No abstract

No abstract

No abstract

Cascaded H-bridge multilevel inverters are currently used because it enables the integration of various sources, such as batteries, ultracapacitors, photovoltaic array and fuel cells in a single system. Conventional modulation schemes for multilevel inverters have concentrated mainly on the generation of a low harmonic output voltage, which results in less effective utilization of connected sources. Less effective utilization leads to a difference in the charging/discharging of sources, causing unsteady voltages over a long period of operation and a reduction in the lifetime of the sources. Hence, a charge balance control scheme has to be incorporated along with the modulation scheme to overcome these issues. In this paper, a new approach for charge balancing in symmetric cascaded H-bridge multilevel inverter that enables almost 100% charge balancing of sources is presented. The proposed method achieves charge balancing without any additional stages or complex circuit or considerable computational requirement. The validity of the proposed method is verified through simulation and experiments.

No abstract

No abstract

No abstract

The number of power semiconductor switches and DC sources will increase with the increase in the number of levels of output voltage of the multilevel inverter. As the number of power semiconductor switches increases, the possibility of its failure and hence the breakdown of the inverter operation also escalate in a nonlinear manner. Hence, the detection of the failure of the power semiconductor switch is of paramount importance, considering the availability and reliability of the system is concerned. The gate unavailability or the transistor open circuit fault detection in asymmetrical multilevel inverter by means of monitoring the mean value of the output voltage is presented in this paper. Simulation of this method is carried out in both binary and trinary combinations of asymmetric multilevel inverter. Keywords-Multilevel inverter (MLI), cascaded H-bridge (CHB), power semiconductor switch fault, fault detection, condition monitoring, asymmetric multilevl inverter.