Design and Analysis of A Novel Current-Fed Three level Three Limb TAB Converter with Auxilary Inductor for DC Micro-grid Application

This paper proposes a new current-fed three-level (3L) three limb triple active bridge (TAB) converter topology with an auxiliary inductor. Three limb transformer provides low inter-winding parasitic capacitances and 3L output gives higher DC voltage compared to the conventional 2L output and offers better control degree of freedom. The operation of the proposed converter is explained with one of the operational modes in detail. The three limb transformer modeling is explained using magnetic circuit and the corresponding electrical equivalent circuit is developed. ZVS analysis of each switch of the proposed converter under different operating conditions are presented. Decoupled proportional integral controller design is also explained briefly for the proposed converter. Closed loop simulation results validate the analysis and the control scheme. Comparative results show lower input current ripple and wider ZVS range in the proposed converter compared to the Voltage Fed TAB converter which is advantageous for DC micro-grid application.