Abstract
Multilevel inverters provide an output signal with low harmonic distortion and superior output voltages. This work proposes a new four-level T-type neutral point piloted (T-NPP) topology with higher efficiency and low total harmonic distortion (THD) and with the ability to withstand high voltage stresses, especially for high-power applications. The proposed topology is designed in such manner that the direct current (DC)-voltage stresses split over the components with strong possibilities to increase the load current and switching frequency. However, the operation of the proposed topology is based on two essential principles. The first principle is that each upper and lower switch of each leg consists of two insulated gate bipolar transistors (IGBTs) connected in series in order to withstand high voltage stresses and make it split over the two IGBTs in each switch. The second principle is using the DC-link circuit (T1 & T2) to generate 2Vdc and 1Vdc by connecting the bidirectional switches of each leg to the DC-link’s mid-point. Furthermore, the proposed four-level T-NPP inverter outperforms other converters by the high number of output voltage level, low number of components, simple structure and higher efficiency. Finally, the proposed T-NPP topology concept was validated via simulation, experiments and theoretical analysis.
Highlights
Multi-level inverters are the most commonly used inverters in industrial applications and other renewable energy applications because they provide pure output voltage’s waveforms
The proposed T-type neutral point piloted (T-NPP) topology is designed for medium-and high-power applications based on the NPP topology which is designed to produce an output voltage with levels either 0 or ±Vdc
T-NPP topology operates with good performance and higher efficiency and one of such a reason for that is the absence of the passive components such as clamping diodes, and flying capacitor (FC) as well as the minimum number of direct current (DC)-link supplies
Summary
Multi-level inverters are the most commonly used inverters in industrial applications and other renewable energy applications because they provide pure output voltage’s waveforms. The issues of neutral-point voltage in NPC such as voltage deviation, the unbalanced voltage across the capacitors of the FC topologies [15], and a large number of separate direct current (DC) supplies in CHB are the main drawbacks to be considered in these topologies [16,17,18,19,20] These topologies are not suitable for low-voltage applications since the switching and conduction losses are getting increased due to the two-series connected switches especially in two-level inverter [21]. The bidirectional switches in NPP topology are used to control the current path and to generate the zero-voltage level This topology can only produce three-level output voltages using the capacitors which are connected to the input DC-link voltage. The proposed topology can be used for high-power applications with less switching and conduction losses compared to the other topologies as presented
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
