A microwave power transmission (MPT) demonstration system was assembled to comprehensively emulate the operating mode of MPT in space solar power station (SSPS). Based on solid power amplifier and ...phased antenna array, this system comprised three main parts, that is, microwave power transmitting subsystem, microwave power rectenna subsystem, and power beam steering subsystem. It was employed to validate the constraint relationship between beam collection efficiency and the sizes of transmitting antenna and rectenna, transmission distance, operation frequency. High efficiency rectifying and accurate beam steering were also demonstrated. The power transmitting antenna was composed of 64 sub‐arrays of patch antennas, with the dimension of 1.2 × 1.2 m2. In addition, the rectenna array was constructed as a corner truncated square with the side length of 2 m. Its design was based on the concept of perfectly matched layer and integrated rectifying surface. The power beam steering subsystem, implemented with software retrodirective idea, pointed the microwave beam to the rectenna according to the direction of arrival of the pilot signal. The experimental MPT system, operating at 5.8 GHz, transmitted 910 W microwave power across 30 m distance. At the power receiving end, the optimum rectenna conversion efficiency of 49.3% was obtained. With aid of the beam steering subsystem, beam granularity, and beam steering accuracy of 0.23 and 0.18° were achieved, respectively. The compositive experiment verified all function as power transmitting, receiving, rectifying, and steering of MPT system. MPT technology is thus driven toward engineering application, and will ultimately space solar power exploration.
The accumulation of pollutants on the surface of a Concentrating Solar Power (CSP) station reduces the power generation efficiency of the whole power plant, affects electricity output, and decreases ...sales income; therefore, it is particularly important to develop a reasonable and effective cleaning process. Surface pollutants which have a strong interaction with the cleaning process of power stations can determine the quality of cleaning to a certain extent. In this paper, the pollutants on the surface of a trough CSP station with different usage times were collected and characterized using a scanning electron microscope (SEM), a particle size analyzer (PSA), and a transmission electron microscope (TEM). It was found that most of the surface pollutants were of a fine size and included amorphous particles which mainly resulted from the sedimentation of particles suspended for a short time or particles in the process of atmospheric circulation for a long time. Considering the service life of the mirror and the scarcity of water resources in the area where the trough CSP power station is located, a brush-based dry cleaning process with different cleaning times was developed. By comparing the changes in the reflectivity and micro-morphology of the mirror surface before and after cleaning, the feasibility and superiority of the brush-based dry cleaning process were fully confirmed.
A space solar power station (SSPS) has become a huge potential candidate to provide abundant and clean electrical energy for terrestrial users by collecting and converting solar power in space. In ...this paper, an innovative two-layer ring truss-based SSPS is proposed. It consists of the top layer concentrator-based spherical one-time reflection region, the bottom layer space radiator using symmetric or asymmetric cable networks, a ring truss for a supporting structure, a photoelectric conversion system, and transmitting antennas. The construction strategies including the triangular facets modularity of top layer concentrator, area requirement of bottom layer space radiator, two-segment optimization design of generatrix of photoelectric conversion system, and aperture derivation of transmitting antenna are carried out. Then, the performance analysis mainly including the modularization theory error calculation, energy collection and distribution, and thermal characteristics in orbit of this proposed SSPS is presented. Finally, the system parameters are estimated and summarized for a better sense of the proposed SSPS. The results indicate that 100% energy collection can be achieved for an ideal concentrator, and 80% with a modular division layer of 6 and tracking error of no more than 2°. The results demonstrate the feasibility of the proposed SSPS concept and can provide a reference for future space energy harvesting and space exploration projects.
In this paper, high-contrast asymmetric transmission film based on periodic one-dimensional photonic crystal with tunable air layers is presented for the spherical concentrator of the orb-shape ...membrane energy gathering array based space solar power station concept. As the thicknesses of the air gaps in the photonic crystal structure are precisely controlled, the optical transmission properties of the photonic crystals structure dynamically vary, allowing transmission of propagation waves in the forward direction but reflection in the reverse direction. The geometric parameters of the proposed photonic crystal structure are optimized to obtain both high forward transmittance and reverse reflectance over a broad operating wavelength range from 400 nm to 1200 nm and wide angle of incidence from 0° to 60°. The numerical simulations demonstrate that the average forward transmittance, reverse reflectance and the total solar ray collection ratio of the optimal structure amount to 99.3%, 95.2% and 94.5%, respectively.
•Asymmetric transmission thin film for SSPS-OMEGA system is proposed.•Asymmetric transmission is based on photonic crystal with tunable air layers.•High contrast transmission is obtained on a wide wavelength and incident angle range.•The total solar ray collection ratio of the optimal structures amount to 94.5%.
The analysis of existing schemes for building solar power stations on photoelectric modules with the revealing of their operation principles and functionality has been conducted. The specified ...technical characteristics of each of the analyzed schemes are given. The structural scheme of the solar charging station for electric cars with determining its functional capabilities and operation features is proposed. The practical application of this scheme will help to reduce the dependence on the general electric power supply network and will create conditions for its total rejection.
This paper presents a damage identification method that consists of a fusion sensitivity matrix that contains information on dynamic and static responses. Based on natural frequency and static ...displacement, the study defines and considers damage criteria such as 1D and 2D single and fusion load cases. To overcome the lack of sufficient information on damage identification in large-scale structures, the authors consider multiple responses to and objective descriptions of uncertainties and various criteria. According to the finite element model and the structural responses described and measured, the fusion methods and damage criteria treat uncertainty as non-probability intervals. As long as we know the bounds of uncertain parameters, the intervals of the elemental stiffness parameters in undamaged and damaged models can be obtained by interval technology. Two numerical examples—a damage-criteria numerical example and a 5-span with 25-bar truss structure in a space solar power station—are proposed. Both examples indicate the veracity of the interval method.
In the Republic of Korea (ROK), photovoltaic power stations (PPSs) are typically installed in mountainous areas because of the low levelized cost of electricity values. However, intensified ...precipitation due to climate change has increased landslide occurrence, threatening PPSs installed in mountainous areas. Previous studies have focussed on the possibility of landslide occurrence considering specific years, which could not generate general landslide susceptibility areas (LSAs). Therefore, this study aimed to analyze the general LSAs and compare it with PPS-installed areas to identify the potential landslide damages to the PPSs. Gangwon-do was selected as the study site and maximum entropy model was used to evaluate LSAs in multiple target years (2006, 2013, 2019, and 2020). The results showed that 3.2-10.6% of PPSs are located in LSAs during 2013-2020. Considering the government PPS installation regulations, 45% of installable areas were identified as LSAs, suggesting that new criteria are required for future PPS installation. We propose that PPS installation should be prohibited in very shallow soil, very deep soil area, areas with good drainage capacity, a slope between 10 and 30°, north aspect, and coniferous forest area. Our results can help in improving the regulatory plans and prevent reckless development of PPSs in susceptible regions.
Solar energy collection and conversion is of great significance to the power transmission of the Space Solar Power Station (SSPS), and has influences on the overall system, technologically and ...economically. For the proposed SSPS-OMEGA concept, the original conceptual design had non-uniform energy distribution and excessive energy density in local areas, which would cause decreases in its optical and electric performance. Aiming at this point, firstly, this paper evaluates the optical performance of the OMEGA concept via ray trace technique. Secondly, the generatrix geometry design of the photovoltaic (PV) cell array based on Bézier curve is carried out to obtain optimal optical performance available for efficient response to sunrays. After that numerical examples achieve good collection efficiency and suitable energy distribution. Finally, modular construction for the main concentrator and its influence on optical performance are investigated. Moreover, the effect of the orbital motion and tracking error are analyzed to provide reference for the realization of the OMEGA.
•Optical performance for the SSPS-OMEGA is analyzed via ray trace technique.•Optimization indicates maximum collection efficiency and uniform distribution.•Increasing the order of Bézier curve will increase the collection efficiency.•Modular strategy for the main concentrator via polygonal mesh is investigated.•The impacts of orbital motion and tracking error are analyzed preliminarily.
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