Natural balancing of the modular AC/DC converter

This paper considers the voltage balancing of the modular AC-DC converter. The measured results of a 12-cell 3.8 kV AC to 700 V DC converter are presented. The converter balances well in the steady state although the balancing can be improved. The converter balancing varies with the delivered power. It is shown that the imperfect balancing and the variance in the balancing with load can be ascribed to variances in the cell filter inductors and the transformer leakage inductance as measured from cell to cell.