A Review of Multilevel Inverter Topology and Control Techniques <s>  Soft-Switched Multilevel Inverter <s> Multilevel voltage source converters are emerging as a new breed of power converter options for high-power applications. The multilevel voltage source converters typically synthesize the staircase voltage wave from several levels of DC capacitor voltages. One of the major limitations of the multilevel converters is the voltage unbalance between different levels. The techniques to balance the voltage between different levels normally involve voltage clamping or capacitor charge control. There are several ways of implementing voltage balance in multilevel converters. Without considering the traditional magnetic coupled converters, this paper presents three recently developed multilevel voltage source converters: (1) diode-clamp, (2) flying-capacitors, and (3) cascaded-inverters with separate DC sources. The operating principle, features, constraints, and potential applications of these converters are discussed. <s> BIB001 </s> A Review of Multilevel Inverter Topology and Control Techniques <s>  Soft-Switched Multilevel Inverter <s> A new control algorithm for a power converter-based device that is capable of alleviating the problems of harmonic interference and voltage regulation on radial distribution lines is introduced. It comprises a relocatable converter in series with a passive filter and is known as the Power Quality Manager. Simulation results based on an existing 88-kV line are presented. Experimental results are presented, based on a three-phase 200-VA scaled model of the existing 88-kV system. It is a cost-effective and flexible solution to improving power quality. <s> BIB002 </s> A Review of Multilevel Inverter Topology and Control Techniques <s>  Soft-Switched Multilevel Inverter <s> Publisher Summary ::: This chapter demonstrates the state of the art of multilevel power converter technology, discussing fundamental multilevel converter structures and modulation paradigms. A multilevel converter not only achieves high power ratings but also enables the use of renewable energy sources. A multilevel converter has several advantages over a conventional two-level converter that uses high switching frequency pulse width modulation (PWM). Multilevel converters produce smaller CM voltage and can draw input current with low distortion. Existing multilevel converters such as diode-clamped and capacitor-clamped multilevel converters can be derived from the generalized converter topology called P2 topology. To reduce the number of separate dc sources for high-voltage, high-power applications with multilevel converters, diode clamped or capacitor-clamped converters can be used to replace the full-bridge cell in a cascaded converter. Two multilevel converters can be connected in a back-to-back arrangement, and then the combination can be connected to the electrical system in a series-parallel arrangement. <s> BIB003
The soft-switching methods can be realized for diverse multilevel inverters to reduce the switching loss and to increase efficiency BIB003 . For the cascaded inverter, because each inverter cell is a bi-level circuit, the implementation of soft switching is not at all different from that of conventional bi-level inverters. For a flying capacitor or neutral point clamped inverters, softswitching circuits have been proposed with different circuit arrangements  . One of the soft switching circuits is zero-voltage-switching type which includes auxiliary resonant commutated pole (ARCP), coupled inductor with zero-voltage transition (ZVT), and their combinations BIB001 , BIB002 .