The multilevel inverter-based drive system is greatly affected by several faults occurring on switching elements. A faulty switch in the inverter can potentially lead to more losses, extensive downtime and reduced reliability. In this paper, a novel fault identification and reconfiguration process is proposed by using discrete wavelet transform and auxiliary switching cells. Here, the discrete wavelet transform exploits a multiresolution analysis with a feature extraction methodology for fault identification and subsequently for reconfiguration. For increasing the reliability, auxiliary switching cells are integrated to replace faulty cells in a proposed reduced-switch 5-level multilevel inverter topology. The novel reconfiguration scheme compensates open circuit and short circuit faults. The complexity of the proposed system is lower relative to existing methods. This proposed technique effectively identifies and classifies faults using the multiresolution analysis. Furthermore, the measured current and voltage values during fault reconfiguration are close to those under healthy conditions. The performance is verified using the MATLAB/Simulink platform and a hardware model.

This paper proposes a forward conversion topology using a multi-winding transformer known as global modular balancing (GMB) for multiple supercapacitor cells connected in a series of high-voltage applications. The proposed topology can easily be modularized and is not limited to the number of supercapacitors existing in the modules. Moreover, the proposed GMB needs merely one MOSFET switch for each supercapacitor, and a one Pulse width modulation circuit that can control all the switches in the modules. Furthermore, the proposed topology is employed to achieve voltage balancing in a supercapacitor string. The proposed topology balancing performance is validated through MATLAB/Simulink Software.

Electric drives of high power applications require power electronic converters of high power rating. To meet this requirement, the multilevel inverter concept has been introduced for medium voltage and high power applications. The multilevel inverter became popular because of its advantages like low harmonic distortion, less rate of change of voltage (dv/dt) and it reduces the bearings stress of a motor. There are different types of multilevel inverters have been introduced in to the market such as diode clamped, flying capacitor and cascaded H-Bridge (CHB) inverter. Out of these, CHB inverter is extensively used with symmetrical and asymmetrical configuration. The major drawback of CHB inverter is, it requires more number of HBridges as the number of levels is increased. Therefore, switches requirement increases which lead to increase the size, cost and complexity. In this paper, a new topology for multilevel inverter is proposed with minimum number of switches in both symmetrical and asymmetrical configuration. The inverter is modeled using Matlab/Simulink software and the results are compared with cascaded H-Bridge inverter. The output of this inverter is fed to the 3 phase induction motor drive and the performance characteristics are also analyzed.

This paper focuses on the total harmonic distortion (THD) analysis of a multi-level inverter (MLI) for fuel cell applications. Furthermore, a 50 kW 625 V proton exchange membrane fuel cell (PEMFC) stack was employed for this analysis. The various modes of operation of the suggested inverter are presented accordingly, along with its switching combinations. Also, a sinusoidal pulse-width modulation (SPWM) controller was employed to drive the power electronic switches in the suggested topology. The suggested inverter can produce sinusoidal voltage with only fundamental frequency switching. Moreover, the number of components and voltage stress of the suggested topology are compared with the conventional topologies presented. In addition, the THD was analyzed with and without the LC filter. Finally, the validity of the system was verified through MATLAB/Simulink software R2022b.