PUBLICATIONS

 The second research work introduces a dual-reference voltage-based pulse width modulation (DRV-PWM) scheme for three-phase five-level hybrid ANPC inverters. This scheme, as an alternative switching scheme, provides the benefits of conventional phaseshifted-carrier-based PWM (PSC-PWM) by naturally balancing voltages without the need for voltage sensors. Additionally, it effectively balances thermal losses across the three phases, thereby improving the reliability and efficiency of the switching devices in the fivelevel hybrid ANPC inverter.The final research work proposes creative modulation schemes based on modified carrier-based PWM with an offset injection to extend the modulation index (MI) to a maximum of 115% (i.e., modified space vector PWM (SVPWM)). By applying these schemes, the lifetime of dc-link capacitors in three-level and five-level hybrid ANPC inverters is enhanced, resulting in improved reliability of the inverters thought the reduction of ripples in both the neutral-point current and common mode voltage (CMV).The research methodology involves a comprehensive analysis of the proposed works with detailed description of system modelling, conventional methods and related studies and addressing their limitations. In addition, the proposed methods are extensively explained toclarify the contribution in improving the overall performance and enhancing inverters reliability. Simulation studies and theoretical analyses are conducted to evaluate the performance and effectiveness of the proposed schemes. The outcomes demonstrate significant improvements in the reliability and efficiency of hybrid ANPC inverters.Overall, this research contributes to advancing the field of multilevel (three- and fivelevel) hybrid ANPC inverter technology by addressing crucial challenges and proposing innovative solutions to enhance their reliability especially the capacitors and switching devices. The developed modulation schemes and strategies offer valuable insights and practical applications for the design and implementation of reliable hybrid ANPC invertersin various power electronic systems.