Research on Hybrid-Clamped Multilevel-Inverter Topologies

The concept of hybrid clamped is proposed in multilevel-inverter topologies, and a hybrid-clamped multilevel-inverter topology comprising active and passive clamping devices is presented in this paper. In this topology, the dc-link capacitor voltages can be balanced without additional circuitry or separated dc voltage sources, regardless of load characteristics. It can be used in real and reactive power conversion applications. The topology structure, operating principle, and self-voltage balancing ability are analyzed. In addition, the validity is confirmed by simulations and experiments based on a five-level inverter. Finally, the functions of different clamping devices are compared