Single-Sourced Double-Stage Multilevel Inverter for Grid-Connected Solar PV Systems

Abstract

Design challenges for grid-connected solar photovoltaic systems related to the power conditioning units are power quality, efficiency, reliability, cost of implementation, etc. This article deals with a single dc-source-based double level-doubling network high-resolution multilevel inverter topology with the appropriate blend of switches to address most of the practical constraints of central inverter application. A two-stage high-resolution multilevel inverter solution is adapted to double the inverter utilization as well as to increase efficiency. Reactive power handling and fault blocking capability of the system are also demonstrated in this work. The converter is extensively simulated using MATLAB/Simulink. Experimental results from the laboratory prototype confirm the usefulness of the proposed concepts.

Keywords

• Central inverter
• grid-connected PV inverter
• high-frequency switching
• level doubling network (LDN)
• maximum power point tracking (MPPT)
• multilevel inverter