Perspective of Voltage-Fed Single-Phase Multilevel DC-AC Inverters

Abstract

Standing out for their remarkable benefits, such as lower voltage stress on integrated semiconductor devices, reduction in total harmonic distortion, as well as lower electromagnetic effects, multilevel inverters (MLIs) increase their share in the field of energy supply. The multilevel inverter is an interesting research topic that realizes the generation of desired output voltage waveforms composed of small voltage steps. However, many studies have put a premium on the structure, efficiency, and output of the multilevel inverter, but there are relatively few studies on the THD and practical product applications. Consequently, in this brief perspective, some puzzles for MLIs are pointed out to explore new ideas as well as to present new questions.

Two Types of Asymmetric Switched-Capacitor Five-Level Single-Phase DC-AC Inverters for Renewable Energy Applications

“…The main half-bridge circuit is operated based on the positive and negative half-cycles of the output voltage, and the multilevel inverter achieves the unipolar PWM-switching strategy by using control force alignment compensation. Since the switched-capacitor circuit consists of one or more capacitors and one or more power switches and is often used to maintain the voltages across the capacitors at several times the input DC voltage, the output voltage of the circuit is controlled by switching the capacitors to charge and discharge through the active components to achieve the output voltage at a relatively high number of voltage levels [32,33].…”

“…times the input DC voltage, the output voltage of the circuit is controlled by switching the capacitors to charge and discharge through the active components to achieve the output voltage at a relatively high number of voltage levels [32,33]. There are many other existing papers presented on the asymmetric five-level singlephase DC-AC inverters [2,[34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50] with voltage gain and circuit structure considered, to be summarized in Table 1.…”

Efficiency and Power Loss Distribution in a High-Frequency, Seven-Level Diode-Clamped Inverter

“…NPC (Neutral-Point Clamped) inverters, in their different variants, are one of the most commonly used system topologies in industrial applications [1,2]. Inverters are developing in both multi-phase and single-phase applications, as exemplified in [2] by numerous inverter concepts for photovoltaics such as double input voltage topologies (two switches H-B inverter, NPC H-B inverter, ANPC H-B inverter, T-type H-B inverter) or single input voltage topologies (full bridge inverter, flying capacitor topologies, buck-boost topologies, and others).…”