A New Single-Phase Dual-Mode Active Neutral Point-Clamped Five-Level Inverter for Renewable Applications

The paper presents a new single-phase Dual-Mode Active Neutral Point-Clamped Five-Level (ANPC-5L) inverter for Renewable applications. It overcomes the shortcoming of ANPC multilevel converters proposed in the recent literature such as excessive voltage stress on devices, utilization of half the dc-link voltage and the requirement of larger than double the dc-link voltage as compared to the grid peak voltage. Therefore, in this paper, a dual-mode ANPC converter is presented which promises the merits of reduced device stress over a wide range of dc input voltages for grid connected operation. The proposed topology is designed with standard T-type modules using 10 power devices and four dc-links and has the features of bidirectional power flow with an integrated flying capacitor (FC) technique. Moreover, it can be operated in two distinct modes such as boost mode and buck mode for a wide range of the input voltage. Simple level-shifted/phase-shifted pulse width modulation scheme is used for both the boost and a buck mode operation to realize the five-level output voltage waveform. A simple proportional-resonant (PR) controller is developed to study the dynamic response of the system under input voltage and their modes of operation using MATLAB/PLECS software and their results are presented. Finally, a detailed comparison is made with the recent ANPC-5L inverter topologies to highlight the merits of the proposed topology.