Comparative study and simulation of optimal converter topologies for SMES systems

In this paper a comparative study between different topologies for SMES (Superconducting Magnet Energy Storage) systems is presented. The study is based on the simulation of different options by using EMTP (Electromagnetic Transients Program). The comparison is mainly centered on two converter types: current and voltage converters. Although both topologies could be used for SMES systems, the simulation results give an excellent tool to select the more appropriate topology for any specific application. All the topologies analyzed are based on self-commutating devices (GTO or IGBT) and PWM mode control. This allows a fast and independent adjustment of both active and reactive powers, AC current harmonics minimization and four quadrants (P,Q) operation.>