Power converter for SMES by use of ICB energy transfer circuit

Inverter-converter bridge (ICB) energy transfer circuit consists of two power converters and the capacitor bank. Two superconducting magnets are connected to the circuit and the stored energy is transferred by use of the circuit. The circuit has been mainly studied as an exciter circuit for pulse superconducting magnets because it enables excitation of the large magnet quickly without affecting the utility. It is easy to achieve the required capacity because the circuit can be made by a natural commutation thyristor. The circuit, which is connected to the power system through the converter (utility tie converter) has attractive features for the SMES power converter, for instance, wide control region of active and reactive power. The relation between utility tie converter control and the ICB circuit control is important for realizing SMES converter system, however, it has not been studied. In this paper, the magnet current control method concerned with the utility tie converter has been discussed to control the energy flows. The theoretical analysis and the experimental results are shown