A DC High-Temperature Superconducting Cable With Self-Sinking Structure for Space Solar Power Station

High-temperature superconducting (HTS) cables are considered an ideal transmission solution for space solar power stations owing to their low-loss characteristics. However, the vacuum and strong irradiation conditions in space can cause external heat sources and heat dissipation problems for HTS cables. Although thermal management of HTS cables for Earth-based applications is well researched, the cables are currently unsuitable for space-based applications because of deficiencies in their electro-thermal characteristics, heat balance mechanism, and lightweight and efficient structural design. In this paper, a segmented self-cooling direct current (DC) HTS cable structure was proposed. Using a finite element simulation model of the HTS cable, its thermal fields in steady and transient states were investigated. The primary steady-state heat source in space is solar irradiation, and radial heat transfer is the primary route to dissipate heat in HTS cables. The process of temperature rise in the superconducting layer exhibits lag and nonlinearity. The heat can be directly dissipated through the heat sink. In the transient state, the main heat sources are metallic heat and superconducting quench heat, and the temperature response is rapid. Owing to its multilayer high heat capacity structure and thermal radiation effect, the proposed HTS cable is resistant to short-term thermal disturbances. Therefore, the cable need not be installed with a refrigeration unit. The HTS cable was compared with the conventional metallic cables. The HTS cable achieved a mass reduction of 79.2% compared with the conventional metallic cables under identical operating conditions and a 99.9% reduction in heat generation in steady-state conditions. In the transient state, under 10 and 20 kA fault currents, heat generation was reduced by 42.9% and 44.1%, respectively. The current transmission efficiency was improved by 3.1%. This study provides a novel thermal management method for HTS cables in space-based applications.