COMPARATIVE ANALYSIS OF MULTILEVEL INVERTER WITH AND WITHOUT TRANSFORMER
Authors: Francesco Russo, Giulia Conti, Luca Benedetti
DOI: 10.87349/JBUPT/27702
Page No: 12-20
Abstract
In this paper/thesis a comparative analysis of multilevel inverter with and without transformer through simulation is carried out. The output voltage and current waveforms are compared for resistive load without any filtering unit. Reduction in device count is also considered to reduce switching losses. In this paper/thesis, a novel cascaded transformer multilevel inverter is proposed. The number of the switching devices is reduced in the proposed topology. This topology comprises of a DC source, several single phase low-frequency transformers, two main power switches and some bidirectional switching devices. In this topology, only one bidirectional switch is employed for each transformer. However, in conventional cascaded transformer multilevel inverter, four switching devices are required for each transformer. Therefore, more output voltage levels can be obtained using fewer switching components. Reduction in the number of switching devices which also means reduction in the number of gate drivers results in smaller size and low implementation cost. Switching power losses are also reduced in this topology. Selective harmonic elimination (SHE) technique is applied to the proposed inverter to obtain a high quality output voltage. Simulation results are also provided to verify the feasibility of the proposed converter.
