Engineering Commons^™

Development Of Digital Twin Applications In Power Systems To Improve Operation Of Emerging Grid Technology, Jeremy Till

Doctoral Dissertations

Power systems are continuously increasing in penetration of renewable energy resources and new technologies. Carbon-neutral requirements across the United States act as a catalyst forcing wide spread acceleration of these implementations. However, grid advancements exacerbate existing problems and potentially create new issues. New technologies for system planning and operation must be developed alongside the advancement of power systems. One such new technology is digital twins. Digital twins are a relatively new research topic in power systems. The main concept of a digital twin is a model of a real-world system that can run online with the physical system utilizing measurement …

Converter-Based Microgrid Testing Platform Development And Fault Detection Method For Inverter-Based Resources By Utilizing Instantaneous Power Theory, Nattapat Praisuwanna

Doctoral Dissertations

Renewable energy sources (RESs) are rapidly being installed into electric systems. Most RESs are inverter-based distributed generations (IDGs). To better manage energy from IDGs, microgrids will play a crucial role. However, microgrids that have high penetration of IDG will have modification in fault current levels and bidirectional power flow causing protective devices to misoperate, so the traditional protection system does not correctly function in the microgrids. Therefore, the integration of IDGs into the microgrids establishes some significant consequences on protection systems.

Overcurrent protection is widely utilized in the electric distribution systems today; however, it is sometimes difficult to distinguish between …

A 4-Switch Buck-Boost Dc/Dc Converter For Electric Vehicle Applications, Andrew Hudak, Ashley Schiller

Electrical Engineering

In this project, we develop a four switch buck-boost DC/DC converter that is to be integrated into a microgrid-inspired power distribution architecture for electric vehicles. The overall architecture includes DC/DC and DC/AC converters for bi-directional energy transfer between the DC and AC ports along with a communications port to control each energy interface. There is also the onboard battery and the internal combustion engine power exchange being done with DC/DC converters and AC/DC inverters to connect to the centralized DC bus. Hardware prototypes using an Arduino and Raspberry Pi for the 500 W DC/DC and DC/AC converters have been previously …

Improvements Of Hybrid Ac/Dc House Prototype, Arden Abude

Electrical Engineering

This is an iteration from previous designs of the Hybrid AC/DC House with a systematic addition of a portable AC power supply unit. This iteration for the Hybrid AC/DC House is an innovation of independence for sustainable housing solutions. It will serve as an alternative for rural communities needing power to rely on self-sustainable microgrids rather than large-scale AC electric grids. The addition of a portable AC power supply would allow the microgrid to remove its reliance on AC power from the larger grid and would elevate the system to complete energy independence. The microgrid has DC power generated from …

Modeling And Mitigating Power Grid Vulnerabilities: A Comprehensive Analysis Of Renewable Energy Integration, Cascading Failures, And Microgrid Resilience, Saikat Das

Theses and Dissertations

In modern power systems, rapid integration of renewable energy and the emergence of microgrid technology emphasize the necessity for a comprehensive understanding of vulnerabilities and robust defense mechanisms. The research begins with an exploration of power grid vulnerabilities to cascading failure amidst the increasing integration of renewable energy sources. A novel power balance technique is employed for cascading failure analysis and power grid vulnerability measurement. Simulation results indicate that the growing penetration of renewable energy has a proportionally higher impact on grid vulnerability to cascading failures. After a certain level of renewable energy penetration, some systems may deteriorate rapidly, necessitating …

Hybrid Wall Outlet For Ac Or Dc Power Delivery, Garrett Knoller, Kerr Allan, Greg Perini

Electrical Engineering

The goal of this project is to develop hybrid DC and AC wall outlets for an efficient, flexible power interface. A DC plug standard is also proposed to allow DC devices to be safely powered by the outlet with the correct DC voltage for each device. The primary objective is to create a power outlet compatible with the proposed DC plug as well as NEMA 5-15 AC plugs, enabling the same outlet to power both types of load as needed. The outlet is intended for buildings and systems transitioning to an isolated DC grid to encourage DC development and adoption. …

Dc To Ac Inverter For A Microgrid-Inspired Power Distribution Architecture For Electric Vehicles, Bryan A. Carrillo Martinez, Eli Blacklock, Paul A. Samson, William S. Holt-Hillis

Electrical Engineering

This project builds upon the prototyping of a microgrid-inspired power distribution architecture for electric vehicles (EVs). The efficacy of this prototype aims to inform a full-scale power distribution system that charges an EV battery, supports the electric grid with important ancillary services, performs peer-to-peer EV charging, and works in conjunction with other AC and DC sources and loads. The scope of this report focuses specifically on the design, construction, and testing of the DC/AC inverter. Future development of this distribution architecture will incorporate synchronous generators, a battery management system, and an Arduino/Raspberry Pi-based communication system to fully simulate an electric …

Design Of Hybrid Inverters Using Wideband Gap Semiconductors For Microgrid Application, Luca Gacy

Electronic Theses and Dissertations

As the world becomes more reliant on renewable energy sources such as solar and wind power, the need for high efficiency high power inverters connected to homes is more relevant than ever. Connecting these renewable energy sources (RES) coupled with an energy storage system (ESS) to the grid through a hybrid inverter, with the highest efficiency and grid stability, is quickly becoming a necessity for the near future. This thesis explores the integration of wide band gap semiconductors for the power stage in these systems, along with the analysis of hybrid inverter topologies and structures. The goal of this thesis …

Paired Storage Distributed Energy System Design For A Local Community Farm, Neil Albert Collison, Lily Goldman

Electrical Engineering

This project considers the design of a renewable energy microgrid for a 19-acre community farm in San Luis Obispo, CA as the farm seeks to increase the magnitude of its electrical loads, and gain back-up electrical capability. The microgrid design will enable lower carbon emissions, reduce demand on the utility grid while saving on energy costs, and provide improved reliability and resiliency to the operator of the community farm. The eventual implementation of the design by a professional engineering entity will allow the community farm to expand its education program to include renewable energy as well as gain notoriety in …

Technical And Economic Feasibility Of A Microgrid For A Fire Station In Humboldt County, California., Nishaant Kumar Sinha

Cal Poly Humboldt theses and projects

Microgrids are emerging as a promising solution to unreliable grid energy. Today, California is not only witnessing grid resiliency challenges from natural disasters such as wildfires, earthquakes, floods and heatwaves, but it is also seeking to green the grid and bring more renewables online. For example, Humboldt County, where this project is focused, has recently experienced an earthquake of 6.4M (on December 22nd, 2022), which shut down the regional grid for ~20 hours.

Microgrid adoption enables critical facilities to operate seamlessly. The Humboldt Bay Fire Station (HBFS) No.1 is one such example, where first responders work to protect citizens against …

Configuration And Sizing Of Small Modular Reactor With Thermal Energy Storage Within A Microgrid For Off-Grid Communities, Michael W. C. Davis

Electronic Thesis and Dissertation Repository

Many off-grid communities in Canada rely on diesel generators for their electricity needs. This is not only expensive but also produces significant greenhouse gas emissions. Small modular reactors (SMRs) have been proposed to replace diesel generators and can be combined with photovoltaic (PV) sources to form a microgrid. However, fluctuations in loads and PV create challenges for SMRs. Integrating a thermal energy storage (TES) system with the SMR can increase the flexibility of the power system to operate more effectively. This thesis first examines methodologies to determine suitable configurations of such a microgrid. Through analysis of the system components and …

Protection Of Microgrids: A Scalable And Topology Agnostic Scheme With Self-Healing Dynamic Reconfiguration, Phani Harsha Gadde

All Dissertations

Momentum towards realizing the smart grid will continue to result in high penetration of renewable fed Distributed Energy Resources (DERs) in the Electric Power System (EPS). These DERs will most likely be Inverter Based Resources(IBRs) and will be an integral part of the distribution system in the near future. The drive towards resiliency with these IBRs will enable a modular topology where several microgrids are tied together, operating synchronously to form the future EPS at the distribution level.

Since the microgrids can evolve from existing distribution feeders, they will be unbalanced in load, phases, and feeder impedances. A typical control …

Microgrid Laboratory Wind Energy Integration, Vincent Liang

Master's Theses

Cal Poly San Luis Obispo’s Electrical Engineering Department and the Power Energy Institute have developed a microgrid laboratory with various generators, loads, and protection systems over the past several years. To improve and make the Cal Poly microgrid laboratory more realistic, this thesis outlines the process of improving the EE microgrid setup by adding a wind energy generation system via an induction generator, excitation capacitors, and a protection relay. By adding an induction generator, the microgrid system becomes more resilient to sudden power fluctuations by maintaining a stable voltage and frequency when the microgrid is islanded. To test this, a …

Microgrid Energy Storage Branch, Evan Luu, Jeffrey Shieh

Electrical Engineering

The microgrid is the future for the electrical utility system. Because of this, future power engineers need to be well-versed in this topic when they go into industry. Cal Poly has created a microgrid laboratory for this very purpose. However, it is missing its battery based energy storage branch. Due to safety concerns, a traditional chemical battery is not suitable for student use. In order to maintain Cal Poly’s learn-by-doing approach, an alternative solution must be implemented. A regenerative power supply meets the criteria for student use. It is capable of simulating the sinking and sourcing capabilities of a battery …

Dc Microgrid Fault Detection Using Multiresolution Analysis Of Traveling Waves, Rudy Montoya

Mechanical Engineering ETDs

Fast detection and isolation of faults in a DC microgrid is of particular importance. Fast tripping protection (i) increases the lifetime of power electronics (PE) switches by avoiding high fault current magnitudes and (ii) enhances the controllability of PE converters. This thesis proposes a traveling wave (TW) based scheme for fast tripping protection of DC microgrids. The proposed scheme utilizes a discrete wavelet transform (DWT) to calculate the high-frequency components of DC fault currents. Multiresolution analysis (MRA) using DWT is utilized to detect TW components for different frequency ranges. The Parseval energy calculated from the MRA coefficients are then used …

Dc Microgrid Fault Detection Using Multiresolution Analysis Of Traveling Waves, Rudy Montoya

Mechanical Engineering ETDs

Fast detection and isolation of faults in a DC microgrid is of particular importance. Fast tripping protection (i) increases the lifetime of power electronics (PE) switches by avoiding high fault current magnitudes and (ii) enhances the controllability of PE converters. This thesis proposes a traveling wave (TW) based scheme for fast tripping protection of DC microgrids. The proposed scheme utilizes a discrete wavelet transform (DWT) to calculate the high-frequency components of DC fault currents. Multiresolution analysis (MRA) using DWT is utilized to detect TW components for different frequency ranges. The Parseval energy calculated from the MRA coefficients are then used …

Modeling Of Inverter-Based Microgrid For Small-Signal And Large-Signal Stability Analysis, Vishal Verma

Graduate Theses, Dissertations, and Problem Reports

Integration of inverter-based resources (IBRs) such as solar photovoltaic, wind, and battery storage, is both a boon and a bane for electric power systems. On one hand, IBRs have helped in making electrical energy a clean (carbon-free) source of energy. On other hand, the dynamics of IBRs have changed the way power system studies have been carried out. With the advantages IBRs offer over conventional resources, it is assumed that a small distribution power system (microgrid) will have a 100% IBRs penetration in the future. Such a microgrid can operate in grid-connected mode or in an islanded mode. Both modes …

Modeling And Evaluation Of Utility-Scale Microgrid Investment For Distribution System Planning, Ian Schomer

Masters Theses

The electrical distribution network faces two great challenges for the immediate future. First, increased affordability of distributed energy resources (DERs)—and advancing control technologies of inverters that interface them to the grid—have driven a shift from a passive to an active distribution network (ADN), which heightens the complexity of system management. Second, the increased frequency of severe weather events and increased potential for a cybersecurity attack necessitate the need for a resilient infrastructure that can respond adaptively to shutdowns within the system. Microgrids (MGs) present a promising framework both to provide hierarchal control of DERs and to increase resiliency with grid-forming …

Development Of A Converter-Based Testing Platform And Battery Energy Storage System (Bess) Emulator For Microgrid Controller Function Evaluation, Dingrui Li

Masters Theses

The microgrid has attracted increasing research attention in the last two decades. Due to the development of renewable energy resources and power electronics technologies, the future microgrid will trend to be smarter and more complicated. The microgrid controller performs a critical role in the microgrid operation, which will also become more and more sophisticated to support the future microgrid. Before final field deployment and test, the evaluation and testing of the controller is an indispensable step in the controller development, which requires a proper testing platform.

However, existing simulation-based platforms have issues with potential numerical oscillation and may require huge …

Automation, Annunciation, And Emergency Safety Shutdown Of A Laboratory Microgrid Using A Real-Time Automation Controller (Rtac), Do Vo

Master's Theses

Over the last decade, microgrid deployments throughout the world have increased. In 2019, a record number of 546 microgrids were installed in the United States [1]. This trend continues upward to combat extreme weather conditions and power shortages throughout the country. To better equip students with the necessary skillsets and knowledge to advance in the microgrid field, Cal Poly San Luis Obispo's Electrical Engineering Department and the Power Energy Institute have invested resources to develop a laboratory microgrid.

This thesis sets to improve the laboratory microgrid's existing automation using the Schweitzer Engineering Laboratory SEL-3530 Real-time Automation Controller (RTAC). The improved …

Real Time Adaptive Relay Settings For Microgrid Protection Verified Using Hardware In Loop, Aadam Harnekar

Dissertations, Master's Theses and Master's Reports

Microgrids with penetration of renewables is imposing new challenges for system protection. Renewables are characterized with high source impedance which limit the short circuit current. The value of short-circuit current is limited due to converters used which limit the current to a maximum of 1.1 to 1.5 times maximum rated load current. This can result in faults during the islanded mode of microgrid to go unnoticed if the relay settings are not adapted to account for it. The presence of such uncleared faults in the microgrid can result in exposing it to overcurrent for a long time which can damage …

Bond Graph Modeling Of Critical Infrastructures For Cyber-Physical Security Implementation, Michele Jane White

Masters Theses

“In developed societies, there exists infrastructure vital to everyday life. This includes water and power systems. Technology is quickly evolving and being implemented on these utilities. This technology can range from smart metering in neighborhoods to volume sensors in local waste water treatment facilities. When networking, sensing, monitoring, or control devices are integrated with infrastructure it is considered a cyber physical system, or CPS. When information about an important physical system is connected to the virtual world, it is opened up to security risks. Cyber security can be provided to the CPS by monitoring the physical state of the system …

Optimization Of Union College’S Microgrid To Meet All Load With A Least-Cost, Low-Carbon Energy Mix, Caitlin Mcmahon

Honors Theses

A microgrid is a localized electric grid that generates some or all of the power used to meet its load. Union College currently has a microgrid that meets 70 percent of the campus’ load and is connected to the main grid. It is made up of a cogeneration plant as well as solar photovoltaic panels and wind turbines, which are renewable energy sources. The goal of this project is to determine the least cost, low-carbon energy mix that meets 100 percent of the campus’ load. The issue with solar and wind power is that they are variable based on time …

A Four-Port Bidirectional Dc-Dc Converter For Renewable Energy System And Microgrid, Xia Du

All Graduate Theses, Dissertations, and Other Capstone Projects

Renewable energy has nowadays become important in electrical power applications. Power converters play an important role in integrating these distributed energy sources. However, due to their intermittence characteristics, e.g., the output power provided by the PV and wind turbine is not stable, either an energy storage system will be used or microgrid is formed between the main grid and the sources. To integrate these renewable energy sources and manage the power flow, a multiport converter is preferred because it is highly beneficial and cost-efficiently than the traditional solution that using multiple individual power converter for each source. This thesis proposed …

Microgrid-Enabled Reactive Power Support To Enhance Grid Economics, Sarhan Hasan

Electronic Theses and Dissertations

Reactive power plays an essential role in voltage control and stability in electric power systems. Various Volt/VAR techniques are utilized in electric power systems to maintain the voltage profile within defined acceptable limits and accordingly provide reliability and stability. Reactive power has been commonly generated through large-scale synchronous generators or distributed capacitor banks to provide proper transmission and distribution level system management, however, reactive power can be further used as an effective means to reduce total system operation cost. In this dissertation, an optimal reactive power model is proposed to determine the optimal nodal reactive powers that result in the …

Computational Intelligence Approaches For Energy Optimization In Microgrids, Tamal Roy

Electronic Theses and Dissertations

The future electrical system termed as smart grid represents a significant paradigm shift for power industry. Nowadays, microgrids are becoming smarter with the integration of renewable energy resources (RESs) , diesel generators , energy storage systems (ESS), and plug-in electric vehicles (PEV or EV) . However, these integration bring with new challenges for intelligent management systems. The classical power generation approaches can no longer be applied to a microgrid with unpredictable renewable energy resources. To relive these problem, a proper power system optimization and a suitable coordination strategy are needed to balance the supply and demand. This thesis presents three …

Microgrid Renewable Energy Integration, Do Quang Thanh Vo

Electrical Engineering

The Microgrid is a small-scale electrical system that is designed to give Cal Poly students hands-on experience on power generation, system protection, distribution, and automation that would otherwise be very difficult to experiment in a large-scale model.

To closely replicate the modern electrical grid, a renewable energy source shall be added to the Microgrid in conjunction with the existing synchronous generators. Electrical engineering student, Virginia Yan initiated this effort, namely Grid-Tied Solar System project [1], by designing and constructing a set of solar panels and microinverter for future connection to the Microgrid. The scope of Virginia’s project was, however, limited …

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 …

Grid-Tied Solar System, Virginia Yan

Electrical Engineering

Distribution level solar energy generation has gained importance and popularity, because it helps create a sustainable electricity system while reducing the harmful environmental impacts our current power systems have. This project proposes an alternative energy source, a laboratory-scale grid-connected photovoltaic system. A KC120-1 solar panel produces 120 Watts maximum. A grid-tied solar power inverter does DC-to-AC conversion and minimizes energy transfer losses. The inverter also has an anti-islanding feature, which senses a power outage and prevents back-feeding through isolating the circuit. The circuit breakers isolate electrical components and protect the circuit. Schweitzer Engineering Laboratories SEL-751 feeder protection relay and SEL-735 …

Circuit Breaker Module, Garvin Yee, Yei Trinh

Electrical Engineering

The circuit breaker module for this design project is a proof of concept that demonstrates the functionality, feasibility, and attainability of a consumer grade power systems analysis device suitable for college laboratory use. The goal of this project was to create the final iteration of a module that has been developed and refined over the course of previous years. The Cal Poly Electrical Engineering Department intends to use this design to produce circuit breaker modules intended for fault analysis. With the current changes made to the previous modules, the current circuit breaker is lighter, safer, and more universally reproducible. The …