microwave circuit, solar power satellite, sandwich structure, large space structure, aerospace environment, antenna array, electric power transmission, thermal characteristic, energy conversion efficiency, research and development, high temperature, thermal analysis
その他のタイトル(英)
Basic research on the thermal characteristics of the microwave circuit for sandwich concept of the solar power satellite
Tokyo University of Science Department of Applied Physics, Faculty of Science
Tokai University Graduate School of Engineering
Institute of Space and Astronautical Science
Tokai University School of Engineering
Tokyo University of Science
Institute of Space and Astronautical Science
出版者
宇宙科学研究所
出版者(英)
The Institute of Space and Astronautical Science (ISAS)
雑誌名
第22回宇宙エネルギーシンポジウム 平成14年度
雑誌名(英)
The 22nd ISAS Space Energy Symposium March 12, 2003
ページ
96 - 100
発行年
2003-05
抄録(英)
Solar Power Satellite (SPS) is a large space facility more than several kilometers square. It handles an enormous amount of electric power, typically 1 GW. Therefore, thermal design of SPS is a very important issue. In this paper, the results of basic experiment is reported for investigating the thermal characteristics of SPS in the space environment. Since NASA/DOE designed Reference Model in the late 1970's, many SPS models have been designed. Sandwich concept of the SPS system is proposed as one of the promising systems. In this concept, one side is used for a power generation and the other is used for a power transmission. The advantage of the concept is that there is no need to use long power lines in the huge satellite and to generate a high voltage to reduce the heat loss. However, it is difficult to get the enough area for heat radiation. Thus, the research of the thermal characteristics is very important for this sandwich concept. SPS is the system to convert DC power into RF power. Transmitted microwave is received by a large antenna to obtain the electric power on the ground. The microwave is generated by the microwave circuit consisting of semiconductor devices. The conversion efficiency of the microwave circuit from DC to RF is about 30 to 40 percent today. In the future, hopefully, 70 percent efficiency is expected by using class F amplifier. Nevertheless, about 30 percent of the electric power will be lost into heat, and will cause the superfluous high temperature in the circuit. The high temperature usually reduces the efficiency of the circuit and leads to functional loss of devices in the worst case. Therefore, heat management is an important problem for reliability of the whole system. In this research, a microwave circuit was used with an antenna element and several devices on a Teflon board. This circuit is the minimum unit of an antenna array for the wireless power transmission. A laboratory experiment was carried out using the circuit and thermal characteristics of the circuit was analyzed. The experiment results using the microwave circuit can be applied to examine the thermal characteristics of the sandwich concept of SPS which consists of many antenna arrays. It is expected that this research would be very useful in the design of the Sandwich concept of the SPS system.