ABSTRACT
Multilevel inverters use a different method to construct DC/AC inverters. This chapter introduces soft-switching technique in DC/AC inverters. Multilevel inverters have been applied to different high-power applications, such as large motor drives, railway traction applications, high-voltage DC transmissions, unified power flow controllers, static VAR compensators, and static synchronous compensators. The voltage synthesis in a five-level capacitor-clamped inverter has more flexibility than a diode-clamped converter. The chapter presents a generalized multilevel inverter topology. The existing multilevel inverters, such as diode-clamped and capacitor-clamped multilevel inverters, can be derived from this generalized multilevel inverter topology. For high-voltage high-power applications, it is possible to adopt multilevel diode-clamped or capacitor-clamped inverters to replace the full-bridge cell in a cascaded multilevel inverter. The generalized multilevel inverter topology provides a true multilevel structure that can balance each DC voltage level automatically at any number of levels, regardless of active or reactive power conversion, and without any assistance from other circuits.
