Quantitative Analysis of Reliability and Cost Function of 15-Level Inverter

Multilevel inverters have gained significant attention in high-voltage and high-power applications due to their high quality and smoother output with reduced harmonic distortion and low dv/dt stress compared to traditional inverters. Despite the reduction in the switches that have been made, reliability remains a critical challenge. The reliability of these inverters tends to decrease due to the high failure rate of the switches and the capacitors involved in those inverters. This paper presents a novel approach to estimating the cost function and conducting a reliability analysis in a reduced-switch multilevel inverter. It compares it with real-time switches using the military handbook 217F. The failure rate of major components like diodes, capacitors, and switches is mathematically calculated and evaluated. Furthermore, the mean time between failures and recovery time is calculated in the reduced switch 15-level MLI, and further steps to improve reliability have been discussed. A performance comparison of silicon and silicon carbide material switches is made. All simulations are performed in the MATLAB software, and the results are validated in a hardware configuration. This work will benefit industry professionals and researchers in the advancement of multilevel inverters to the next level.