This paper presents the first experimental results obtained with a 6-pulse, 50 kW GTO current source inverter (CSI) feeding a 25 kJ superconducting coil. This SMES system is the first step into the project AMAS500 which consists of developing a 1 MJ SMES fed by a 500 kW CSI. The complete system will be in operation at the end of this year, but this paper shows the first results of the 25 kJ SMES when compensating a voltage oscillation in a scaled network. The paper is mainly focused on showing the experimental results of the 50 kW power converter and its comparison with simulation results obtained by means of EMTP and SABER/sup TM/ simulators. The very good agreement obtained between both results has validated the simulation models. Based on these models, the design of a 500 kW power converter has been carried out. The results of simulating the 12-pulse 500 kW CSI feeding a 1 MJ superconducting coil are also presented in this paper.