Switched-Boost Common-Ground Five-Level (SBCG5L) Grid-Connected Inverter With Single-Stage Dynamic Voltage Boosting Concept

Dynamic voltage boosting feature in photovoltaic (PV) grid-integrated application is a necessity to achieve the maximum power point of PV arrays as well as boost the input voltage to the necessary dc-link voltage requirement. Such feature is usually achieved by incorporating a front-end boost or buck-boost dc-dc converter tendem with a conventional two or three-level inverter. However, such an integration cannot efficiently meet many IEEE strict grid codes from the power quality, ground leakage current, and the overall efficiency per power density aspects. The aim of this paper is to present a new five-level (5L) inverter with an integrated single-stage dynamic voltage-boosting concept and a common-grounded (CG) feature. As a result, the concern of ground leakage current is addressed through the provided CG feature, whilst both the power quality and overall efficiency of the system are improved with a 5L single-stage boosted output voltage waveform. To confirm the effectiveness of the proposal, apart from the circuit description, some experimental results are also presented.