Power and Energy Commons^™

Pt/G-C3N4 Nanosheet For Visible Light-Induced Enhancement Of The Activity For Formic Acid Electro-Oxidation, Yong-Rong Sun, Chun-Yu Du, Guo-Kang Han, Ya-Jing Wang, Yun-Zhi Gao, Ge-Ping Yin

Journal of Electrochemistry

By using graphitic carbon nitride nanosheet (g-C₃N₄ nanosheet) as a support,Pt/g-C₃N₄ nanosheet catalyst was fabricated by microwave assisted polylol process. The nanoparticles size,composition,structure and optical properties of Pt/g-C₃N₄ nanosheet were characterized by TEM,XRD,XPS and UV-Vis diffuse reflectance spectroscopy. Comparing with the catalytic activities toward formic acid electro-oxidation under dark and visible light illumination,the superior activity of Pt/g-C₃N₄ nanosheet catalyst was achieved under visible light illumination. This visible light-driven enhancement in the formic acid performance could be attributed to the plasmon-induced electron-hole separation on g-C₃N₄ with …

Carbon Composite Fe3O4 Nanoparticles Based Electrochemical Sensor For Hydrogen Peroxide Detection, Si-Yu Zhang, Hui-Juan Wang, Shu-Fang Li, Jian-Ying Qu

Journal of Electrochemistry

In this work, a novel hydrogen peroxide electrochemical sensor was constructed with ferroferric oxide (Fe₃O₄) magnetic nanoparticles, which demonstrated good electrocatalytic activity for hydrogen peroxide. There existed a good linear relationship between the concentration of hydrogen peroxide and the oxidation peak current in the range of 1.00 × 10^-6 ~ 1.00 × 10^-3 mol·L^-1 (R = 0.9980) with the detection limit of 6.60 × 10-7 mol·L^-1. The sensor exhibited good anti-interference ability, high reproducibility and stability.

Lead Modified Nanoporous Platinum Electro-Catalysts For Formic Acid Oxidation, Yuan-Yuan Zhang, Qing-Feng Yi, Ge-Kun-Kun Zuo, Tao Zou, Xiao-Ping Liu, Xiu-Lin Zhou

Journal of Electrochemistry

Platinum (Pt) catalysts modified by other suitable metals significantly enhance their electrochemical activities for formic acid oxidation. In this work, a titanium-supported nanoporous network platinum (nanoPt/Ti) electrode was prepared using a hydrothermal method. The as-prepared nanoPt/Ti electrode was modified with a certain amount of lead by using cyclic voltammetry for different scan cycle numbers (n), namely, n = 10, 15, 20 and 30, to synthesize the novel lead-modified nanoporous Pt (nanoPb_(n)-Pt/Ti) electrodes. Electro-oxidation of formic acid on these electrodes was studied with cyclic voltammetry (CV), chronoamperometry and chronopotentiometry in sulfuric acid solution. CV curves showed that both nanoPt/Ti …

Chemical Stability Investigations Of Catalyst Layer In Pemfc, Yan-Yan Gao, Ming Hou, Yong-Yi Jiang, Dong Liang, Jun Ai, Li-Min Zheng

Journal of Electrochemistry

This work was intended to study the effect of free radicals on the chemical stability of catalyst layer via ex situ accelerated stress test (AST). Fenton reagent was used as the free radical provider in this research. Apart from the decomposition of Nafion in catalyst layer, the agglomerated Pt nanoparticles and the corroded carbon support were also observed after being treated in Fenton reagent for 100 h. Firstly, the existence of fluoride (F) ions evidenced the chemical decomposation of Nafion after being attacked by trace radical species, which was supported by the intensity decrease in the C-F stretching and vibration …

Co3(Hcoo)6@Rgo As A Promising Anode For Lithium Ion Batteries, Heng Jiang, Jing-Min Fan, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

Metal–organic framework(MOF) is a kind of novel electrode materials for lithium ion batteries. Here, a composite material Co₃(HCOO)₆@rGO was synthesized for the first time by in situ loading of Co₃(HCOO)₆ on rGO (reduced oxide graphene) through a solution chemistry method. As an anode material for lithium ion batteries, it exhibited an excellent cycle stability as well as a large reversible capacity of 926 mAh·g^-1 at a current density of 500 mA·g^-1 after 100 cycles within the voltage range of 0.02 ~ 3.0 V vs. Li/Li⁺ with a good rate capability. …

Preparations And Electrochemical Performances Of Carbon Coated Silicon/Graphite Composites, Tian-Yi Gao, Zheng-Liang Gong

Journal of Electrochemistry

In this work, the carbon coated silicon (Si@C) composite materials were synthesized based on the industrial silicon powder (600 meshes) via a high energy ball milling combing with in-situ carbon coating (carbonization) method. The Si@C/graphite (Si/C) composite anode materials were prepared by a simple mechanical ball-milling approach. The effects of carbon coating and the ratio of Si to graphite on electrochemical performances of Si/graphite composite materials were investigated systematically. Compared with the nano-Si/graphite composites, the Si/C composites showed higher reversible capacity, better rate capability and cycle performance. The Si@C materials composited of amorphous carbon and crystal silicon with the primary …

Investigation Of The Skin Effect In Alternating Currents, Matthew Liang

The International Student Science Fair 2018

My research is on the investigation of the skin effect in alternating currents. My project is broken down into 4 sub-aims. The first aim would be, to be able to mathematically model the distribution of current in the radius of the wire, which consists of the applications of the Maxwell equation and solving zeroth order differential Bessel equations of the first kind. The next aim would be to computationally plot out the desired current readings as the depth of the wire increases from the surface, using the Matlab software. The third aim that I have would be conducting an experiment, …

Energy Conversion System For Travelers (Ecost), Thipok Bovornratanaraks

The International Student Science Fair 2018

We have innovated “The Energy Conversion System for Travelers” or the ECoST. With the fact that most travelers have wheeled cabin-bags, whilst walking, the wheels will rotate so why don’t we harvest electricity from this kinetic energy? We thus install our innovation, the ECoST, to the bag to generate electricity from the spinning wheels. The electricity is then kept in the storage unit and ready to charge your empty battery devices in an emergency case via a USB port. To make life easy, our ECoST was designed to replicate the power bank charging method; therefore, we can charge …

Wind Turbine Design: Analysis And Experimentation Of Electro-Magnetic Alternator Design, Mark Hans Ewald Steinke

Honors Projects

This article explores the alternator designs for small scale wind turbines and the aspects that affect the performance of these alternators. It explores the design and testing process used to quantify, visualize, and understand the relationship between the wind turbine stator design and the performance. Additionally, the paper analyzes the data collection method using a test jig powered by a hydraulic motor set up by previous groups of students and the data intended to be collected using actual field tests on Whidbey Island located at Camp Casey. These tests were intended to identify favorable combinations of alternators and blades. However, …

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 …

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 …

A Comparative Study Of Constant Power Operation Techniques For Low Inductance Machines, Damien Lawhorn, Narges Taran, Vandana Rallabandi, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

In traditional electric machines, it is usually possible to achieve constant power high-speed operation by employing field weakening through the injection of a negative d-axis current component. However, in machines with low armature inductance, such as high power density permanent magnet synchronous machines, and more specifically, coreless machines, which are gaining increasing attention because of their high specific torque, the extended speed range obtained using this method is very narrow. This paper summarizes the performance characteristics of existing approaches for obtaining constant power operation and proposes two new techniques, specially applicable to coreless axial flux permanent magnet machine namely, current …

Multi-Physics Modeling For Electric And Hybrid Vehicles With In-Wheel Electric Motors, Vandana Rallabandi, Damien Lawhorn, Dan M. Ionel, Xiao Li

Power and Energy Institute of Kentucky Faculty Publications

This paper discusses multi-domain and multi-physics modeling of in-wheel electric vehicles using ANSYS Simplorer and ANSYS Maxwell. The study includes component level modeling of the vehicle, brakes, wheels, battery, traction motor, inverter, solar panels and boost converter. The traction motor used is an axial flux permanent magnet synchronous machine. In order to accommodate both the large time constants of the mechanical system and the high switching frequency power electronics, average models of the inverter and boost converter are considered. Simulation examples are provided for the University of Kentucky Gato Del Sol V car.

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; …

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 …

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 …

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 …

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 …

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 …

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 …

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.

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 …

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 …

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 …

Photovoltaic System Optimization For An Austere Location Using Time Series Data, Torrey J. Wagner, Eric Lang, Warren Assink, Douglas S. Dudis

Faculty Publications

In this work we test experimental photovoltaic, storage and generator technologies and investigate their potential to meet austere location energy needs. After defining the energy requirements and insolation of a 1,100-person base, we develop a microgrid model and simulation. Cost optimizations were then performed using hourly time-series data to explore the cost and performance trade-space of a PV-battery-generator system. The work highlights the cost of resiliency and the dependencies of optimum system component sizes on duration and the fully burdened cost of fuel.

Fault Identification And Location For Distribution Network With Distributed Generations, Wen Fan, Yuan Liao

Electrical and Computer Engineering Faculty Publications

Power distribution networks with distributed generations may experience faults. It is essential to promptly locate the fault for fast repair and restoration. This paper presents a novel method for identifying the faulted section and accurate location of faults that occur on power distribution grid. Appropriate matrices are set up to represent meter locations on the grid and the topology of the grid. The voltage and current measurements obtained are utilized to decide the fault sections. Then fault location is determined by solving equations that link measurements and fault locations through bus impedance matrix. The method is applicable to both single …

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 …