Supercapacitor power management module

The purpose of this senior design project is to create a charge management and output converting power module incorporating an array of supercapacitors as the energy storage medium. Conventional energy storage components, such as lithium-ion batteries, use electrochemical reactions to store and release electrons into a system. These batteries are slow to charge, highly toxic to the environment and delicate compared too many of the systems they are used in. Supercapacitors are noticeably more rugged and last hundreds to thousands of times longer than the average chemical reaction-based batteries we are used to using while capable of charging in less than half the time. Creating a power module that properly handles the use of supercapacitors is the main focus of this project. The power circuitry included in this design compensates for the design complications inherent to using supercapacitors, allowing future designers to more easily integrate supercapacitors as an energy storage solution into their designs. The power module is capable of charging three supercapacitors in series to 8.1 volts in one hour

NiO-based electronic flexible devices

Personal, portable, and wearable electronics have become items of extensive use in daily life. Their fabrication requires flexible electronic components with high storage capability or with continuous power supplies (such as solar cells). In addition, formerly rigid tools such as electrochromic windows find new utilizations if they are fabricated with flexible characteristics. Flexibility and performances are determined by the material composition and fabrication procedures. In this regard, low-cost, easy-to-handle materials and processes are an asset in the overall production processes and items fruition. In the present mini-review, the most recent approaches are described in the production of flexible electronic devices based on NiO as low-cost material enhancing the overall performances. In particular, flexible NiO-based all-solid-state supercapacitors, electrodes electrochromic devices, temperature devices, and ReRAM are discussed, thus showing the potential of NiO as material for future developments in opto-electronic devices

Energy storage systems for wave energy converters and microgrids

The thesis initially gives an overview of the wave industry and the current state of some of the leading technologies as well as the energy storage systems that are inherently part of the power take-off mechanism. The benefits of electrical energy storage systems for wave energy converters are then outlined as well as the key parameters required from them. The options for storage systems are investigated and the reasons for examining supercapacitors and lithium-ion batteries in more detail are shown. The thesis then focusses on a particular type of offshore wave energy converter in its analysis, the backward bent duct buoy employing a Wells turbine. Variable speed strategies from the research literature which make use of the energy stored in the turbine inertia are examined for this system, and based on this analysis an appropriate scheme is selected. A supercapacitor power smoothing approach is presented in conjunction with the variable speed strategy. As long component lifetime is a requirement for offshore wave energy converters, a computer-controlled test rig has been built to validate supercapacitor lifetimes to manufacturer’s specifications. The test rig is also utilised to determine the effect of temperature on supercapacitors, and determine application lifetime. Cycle testing is carried out on individual supercapacitors at room temperature, and also at rated temperature utilising a thermal chamber and equipment programmed through the general purpose interface bus by Matlab. Application testing is carried out using time-compressed scaled-power profiles from the model to allow a comparison of lifetime degradation. Further applications of supercapacitors in offshore wave energy converters are then explored. These include start-up of the non-self-starting Wells turbine, and low-voltage ride-through examined to the limits specified in the Irish grid code for wind turbines. These applications are investigated with a more complete model of the system that includes a detailed back-to-back converter coupling a permanent magnet synchronous generator to the grid. Supercapacitors have been utilised in combination with battery systems for many applications to aid with peak power requirements and have been shown to improve the performance of these energy storage systems. The design, implementation, and construction of coupling a 5 kW h lithium-ion battery to a microgrid are described. The high voltage battery employed a continuous power rating of 10 kW and was designed for the future EV market with a controller area network interface. This build gives a general insight to some of the engineering, planning, safety, and cost requirements of implementing a high power energy storage system near or on an offshore device for interface to a microgrid or grid.Irish Research Council for Science Engineering and Technology (Embark

Energy Harvesting and Energy Storage for Wireless and Less-Wired Sensors in Harsh Environments

Engineering requires sensors to control and understand the environment. This is particularly important in harsh environments. The drawbacks, especially in gas turbines is the complexity of installing a wired sensor and the weight of the wires. This makes wireless sensors attractive.A wireless sensor requires a power source for transmission of data. Batteries have previously taken the role of power source for most wireless sensors, but is unfortunately not suitable for all applications. Lately, with energy harvesting and supercapacitors in the picture, sensor applications in high temperature environments, with high power requirements or with long life requirements have the possibility of wireless interface.A supercapacitor can handle higher temperatures, higher power output and can have a cycle life that exceeds batteries by a factor of 10000. The lower energy density and high self-discharge makes it unsuitable to power a wireless sensor without power source. However, connected to an energy harvester converting waste energy into electricity makes this a powerful combination.Energy harvesters thrives in environments where waste energy is plentiful and low conversion efficiencies can be enough to power both the sensor and the transmitter. A thermoelectric harvester is designed and fabricated for the middle to rear part of a gas turbine. The temperature in this region can reach 1600 ◦ C and require extensive cooling. In the cooling channels the wall temperature reach 800-950 ◦ C when the cooling air is 450-600 ◦ C. In this location a thermoelectric harvester will have access to high thermal gradients and active cooling.To harvest the vibrations a piezoelectric energy harvester was built. To harvest enough energy the resonance frequency of the energy harvester is frequency-matched with the high energy vibrations. In many applications these frequencies drift and thus require a broad bandwidth harvester. Simulation and assembly of a broadband coupled piezoelectric energy harvester is presented in the thesis.A piezoelectric harvester require electronics and energy storage to gather enough energy to power up and run a wireless sensor. The thesis covers the fabrication of a high temperature supercapacitor capable of temperatures up to 181 ◦ C

Development of Redox-Gel Electrolyte for Wearable Thermocells

The thermo-electrochemical cells (TECs, known as thermocells) provide a new potential for self-powered devices by converting heat energy into electricity through redox reactions driven by the presence of a temperature gradient. Among multiple power sources, human body heat has attracted the attention in last decades due to its continuously releasing heat energy. For harvesting body waste heat, the wearable thermocell is urgent to develop, where the gel electrolyte is the most essential component. Wearable thermocell devices could be twisted or stretched during realistic applications, therefore flexible gel-based solid-state electrolytes are the ideal candidate to avoid the leakage issue and maintain integrity while deformations. Tremendous progress has been achieved in developing flexible gel electrolytes, however, challenges are still remained in compatibility, mechanical strength and electrochemical performance. In this thesis, the primary purpose is to develop high performance gel electrolytes for wearable thermal-electrochemical cells. Initially, the suitable polymer will match the unique redox couple. Additionally, the effort should focus on improving electrochemical properties especially the issue of ion transfer limited by the gel system. Meanwhile, the mechanical strength of gel electrolytes is also needed to pursue to satisfy the movement of human limbs

Design and Implementation of New Measurement Models and Procedures for Characterization and Diagnosis of Electrical Assets

The measurement is an essential procedure in power networks for both network stability, and diagnosis purposes. This work is an effort to confront the challenges in power networks using metrological approach. In this work three different research projects are carried out on Medium Voltage underground cable joints diagnosis, inductive Current Transformers modeling, and frequency modeling of the Low power Voltage Transformer as an example of measurement units in power networks. For the cable joints, the causes and effects of Loss Factor have been analyzed, while for the inductive current transformers a measurement model is developed for prediction of the ratio and phase error. Moreover, a frequency modeling approach has been introduced and tested on low power voltage transformers. The performance of the model on prediction of the low power voltage transformer output has been simulated and validated by experimental tests performed in the lab

Flexible and Stretchable Electronics

Flexible and stretchable electronics are receiving tremendous attention as future electronics due to their flexibility and light weight, especially as applications in wearable electronics. Flexible electronics are usually fabricated on heat sensitive flexible substrates such as plastic, fabric or even paper, while stretchable electronics are usually fabricated from an elastomeric substrate to survive large deformation in their practical application. Therefore, successful fabrication of flexible electronics needs low temperature processable novel materials and a particular processing development because traditional materials and processes are not compatible with flexible/stretchable electronics. Huge technical challenges and opportunities surround these dramatic changes from the perspective of new material design and processing, new fabrication techniques, large deformation mechanics, new application development and so on. Here, we invited talented researchers to join us in this new vital field that holds the potential to reshape our future life, by contributing their words of wisdom from their particular perspective

Advanced Fault Diagnosis and Health Monitoring Techniques for Complex Engineering Systems

Over the last few decades, the field of fault diagnostics and structural health management has been experiencing rapid developments. The reliability, availability, and safety of engineering systems can be significantly improved by implementing multifaceted strategies of in situ diagnostics and prognostics. With the development of intelligence algorithms, smart sensors, and advanced data collection and modeling techniques, this challenging research area has been receiving ever-increasing attention in both fundamental research and engineering applications. This has been strongly supported by the extensive applications ranging from aerospace, automotive, transport, manufacturing, and processing industries to defense and infrastructure industries