A three‐phase inverter circuit using half‐bridge cells and T‐NPC for medium‐voltage applications

Abstract

Three-phase single DC-source based multilevel inverter topologies play a pivotal role in industrial applications due to the reduced number of components and higher efficiency. This paper emphasizes the inverter for medium-voltage applications that employ a conventional three-phase T-type structure (T-NPC). The primary circuit of the proposed configuration consists of a T-NPC structure connected to the half-bridge cells at the top and the bottom sides of each phase. The secondary circuit consists of DC-link capacitors whose voltage balancing is attained through a separate voltage balancing circuit (VBC). Using the proposed configuration, the number of components and independent DC supplies are reduced compared with the conventional topologies such as a neutral point clamped (NPC) inverter, a flying capacitor (FC) inverter, and a cascaded H-bridge (CHB) inverter for the same number of output voltage levels. Hence, the proposed topology results in the reduction of weight, volume, and power losses of the inverter. A sine-triangle comparison method is employed in the field programmable gate array (FPGA) platform to generate the firing pulses of the circuit switches. The effectiveness of the proposed topology is verified with simulation studies and is experimentally validated with a scaleddown prototype.

Implementation and Analysis of a 15-Level Inverter Topology With Reduced Switch Count

“…The cost of a particular device depends on its rating which is determined by the maximum voltage required to be blocked by that particular device. The proposed topology is different from the discussed topologies of [11], [28]- [31]. The components with only three different ratings are required in the proposed topology whereas components with four or five different types of ratings are required in the case of topologies discussed in [11]- [16].…”

Isolated seven‐level inverter for grid‐connected power systems with predictive control method

“…have received more attention from researchers who want to develop it further. Among the MLI topologies, while flying capacitor MLI (FC‐MLI) topology uses several DC‐link capacitors and single DC voltage source, neutral‐point‐clamped MLI (NPC‐MLI) uses a several diodes and a single DC voltage source 5,6 …”

“…Among the MLI topologies, while flying capacitor MLI (FC-MLI) topology uses several DC-link capacitors and single DC voltage source, neutral-point-clamped MLI (NPC-MLI) uses a several diodes and a single DC voltage source. 5,6 The NPC-MLI topology requires a higher number of clamping diodes as the voltage level increases (>3L). This causes voltage unbalance of DC-link capacitors and unbalanced power distribution in switches.…”

A cascaded converter using hybrid cells and H-bridge structure

“…Cascaded converters are highly flexible and modular in the family of multilevel inverters. In this group cascaded H-bridge (CHB) converters [1]- [3] are the classical and traditional types. CHB converters have the advantages of equal voltage stress in symmetrical configurations and easy to add/remove number of output voltage levels can be reduced or increased using H-bridges.…”