Abstract
In this paper, a novel four-level single-phase multilevel converter is introduced, consisting of six active switches arranged in a quasi-nested configuration. The proposed topology synthesizes its output voltage levels with respect to a floating neutral point, using four cascaded capacitors with identical voltage levels. The proposed converter contains a reduced number of components compared to the neutral point clamped (NPC) or active-NPC topologies (ANPC) for the same number of output voltage levels, since it does not require diode or active switch clamping to a neutral point. Moreover, no floating capacitors with asymmetric voltage levels are employed, thereby simplifying the capacitor voltage balancing. The switching operation principles, modulation technique and control scheme for supplying a single-phase resistive-inductive load are addressed in detail. The proposed four-level inverter allows generating an additional output voltage level with the same semiconductor count as conventional three-level inverters such as NPC and ANPC which allows a superior waveform quality, with a THDv reduction of 32.69% in comparison the clamped inverters. Experimental tests carried out in a laboratory-scale setup verify the feasibility of the proposed topology.
Original language | English |
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Article number | 233 |
Pages (from-to) | 1-19 |
Number of pages | 19 |
Journal | Electronics (Switzerland) |
Volume | 10 |
Issue number | 3 |
DOIs | |
State | Published - 1 Feb 2021 |
Keywords
- DC-link voltage self-balancing
- Levelshifted PWM
- Multilevel inverter
- Proportional multi resonant controller
- Quasi-Nested topology
- Reduced active switches topology
- Single-phase applications