Engineering Commons^™

Synergetic Synthesis Of Multivariate Nonlinear Dynamic Objects, Isamiddin Siddikov, Komil Usmanov

Chemical Technology, Control and Management

Based on the synergetic approach, the article solves the problem of analyzing a chemical reactor as a control object and formulates recommendations on the structural and topological synthesis of various control system options. The main feature of technological control objects, in which, as a result of hydromechanical, physical, chemical influences on the flows of the starting substances, their physical properties, state of aggregation and composition change, is their multidimensionality, nonlinearity, multiconnectedness, as well as parametric uncertainty of the mathematical model at the design stage. This type of facility includes a chemical reactor, thermal management, which in most cases is carried …

Adaptive Fuzzy Supplementary Controller For Ssr Damping In A Series-Compensated Dfig-Based Wind Farm, Mohamed Abdeen, Sayed Hosny Ahmed El-Banna, Sara Elgohary, Hend Mostafa, Nora Ghaly, Nourhan Adel, Zeinab Elkhwas, Mohamed Alahmady, Hossam Zawbaa, Salah Kamel

Articles

Although using a series compensation technique in a long transmission line effectively increases the transmittable power; it may cause a sub-synchronous resonance (SSR) phenomenon. Gate-controlled series capacitor (GCSC) is an effective method for SSR damping by controlling the turn-off angle. In the previous studies, a constant supplementary damping controller (SDC) was used for controlling the turn-off angle, which can mitigate the SSR phenomenon. However, these methods can not capture the maximum transmittable power at different operating points. In this paper, a fuzzy logic controller (FLC) is proposed to compute the gain of SDC based on the wind speed and the …

Evaluating Energy Storage Methods For The Stabilization Of Rural Microgrids, Colin Pennock

Honors Theses

Microgrids are a hot topic in industry at the moment due to their ability to help integrate renewables into the national grid. However, they are mainly used in urban settings, despite the stability benefits they could provide to rural communities. This research aims to help expand microgrids into a rural context by building a streamlined, phasor-domain model of a microgrid in MATLAB-Simulink’s toolbox Simscape Electrical and using it to evaluate three energy storage options: a national grid connection, battery, and flywheel. My capstone involved testing models of these three solutions by subjecting my overall microgrid to faults typical of a …

Stability Analysis In Central America’S Power Grid, Sergio Sunley

English Language Institute

Finding the source of instability is key in ensuring an electric power grid proper functioning. This poster shows the results obtained from a stability analysis performed in Central America’s power grid in order to find the source of instability of that grid.

Active Stability Monitoring And Stability Control Of Dc Microgrids Using Incremental Continuous Injection, Rohail Hassan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Electrified transportation and integration of renewable energy in the electric power grid requires the use of power electronic converters for integrating different forms of power; from ac to dc, dc to ac, dc to dc, etc. Recent trend towards electrifying automobiles, aircraft and ships, and increasing penetration of renewable energy has increased the required power levels and number of the power electronics converters connected together in a dc microgrid system. Stable operation of these interfacing converters for all operating conditions has been a topic of renewed interest in the last couple of decades. Traditionally, dc microgrids have been designed conservatively …

Lyapunov Function-Based Stabilizing Control Scheme For Wireless Power Transfer Systems With Lcc Compensation Network, Abu Shahir Md Khalid Hasan

LSU Master's Theses

A stabilizing control scheme based on a Lyapunov function is proposed for wireless power transfer (or WPT) systems. A state-space model of the WPT system is developed and the Lyapunov function is formulated based on an energy equation of the system involving state variables. The internal resistance of a battery varies during charge and discharge. Therefore, if a WPT system is used to charge a battery, its output load will vary. Furthermore, the coupling coefficient between the transmitter (primary) and receiver (secondary) coils decreases when they are misaligned. Comparative case studies are conducted to verify the efficacy of the proposed …

Controller Modeling And Stability Analysis Of Multiple Input Single Output Dc-Dc Converter, Astha Adhikari

Master's Theses

This thesis entails the stability analysis of the Multiple Input Single Output (MISO) DC-DC converter developed for the DC House Project at Cal Poly. A frequency domain control system model of the MISO converter was designed and constructed using MATLAB Simulink. Transfer functions were derived and modeled for each stage of the converter to best fit the converter circuit system used in the original MISO circuit. Stability metrics such as overshoot, undershoot, rise time, phase margin and gain margin were measured to evaluate and analyze the stability of the converter. These metrics were measured with the original model including the …

Stability Studies For A Membrane Electrode Assembly Type Co2 Electro-Reduction Electrolytic Cell, Qing Mao, Bing-Yu Li, Wei-Yun Jing, Jian Zhao, Song Liu, Yan-Qiang Huang, Zhao-Long Du

Journal of Electrochemistry

Electro-catalytic reduction is an efficient way to achieve resourcable transformation of CO₂, which is one of the important techniques to solve the global environmental problems originated from excessive CO₂ emission. In this study, a membrane electrode assembly(MEA) type CO₂ electro-reduction electrolytic cell was constucted, which enables CO₂ feeding and real-time KHCO₃ aqueous updating on both sides of the cathode gas diffusion electrode (GDE). By means of the electrolytic cell, effects of KHCO₃ concentration and updating inside the liquid electrolytic chamber on CO₂ electro-reduction activity, production distribution and stability were investigated. The experimental …

A Comparative Study On The Stability And Degradation Of Perovskite Solar Cells, Jyotiska Chakraborty

Masters Theses

This study aims to investigate the environmental factors that affect the performance and longterm stability of the perovskite solar cells (PSCs). PSCs are based on organo-metallic halides (perovskites) that act as a light-sensitive compound that produces excitons when placed under the light. However, PSCs have a limited operating lifetime due to the degradation of the perovskite layer. There are many factors like moisture, UV light, and temperature that lead to the degradation of the perovskite layer. From the literature review, it was found that the PSCs do not degrade with the presence of oxygen in a dry and dark environment. …

Underwater Remotely Operated Vehicle Controller With Pid Stability Regulation, Christian E. Aguirre

Electrical Engineering

The earth’s oceans and rivers remain widely unexplored. Hobbyists and companies across the globe invest money and resources into remotely operated vehicles (ROV) to further expand underwater knowledge. Each ROV includes a controller that operates motors and monitors other crucial system vitals. The ROV Controller project makes the process of designing an ROV simpler and more affordable by providing a multi-purpose programmable controller.

The ROV controller features programmable digital inputs/outputs and analog inputs. The controller processes control signals from analog joysticks, digital signals from a gyroscope and utilizes a MUX to expand the analog input capabilities of the Arduino. The …

H2 Control For Improved Stability Of Multi-Area Electric Power System With High Levels Of Inverter-Based Generation, Muthanna Abdulkareem Al-Sarray

Graduate Theses and Dissertations

Increased generation capacity from non-dispatchable energy resources such as wind and solar has created challenges to ensuring the reliable delivery of electric power. This research develops a systematic three-step method of assessing the reliability of electric power systems under a variety of different possible fault conditions to ensure that overall system stability is preserved in a manner the meets regulatory requirements. The first step is a risk-based reliability method (RBRM) that accounts for the probability of a line outage versus the severity of impact. This allows system planners to judiciously allocate expenses for reliability improvements based on the greatest economic …

Análisis De Estabilidad De Una Microrred Conectada A Un Sistema De Potencia Convencional, Manuel Alberto Silva Rios, Nicolas Trujillo Alfaro

Ingeniería Eléctrica

En este documento se analiza la estabilidad transitoria y de tensión, para una Microrred que incluye Fuentes No Convencionales de Energía Renovable (FNCER). En el sistema de pruebas seleccionado, realice estudios de caso donde puede variar el funcionamiento del sistema por medio de software especializado en sistemas de potencia, en el cual se modela el sistema eléctrico en estudio, para modificar el comportamiento del mismo, contingencias y salidas de operación de los generadores del sistema, como también la viabilidad de mantener conectadas o no la Microrred. Adicional a esto desde la perspectiva de la normativa vigente en Colombia, consulte las …

Optimal Siting, Sizing, And Parameter Tuning Of Statcom And Sssc Using Mpso And Remote Coordination Of The Facts For Oscillation Damping Of Power Systems, James Garba Ambafi, Sunusi Sani Adamu

Turkish Journal of Electrical Engineering and Computer Sciences

In electromechanical oscillation damping within power system, power system stabilizers (PSSs) are often deployed. However, a PSS is less effective in damping interarea oscillation and is limited by changes in network configuration due to weak tie-lines and load variations. Consequently, this paper presents a wide-area coordination approach that damps interarea oscillations using FACTS devices and phasor measurement units. We selected a static synchronous compensator (STATCOM) and static series synchronous compensator (SSSC) for realistic power system interarea oscillation damping. The performance of the coordinated FACTS installed in a power system depends on their suitable locations, sizes, tuned parameters, and remote input …

High Performance Distributed On-Chip Voltage Regulation For Modern Integrated Systems, Longfei Wang

USF Tampa Graduate Theses and Dissertations

Distributed on-chip voltage regulation where multiple voltage regulators are distributed among different locations of the chip demonstrates advantages as compared to on-chip voltage regulation utilizing a single voltage regulator. Better on-chip voltage noise performance and faster transient response can be realized due to localized voltage regulation. Despite the advantages of distributed on-chip voltage regulation, unbalanced current sharing issue can occur among each voltage regulator, which has been demonstrated to deteriorate power conversion efficiency, stability, and reliability of the power delivery network. An effective balanced current sharing scheme that can be applied to most voltage regulator types is proposed to balance …

Generalized Scattering-Based Stabilization Of Nonlinear Interconnected Systems, Anastasiia Usova

Electronic Thesis and Dissertation Repository

The research presented in this thesis is aimed at development of new methods and techniques for stability analysis and stabilization of interconnections of nonlinear systems, in particular, in the presence of communication delays. Based on the conic systems' formalism, we extend the notion of conicity for the non-planar case where the dimension of the cone's central subspace may be greater than one. One of the advantages of the notion of non-planar conicity is that any dissipative system with a quadratic supply rate can be represented as a non-planar conic system; specifically, its central subspace and radius can be calculated using …

Applications Of Complex Network Analysis In Electric Power Systems, Mahmoud Saleh, Yusef Esa, Ahmed Mohamed

Publications and Research

This paper provides a review of the research conducted on complex network analysis (CNA) in electric power systems. Moreover, a new approach is presented to find optimal locations for microgrids (MGs) in electric distribution systems (EDS) utilizing complex network analysis. The optimal placement in this paper points to the location that will result in enhanced grid resilience, reduced power losses and line loading, better voltage stability, and a supply to critical loads during a blackout. The criteria used to point out the optimal placement of the MGs were predicated on the centrality analysis selected from the complex network theory, the …

Strong Stability Of A Class Of Difference Equations Of Continuous Time And Structured Singular Value Problem, Qian Ma, Keqin Gu, Narges Choubedar

SIUE Faculty Research, Scholarship, and Creative Activity

This article studies the strong stability of scalar difference equations of continuous time in which the delays are sums of a number of independent parameters tau_i, i = 1, 2, . . . ,K. The characteristic quasipolynomial of such an equation is a multilinear function of exp(-tau_i s). It is known that the characteristic quasipolynomial of any difference equation set in the form of one-delayper- scalar-channel (ODPSC) model is also in such a multilinear form. However, it is shown in this article that some multilinear forms of quasipolynomials are not characteristic quasipolynomials of any ODPSC difference equation set. The equivalence …

Strong Stability Of A Class Of Difference Equations Of Continuous Time And Structured Singular Value Problem, Qian Ma, Keqin Gu, Narges Choubedar

SIUE Faculty Research, Scholarship, and Creative Activity

This article studies the strong stability of scalar difference equations of continuous time in which the delays are sums of a number of independent parameters τi, i = 1, 2, . . . , K. The characteristic quasipolynomial of such an equation is a multilinear function of e−τis. It is known that the characteristic quasipolynomial of any difference equation set in the form of one-delay-per-scalar-channel (ODPSC) model is also in such a multilinear form. However, it is shown in this article that some multilinear forms of quasipolynomials are not characteristic quasipolynomials of any ODPSC difference equation set. The equivalence between …

Supercapacitor Utilization For Power Smoothening And Stability Improvement Of Ahybrid Energy System In A Weak Grid Environment, Rahul Sharma, Sathans Suhag

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a novel control scheme based on the application of a supercapacitor (SC) is proposed for power smoothening and stability improvement of a hybrid energy system (HES) in weak grid conditions. The basic property of fast charging/discharging of the SC is utilized to design the proposed control. In weak grid conditions, the control structure is proposed for power smoothening and DC link voltage regulation with the help of the SC. Moreover, the stability is increased, ripples in voltage are reduced, there is fast dynamic response, and oscillations are damped out under different conditions. In conventional control, voltage controller …

Robust Power Interface For Smart Grid With Renewable Energy Source-To-Grid Functionality, Bohyun Ahn

All Graduate Theses, Dissertations, and Other Capstone Projects

Many renewable energy companies design wind turbine generators, solar panels, or electrical car batteries with different specifications according to their management philosophy. And typical commercial power converters are not universally designed for all different types of renewable energy systems. Because of this lack of flexibility and interoperability, a universal and scalable smart grid power converter design is desirable. Designing a robust controlled bi-directional power converter is the motivation for this thesis as the first step to develop a more universal converter topology connecting renewable energy sources and the electrical smart-grid of the future.

Renewable energy such as wind or solar …

Examination Of Gain Scheduling And Fuzzy Controllers With Hybrid Reachability, Aaron W. Fifarek

Browse all Theses and Dissertations

Modern aircraft with nonlinear flight envelopes predominately utilize gain scheduled controllers to provide stability of flight. Using gain scheduled control techniques, nonlinear envelopes can be linearized into collections of linear systems that operate under various system dynamics. Linear controllers approximate the nonlinear response over setpoints of operating conditions which allow traditional linear theory to be applied to maintain stability. Techniques to prove linear stability are well understood and realized in control systems, but when controllers are switched, interpolation methods must be used. Interpolation is necessary as gain scheduled systems do not have foundational switching paradigms as part of their realization …

Stability Improvements For Generalized Average-Value Model Of Dc-Dc Converters, Mahsen Salah Al-Ani

Theses and Dissertations--Electrical and Computer Engineering

Power electronics have a significant role in modern electrical devices, for instance, hybrid electric vehicles. Power electronics are the technology in between the source and the load circuits and can convert the power from dc to ac or from dc to ac. There are also many types of dc-dc converters, like such as boost and buck converters, which exhibit switching ripple behavior. A boost converter increases the output voltage (with respect to the input voltage) and reduces the output current. A buck converter decreases the output voltage and increases the output current. Many models are used to predict the behavior …

Impedance-Based Stability Analysis And Controller Design Of Three-Phase Inverter-Based Ac Systems, Wenchao Cao

Doctoral Dissertations

Three-phase voltage-source power inverters are widely used for energy conversion in three-phase ac systems, such as renewable energy systems and microgrids. These three-phase inverter-based ac systems may suffer from small-signal instability issues due to the dynamic interactions among inverters and passive components in the systems. It is crucial for system integrators to analyze the system stability and design the inverter controller parameters during system planning and maintenance periods to guarantee stable system operation. The impedance-based approach can analyze the stability of source-load systems, by applying the Nyquist stability criterion or the generalized Nyquist stability criterion (GNC) to the impedance ratio …

Design And Implementation Of A Modified Communication Disturbance Observer For Teleoperation Systems, Zahra Zeinaly, Amin Ramezani, Sadjaad Ozgoli

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a novel structure for a communication disturbance observer in teleoperation systems is proposed to achieve robust stability. A time delay compensation method based on the concept of network disturbance and a communication disturbance observer (CDOB) has been proposed in past research. Unlike model-based approaches, it works without a time delay model. Therefore, it can be implemented in teleoperation systems with unknown and time-varying delay. However, it has been observed that the system model errors and external disturbances seriously affect the steady-state characteristics. Hence, in this paper, to achieve robustness against disturbance and model uncertainty, the structure of …

Concurrent Optimal Design Of Tcsc And Pss Using Symbiotic Organisms Search Algorithm, Muwaffaq Alomoush

Turkish Journal of Electrical Engineering and Computer Sciences

The symbiotic organisms search (SOS), which has been recently introduced, is a robust powerful metaheuristic global optimizer. This nature-inspired algorithm imitates the symbiotic interaction strategies in an ecosystem exercised by organisms involved in interrelationships to survive and reproduce. One of the main beneficial features of the SOS in contrast to many other competent metaheuristic algorithms is that the algorithm does not need any specific algorithm parameters or tuning process. This paper applies the SOS algorithm to simultaneously design optimal controllers of a power system equipped with both a power system stabilizer (PSS) and a thyristor-controlled series compensator (TCSC). The algorithm …

Temporal Preconditioners For Marching-On-In-Time-Based Time Domain Integral Equation Solvers, Hüseyi̇n Arda Ülkü

Turkish Journal of Electrical Engineering and Computer Sciences

Temporal preconditioners to stabilize the marching-on-in-time (MOT)-based time domain integral equation (TDIE) solvers are proposed. Exponentially decaying functions are used as temporal preconditioners and the proposed scheme is applied to analyze scattering from perfect electrically conducting objects using the second-order formulation. The effectiveness of the proposed scheme is demonstrated via numerical examples. It is shown that the temporal preconditioners stabilize the MOT system and the solution. In addition, the initial condition problem of TDIEs is investigated by extending the second-order formulation of the time domain electric field integral equation to the time domain magnetic and combined field integral equations.

Matrix-Free Time-Domain Methods For General Electromagnetic Analysis, Jin Yan

Open Access Dissertations

Many engineering challenges demand an efficient computational solution of large-scale problems. If a computational method can be made free of matrix solutions, then it has a potential of solving very large scale problems. Among existing computational electromagnetic methods, the explicit finite-difference time-domain (FDTD) method is free of matrix solutions. However, it requires a structured orthogonal grid for space discretization. In this work, we develop a new time-domain method that naturally requires no matrix solution, regardless of whether the discretization is a structured grid or an unstructured mesh. No dual mesh, interpolation, projection and mass lumping are needed. Furthermore, a time-marching …

Impact Of Clustering Microgrids On Their Stability And Resilience During Blackouts, Mahmoud S. Saleh, Ammar Althaibani, Yusef Esa, Yassine Mhandi, Ahmed Mohamed

Publications and Research

In this paper, the impact of clustering multiple microgrids during blackouts, on their stability and supply availability, will be investigated. Microgrids have the capability of satisfying their emergency loads during blackouts. However, distributed energy resources (DERs)-dominated microgrids are affected by the uncertainty of their input energy supply, e.g. impact of solar irradiance on photovoltaic (PV) output. Moreover, an individual islanded microgrid is prone to instability issues due to large sudden load/generation changes. In order to increase the supply security, and enhance system stability, we propose to use the existing distribution grid infrastructure, if applicable, during blackouts to form microgrid clusters. …

Out-Of-Loop Compensation Method For Op-Amps Driving Heavy Capacitive Loads, Shubham Gandhi

Master's Theses

It is well known that real op-amps do not share most of the desirable characteristics of an ideal one, particularly those of gain and output impedance. When presented with a capacitive load, such as a MOSFET or ADC, feedback in an op-amp circuit can quickly become unstable. This thesis studies and characterizes an op-amp’s output impedance and how its interaction with this type of load creates a parasitic pole which leads to instability. Applying ideas from feedback control theory, a model for studying the problem is developed from which a generalized method for compensating the undesirable circumstance is formulated.

Even …

Fully Solution Processed Pedot:Pss And Silver Nanowire Semi-Transparent Electrodes For Thin Film Solar Cells, Bjorn Vaagensmith

Electronic Theses and Dissertations

Building integrated photovoltaics (BIPV), such as semitransparent organic solar cells (OSC) for power generating windows, is a promising method for implementing renewable energy under the looming threat of depleting fossil fuels. OSC require a solution processed transparent electrode to be cost effective; but typically employ a nonsolution processed indium tin oxide (ITO) transparent electrode. PEDOT:PSS and silver nanowire transparent electrodes have emerged as a promising alternative to ITO and are solution processed compatible. However, PEDOT:PSS requires a strong acid treatment, which is incompatible with high throughput solution processed fabrication techniques. Silver nanowires suffer from a short lifetime when subject to …