A novel current source converter array with swapping of module control signal

A current source converter array designed for superconducting magnetic energy storage system was investigated. This array is controlled by modulation-signal phase-shifting SPWM method. The DC side current of each converter module of the converter array can balance automatically at the unity power factor, but unbalanced seriously with the decrease of input power factor. In addition, the DC side current unbalancing causes higher distortion of AC input current. Swapping of the gating signal of each converter module in same row is introduced to average the DC side currents. The harmonics of the AC currents is reduced while the DC side currents are balanced. 2×2 array and 2×4 array are studied in the experiments.