A Seven-Level Inverter With Natural Balance and Boosting Capability

Abstract

This paper introduces a new active-neutral-point clamped (ANPC) seven-level inverter with a switched-capacitor technique. The introduced inverter generates a seven-level ac output voltage with a maximum voltage-boosting gain of 1.5. Also, a simple modulation technique was proposed, where the capacitors voltages are naturally balanced by the series-parallel connection of the input voltage source. Compared with seven-level inverter topologies, the proposed topology is simpler and its control system does not requires sensors or balancing circuits to stabilize the dc-link voltages. Additionally, the dc-link voltage requirement is reduced by 33.33%, eliminating the need for an intermediate dc-boosting stage and making the introduced inverter a good candidate for applications such as photovoltaic panels and full-cells systems, both characterized by a low input voltage. The operation and performance of the proposed topology is validated through simulation and experimental results.