Control of cascaded H-bridge inverters using an FPGA-based platform

Cascaded H-bridge multilevel inverters are highly modular converters particularly suitable for generating high output voltages and connecting independent dc sources like solar arrays or fuel cells. Three-phase multilevel inverters based on cascaded H-bridge inverters require a large number of control signals, particularly if the number of levels is high. In this case, Field-Programmable Gate Array appears as the right solution to generate the control signals for the multilevel inverter. This paper presents the analysis and design of a FPGA-based multi-carrier PWM control method for a five-level three-phase inverter suitable for photovoltaic applications and shows simulation and experimental data demonstrating the expected theoretical results.