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.

This research offers a thorough analysis of the dynamic behavior of 1-, 2-, and 3-DoF mechanical systems under a sinusoidal force, examining both mechanical and dq coordinates. By utilizing standardized initial conditions, the 1-DoF system displays fascinating oscillatory patterns with dual frequency components, highlighting the significance of low damping. The adaptation to dq coordinates simplifies the analysis and highlights the system's nuanced behavior. In contrast, the 2-degree-offreedom system exhibits intricate interactions, oscillation phenomena, and multiple frequency components in mechanical coordinates. The contribution of masses that do not experience external forces in dq coordinates is minimal. On the other hand, the 3-degree-of-freedom system shows diverse interactions and frequency components that are different from the dq transformations. The observed dynamics not only enhance comprehension of these systems but also provide valuable insights for refining analytical approaches in the analysis of dynamic systems. This study sets the stage for future investigations and urges the development of streamlined analytical frameworks for a more focused exploration of externally influenced variables in dynamic mechanical systems.

Exploring the fundamental principles of system modeling in electrical engineering, this study delves into the transformative power of the d-q transformation, highlighting its pivotal role in rendering time-varying systems into a coherent steady-state representation. Departing from conventional approaches, the study carefully navigates the complexities of single-phase transformer configurations, utilizing the Clarke and Park transformations to seamlessly transition between electrical coordinates and the d-q frame. Through extensive derivations, dynamic equations are formulated in both α-β and d-q coordinates, providing a detailed understanding of system dynamics under specific loads. In addition, the study extends the analysis to a generalized multi-winding transformer model that accommodates a wide range of transformer setups. With detailed mathematical derivations, insightful visual aids, and clear state-space representations, this work attempt to be a resource for researchers, engineers, and practitioners seeking to unravel the intricacies of electrical system modeling and analysis.

This study presents a comprehensive analysis of a two-level battery charger for electric vehicles, focusing on modeling, simulation, and performance evaluation. The proposed charger topology employs two switches operating complementarily, along with essential components such as inductors, capacitors, and batteries. Detailed modeling in steadystate and dynamic regimes reveals the influence of nonlinearities, particularly switch and energy storage element characteristics, on charger efficiency and performance. Efficiency calculations highlight the significance of precise modeling and control strategies. Controller synthesis involves designing a robust proportional-integral compensator for effective battery charging current regulation. Analysis of non-idealities underscores the need for accurate component sizing and control strategies. The findings provide valuable insights for optimizing charger design and control, with implications for enhancing electric vehicle performance and reliability.

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 paper presents a comprehensive study of the single-stage capacitor microphone, an electromechanical device. It integrates temporal modeling and an efficient linear-quadratic regulator control system. Simulations are used to verify the reliability and performance of the single-stage capacitor microphone and the linear-quadratic regulator control system, demonstrating zero steady-state error and rapid convergence.

This paper introduces a static model in dq coordinates for a common-emitter amplifier configuration to address low-power signal amplification. The model is derived through the transformation from sinusoidal to rotational coordinates. Linear compensators face challenges with sinusoidal waveforms, hence the need for static modeling. Simulations validate the model’s reliability. Overall, this contribution improves the common-emitter amplifier configuration modeling and analysis.

This paper presents a unified analysis of an integrated electromechanical system and a two-level full-bridge dc-dc converter. The study seeks to prove the feasibility and the behavior of the system using simulations. The analysis includes a stability study and reveals low-pass filter and amplifier characteristics in the transfer functions. The simulations confirm the stability of the system and provide valuable insights into its dynamics, providing a solid basis for further research and optimization of control strategies.

A single-component single-stage vaporizer is studied in this work. It is modeled by obtaining a set of coupled nonlinear equations. From this nonlinear model, a linearization is carried out by deriving a linear model of multivariable nature in the form of state space. From the multivariable linear model, a control system is designed, using a single compensator structure and a structure in which two compensators are connected in a cascade. Finally, the process is simulated, verifying the feasibility of the operation with the designed control system.

This study focuses on the dynamic modeling and control system design of an X-filter for filtering green liquor. It includes the derivation of nonlinear and linear models, design of three linear controllers, and analysis of control element dynamics. The controllers demonstrate excellent performance with minimal overshoots and fast response times to disturbances. Finally, the model is simulated to assess its feasibility and performance, providing valuable insights for optimization and practical implementation of the X-filter system.

In this paper, an oil-heating tank is presented, developing its respective modeling through the application of the laws of conservation of mass and energy. Then a set of nonlinear differential equations are obtained representative of the process. Subsequently, this system is linearized obtaining its linearized model. With this linear model, the design of two control systems is presented, based on a PI feedback output compensator and based on a linear-quadratic regulator, where the control objectives are the storage temperature and the fuel oil level. Finally, the process is simulated, verifying the feasibility of the operation with the designed control system.

Dynamic modeling and its control of two nonlinear processes are presented in this work. The processes emulate a clean water storage plant and are configured by interconnecting two tanks. According to the way, the tanks are interconnected, i.e., in cascade or in series, the dynamic behavior of the process changes from a non-interacting to an interacting system, both nonlinear. Three controllers (two linear and one nonlinear) have been designed and applied to the process. In order to evaluate the performance of the system, as a function of the controller applied, three figures of merit have been selected and compared. From the comparison results of these figures of merit, the advantages and drawbacks of each designed controller are identified. Finally, through simulation results, the feasibility of the system operation is verified.