Engineering Commons^™

Consensus-Based Active And Reactive Power Control And Management Of Microgrids, Shruti Singh

Electronic Theses and Dissertations

Microgrids incorporating distributed generation and renewable energy sources offer potential solutions to the energy crisis while modernizing traditional grids. Despite cost-effectiveness in some technologies, financial support remains crucial for expensive ones like PV, fuel cells, and storage technologies. Microgrids bring economic benefits, efficiency, reduced emissions, and improved power quality. Their success hinges on cost reductions in renewables, storage, reliability, and energy management systems, enabling operation both with and without the utility grid.

Economic Dispatch optimizes system costs, considering all constraints. Various methods tackle this problem, including quadratic convex functions, Lagrangian relaxation, and quadratic programming. For microgrids with distributed generators, seamless …

Power System Dynamic Control And Performance Improvement Based On Reinforcement Learning, Wei Gao

Electronic Theses and Dissertations

This dissertation investigates the feasibility and effectiveness of using Reinforcement Learning (RL) techniques for power system dynamic control, particularly voltage and frequency control. The conventional control strategies used in power systems are complex and time-consuming due to the complicated high-order nonlinearities of the system. RL, which is a type of neural network-based technique, has shown promise in solving these complex problems by fitting any nonlinear system with the proper network structure.

The proposed RL algorithm, called Guided Surrogate Gradient-based Evolution Strategy (GSES) determines the weights of the policy (which generates the action for our control reference signal) without back-propagation process …

Distributed Control, Optimization, And State Estimation For Renewable Power System, Qiao Li

Electronic Theses and Dissertations

The traditional power systems are usually centralized systems, in which the control, operation and monitoring are performed by the centralized control center, e.g., SCADA. However, with the development of renewable energy, power systems are getting more and more distributed. So, it becomes necessary to establish the distributed power system operation methods for these power systems. In this research, the distributed techniques for the renewable power systems are proposed based on the consensus protocol technique from graph theory. These techniques cover the three important problems in power systems, i.e., economic dispatch, state estimation, and optimal power flow. First, the Distributed Economic …

Experimental Investigation Of Low-Voltage Silicon Carbide (Sic) Semiconductor Devices For Power Conversion Applications, Saleh Salem H. Alharbi

Electronic Theses and Dissertations

Enhancing the performance and efficiency of power converter systems requires fast-switching power devices with considerably low switching and conduction losses. Silicon (Si) semiconductor devices are the essential components in electronic converter designs, and their behaviors and switching characteristics determine the system’s overall performance and efficiency. These conventional Si devices are nearing to hit their physical and operational limits in meeting power converter requirements with respect to high temperature and large voltage conditions. However, silicon carbide (SiC) power devices enable greater converter efficiency and better power density, particularly under hard switching frequencies and high output voltages due to their outstanding material …

Experimental Evaluation Of Medium-Voltage Cascode Gallium Nitride (Gan) Devices For Bidirectional Dc–Dc Converters, Salah Salem H. Alharbi

Electronic Theses and Dissertations

As renewable energy sources, such as photovoltaic (PV) cells and wind turbines, are rapidly implemented in DC microgrids, energy storage systems play an increasingly significant role in ensuring uninterrupted power supply and in supporting the reliability and stability of microgrid operations. Power electronics, especially bidirectional DC–DC converters, are essential parts in distributed energy storage and alternative energy systems because of their grid synchronization, DC power management, and bidirectional power flow capabilities. While there is increasing demand for more efficient, compact, and reliable power converters in numerous applications, most existing power converters are hindered by traditional silicon (Si) based semiconductors, which …

Control Strategy For A Small-Scale Microgrid Based On Battery Energy Storage System-Virtual Synchronous Generator (Bess-Vsg), Wei Gao

Electronic Theses and Dissertations

As one of widely deployed renewable energy resources, PV power is playing a very important role in microgrids today. It has advantages such as making the best of natural solar energy and being friendly to our environment. In this thesis, solar PV based microgrid is studied using modeling and simulation. Microgrid can run in either grid-connected-mode or islanded-mode. However, there are also some disadvantages for solar power. For solar panel, its output is influenced by weather conditions such as illumination intensity and temperature. In addition, during the control process of grid-connected mode, it is hard to guarantee its output power …

Paving The Way For Multidisciplinary Smart Campus Infrastructure: Leveraging Du's Unique Campus For The Advancement Of Smart Campus Culture, Camerron T. Mismash

Electronic Theses and Dissertations

Institutions are embracing smart technologies to reap their benefits while simultaneously innovating new uses. From localized renewable energy generation to health monitoring and everything in between, academic campuses globally are paving the way for smart technology application. Eight primary categories have been identified in which institutions are applying smart technologies. Energy development is on the forefront of these smart initiatives. The University of Denver has begun its Smart Campus Initiative by implementing a revolving fund to invest in campus improvements related to the offset of carbon. By comparing how institutions are investing in smart campus initiatives and analyzing costs associated …

Design And Evaluation Of High Efficiency Power Converters Using Wide-Bandgap Devices For Pv Systems, Fahad Almasoudi

Electronic Theses and Dissertations

The shortage of fossil resources and the need for power generation options that produce little or no environmental pollution drives and motivates the research on renewable energy resources. Power electronics play an important role in maximizing the utilization of energy generation from renewable energy resources. One major renewable energy source is photovoltaics (PV), which comprises half of all recently installed renewable power generation in the world. For a grid-connected system, two power stages are needed to utilize the power generated from the PV source. In the first stage, a DCDC converter is used to extract the maximum power from the …

Synchrophasor Sensing And Processing Based Smart Grid Security Assessment For Renewable Energy Integration, Huaiguang Jiang

Electronic Theses and Dissertations

With the evolution of energy and power systems, the emerging Smart Grid (SG) is mainly featured by distributed renewable energy generations, demand-response control and huge amount of heterogeneous data sources. Widely distributed synchrophasor sensors, such as phasor measurement units (PMUs) and fault disturbance recorders (FDRs), can record multi-modal signals, for power system situational awareness and renewable energy integration.

An effective and economical approach is proposed for wide-area security assessment. This approach is based on wavelet analysis for detecting and locating the short-term and long-term faults in SG, using voltage signals collected by distributed synchrophasor sensors.

A data-driven approach for fault …

Plug-In Hybrid Electric Vehicle In Smart Grid, Yin Yao

Electronic Theses and Dissertations

In this thesis, in order to investigate the impact of charging load from plug-in hybrid electric vehicles (PHEVs), a stochastic model is developed in Matlab. In this model, two main types of PHEVs are defined: public transportation vehicles and private vehicles. Different charging time schedule, charging speed and battery capacity are considered for each type of vehicles. The simulation results reveal that there will be two load peaks (at noon and in evening) when the penetration level of PHEVs increases continuously to 30% in 2030. Therefore, optimization tool is utilized to shift load peaks. This optimization process is based on …