A novel multi modular GTO current source converter structure is presented to application to superconducting magnetic energy storage system. N_??_N converters are arranged in a array form. The GTO current source converter array with appropriate arrangement of modulation and carrier signals can output large power with high quality line current waveforms. With using of only <i>N</i> transformers, 6N<sup>2</sup> pulse number converter performance is obtained. Only low switching of GTO is required since PWM is primarily used as a method to control flow of power instead of reducing harmonics. It is compared with conventional direct paralleled multi modular converter structure. The results of simulation are presented in this paper.