This paper presents a detailed investigation into the performance of multi-level converter topologies (2L-1P-NPC, 3L-1P-NPC, and 4L-1P-NPC) in regulating the angular position and velocity of a switched reluctance motor (SRM). Utilizing the MATLAB-Simulink environment, the study rigorously simulates various operational scenarios under distinct modulation schemes: BVPWM, UVPWM, LSPWM, and VVPWM, all functioning at a constant switching frequency of 10 kHz. Key parameters, including inductances, resistances, and mechanical properties of the load, are meticulously defined to ensure realistic representations of operating conditions. The analysis encompasses both steady-state and transient responses, highlighting the converters' ability to minimize total harmonic distortion (THD) in voltage and electromagnetic torque outputs. Specifically, topology C exhibited the lowest voltage THD of 23.66 % under LSPWM, underscoring the advantages of higher-level converters. Furthermore, the study investigates the effects of duty cycle variations on harmonic profiles and torque characteristics, revealing significant reductions in torque ripple with advanced modulation techniques. Transient performance assessments demonstrate the system's stability and accuracy, with negligible steady-state errors in angular position and responsive behavior to step changes in reference inputs. These findings affirm the efficacy of proportional-integral (PI) control strategies in achieving precise control of the SRM. The results substantiate the superiority of multi-level converter topologies in high-performance applications, providing compelling evidence of their enhanced harmonic performance and control capabilities. This research contributes to the growing body of knowledge in electric motor drive systems, offering insights into the implementation of advanced modulation strategies and the potential for future innovations in converter technologies.
This study presents a comprehensive analysis of three bipolar-junction-transistor (BJT) amplifier topologies common-emitter, common-collector, and common-base amplifiers-under transient conditions across low and high frequencies. Utilizing MATLAB-Simulink simulations, the response of each amplifier topology to varying frequency inputs is investigated, with a particular emphasis on state space modeling. Beginning with low-frequency models characterized by specific voltage or current sources, the study delves into the steady-state dynamics of output variables, employing state space equations to elucidate amplifier behavior. Notably, the common-emitter amplifier topology exhibits high gains, as corroborated by established literature, underlining its potential for high-performance applications. Conversely, the common-collector and common-base amplifier topologies demonstrate lower gains, reflecting distinct design characteristics. Transitioning to high-frequency operation, the impact of Miller capacitance on gain reduction is explored, especially pronounced in the common-emitter amplifier topology. Despite this, all amplifier configurations remain functional, with state space models validated through meticulous simulations. Simulation parameters are meticulously adjusted to accurately represent real-world scenarios, enhancing the reliability of the findings. These insights underscore the importance of comprehending amplifier behavior across different frequency domains, with state space modeling offering a powerful framework for analysis. By providing detailed insights into BJT amplifier performance under transient conditions, this study facilitates informed decisions regarding amplifier configuration selection and design, tailored to specific application requirements and frequency considerations.