FPGA-based pulse-width modulation control for single-phase multilevel inverter

Presented is pulse-width modulation (PWM) for single-phase five-level inverter via field-programmable gate array (FPGA). The proposed inverter has conventional full-bridge configuration and one bidirectional switch. The control technique is digitally generated based on multicarrier PWM in Altera DE2 board, which has many features that allow implementation of the system design through Cyclone II FPGA device. A sinusoidal reference signal and two triangular carrier signals in phase and of the same frequency but different offset voltages were used to generate the PWM signals for the inverter switches. Besides Altera Quartus II software, Matlab/Simulink software was used to simulate and verify the proposed circuit before it was implemented in a prototype hardware. Simulation and experiment results closely agreed.