Four quadrant multilevel current source power conditioning for superconductive magnetic energy Storage

The main purpose of this paper is to describe advances in high current source converter (CSC) and control for use in superconductive magnetic energy storage (SMES) schemes instead of the conventional PWM-chopper based VSC configurations. The multi-level current reinjection (MLCR) CSC provides the simplest structure, as well as switching at zero current, a property that permits retaining the use of basic thyristors in the main converter bridges. Extensive PSCAD/EMTDC simulation is carried out to verify the theoretical predictions.