Test Results on Experimental SMES System With Normal Conducting Shielding Coils

A shielding coil system is effective to reduce pulse losses of the superconducting coil of the SMES system for power system control, such as power line stabilization and compensation of power fluctuation. The shielding coil system is consisted of a main superconducting coil and a normal conducting shielding coil connected in parallel. If a mutual inductance between them is equal to a self inductance of the latter, fluctuated current at energy transfer is diverted to the shielding coil and constant current flows in the main superconducting coil. In addition to the above inductance condition, to work the shielding operation completely, it is necessary to compensate the voltage decent due to the normal resistance of the shielding coil. We have been studying about the compensation system for the voltage decent in the shielding coil and have made an experimental shielding coil system to verify the operation of the voltage compensator. The experimental shielding coil system is composed of coaxial solenoid type coils which are a main superconducting coil, a shielding coil and a pair of correction shielding coils to achieve the inductance condition. Here, results of performance tests on the shielding coil system including work of the voltage compensator are presented.