Astronomical algorithm

Abstract: This paper presents a proposed technique for dual-axis solar tracking system using fusion based approach of an astronomical based estimation and a visual sensor based feedback to locate and track sun position continuously time by time. The astronomical based calculation is used to estimate azimuth and elevation angles of a dual-axis solar power plant with respect to the time and location of the plant. Meanwhile, the visual based correction is used to localize the sun on the captured image when the camera can detect the sun (i.e. at sunny). The main purpose of this designed method is to improve efficiency of a dual-axis solar power plant system in absorbing sun energy continuously time by time with stable performance in various weather conditions. According to the simulation results, it shows that the proposed algorithm outperform to the only astronomical algorithm based. The sum squared error on azimuth and elevation angles resulted from the proposed algorithm along the simulation are 0.3688 and 0.3874 degree, respectively. On the other hand, the astronomical algorithm only method result sum squared error 1.0997 and 1.2877 degree on azimuth and elevation angles, respectively.

Abstract: The invention discloses a solar photovoltaic tracking astronomic control system, which relates to a photovoltaic tracking system for a solar module and consists of a computing system (1), an angle sensor system (2) and a control system (3). The computing system (1) is connected with the angle sensor system (2). The angle sensor system (2) is connected with the control system (3). The solar photovoltaic tracking astronomic control system has simple structure, uses an astronomical algorithm tracking system to compute an azimuth angle and an elevation angle of the sun according to the parameters including the local latitude, longitude, time and the like, has good tracking effect, is not influenced by the weather, and more effectively utilizes the energy of the sun.

Abstract: This article discusses the design, operation, and performance evaluation of a unique cable-operated 6.24 kWp commercial-size solar tracking system called iPV dual-axis tracker or iPV DAT with a position detector to gain the maximum power from the sunlight. Compared with other solar tracking systems, low cost, simplified hardware structure, and controlling algorithm are the advantages of this system. The operating method of the 6.24 kWp iPV DAT follow a simple pull and release of the steel cables connecting the corners of the PV module frame to the electric motors and directed by an electronic control system. The steel cables attached to the corners of the module frame also provide an extra stability in the event of high wind of up to 220 km/h. The accuracy of the tracking effect is managed by an astronomical algorithm that enables a full 360° azimuth rotation and altitude tilt of −40° to 40° (0 = horizontal). The controller algorithm also includes backtracking capability that allows optimization of ground cover ratio. Performance evaluation of the iPV DAT installed and operated in Taiwan for 12 months is compared with a fixed-tilt PV system. An average electricity gain of 30.1% and performance ratio of 93% are realized using iPV DAT.