Proc. SPIE. 10692, Optical Fabrication, Testing, and Metrology VI
KEYWORDS: Photovoltaics, Mirrors, Solar concentrators, Solar radiation models, Reflection, Solar cells, Silicon, Bidirectional reflectance transmission function, Systems modeling, Temperature metrology
The article presents the basics of modeling the surface microstructure using a bidirectional reflectance distribution function. Presented new model based on selected elements of the Torrance-Sparrow model and the HTSG model. The combination of empirical and physical model has made it possible to reduce the computational cost, without lowering accuracy of estimated parameters of material microstructure. Analysis of the computational cost was performed for empirical models: Lambert, Phing, Torrance-Sparrow, Shlick-Phong and physical model: Ward, Shlick, HTSG, Lafortune. The results showed that the presented model requires 30% more computational cost compared to empirical models but compared to physical models, the computational cost was reduced by 2.5 times, while maintaining the same accuracy of estimated parameters. The next part presents the temperature influence on power output of photovoltaic panels. The analysis was made for silicon cells SRT-100, SRT-50 and the amorphous tandem MST-50.
The article presents a methodology for analysis of power output the photovoltaic system depending on geometry of solar contractor mirrors. The concentrator directs the solar radiation reflected from mirrors onto photovoltaic surface, which increases the efficiency of solar panels. An essential element of the concentrator system is a two-axis tracking system which tracks the apparent position of the Sun on the celestial sphere. The analysis of luminance stream falling on photovoltaic surface depending on inclination angle of the concentrator mirrors made of electrochemically polished steel and resolution of step tracking system was performed. The technical light properties of the concentrator mirrors were determined using the BRDF function. The results of analysis were used to calculate the voltage, current and power output of photovoltaic system.
The article presents a tracking system controller that tracks apparent position of the Sun on celestial sphere. The device does not require any operating by user. Applying the GPS module, gyroscope, magnetometer and accelerometer ensures the autonomy of device. In controller was implemented authorial algorithm which on the basis of collected data automatically selects appropriate value of inclination angle the photovoltaic surface in relation to direction of incidence solar radiation and resolution step tracking system. The efficiency analysis of the presented system was performed depending on sunlight conditions. Then, the device was compared with the analogical solution that does not use the authorial algorithm. The results of simulations showed that this tracking controller allows to increase in the power output of photovoltaic panels from 4% to 7%.
The paper presents the modeling of surface microstructure using a bidirectional reflectance distribution function. This function contains full information about the reflectance properties of the flat surfaces - it is possible to determine the share of the specular, directional and diffuse components in the reflected luminous stream. The software is based on the authorial algorithm that uses selected elements of this function models, which allows to determine the share of each component. Basing on obtained data, the surface microstructure of each material can be modeled, which allows to determine the properties of this materials. The concentrator directs the reflected solar radiation onto the photovoltaic surface, increasing, at the same time, the value of the incident luminous stream. The paper presents an analysis of selected materials that can be used to construct the solar concentrator system. The use of concentrator increases the power output of the photovoltaic system by up to 17% as compared to the standard solution.
Proc. SPIE. 10249, Integrated Photonics: Materials, Devices, and Applications IV
KEYWORDS: Mathematical modeling, Digital signal processing, Optical sensors, Modulation, Sensors, Combustion, Magnetism, Control systems, Signal processing, Process control, Transistors, Optical fiber cables, Electromagnetism, All optical signal processing, Feedback signals
The article presents field oriented control method of synchronous permanent magnet motor equipped in optical sensors. This method allows for a wide range regulation of torque and rotational speed of the electric motor. The paper presents mathematical model of electric motor and vector control method. Optical sensors have shorter time response as compared to the inductive sensors, which allow for faster response of the electronic control system to changes of motor loads. The motor driver is based on the digital signal processor which performs advanced mathematical operations in real time. The appliance of Clark and Park transformation in the software defines the angle of rotor position. The presented solution provides smooth adjustment of the rotational speed in the first operating zone and reduces the dead zone of the torque in the second and third operating zones.
Proc. SPIE. 9898, Photonics for Solar Energy Systems VI
KEYWORDS: Mathematical modeling, Photovoltaics, Solar concentrators, Solar radiation models, Reflection, Metals, Solar cells, Reflectivity, Surface roughness, Computer simulations, 3D modeling, Bidirectional reflectance transmission function, Solids, Solar radiation, Systems modeling
The paper presents a new algorithm that uses a combination of two models of BRDF functions: Torrance-Sparrow model and HTSG model. The knowledge of technical parameters of a surface is especially useful in the construction of the solar concentrator. The concentrator directs the reflected solar radiation on the surface of photovoltaic panels, increasing the amount of incident radiance. The software applying algorithm allows to calculate surface parameters of the solar concentrator. Performed simulation showing the share of diffuse component and directional component in reflected stream for surfaces made from particular materials. The impact of share of each component in reflected stream on the efficiency of the solar concentrator and photovoltaic surface has also been described. Subsequently, simulation change the value of voltage, current and power output of monocrystalline photovoltaic panels installed in a solar concentrator system has been made for selected surface of materials solar concentrator.
The paper presents the Λ-ridge and V-trough concentrator system with a low concentration ratio. Calculations and simulations have been made in the program created by the author. The results of simulation allow to choose the best parameters of photovoltaic system: the opening angle between the surface of the photovoltaic module and mirrors, resolution of the tracking system and the material for construction of the concentrator mirrors. The research shows the effect each of these parameters on the efficiency of the photovoltaic system and method of surface modeling using BRDF function. The parameters of concentrator surface (eg. surface roughness) were calculated using a new algorithm based on the BRDF function. The algorithm uses a combination of model Torrance-Sparrow and HTSG. The simulation shows the change in voltage, current and output power depending on system parameters.
This paper presents an algorithm that uses the modified BRDF function. It allows the calculation of the parameters of Λ-ridge concentrator system. The concentrator directs reflected solar radiation on photovoltaic surface, increasing its efficiency. The efficiency of the concentrator depends on the surface characteristics of the material which it is made of, the angle of the photovoltaic panel and the resolution of the tracking system. It shows a method of modeling the surface by using the BRDF function and describes its basic parameters, e.g. roughness and the components of the reflected stream. A cost calculation of chosen models with presented in this article BRDF function modification has been made. The author’s own simulation program allows to choose the appropriate material for construction of a Λ-ridge concentrator, generate micro surface of the material, and simulate the shape and components of the reflected stream.