Integrated Power Take-Off and Virtual Oscillator System for the VIVACE Converter: VCK System Identification

Author(s):  
Jonghun Lee ◽  
Che-Chun Chang ◽  
Nikolaos I. Xiros ◽  
Michael M. Bernitsas

The first step in the development of an integrated system encompassing Power Take-Off (PTO) with virtual Mass-Damping-Spring (VMCK) for the VIVACE Converter (Vortex Induced Vibration for Aquatic Clean Energy) is achieved. VIVACE converts hydrokinetic energy of ocean/river currents to mechanical energy using Vortex Induced Vibrations (VIV). Subsequently, its PTO converts the mechanical energy to electricity. The objective integrated system acts as VMCK to support the hydro-mechanical component of VIVACE. The second function of the system is to act as PTO to implement the electro-mechanical component converting the harnessed mechanical energy to electrical energy without suppressing the hydro-mechanical energy harnessing mechanism of VIV. Vortex Induced Vibrations (VIV) are motions induced on long elastic bodies with bluff cross-section placed with their long axis perpendicular to a fluid flow due to periodic irregularities in this fluid-structure interaction phenomenon. In this paper, a single cylinder of VIVACE is considered. Even in this simplest case, the underlying physics of this phenomenon is strongly nonlinear. Special care is needed in designing systems that either support or enhance VIV or harvest the energy of VIV oscillations. In the first physical model of VIVACE, a mass-damper-spring arrangement was employed in the Marine Renewable Energy Laboratory (MRELab) of the University of Michigan to transmit mechanically the power to an electrical generator, which converted it to useful electrical power. A Virtual mass-damping-spring (VMCK) mechanism is intended to substitute the existing physical elements in the MRELab consisting of an electric motor driven by a power electronic converter allowing for programmable mass, stiffness and damping values. The integrated VMCK system enables improved control of the mechanism originally generating and supporting VIV as well as improved power take-off efficiency and capability. The VMCK system employs advanced switching control of the power transfer process so that VIV for a given damping is not affected. The first step taken in this paper towards development of the integrated system consists of the identification of the VCK system. The mechanical transmission system consists of a belt and two pulleys. The cylinder in VIV is attached to one side of the belt causing it to oscillate and in turn drive the pulleys.

Author(s):  
Archana Sudhakar Talhar ◽  
Sanjay B. Bodkhe

This paper gives a review of energy scenario in India and other countries. Today’s demand of the world is to minimize greenhouse gas emissions, during the production of electricity. Henceforth over the world, the production of electrical power is changing by introducing abundantly available renewable energy sources like sun and wind. But, because of the intermittent nature of sustainable power sources, the electrical power network faces many problems, during the transmission and distribution of electricity. For resolving these issues, Electrical Energy Storage (EES) is acknowledged as supporting technology. This paper discusses about the world electrical energy scenario with top renowned developed countries in power generation and consumption. Contribution of traditional power sources changed after the introduction of renewable energy sources like sun and wind. Worldwide Agencies are formed like International Energy Agency (IEA), The Central Intelligence Agency, (CIS) etc. The main aim of these agencies is to provide reliable, affordable and clean energy. This paper will discuss about the regulatory authority and government policies/incentives taken by different countries.  At the end of this paper, author focuses on obstacles in implementation, development and benefits of renewable energy.


2018 ◽  
Vol 29 (18) ◽  
pp. 3572-3581
Author(s):  
Suihan Liu ◽  
Ali Imani Azad ◽  
Rigoberto Burgueño

Piezoelectric energy harvesting from ambient vibrations is well studied, but harvesting from quasi-static responses is not yet fully explored. The lack of attention is because quasi-static actions are much slower than the resonance frequency of piezoelectric oscillators to achieve optimal outputs; however, they can be a common mechanical energy resource: from large civil structure deformations to biomechanical motions. The recent advances in bio-micro-electro-mechanical systems and wireless sensor technologies are motivating the study of piezoelectric energy harvesting from quasi-static conditions for low-power budget devices. This article presents a new approach of using quasi-static deformations to generate electrical power through an axially compressed bilaterally constrained strip with an attached piezoelectric layer. A theoretical model was developed to predict the strain distribution of the strip’s buckled configuration for calculating the electrical energy generation. Results from an experimental investigation and finite element simulations are in good agreement with the theoretical study. Test results from a prototyped device showed that a peak output power of 1.33 μW/cm2 was generated, which can adequately provide power supply for low-power budget devices. And a parametric study was also conducted to provide design guidance on selecting the dimensions of a device based on the external embedding structure.


2013 ◽  
Vol 8 (1) ◽  
pp. 155892501300800
Author(s):  
François M. Guillot ◽  
Haskell W. Beckham ◽  
Johannes Leisen

In the past few years, the growing need for alternative power sources has generated considerable interest in the field of energy harvesting. A particularly exciting possibility within that field is the development of fabrics capable of harnessing mechanical energy and delivering electrical power to sensors and wearable devices. This study presents an evaluation of the electromechanical performance of hollow lead zirconate titanate (PZT) fibers as the basis for the construction of such fabrics. The fibers feature individual polymer claddings surrounding electrodes directly deposited onto both inside and outside ceramic surfaces. This configuration optimizes the amount of electrical energy available by placing the electrodes in direct contact with the surface of the material and by maximizing the active piezoelectric volume. Hollow fibers were electroded, encapsulated in a polymer cladding, poled and characterized in terms of their electromechanical properties. They were then glued to a vibrating cantilever beam equipped with a strain gauge, and their energy harvesting performance was measured. It was found that the fibers generated twice as much energy density as commercial state-of-the-art flexible composite sensors. Finally, the influence of the polymer cladding on the strain transmission to the fiber was evaluated. These fibers have the potential to be woven into fabrics that could harvest mechanical energy from the environment and could eventually be integrated into clothing.


2014 ◽  
Vol 14 (4) ◽  
pp. 664-671 ◽  
Author(s):  
Norashikin Ahmad Kamal ◽  
Heekyung Park ◽  
Sangmin Shin

Small-scale hydropower is the generation of electrical power of 10 MW or less from the transformation of kinetic energy in flowing water to mechanical energy in a rotating turbine to electrical energy in a generator. The technology is especially useful when installed with a stormwater infrastructure in countries teeming with abundant rainfall. It is upon this concept that this study is being pursued to assess the implementation of microhydropower within a stormwater infrastructure. In order to achieve sustainability of development, small-scale hydropower should be beneficial in the implementation of stormwater infrastructure, especially in countries that have abundant rainfall. The aim of this study is to provide an assessment method for microhydropower implementation within a stormwater infrastructure. PCSWMM software was used to simulate the flowing water at a detention outlet. Modification of the current detention pond was made to optimise the quantity and quality of water supplied to the turbine. Two important parameters in the modification design are quantity and quality of storm water, which optimise the energy generated. The total power that can be harnessed from the design is theoretically from 500 W to 0.5 MW. Therefore, it can be safely concluded that the implementation of microhydropower within a stormwater infrastructure is technologically feasible.


Author(s):  
Gunnar Tamm ◽  
J. Ledlie Klosky ◽  
Jacob Baxter ◽  
Luke Grant ◽  
Isaac Melnick ◽  
...  

Electrical power generation in austere settings, such as combat zones, places a heavy burden on the US Army; high costs in both dollars and lives lost require that every drop of fuel be used effectively and efficiently. In remote locations such as combat outposts (COPs) and small forward operating bases (FOBs) in Afghanistan, electrical power derived from the Army’s standard Advanced Medium Mobile Power Sources (AMMPS) generator is even used to heat water for showers and heat living spaces. This heating requires conversion of thermal energy to mechanical energy, which is then converted to electrical energy and back to heat. Thus, a significant fuel savings could be realized through the more efficient production of heat. A combined heat and power system is proposed; efficiency is increased by routing the generator exhaust through simple ducting to a standard gas hot water heater to produce hot water with waste heat. With funding from the U.S. Army Rapid Equipping Force, cadets and faculty at the United States Military Academy designed, built and tested a system for under $1,000 in parts which was readily coupled to a 5 kW AMMPS generator to produce hot shower water. Results indicate a possible fuel savings of 1500–2000 gallons per year, 20–35% increased fuel utility, and the ability to provide 10–20 five gallon showers during every 5 hours of operation of each 5 kW generator. At a fuel cost of $20–50 per gallon in the deployed environment, and considering the large inventory of deployed generators, the payback for the Army could be tremendous.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Shoaib Khanmohammadi ◽  
Kazem Atashkari ◽  
Ramin Kouhikamali

The use of biomass due to the reduction in greenhouse gas emissions and environmental impacts has attracted many researchers’ attention in the recent years. Access to an energy conversion system which is able to have the optimum performance for applying valuable low heating value fuels has been considered by many practitioners and scholars. This paper focuses on the accurate modeling of biomass gasification process and the optimal design of a multigeneration system (heating, cooling, electrical power, and hydrogen as energy carrier) to take the advantage of this clean energy. In the process of gasification modeling, a thermodynamic equilibrium model based on Gibbs energy minimization is used. Also, in the present study, a detailed parametric analysis of multigeneration system for undersigning the behavior of objective functions with changing design parameters and obtaining the optimal design parameters of the system is done as well. The results show that with exergy efficiency as an objective function this parameter can increase from 19.6% in base case to 21.89% in the optimized case. Also, for the total cost rate of system as an objective function it can decrease from 154.4 $/h to 145.1 $/h.


Author(s):  
Omid Safari ◽  
Mohammad Reza Zakerzadeh ◽  
Mostafa Baghani

In recent years demand for mobile electrical power has been increased and due to this application, energy harvester systems have been developed to convert mechanical energy into electrical energy using smart materials. In this investigation, a novel arrangement of an energy harvester using Magnetic Shape Memory Alloys (MSMAs) is developed. Elements of MSMA are attached to a corrugated beam and their roots are fixed. The way of harvesting energy from this system is based on conversion of vibration motion energy to the magnetic flux gradient. There is a number of copper coils that wrapped around the MSMA elements in a constant magnetic field. If strain or stress field is applied to the MSMA elements, the electrical current is induced to coils. The problem is studied with analytical methods, and for this purpose, MATLAB solver is used. To simulate the behavior of MSMA substance Kiefer and Lagoudas nonlinear model is used. To verify the results, these two arrangements have been analyzed in ABAQUS. To provide the material properties of MSMA elements, UMAT code has been used. It will be shown that size of this MSMA based energy harvester can become smaller with using corrugated beam structure instead of simple cantilever beam.


2018 ◽  
Vol 14 (21) ◽  
pp. 318 ◽  
Author(s):  
Iqbal Mahmud

Electricity is the most general forms of energy used across the world. This paper focuses on designing a setup that leads to the generation of electrical energy which is going to waste when humans are walking. Footsteps are an untapped natural resources. This generated energy is, however, costeffective and nonhazardous for human. Electrical energy can be produced by converting mechanical energy using footsteps. Generating the electric power through the fabrication of footstep arrangement by a prototype comprises of a pipe, nozzle, unidirectional valve, water reservoir, turbine, and DC motor. Whenever pressure is exerted on the reservoir, water flows through the nozzle into the turbine and generates electrical energy. This energy is stored in the battery. This project will reduce the global warming and load shedding in a much cleaner cost-effective way. Since this project is related directly to the human movement, the weight of the setup is a crucial factor.


2020 ◽  
Vol 2 (1) ◽  
pp. 180-185
Author(s):  
Aris Suryadi

Indonesia is actively developing the potential for renewable energy as a substitute for depleting fossil energy reserves. Wind energy is clean energy without polling the environment. Wind energy in Indonesia has great potential, but it is still not optimal enough for its utilization. One form of alternative energy that can be utilized as mechanical energy by wind turbines to convert into electrical energy by dc generators. Ventilators that operate for 24 hours function to suck water and, located on the roof of a warehouse, sports hall . Utilization of wind to become electrical energy is designed from the use of a turbine ventilator as a medium to convert wind into motion energy, where the movement of the turbine is continued by pulley and v-belt comparisons to the generator, this generator produces electricity. This research examines how much electrical energy is produced at different wind speeds ranging from 3 to 5.4 m/s. From the tests conducted, the generator rotation, and the lowest voltage is at wind speed of 3 m/s which is 3.6 V. while the generator speed and the highest voltage is obtained if the wind speed is 5.4 m/s which is 10.3 V.


2016 ◽  
Vol 26 (7) ◽  
pp. 2013-2032 ◽  
Author(s):  
Nicolas Chauchat ◽  
Eric Schall ◽  
Mathieu Mory ◽  
Marta de la Llave Plata ◽  
Vincent G. Couaillier

Purpose The purpose of this paper is to investigate a new cooling process of a heated cylinder with confined impacting air jet. Design/methodology/approach To do this the authors used experience-numerical and numerical-numerical comparisons. The experimental facility, designed and built at the Pau University, consists in air jets impacting around a heated circular cylinder. As the inlet velocity magnitude is low (Vin=4.37 m/s – Machin=0.0125), using a compressible solver for numerical simulations presents a number of difficulties. For this low Mach number configuration, the authors compare the performance of three different solvers in this paper. Two of them are compressible, one based on the finite volume approach and the other on a discontinuous Galerkin method, and the third one is an incompressible solver. Some of the numerical results are compared to experimental data. Findings Comparisons between the results from 3D and 2D computations support the relevance of 2D models. Some of the numerical results are compared to experimental data. Research limitations/implications The confined aspect of the set-up reduces experimental measurement to intrusive measures. It should be noted that the temperature measurement given by thermocouples is always considered as “global” or “average”. Originality/value Future aircraft technology will increasingly rely on electrical power. The substitution of mechanical energy by electrical energy will lead to an increasing amount of heat power that need be evacuated. Innovative cooling processes have to be set up according to constraints imposed by the technological design.


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