DOCUMENT
This paper discusses an Induction Generator (IG) system that provides regulated voltage at any load condition. It utilizes the classical self-excitation principle but, in addition to that, it makes use of a current regulated PWM inverter to control the output voltage magnitude. It is primarily intended for micro hydro plants to be used in rural areas, where the cost of conventional distribution system is high, and the water resources are available to drive an unregulated low hear turbine. The proposed topology is presented, followed by an analysis of the control structure. The methodology is validated via simulation studies.
DOCUMENT
TU Delft, in collaboration with Gravity Energy BV, has conducted a feasibility study on harvesting electric energy from wind and vibrations using a wobbling triboelectric nanogenerator (WTENG). Unlike conventional wind turbines, the WTENG converts wind/vibration energy into contact-separation events through a wobbling structure and unbalanced mass. Initial experimental findings demonstrated a peak power density of 1.6 W/m² under optimal conditions. Additionally, the harvester successfully charged a 3.7V lithium-ion battery with over 4.5 μA, illustrated in a self-powered light mast as a practical demonstration in collaboration with TimberLAB. This project aims to advance this research by developing a functioning prototype for public spaces, particularly lanterns, in partnership with TimberLAB and Gravity Energy. The study will explore the potential of triboelectric nanogenerators (TENG) and piezoelectric materials to optimize energy harvesting efficiency and power output. Specifically, the project will focus on improving the WTENG's output power for practical applications by optimizing parameters such as electrode dimensions and contact-separation quality. It will also explore cost-effective, commercially available materials and best fabrication/assembly strategies to simplify scalability for different length scales and power outputs. The research will proceed with the following steps: Design and Prototype Development: Create a prototype WTENG to evaluate energy harvesting efficiency and the quantity of energy harvested. A hybrid of TENG and piezoelectric materials will be designed and assessed. Optimization: Refine the system's design by considering the scaling effect and combinations of TENG-piezoelectric materials, focusing on maximizing energy efficiency (power output). This includes exploring size effects and optimal dimensions. Real-World Application Demonstration: Assess the optimized system's potential to power lanterns in close collaboration with TimberLAB, DVC Groep BV and Gravity Energy. Identify key parameters affecting the efficiency of WTENG technology and propose a roadmap for its exploitation in other applications such as public space lighting and charging.
Europa wil in 2050 volledig klimaatneutraal zijn, en zet in op waterstof als energiedrager die een hoofdrol zal spelen in die transitie. Nederlandse bedrijven die dieselaggregaten produceren zetten voor de volledige reductie van de CO2-emissie van hun producten nu voornamelijk in op het vervangen van fossiele door zogenaamde groene diesel. Recent zijn diverse studies verschenen die aantonen dat de ontwikkeling en inzet van waterstofmotoren, zeker voor toepassingen in wegtransport, zowel technisch als economisch zinvol is. Dergelijk productontwikkeling zou ook bij generatorsets een versnelling van de energietransitie mogelijk maken en bovendien kunnen functioneren als een brugtechnologie tot het ogenblik dat brandstofcellen voldoende goedkoop en duurzaam zijn geworden. Doel van dit project is om de economische en technische haalbaarheid van een dergelijke productontwikkeling in kaart te brengen. Bijzonder is daarbij dat het hierbij gaat om een retrofit van bestaande motoren die massaal geproduceerd worden voor automotive doeleinden. Omdat voorlopig gebruik zal worden gemaakt van componenten die ontwikkeld zijn voor de huidige aardgasmotoren voorziet het project ook in versneld duurproefonderzoek van deze componenten. In dit project wordt samengewerkt tussen Fontys Hogeschool Engineering, NPS Diesel B.V., H2Trac B.V., Prins Autogassystemen B.V. en TNO.
Water quality is under pressure worldwide and requires urgent attention according to recent reports, calling for technological development and more cost-effective solutions. One such development is the use of nanobubbels (NBs). NBs have been gaining interest in both scientific and industrial fields over the past years due to their broad applicability and unique characteristics opposed to larger bubbles used in traditional applications, e.g. dissolved air flotation and aeration. NBs is promising in water technology applications, especially in aeration, as due to their small size they provide a large air-water interface and are stable (present in the bulk) for many days. Due to that, different companies have been introducing NBs based technology in the market. The start-up company BIMCO Holland is one of them. They have developed three types of Ultra Fine Bubble (UFB)-generators to integrate in various (household) applications: I) a tap connection for water taps, II) a pipe adaptor for household appliances and III) a shower coupling. In order to prove their concept, BIMCO Holland wants to test the UFB-generators together with NHL Stenden. During these tests, the intended formation of NBs in tap water will be determined, as well as possible effects on the water quality. Additionally, potential applications will be (theoretically) explored, such as reduced water- and surfactant usage and prolonged lifetime of materials and appliances. With NanoBGen, the consortium aims to understand better the functioning of the newly developed UFB-generators. The tests are required to prove the system is (or not) related to the presence of NBs. Also, to support the company finding other applications of the UFB-generators and contribute to bringing the technology to a higher TRL.
