A Comparative Study on Solar-based Multilevel Inverters as A substitute for OLTCs

In this paper, a comparative study is proposed on a converter-based OLTC (COLTC) when it is utilized as a substitute for an electromechanical tap changer in power transformers to vary the output voltage. Different structures of converters have been studied and compared in the converter-based OLTC, and the transient voltages and the maximum regulation of the desired voltage on the load side have been taken into account. All inverters are supplied by a photovoltaic system or any DC system and are in series with a grid voltage on the output side. A simulation has been performed in the PLECS software to compare the results of the converters while they are used in COLTC. The results prove that the diode-clamped multilevel inverter is a better choice in the application of the converter-based OLTC, as it has lower transient voltage, and also the voltage regulation in the load side is performed much better than the other multilevel structures.