Six-Switch Five-Level Boost-Type ANPC Inverter With Full DC Source Utilization

This article proposes a five-level (5L) boost active neutral point clamped (BANPC) switched capacitor (SC) inverter topology with reduced device count. Unlike conventional ANPC inverters, the proposed topology utilizes the full DC-link voltage, eliminating the need for additional boost converter stages. The SC impulse charging current is suppressed by approximately 20% even without employing a soft charging technique. To further minimize the inrush current, a soft charging technique is employed. As a result, the charging current is limited to two times the load current. Moreover, the proposed DC-link and switched capacitor voltages are self-balanced and do not require additional balancing circuits. Design considerations and a comparative analysis with other recent ANPC topologies are discussed, demonstrating that the proposed BANPC is superior in achieving dual operation with the least device count. Experimental results for a 500 W system are presented to validate the effectiveness and feasibility of the proposed BANPC inverter.