Energy Loss Analysis In The Magnet Of A H-Tc SMES

SMES (Superconducting Magnetic Energy Storage) has the characteristics of high efficiency, fast response and good capability of exchanging active and reactive power independently with electric power system. It can be predicted that SMES will be widely used in the future. However, the energy loss of a conduction-cooled HTc magnet is one of key factors restricting the development of SMES , so, how to minimize the energy loss is an important problem .There are a lot of reports on the analysis of the energy loss in the superconducting tape, but few about that of HTc magnet because the electromagnetic characteristics of a HTc magnet are more complicate than that of superconducting tape. Through simulation and analyzing the results coming from the experiment, we found some useful results for the optimal design of the magnet. The research mainly contains three parts as follows:1. The simulation model is built. The magnetic distribution around and inner of the HTc magnet is analyzed, which establishes the base for analyzing the critical current and other electromagnetic characteristics of the HTc magnet.2. The relation between frequency and impedance is discussed by analyzing the results coming from the experiment of HTc magnet transporting different frequencies small ac signals. The analysis shows there exists great electromagnetic couple between superconducting coil and other structure parts of the magnet, which provides a reliable theory basis for the necessity of calculating the eddy loss of other structure parts of the magnet.3. The energy loss of a conduction-cooled HTc magnet is analyzed, which is used in a SMES for improving the stability of electric power system. In steady state, there is little loss, but , during the period of energy exchange, losses are produced in superconducting coil and other structure parts of the magnet. Loss distribution in the magnet is also discussed, and those results are very useful for the optimal design of the magnet.