Multi-Layer and Multi-Objective Optimization Design of Supporting Structure of Large-Scale Spherical Solar Concentrator for the Space Solar Power Station

Abstract

Space solar power station is a novel renewable energy equipment in space to provide the earth with abundant and continuous power. The Orb-shaped Membrane Energy Gathering Array, one of the alternative construction schemes in China, is promising for collecting space sunlight with a large-scale spherical concentrator. Both the structural and optical performances such as root mean square deformation, natural frequency, system mass, and sunlight blocking rate have significant influences on the system property of the concentrator. Considering the comprehensive performance of structure and optic, this paper proposes a novel mesh grid based on normal polyhedron projection and spherical arc bisection for the supporting structure to deal with the challenge of the large-scale structural modular design. For both achieving low system mass and high surface precision, a multilayer and multi-objective optimization model is proposed by classifying the supporting structure into different categories and optimizing their internal and external diameters. The Particle Swarm Optimization algorithm is adopted to find optimal sectional dimensions of the different kinds of supporting structure. The infinite model is also established and structural analysis is carried out, which are expected to provide a certain reference for the subsequent detailed structural design. The numerical results indicate that the spherical concentrator designed by the novel mesh grid would obtain as high as 94.37% sunlight collection efficiency. The supporting structure constructed with the multiple layers would reduce the system quality by 6.92%, sunlight blocking rate by 28.54%, maximum deformation by 41.50%, and root mean square by 9.48% to the traditional single layer, respectively.