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In recent years, common ground (CG)‐type transformerless (TL) inverters have been paid more attention. However, the existing topologies have more voltage stress on either switch or on capacitor voltage or in both. This article proposes a novel five‐level TL inverter topology with a CG type and a voltage stress reduction on power components. The proposed topology offers less component count and a simple structure. Here, the quasi‐soft charging (QSC) technique is proposed to minimize the high charging current during the capacitor charge. Since the proposed topology is the family of switched capacitors (SC), the determination of SC and QSC is presented. A detailed comparison of the proposed topology with other recent five‐level topologies is presented, and the proposed topology's advantage is highlighted. Further, the performance of the proposed topology is verified in simulation software and verified in a scale‐down hardware setup developed for 400 W. The various experimental results are presented to ensure the feasibility of the proposed topology. [ABSTRACT FROM AUTHOR]

Fault analysis is necessary to design a protection system and circuit breakers for a power system network. The multiphase system is a new technology so very little work is found for the fault analysis of a multiphase system contrary, unlike a three‐phase system. The faults in a seven‐phase system may be either symmetrical or non‐symmetrical. A non‐symmetrical fault requires studying the sequence components of a seven‐phase system using Fortescue transformation. In the paper, non‐symmetrical fault analysis of the seven‐phase system has been analysed. For this, a new definition of sequence components of an unbalanced seven‐phase system has been proposed in this paper. Then the proposed sequence components are applied to different faults studies at the input and output sides of a seven‐phase transformer. Further, the effect of the construction of a seven‐phase transformer, that is, core type and shell type on its output is studied. Moreover, the effect of open‐phase input is analysed using simulation and hardware results. From the analysis, it is found that in certain configurations of a seven‐phase transformer, the seven‐phase output is produced even though open‐phase fault is present at the input while in other configurations, seven‐phase is not produced in the case of open‐phase fault. [ABSTRACT FROM AUTHOR]