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Issues concerning the method development and results for the simultaneous estimation of the resistivity and magnetic penetration depth of circular solenoids, with and without cylindrical superconductors, are discussed.

The authors have addressed developments of SMES system effective for power system stabilizing control. Focused on control logics that can be used to efficiently regulate SMES, a number of unique control logics were devised by combining the popularly used power deviation (ΔP) of a generator with the angular velocity deviation (Δw) of a generator or the phase correction. We practiced a digital simulation analysis for the created logics under both conditions of one- and multi-machine infinite-bus systems using the Y-method power system dynamics analysis program, which was compiled by the CRIEPI. As a result, it was revealed that the rated capacity and the amount stored energy of SMES necessary for power system stabilizing can be reduced by approximately 3 to 5% when compared to that obtained by employing the conventionally used ΔP control method alone. [ABSTRACT FROM AUTHOR]

The authors have developed a solenoid model coil used for superconducting magnetic energy storage (SMES) for power system control, aimed at drastically reducing the costs of the SMES system. The single solenoid model coil of 2.9 MJ is designed with the rated current of 9.6 kA, a maximum magnetic field of 5.5 T and coil charge rates equivalent to those of the practical 100 MW/54 MJ class SMES. The coil is characterized by the use of an aluminum stabilized NbTi CIC (Cable-in-conduit) conductor. The experimental SMES consists mainly of a 2.9 MJ coil, the cooling system for the CIC conductor and the 1 MW class AC/DC converter. The SMES is connected to 6 kV distribution lines at a substation. In the field test, the SMES's 17 ms responses for the step input of active and reactive power were ascertained. Furthermore, its function of compensating for load fluctuation in the 6 kV distribution line was confirmed. The test results show the realization of a practical SMES system for power line control. [ABSTRACT FROM AUTHOR]

An energy storage device with high energy density and high power density is desired for compensation of fluctuating loads such as railway substations and distributed generations such as wind turbines. Typically, a SMES (Superconducting Magnetic Energy Storage) has higher power density than other devices of the same purpose, and secondary batteries have higher energy density than SMES. In this study, the authors propose a hybrid energy storage system composed of a superconducting magnet and secondary battery for an energy storage system with high energy density and high power density. The sharing method of power for each storage device using a Fuzzy control and filters, simulation for the compensation of railway loads and the power of wind turbines are presented. [ABSTRACT FROM AUTHOR]