Controls and Control Theory Commons^™

Self-Oscillating Induction Heater, Patrick Rice

Dissertations, Master's Theses and Master's Reports

This report develops a control system to keep an induction heater in resonance. When a metallic workpiece is inserted in the air core of the workcoil, the resonant frequency changes. Different workpiece materials affect the resonant frequency and power. This presents a problem since changing the resonant frequency of the circuit while keeping the frequency constant reduces the maximum power of the circuit. Finite element analysis is used to find the circuit parameters of the workcoil and workpiece interaction. A non-linear controller which oscillates based on the resonant frequency of an LC tank is created. Nyquist and describing function analysis …

Study Of Electric Vehicle Smart Charging And Energy Management For Vehicle-Grid Integration Systems, Zhouquan Wu

Dissertations, Master's Theses and Master's Reports

The emerging need of building an efficient Electric Vehicle (EV) charging infrastructure requires the investigation of all aspects of Vehicle-Grid Integration (VGI). This dissertation studies the optimal EV charging control and energy management of VGI system to address the economic benefits of EV charging customers and operation stability of distribution power grids. First of all, a centralized EV charging control method is developed under the transactive energy environment to minimize the EV charging cost and avoid the distribution power grid overloading. The quadratic programming is used to obtain optimized charging control actions. Case studies with hundreds of EVs are conducted …

Stability Approximation Method For Pulse Loads In Power Electronic Systems, Eduardo A. Marmol D

Dissertations, Master's Theses and Master's Reports

Pulse loads on power electronic distribution systems are becoming very popular nowadays as the components of ships and airplanes are moving to more electric power. However, the pulse loads have a destabilizing effect on the power distribution system. Usually, the method used to study the stability of this type of system are small-signal analyses and are based on a system where the load is modeled as a constant. Since DC-DC systems with pulsed loads are very nonlinear, a small-signal analysis does not provide helpful information related to the stability of the system. The work presented in this thesis focuses on …

Inductor Free Methods For Breaking Dc Currents, Sudipta Sen

LSU Doctoral Dissertations

The current interruption in dc circuits is more difficult to achieve compared to the ac circuits because, unlike ac systems, dc circuits do not have the natural current zero-crossing. Presently there are three categories of basic dc breaker models namely mechanical, static, and hybrid dc breakers. As current power systems is moving more towards microgrids, DERs, Electric Vehicles (EVs), and with recent advancements in dc circuits, wide verities of dc power sources, and loads, dc breakers are very important in future system protection.

New alternate methods to break dc currents for low-voltage applications are proposed in this work. The proposed …

Torque Vectoring To Maximize Straight-Line Efficiency In An All-Electric Vehicle With Independent Rear Motor Control, William Blake Brown

Theses and Dissertations

BEVs are a critical pathway towards achieving energy independence and meeting greenhouse and pollutant gas reduction goals in the current and future transportation sector [1]. Automotive manufacturers are increasingly investing in the refinement of electric vehicles as they are becoming an increasingly popular response to the global need for reduced transportation emissions. Therefore, there is a desire to extract the most fuel economy from a vehicle as possible. Some areas that manufacturers spend much effort on include minimizing the vehicle’s mass, body drag coefficient, and drag within the powertrain. When these values are defined or unchangeable, interest is driven to …

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 …

Direct Torque Control For Silicon Carbide Motor Drives, Mohammad Hazzaz Mahmud

Graduate Theses and Dissertations

Direct torque control (DTC) is an extensively used control method for motor drives due to its unique advantages, e.g., the fast dynamic response and the robustness against motor parameters variations, uncertainties, and external disturbances. Using higher switching frequency is generally required by DTC to reduce the torque ripples and decrease stator current total harmonic distortion (THD), which however can lower the drive efficiency. Through the use of the emerging silicon carbide (SiC) devices, which have lower switching losses compared to their silicon counterparts, it is feasible to achieve high efficiency and low torque ripple simultaneously for DTC drives.

To overcome …

Use Of The Igbt Module In The Active Region To Design A High Current Active Filter, Jorge F. Galarraga

Graduate Theses and Dissertations

Particle accelerators require high-precision magnetic fields on the order or 100ppm or less. This implies that the precision of the associated electrical current in the electromagnet that generates these fields should be smaller than 100ppm. However, conventional switching power supplies cannot offer this precision due to the frequency limitation of the switches. This research considers the use of power electronics devices operating in a linear as an alternative solution to meet the requirements of particle accelerator electromagnets.

This thesis presents the study of an insulated-gate bipolar transistor (IGBT) driver using a new control method that linearizes the IGBT’s collector-emitter voltage …

Solar Pv Emulator, Tristan Studer, Cody Kremer

Electrical Engineering

The implementation of a solar PV emulator. Creating a controllable testing environment which sufficiently recreates realistic conditions a photovoltaic cell would experience in real world use. The project aims to accurately show the efficiency and reliability of a solar PV cell, opposed to an ideal model which creates unrealistic expectations. The PV emulator implements conditions such as: irradiance, soiling and temperate changes. It gives feedback on a displayed IV curve and/or PV curve so the user may graphically analyze the output their PV cell produces given various conditions. It allows the user selectable conditions the solar cell may experience this …

Data Forgery Detection In Automatic Generation Control: Exploration Of Automated Parameter Generation And Low-Rate Attacks, Yatish R. Dubasi

Computer Science and Computer Engineering Undergraduate Honors Theses

Automatic Generation Control (AGC) is a key control system utilized in electric power systems. AGC uses frequency and tie-line power flow measurements to determine the Area Control Error (ACE). ACE is then used by the AGC to adjust power generation and maintain an acceptable power system frequency. Attackers might inject false frequency and/or tie-line power flow measurements to mislead AGC into falsely adjusting power generation, which can harm power system operations. Various data forgery detection models are studied in this thesis. First, to make the use of predictive detection models easier for users, we propose a method for automated generation …

Improvement Of Stability Of A Grid-Connected Inverter With An Lcl Filter By Robust Strong Active Damping And Model Predictive Control, Seungyong Lee

Graduate Theses and Dissertations

This study addresses development and implementation of robust control methods for a three-phase grid-connected voltage source inverter (VSI) accompanied by an inductive-capacitive-inductive (LCL) filter. A challenge of current control for the VSI is LCL filter resonance near to the control stability boundary, which interacts with the inverter control switching actions and creates the possibility of instability. In general, active damping is needed to stabilize the system and ensure robust performance in steady-state and dynamic responses. While many active damping methods have been proposed to resolve this issue, capacitor-current-feedback active damping has been most widely used for its simple implementation.

There …

Implementation Of Model-Free Adaptive Power Flow Control For Dual-Active-Bridge-Based Ac-Dc Converters, Qinghang Shen

All Graduate Theses, Dissertations, and Other Capstone Projects

With the rising energy consumption and environment destruction problems worldwide, the development of renewable energy and energy recapture methods to improve the energy utilization rate has become more important as two of the most efficient processes to solve those problems. Bidirectional AC/DC converter and its modulation strategies are widely used as the essential part of implementing bidirectional power conversion between power grid and energy storage systems. To improve the efficiency and accuracy of the power conversion within AC/DC converters, a stable, robust power flow control system with quick response and disturbance rejection ability is desired. This thesis proposes a model-free …

Control Hierarchies For Critical Infrastructures In Smart Grid Using Reinforcement Learning And Metaheuristic Optimization, Oindrilla Dutta

Dissertations and Theses

The objective of this work is to develop robust control framework for interdependent smart grid infrastructures comprising two critical infrastructures: 1) power distribution networks that are characterized by high penetration of distributed energy resources (DERs), and 2) DC-rail transportation systems in congested urban areas. The rising integration of DERs into the power grid is causing a paradigm shift in the power distribution network. Consequently, new control challenges for efficient and robust operation of the power grid have surfaced. For instance, the intermittency of renewable energy resources necessitates coordinated control of power flows, voltage regulators, and protection device settings of the …

Analysis Of Three-Phase Rectifier Via Three Different Control Methods And Switch Power Loss Comparison, Yichao Wang

All Graduate Theses, Dissertations, and Other Capstone Projects

Traditional uncontrolled or phase-controlled rectifiers have the defects of lower power factor and nontrivial higher harmonics which causes the low efficiency of power, bad power quality, and so on. However, PWM rectifiers overcome the drawbacks mentioned above. They reduce the higher harmonics yielding better sinusoidal current on the grid side, achieve unity power factor and bidirectional power flow, and have better dynamic performance. So, it is favored more by academia and widely applied in high-performance power electronics devices. In this paper, the PWM rectifier is analyzed and a comparison of the switch loss on three-phase rectifier using three different control …

Light Loaded Automated Guided Vehicle, Marcus Radtka, Nazar Paramashchuk, Lawrence Shevock

Williams Honors College, Honors Research Projects

The objective of the locomotion system was to design and implement the mechanical, electrical, and software related functions to ensure the LLAGV had the capability of maneuvering its surroundings. The LLAGV’s motors were represented in an open loop transfer function to utilize RPM feedback and a compensator when needed. The modeled compensator helped control the LLAGV’s speed and acceleration, enabling further control of the LLAGV. The internal circuitry has the means to properly distributed power to all components and allowed the user to control the LLAGV to their desire. The application software within the LLAGV locomotion system (LLAGV-LS) had consideration …

Consensus Based Control Strategy For Virtual Synchronous Generators In Microgrids, Anusha Kandula

Graduate Theses, Dissertations, and Problem Reports (ETD)

Renewable energy sources such as photo-voltaic and wind energy are integrating very rapidly in power systems. These energy-based systems typically adopt power-electronic interfaced inverters to connect to the grid. However, unlike traditional generators, these sources have low inertia, resulting in system stability issues, especially in microgrids where they are the primary sources. To mitigate the low-inertia effect, the inverters are modeled as virtual synchronous generators (VSG), and their control is designed. The VSG emulates the inertia effect of the synchronous generator and maintains the stability of the system. Even though the droop control provides the primary control, it is insufficient …

Field Testing The Effects Of Low Reynolds Number On The Power Performance Of The Cal Poly Wind Power Research Center Small Wind Turbine, John B. Cunningham

Master's Theses

This thesis report investigates the effects of low Reynolds number on the power performance of a 3.74 m diameter horizontal axis wind turbine. The small wind turbine was field tested at the Cal Poly Wind Power Research Center to acquire its coefficient of performance, C­_p, vs. tip speed ratio, λ, characteristics. A description of both the wind turbine and test setup are provided. Data filtration and processing techniques were developed to ensure a valid method to analyze and characterize wind power measurements taken in a highly variable environment. The test results demonstrated a significant drop in the …

Fractional Order Identification Method And Control: Development Of Control For Non-Minimum Phase Fractional Order System, Majid Abdullah Alhomim

Graduate Theses and Dissertations

The increasing use of renewable energy has resulted in the need for improved a dc-dc converters. This type of electronic-based equipment is needed to interface the dc voltages normally encountered with solar arrays and battery systems to voltage levels suitable for connecting three phase inverters to distribution level networks. As grid-connected solar power levels continue to increase, there is a corresponding need for improved modeling and control of power electronic converters. In particular, higher levels of boost ratios are needed to connect low voltage circuits (less than 1000 V) to medium voltage levels in the range of 13 kV to …

Robust Control Of A Multi-Phase Interleaved Boost Converter For Photovoltaic Application Using Μ-Synthesis Approach, Badur Mueedh Alharbi

Graduate Theses and Dissertations

The high demand of energy efficiency has led to the development power converter topologies and control system designs within the field of power electronics. Recent advances of interleaved boost converters have showed improved features between the power conversion topologies in several aspects, including power quality, efficiency, sustainability and reliability.

Interleaved boost converter with multi-phase technique for PV system is an attractive area for distributed power generation. During load variation or power supply changes due to the weather changes the output voltage requires a robust control to maintain stable and perform robustness.

Connecting converters in series and parallel have the advantages …

Design Of A Single-Carrier Pulse Width Modulation With Submodule Fault-Tolerant Capability For Modular Multilevel Converter, Tuanku Badzlin Hashfi

Student Works (2020-2029)

Multilevel converters are attracting a lot of attention and becoming one of the energy conversion choices for new topologies and control in industry applications and research fields. Modular multilevel converters (MMCs) are considered very promising among converter topologies for future medium-voltage and high-power applications compared to NPC, FC and CHB topologies. The improved phase disposition pulse width modulation (PDPWM) technique control for MMCs, which has a fault-tolerant capability, is presented. This study presents two methods to distribute pulses into submodules (SMs) by using PDPWM which has drawback to distribute the power equally among the submodules (SMs). First method, this study …

Research And Simulation Of Dc Microgrid Three-Phase Ac-Dc Converter Control Strategy Based On Double Loop, Boning Wu, Zhiqiang Gao, Xuesong Zhou, Youjie Ma, Chenglong Wang

Electrical and Computer Engineering Faculty Publications

The new voltage and current double loop control strategy is proposed to solve the DC microgrid bus voltage fluctuation caused by loads fluctuation, parameters perturbation and unbalanced three-phase power supply. Firstly, the dq axis mathematical model of three-phase AC-DC bidirectional converter in DC microgrid is analyzed and established, and then the controllers are designed according to the dq axis mathematical model. The outer loop is a voltage loop based on variable gain linear extended state observer (VGLESO) and sliding mode theory. VGLESO can not only effectively overcome the problem of peak output of traditional high-gain LESO in the initial stage …

Trust-Based User Interface Design For Islanded Alternating Current Microgrids, Yuliya Matlashova

Electrical and Computer Engineering ETDs

Futuristic microgrid systems may be capable of providing extensive information to the operator. As microgrid systems become more pervasive there will be a need to adjust the information an operator requires, to provide an optimized user-interface. In this paper, a combinatorial optimization strategy is used to provide an optimal user-interface for the microgrid operator that selects information for display depending on the operator's trust level in the system, and the assigned task. We employ a method based in sensor placement by capturing elements of the interface as different sensors, that find an optimal set of sensors via combinatorial optimization. However, …

Model-Based Control Methods To Improve The Power Qualify Of Grid-Connected Single-Phase Inverters., Moath Alqatamin

Electronic Theses and Dissertations

Power electronic converters are commonly used for interfacing distributing generation sources (DGs) to the electrical power system networks. This is necessary because these DGs usually have different output characteristics and cannot be connected directly to the local load and/or the grid. The power electronic front-end converter is an inverter whose dc link is fed by an ac/dc converter or by a dc/dc converter, according to the DG source type. The commercial front-end inverters are designed to operate either in grid-connected (GC) mode or in stand-alone (SA) mode. In the SA mode, the inverter is connected to local load, but in …

Analysis Of Protection System Setting In 11kv Distribution System, Alamshah Ammar

Student Works (2020-2029)

One of the fundamental protections used in electrical network power system is Overcurrent and Earth Fault (OCEF) protection. They have to be both sensitive and quick in minimizing the electrodynamic and thermal stress imposed on the equipment during the fault time interval. It is utmost important for the relays to be capable of removing only the faulty section while keep up the flexibly to solid areas in the system. In order to achieve this objective, correct relay coordination setting is important to prevent the system from suffering catastrophic effects. These days, the consumer is enforcing raising performance demands by reducing …

Towards High Efficiency And High Power Density Converter: System Level Design, Modulation, And Active Emi Filters, Hongwu Peng

Graduate Theses and Dissertations

Power converter exposes strong challenges to its efficiency, power density and reliability. For the grid-connected inverter application, three-level (3-L) T-type neutral-point-clamped (TNPC) inverters has higher efficiency and lower total harmonic distortion (THD) compared to two-level inverter. Hybrid switch concept combines the benefit of both silicon carbide (SiC) MOSFET and Si IGBT. By applying hybrid switch structure in 3-L T-type inverter, the total power density of 3-L TNPC inverter will be higher while the cost will be lower than that of all-SiC 3-L T-type inverter. The hybrid switch based 3-L TNPC inverter also imposes challenge to its modulation and control, a …

High- And Low-Voltage Mitigation In Distribution Systems Using Residential Static Volt-Ampere Reactive Compensators, Andrés Valdepeña Delgado

Boise State University Theses and Dissertations

Power distribution systems are experiencing a fast transformation from simple one-way radial feeders to complex systems with multiple sources and bidirectional power flows. The rapid increase of Distributed Generation (DG) connected to the distribution system over the last decade, especially solar photovoltaic (PV), has been the key element to this transformation.

The variable nature of PV-based DG has increased the complexity of voltage regulation in distribution systems. Electric Utilities are facing an increasing number of voltage issues in distribution systems with high penetration of DGs, leading customers to experience voltage levels outside of range A of the ANSI C84.1 standard. …

Optimizing Llrf Parameters In The Electron-Ion Collider, William M. Bjorndahl

Physics

To improve particle interaction in the future Electron-Ion Collider (EIC), we investigated different feedback implementations to control the accelerating voltage and examined the power and beam phase for each instance. Using MATLAB, we studied three feedback mechanisms: Direct, One Turn, and Feedforward. Enacting feedforward yielded the best performance. To minimize the klystron power consumption, we analyzed different Low-Level Radio Frequency (LLRF) parameters such as detuning. Combining theory and simulated results, we found the optimal detuning value that minimizes klystron power consumption.

Residential Thermal Storage And Cooling, Joao Marcelo Rocha Belmonte, Jacob Anderson, Andrew Clarke, Daphne Forester, Bianca Hardtke, Josh Hartman, Marc D. Compere

Sustainability Conference

No abstract provided.

Dual-Axis Solar Tracker, Bryan Kennedy

All Undergraduate Projects

Renewable energies, and fuels that are not fossil fuel-based, are one of the prolific topics of debate in modern society. With climate change now becoming a primary focus for scientists and innovators of today, one of the areas for the largest amount of potential and growth is that of the capturing and utilization of Solar Energy. This method involves using a mechanical system to track the progression of the sun as it traverses the sky throughout the day. A dual-axis solar tracker such as the one designed and built for this project, can follow the sun both azimuthally and in …

Control Of A Grid-Tied Single-Phase Inverter For Renewable Energy Integration, Dianzhi Yu

All Graduate Theses, Dissertations, and Other Capstone Projects

With increasing demand for generating electricity from clean energy, renewable energy sources (RESs), such as wind and solar, has gained much attention due to the clean and quiet characteristics. In many applications, connecting multiple RESs of different types (e.g., wind and solar), voltages, and capacities to a power grid or load is required. Single- phase inverters have been widely installed in residential power system to meet the full or partial load demand. In this work, multiport converters were developed for integrating multiple RESs, wind turbine and photovoltaic (PV) panel. Since the intermittent characteristic of the RESs, an energy storage device, …