Multilevel Inverters and DC–DC Converters for PV–EV Charging: A Comprehensive Survey of Topologies, Controls, and Open Challenges

Abstract

There is an increasing demand for an effective, dependable and affordable power conversion systems, because of significant improvement of renewable energy (RE) and application of EV. In photovoltaic (PV) applications, Multilevel inverters (MLI) are receiving more attention. For grid-integrated and charging infrastructures, this MLI offers adaptable voltage levels, and it also have the potential in offering better energy supply, low Total Harmonic Distortion (THD), so these are the reason behind its popularity.  By utilizing conventional MLI topologies, high switch counts, multiple isolated DC sources, increased circuit complexity, and inefficiency of the system will exist. These challenges made conventional MLI ineffective. Many RSC and switched capacitor (SC) inverter topologies, innovative DC–DC converter designs and advanced MPPT algorithms were analyzed by the authors for the purpose of resolving those challenges. With these algorithms, compactness, efficiency and dynamic efficiencies are all improved. Despite these improvements, there are still some difficulties, they are scalability, voltage stress management, thermal issues, and control complexity. The MLI topologies and related power electronic converters used in PV and EV charging applications are thoroughly analyzed in this survey. The design trade-offs, operating principles are all highlighted in this survey. This review also analyses performance features, and assess its benefits and drawbacks. Main research gaps are identified in this review. Possible solutions like wide band gap device adoption, hybrid renewable integration, AI-driven control strategies, and smart grid compatibility are also discussed. Researchers and engineers can create scalable, efficient, and reliable inverter-converter architectures for next-generation RE and EV charging systems with the support of this survey.