Research on Dual Buck Half Bridge Five-level Inverter for Rooftop Solar System

This paper presents a novel design for dual buck half bridge five-level inverter (DBHBFLI), which based on field-programmable gate array (FPGA), and was used for photovoltaic power system. This topology is derived from dual buck half bridge inverter (DBHBI), which has the characteristics of no shoot-through problem, no body diode reverse-recovery problem, and current half-period work mode, these merits are retained in the proposed inverter. FPGA logic device is chosen for the hardware implementation of control circuit. The FPGA controller consists of six main modules: the sine wave generator module, the triangle wave generator module, the voltage proportion integration (PI) module, the current proportion (P) module, sinusoidal pulse width modulation (SPWM) module, and SPWM distribution module. VHDL is used in the design of each module. The simulation and experiment results which confirm the validity and performance of the design are shown in the paper.