系統安定度測定装置としてのSMES の可能性

抄録

This paper discusses the feasibility of SMES as a measurement apparatus for electric power system stability. The system stability is evaluated by eigenvalues that express the oscillation modes of the electric power system. To measure the eigenvalues, the storage system requires controllability of charge/discharge with a rapid cycle of less than 1 s. Because the oscillation modes of the power system vary in real time and their distribution is complex, the mobility of the SMES system is the most important parameter for system stability measurement. In this work, the author carried out a design study on a 1-MJ-class mobile SMES system using MgB2 Rutherford cables. The results showed that 1) the 1-MJ-class mobile SMES components can be installed in a 40-feet dry container; 2) because of the effect of the force-balanced coil (FBC) design, the SMES coil can be excited up to 2.0 T or 3.0 T without reinforcements for the MgB2 Rutherford cables; and 3) the 1-MJ-class mobile SMES coil can be cooled using 3 or 4 sets of conventional cryocoolers, including the cooling system for a 80 K thermal shield at a cooling temperature of 20 K or 10 K. Compared to the conventional lithium-ion battery energy storage, the SMES system has a current supply capability with a minimum influence on the power system and a design flexibility of the stored energy achieved by selecting an optimal cooling temperature depending on the power system conditions without an increase in the total weight of the SMES coils. These features show the technical advantages of SMES as a measurement apparatus for electric power system stability.