracking module by shadow cast during a projection of the shadow cast (2) on the ring of sensors (1) during a misalignment with the rays of the sun; as well as the signal curve (3) associated with the brightness sensors.

[0011] [Fig.2] shows a diagram of the operating principle of the precision solar tracker with the different inputs.

[0012] The high-precision shadow-cast solar tracking device comprises a base, a central tube, and a disc which serves as a shade for the brightness sensors.

[0013] The base is circular and fixed to the face of a solar machine which must be continuously aligned with the sun. This base accommodates the light sensors.

[0014] The central tube is concentric with the sensor crown. It is fixed on this base and supports the disc which will shade the light sensors. This central tube is designed to be telescopic and adjustable in length.

[0015] The disc that acts as a shade is concentric with the light sensor ring. When the sun's rays are orthogonal to the disc and the base, the disc shades all the sensors. This disc is attached to the central tube.

[0016] As a non-limiting example, the device will comprise 40 light sensors, the crown of which has a nominal diameter of 70 mm.

[0017] The device according to the invention is particularly intended for industrial machines operating on solar energy, and will contribute to optimizing the use of solar energy in industry.

Claims

Claims

1. High-precision solar tracking device characterized in that it comprises: a. Several brightness sensors (1), hereinafter called “sensors”, arranged in a ring. b. A part concentric with the sensor ring and placed above it at an adjustable distance, projects a shadow (2) onto the sensors when light is directed towards the sensors.

2. A high-precision solar tracking device characterized in that an algorithm combines multiple signal and data sources to calculate an alignment deviation orthogonal to the direction of incidence of the sun's rays, and provide position and direction correction control of a solar machine.

3. Device according to claim 2 characterized in that one of the sources of signals entering the algorithm is information from the brightness sensors.

4. Device according to claim 2 characterized in that one of the sources of signals entering the algorithm is satellite geopositioning information.

5. Device according to claim 2 characterized in that one of the sources of signals entering the algorithm is image processing information for observation of the optical focus of the solar machine.

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