Cascaded H-Bridge Based on Interleaved Full-Bridge Submodules

This paper presents a novel cascaded H-bridge converter based on interleaved full-bridge submodules, which offers significantly improved scalability in current ratings compared to traditional cascaded H-bridge configuration. The proposed design enables the use of low-cost, low-current power switches, reducing dependency on the larger and more expensive switches typically required in conventional systems. A key advantage of the interleaved configuration is its ability to virtually increase the number of output voltage levels by interleaving the operation of its submodules. This approach allows the system to replicate the benefits of traditional cascaded H-bridge converters, such as improved waveform quality and reduced harmonic distortion, even in low-voltage, high-power applications, without requiring additional hardware. A tailored modulation scheme is developed for the proposed interleaved architecture and is thoroughly explained in the paper. Additionally, a comprehensive comparative analysis is conducted, evaluating the proposed topology against the conventional configuration in terms of the number of output voltage levels and harmonic content in the output voltage and current, while maintaining a fixed number of submodules. Experimental results validate the performance and feasibility of the proposed interleaved converter and its associated modulation strategy. Although the study focuses on a single-phase implementation, the approach can be seamlessly extended to three-phase systems with minimal modifications.