A Review of Five-level Active Neutral-Point Clamped (5L-ANPC) Converter

The five-level active neutral-point clamped (5L-ANPC) converter has been a subject that has attracted more research and development for medium/high-power energy conversion systems in industrial application due to the advantages of high quality of voltages and currents, low voltage stresses, etc. In this paper, a review of the research and development achieved in recent years on the 5L-ANPC converter is discussed about the challenges and proposed solutions for this power converter. Introducing typical 5L-ANPC converter topology and operation principles, this paper focused on photovoltaic (PV) system and motor drive to summarize the derived topologies of the 5L-ANPC. Then the analysis and theoretical research on the unbalanced capacitor voltage of the 5L-ANPC converter is carried out. On this basis, various voltage equalization methods based on different modulation strategies and model predictive control (MPC) are fully explained and analyzed. Furthermore, additional key issues, such as the capacitor voltage pre-charge process and the compensation of the dead-time effect, are also identified. This indicates that the 5L-ANPC converter has a promising future in next-generation high-voltage high-power conversion systems.