Digital Commons Network^™

Solar Irradiance Microforecasting, Austin Jeffrey Fite, Sara Naseem Kipps

Computer Engineering

In late winter quarter 2018 the University of New Mexico and Microgrid Labs provided the Cal Poly Electrical Engineering department with their prototype Solar Irradiance Microforecasting (SIMF) hardware. This hardware was provided to the University under the lone condition that data collected with it would be returned to Microgrid Labs to train their weather model. The goal of this senior project was to take the provided hardware and software and make it usable for students in the Cal Poly Electrical and Computer Engineering departments to hack and expand. The end goal with the hardware is near term cloud and weather …

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 …

Comparison Of Organic And Inorganic Solar Photovoltaic Systems, Khulan Orgil

Electrical Engineering

This senior project report addresses the consumer’s need for accurate and easily accessible information when making a solar panel purchasing decision. Thus, the project analyzes and compares the costs and benefits of organic and inorganic photovoltaic systems during their life cycle. The cost comparison includes analysis of the environmental and economic costs of materials, production, installation, and disposal. The benefit comparison includes analysis of the economic, environmental, and social benefits accrued during the system’s lifetime. With the project’s data, consumers can make more informed decisions to fit their specific needs.

Dc-Dc 4-Switch Buck-Boost Converter For Energy Harvesting From Elliptical Machines, Alexander C. Samietz, Gustavo Guzman

Electrical Engineering

The senior project report documents the process of replacing the network of resistors inside an elliptical machine with a DC-DC buck-boost converter. The buck-boost DC-DC converter accepts a wide input range of 5-60 Volts, with an output of 36 Volts for the most efficient use of the already available microinverter. The microinverter reclaims the lost energy and safely distributes it back to the electrical grid. The addition of this project reduces heat emissions from wasted energy and shrinks the carbon footprint of its users.

Analog Sorting Using Pulse Width Modulation, Riley C. Olson

Computer Engineering

As time goes on, computers become more and more powerful. However, as processing time becomes less of a limiting factor for computing tasks, power consumption takes its place for many tasks. This paper proposes and tests a new method for sorting analog signals. This new sorting method converts analog signals into Pulse Width Modulated(PWM) signals of varying duty cycle , which are then sorted by a simple network of combinational logic, and then converted to a normal binary representation. In order to implement this new method, multiple circuits had to be designed and and tested to ensure their functionality and …

Investigating Efficiency Of Ac Direct Drive Of Led Lighting, Miles Davis Head

Electrical Engineering

This project explores the rapidly-expanding area of AC direct drive for LED lighting. AC LED driving does not use typical DC-DC converter-based driving but uses semiconductor switches and a linear regulator to activate a number of LEDs proportional to the input voltage at any given time. This allows bulky, expensive magnetics to be eliminated from the system. The goal of this project was to develop a flexible simulation of a common AC LED system to find areas of significant power loss and attempt to improve them. This allows future versions of an AC LED system to start with major loss …

Wind/Hydro Generator Simulator, Michael Timothy Djaja, Christopher James Rotsios

Electrical Engineering

The intention of this project is to make it easier for people without reliable access to electricity to implement their own sources of electrical generation. The ability to simulate different sources of generation allows people in need to find what source of generation will most properly meet their electricity needs. The goal of this project was to provide a wind or water flow profile from any area in the world and output a corresponding amount of power that would be expected from a small-scale wind or hydro generator. Due to difficulties with the microcontroller and incorrect sizing of components, this …

Design And Test Of Wide Input And Output Constant Current Led Driver, Kean Wee

Electrical Engineering

This senior project aims to provide design and test the performance of a DC-DC constant current LED driver for use in a larger DC smart building infrastructure. In this instance, a SEPIC topology is chosen to provide high efficiency output current at output voltages that can be above or below the input voltage. This is challenging since the same design must operate at similar efficiency for vastly different environmental conditions. As a part of a larger system, the design must be able to perform the given task consistently regardless of changes to the source and load power.

The design uses …

Ewall Inverter Project, Andrew Douglas Tsau, Alex Lopez

Electrical Engineering

The objective of this project is to demonstrate the capabilities of a Raspberry Pi when used as a grid-tied, bi-directional power inverter for renewable energy storage applications. Due to its economical nature, this system would play a large role in the growing solar industry by making solar energy more accessible, affordable, and easier to install. The inverter uses a single-phase H-Bridge to generate a sine wave from a proprietary wall mounted battery. To improve power quality, an enhanced low pass filter is added to provide a better drop off to reduce extraneous harmonics. The system synchronizes this synthetic sine wave …

Dc House Solar Panel Cleaner, Sarahanne Heredia, Sophia Deguia

Electrical Engineering

Solar panels lose 0.05% of their power conversion efficiency per day due to soil accumulation, according to an experiment conducted by the University of California, San Diego in 2013 [18]. The project is an electro-mechanical cleaning system that effectively and efficiently cleans solar panels at set intervals. A drip irrigation system with spray jets was attached to a water pump and Arduino, both powered by the DC House Project solar panel battery. The DC House solar panel was the targeted panel set up for the project. Several components of the design could have been chosen more optimally for the system; …

Electric Upgrades - Supercapacitor Electric Bicycle, John Chen, Wilson Fletcher, Spencer Esparza

Electrical Engineering

Supercapacitors provide high current capabilities compared to conventional lithium-ion batteries, allowing for fast charging and discharging of electrical energy. This project seeks to test the benefits of supercapacitors in an electric bicycle unit in order to gain higher regenerative energy. The main components of the bicycle are its regenerative motor, supercapacitor array, and motor controller. Developing the project will provide data on the feasibility of using alternative battery storage and charging.

Passive Balancing Battery Management System For Cal Poly Racing's Formula Sae Electric Vehicle, Alvin Joseph Ha

Electrical Engineering

This senior project aims to replace the current battery management system (BMS) on Cal Poly’s Formula SAE electric vehicle with a more versatile, advanced, and reliable system. A BMS manages a rechargeable battery by ensuring the battery device operator’s safety, protecting battery cell integrity, prolonging battery lifetime, maintaining functional design requirements, and sending optimal usage information to the application controller. Passive balancing maximizes a battery pack’s capacity by dissipating excess energy through heat to regulate cell state of charge.

Analysis Of Improved Multiphase Buck Converter, Usamah Riaz Ahmad, Scott Wu

Electrical Engineering

While the number of transistors per microprocessor is rapidly increasing, the power requirements of converters are getting more and more important. The amount of current is increasing, while at the same time the output voltage is steadily decreasing. Today’s boards are exceeding 100A, while the buck converters have their output voltage below 1 V. Due to these new power requirements, multiphase buck converters are becoming more popular. In addition, this topology is usually used with voltage regulator modules (VRM).

The TPS40090EVM-002 board was used as the original multiphase buck with an input voltage of 12 V and output voltage of …

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 …

Microgrid Protection Student Laboratory: Human-Machine Interface And Scada Database, Nathan P. Martinez

Electrical Engineering

The electric utility system, a ubiquitous and fundamental component of modern life, has changed more in the last 20 years than the last 100. With more homes and businesses installing distributed energy resources (DERs) such as solar panels, battery storage, and other intermittent sources, massive changes need to take place in the electric transmission and distribution systems. Engineers must develop a new skill set for a modern utility industry. This project summarizes a component for a new laboratory class aimed at power engineering students at Cal Poly which supports the laboratory through the creation of a human-machine interface (HMI) and …

A Multiphase Modified Boost Converter With Reduced Input Current Ripple: Combined Capacitors, Omri Nissan

Master's Theses

The delivery of high power and smaller footprints through a non-isolated topology demands for the use of multiphase topology in DC-DC converters. Multiphase reduces the ripple observed on both the input and output waveforms; however, it may not be enough to connect to sensitive power sources such as renewable energy sources. A single-phase modified boost converter demonstrates the ability to acquire very minimal input current ripple by addition of passive components. The expansion to multiphase topology is the next logical step for higher power application while furthering the low input current ripple benefit. In this thesis, the multiphase modified boost …

Design, Simulation, And Hardware Construction Of A 600 W Solid State Dc Circuit Breaker For The Dc House Project, Calin Matthew Bukur

Master's Theses

DC circuit breakers must be able to arrest overcurrent conditions to prevent electrical equipment and wiring from causing building fires or other hazards from occurring. With more DC renewable sourced structures such as Cal Poly’s DC House, an inexpensive and reliable protection system is necessary to ensure safe energy transfer to the loads. One method of protecting a system is preventing excessive amounts of current to be drawn by the load when the surrounding components are rated at a lesser value. DC circuit breakers act as a monitoring system and barely presents an effect on the voltage or power. With …

The Analysis And Study Of Power System Designs For Same Polytechnic College In Tanzania, Kevin Lum Hua

Master's Theses

The Mbesese Initiative for Sustainable Development (MISD) is a group aiming to help eliminate extreme poverty in Africa by creating educational opportunity. One project that the group is currently doing is to build Same Polytechnic College (SPC) in Tanzania. As part of the project, this thesis aims to study and analyze the electrical power system and distribution for the college. Based on the projected load profile of the college and high potential for solar generation in Tanzania, several different power systems utilizing local utility AC electricity and/or photovoltaic (PV) DC electricity are explored and simulated for their feasibility and performance. …

The Modified-Multiphase Boost Converter: Combined Inductors And Capacitors Topology, Zachary L. Eldredge

Master's Theses

In this work, a modified boost converter design has been implemented in a multiphase configuration with a condensed topology. The modified aspect of the design has already been proven to drastically reduce input current ripple by about 40% in a single-phase implementation. By placing two modified boost converters in parallel with interleaving main switches (multiphase), the input inductors and modified capacitors of the modified topology can be reduced to just one of each, lowering the number of components, size, and cost. Additionally, multiphase DC/DC converters lower input/output voltage and current ripples while delivering more power compared to single-phase converters. By …

A Modified Multiphase Boost Converter With Reduced Input Current Ripple: Split Inductance And Capacitance Configuration, Zoe M. Hay

Master's Theses

This thesis presents the simulation, design, and hardware implementation of a modified multiphase boost converter. Converter design must consider noise imposed on input and output nodes which connect to and influence the operation of other devices. Excessive noise introduces EMI which can damage sensitive circuits or impede their operation. High ripple current degrades battery lifetime and reduces operating efficiency in connected systems such as PV arrays. Converters with high ripple current also experience greater peak conduction loss and require larger components. A two-phase implementation of a modified boost converter demonstrates the input current filtering benefits of the modified topology with …

Protection, Automation, And Frequency Stability Analysis Of A Laboratory Microgrid System, Christopher Eric Osborn

Master's Theses

Due to increasing changes in the power industry, Cal Poly San Luis Obispo's electrical engineering department introduced a set of initiatives to adequately equip students with the skills and knowledge to interact with new technologies. Specifically, the department proposed a microgrid and power systems protection and automation laboratory to strengthen students' knowledge of microprocessor-based relays. This paper outlines a microgrid laboratory system that fulfills the initiative's goal and proposes a collection of laboratory experiments for inclusion in a new laboratory course at Cal Poly. The experiments provide students with practical experience using Schweitzer Engineering Laboratory (SEL) relays and teach fundamental …

Protection Against Ungrounded Single Phase Open Circuit Faults In 3-Phase Distribution Transformers, Higinio Ariel Montoya

Master's Theses

This thesis explores the impacts and behavior of 3-phase distribution transformers when subject to ungrounded single phase open circuit faults. A simple 3-phase system is modeled using MATLAB Simulink and operation under fault conditions are simulated and studied. Simulation results are confirmed via lab experimentation. Finally, a robust detection and protection method using neutral current injection (as proposed in industry literature) is built and demonstrated.

Electric utility operating experience has demonstrated that all too often, loads on 3-phase distribution transformers are not adequately protected against an ungrounded single phase open circuit fault (commonly called “single phasing”). This type of fault …