Wave Energy Hyperbaric Converter: Small Scale Models, Prototype and Control Strategies

2012 ◽  
Author(s):  
Segen F. Estefen ◽  
Paula B. Garcia-Rosa ◽  
Eliab Ricarte ◽  
Paulo Roberto da Costa ◽  
Marcelo M. Pinheiro ◽  
...  
Keyword(s):  
Control Strategies ◽  
Applied Pressure ◽  
Ocean Waves ◽  
Wave Climate ◽  
Small Scale ◽  
Scale Models ◽  
Pressure Water ◽  
Climate Analysis ◽  
Brazilian Northeast ◽  
And Control

A device for electricity generation from ocean waves has been developed for installation on the Brazilian northeast coast. It is based on pumping modules and a two-stage accumulator linked to a hyperbaric chamber in order to provide a prescribed high pressure water flow, which operates a turbine coupled with an electrical generator. In the period between 2001 and 2007, wave tank testing of small-scale models have been carried out. A prototype with two pumping modules is presently installed in the Port of Pecém. This paper describes an overview of the device development since the first tests to the installation of the prototype. Wave climate analysis, design analysis and optimization studies have been developed and are briefly revised in this study. Furthermore, control strategies are proposed to optimize the electrical output considering the proper combination of both pressure and flow rate as a function of the predominant wave climate, when the applied pressure is constant and the generator is a synchronous machine.

The Development of an Experimental Force Feedback Dynamometer to Investigate the Real Time Control of an Oscillating Wave Surge Converter

2013 ◽  
Author(s):  
Daniel Banks ◽  
Jos van ’t Hoff ◽  
Kenneth Doherty
Keyword(s):  
Force Feedback ◽  
Position Control ◽  
Experimental Testing ◽  
Control Strategies ◽  
Small Scale ◽  
Real Time Control ◽  
Time Control ◽  
Scale Models ◽  
Damping Torque ◽  
And Control

An Oscillating Wave Surge Converter (OWSC) is a Wave Energy Converter (WEC) that consists of a bottom-hinged flap which oscillates due to wave action. Extensive research has been performed on this type of WEC through small scale experimental wave tank tests. One of the key challenges of experimental testing is replicating the characteristics of the Power Take-Off (PTO) system of the equivalent full scale WEC. Many scale models rely on simplified mechanical designs to simulate a PTO system. This can often restrict the experimental research into the influence of PTO design and control strategies of WECs. In order to model PTO systems and control strategies more accurately other tools are needed. This paper describes the design and build of a PLC controlled Force Feedback Dynamometer (FFD) system that enables the testing of more sophisticated control strategies applicable to an OWSC through fast application of a variable PTO damping torque. A PLC system is shown to be a viable control for PTO strategy investigations through velocity triggered damping levels. Examples of both PTO and position control strategies are presented.

Small Scale Wind Generation System: Part II – A Novel Quasi-Z-Source Inverter and FRG-QZSI-Micro Grid Interface

2017 ◽  
Vol 6 (1) ◽  
pp. 13
Author(s):  
M. Ramkumar ◽  
K. N. Srinivas
Keyword(s):  
Control Strategies ◽  
Research Work ◽  
Open Loop ◽  
Small Scale ◽  
Loop Control ◽  
Power Injection ◽  
System Part ◽  
Micro Grid ◽  
Wind Generation System ◽  
And Control

<p>This paper proposes modelling, analysis and control of a small scale wind energy conversion system employing a direct driven Flux Reversal Generator (FRG) connected to the micro grid through a quasi-Z-source inverter (QZSI). This entire research is made up of two major parts viz., FRG and QZSI. In the part I report of this research work, the role of FRG has been thoroughly modelled and verified. In this part II, the modelling and analysis of QZSI for this purpose is presented. In addition, the modified space vector PWM (SVPWM) technique is proposed in this paper to satisfy the shoot-through characteristic of QZSI, which is a novel. The interface of FRG and QZSI to inject power in to micro grid has been finally presented. The simulation results are validated with the analytical results. Section I discusses the open loop control of QZSI. The mathematical modelling of QZSI for this purpose is given and analytically validated. This flowed by section II in which the proposed SVPWM is presented. The procedure to obtain triggering pulses using this proposed modulation technique is discussed. Section III presents closed loop control strategies for QZSI. Section IV presents the micro grid<br />inte face and power injection.</p>

scholarly journals Assessment of Risk Factors of African Swine Fever in India: Perspectives on Future Outbreaks and Control Strategies

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1044
Author(s):  
Mousumi Bora ◽  
Durlav Prasad Bora ◽  
Mohan Manu ◽  
Nagendra Nath Barman ◽  
Lakshya Jyoti Dutta ◽  
...  
Keyword(s):  
Risk Factors ◽  
Disease Transmission ◽  
Control Strategies ◽  
African Swine Fever ◽  
Small Scale ◽  
Wild Pigs ◽  
Wildlife Reservoirs ◽  
Potential Risk Factors ◽  
And Control ◽  
Near Future

African swine fever (ASF) is one of the most important transboundary diseases of pigs. ASF has been identified in India for the first time in domestic pigs from outbreaks reported in two of the northeastern states, Arunachal Pradesh and Assam in 2020. A total of 11 ASF outbreaks in different regions killed over 3700 pigs and devastated the economy of small-scale livestock owners of both the states. Considering the first outbreak of ASF in India, a generic risk assessment framework was determined to identify potential risk factors that might favor future emergence of the disease. Based on the Indian scenario, we considered population density of host, farming practice, availability of biological vectors and wildlife reservoirs, epidemiological cycles, and international trade to analyze the possibility of future outbreaks of ASF and chances of establishment of endemism. On critical analysis of the identified risk factors associated with ASFV transmission, we observed that the risk factors are well preserved in the Indian geography and might participate in future outbreaks, further disseminating the disease to nearby countries. Since no vaccine is currently available against ASF, the domestic and the wild pigs (wild boars and the endangered pygmy hogs native to India) of this region are under constant threat of infection. For the near future, this region will have to continue to rely on the implementation of preventive measures to avoid the devastating losses that outbreaks can cause. The various adaptive control strategies to minimize the risks associated with the transmission of ASF, keeping our views to Indian settings, have been described. The risk-analysis framework presented in the study will give a further understanding of the dynamics of disease transmission and will help to design control strategies and corresponding measures to minimize the catastrophic consequences of ASF disease.

Spatiotemporal trends of Chagas disease-related mortality in the Northeast of Brazil, 2007–2017

Parasitology ◽  
2020 ◽  
Vol 147 (13) ◽  
pp. 1552-1558
Author(s):  
G. J. B. Sousa ◽  
M. S. Farias ◽  
V. R. F. Cestari ◽  
T. S. Garces ◽  
T. A. Maranhão ◽  
...  
Keyword(s):  
Chagas Disease ◽  
Empirical Bayes ◽  
Control Strategies ◽  
Scan Statistics ◽  
Planning And Control ◽  
Spatiotemporal Trends ◽  
Local Moran ◽  
Brazilian Northeast ◽  
And Control ◽  
Global And Local

AbstractChagas disease (CD) is a neglected disease and endemic in Brazil. In the Brazilian Northeast Region, it affects millions of people. Therefore, it is necessary to identify the spatiotemporal trends of CD mortality in the Northeast of Brazil. This ecological study was designed, in which the unit of analysis was the municipality of the Brazilian northeast. The data source was the Information System of Mortality. It was calculated relative risk from socioeconomic characteristics. Mortality rates were smoothed by the Local Empirical Bayes method. Spatial dependency was analysed by the Global and Local Moran Index. Scan spatial statistics were also used. A total of 11 287 deaths by CD were notified in the study. An expressive parcel of this number was observed among 70-year-olds or more (n = 4381; 38.8%), no schooling (n = 4381; 38.8%), mixed-race (n = 4381; 62.3%), male (n = 6875; 60.9%). It was observed positive spatial autocorrelation, mostly in municipalities of the state of Bahia, Piauí (with high-high clusters), and Maranhão (with low-low clusters). The spatial scan statistics has presented a risk of mortality in 24 purely spatial clusters (P < 0.05). The study has identified the spatial pattern of CD mortality mostly in Bahia and Piauí, highlighting priority areas in planning and control strategies of the health services.

scholarly journals Small-Scale Rotor Aeroacoustics for Drone Propulsion: A Review of Noise Sources and Control Strategies

2019 ◽  
Author(s):  
Paolo Candeloro ◽  
Tiziano Pagliaroli ◽  
Daniele Ragni ◽  
Silvia Di Francesco
Keyword(s):  
Control Strategies ◽  
Fluid Dynamic ◽  
Noise Pollution ◽  
Reynolds Numbers ◽  
Small Scale ◽  
Noise Sources ◽  
Lower Altitude ◽  
Source Mechanisms ◽  
Key Aspects ◽  
And Control

In the last decade, the drone market has grown rapidly for both civil and military purposes. Due to their versatility, drones demand is constantly increasing, with several industrial players joining the venture to transfer urban mobility to the air. This has exacerbated the problem of noise pollution, mainly due to the relatively lower altitude of these vehicles and to the proximity of their routes to extremely densely populated areas. In particular, both the aerodynamic and aeroacoustic optimization of the propulsive system and of its interaction with the airframe are key aspects of the design of aerial vehicles for the success or the failure of their mission. The industrial challenge involves finding the best performance in terms of loading, efficiency and weight, and, at the same time, the most silent configuration. For this reason, research has focused on an initial localization of the noise sources and, on further analysis, of the noise generation mechanism, focusing particularly on directivity and scattering. The aim of the present study is to review the noise source mechanisms and the state-of-the-art technologies available in literature for its suppression, focusing especially on the fluid-dynamic aspects of low Reynolds numbers of the propulsive system and on the interaction of the propulsive-system flow with the airframe.

Estimating Demand Response Potential of Buildings Using a Predictive HVAC Model

2014 ◽  
Author(s):  
Froylan E. Sifuentes ◽  
Taylor Keep
Keyword(s):  
Demand Response ◽  
Control Strategies ◽  
Renewable Electricity ◽  
Variable Air Volume ◽  
Air Volume ◽  
Challenges And Opportunities ◽  
Predictive Controller ◽  
Climate Analysis ◽  
And Control

Increasing penetration of intermittent renewable electricity into the grid, coupled with development of new communication and control strategies, is creating challenges and opportunities for demand response (DR) to balance the grid. This paper presents a model characterization of a controllable buildings Variable Air Volume HVAC (VAV HVAC) system capable of implementing control strategies that provide flexibility to the grid. A Model Predictive Controller (MPC) capable of reliably varying the modeled power by ±20%, or up to ±2 GW on a national scale, every five minutes without compromising occupants comfort was built. A climate analysis was performed in order to assess the availability of controllable resources in sixteen cities. It is found that this control strategy could be implemented up to 99% of the time in the hottest regions, but as low as 10% of the time in the coldest.

Domestic wastewater treatment with a small-scale membrane bioreactor

2006 ◽  
Vol 53 (3) ◽  
pp. 69-78 ◽  
Author(s):  
C. Abegglen ◽  
H. Siegrist
Keyword(s):  
Membrane Bioreactor ◽  
Control Strategies ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Phosphate Removal ◽  
Small Scale ◽  
First Year ◽  
Effluent Quality ◽  
Domestic Wastewater Treatment ◽  
And Control

A small-scale membrane plant for treating the domestic wastewater of a four-person household is presented. The membrane bioreactor has been in operation for 6 months and achieves elimination rates of 90, 95 and 80% for total organic carbon, chemical oxygen demand and total nitrogen, respectively. Only a small amount sludge is produced. The permeate is reused for flushing toilets and has a yellowish colour. After investigations of the effluent quality, decolourisation of the permeate, energy efficiency and control strategies in the first year, urine will be treated separately in an automated precipitation reactor where struvite is produced to improve the overall phosphate removal of the plant.

scholarly journals DEVELOPMENT OF A HIGH CURRENT STREAMLINED OIL BOOM/SKIMMER FOR INLAND WATERWAYS1

1977 ◽  
Vol 1977 (1) ◽  
pp. 323-327
Author(s):  
Blair A. Folsom ◽  
Clyde Johnson
Keyword(s):  
High Speed ◽  
Oil Spills ◽  
Stability Control ◽  
Small Scale ◽  
Prototype Model ◽  
High Current ◽  
Oil Boom ◽  
Scale Models ◽  
Current Area ◽  
And Control

ABSTRACT The streamlined oil boom/skimmer uses a slightly submerged slotted hydrofoil to skim a thin layer of oil and water into an attached sump where kinetic energy is dissipated, the oil and water are separated and the oil is retained and recovered. Because of the system's simplicity and low drag, it can be deployed as a high speed skimmer supported by a catamaran or as a high current boom with several adjacent sections spanning a high current area. Earlier work, reported in the 1973 and 1975 Joint Conferences on the Prevention and Control of Oil Spills, included preliminary feasibility tests, in which the potential for excellent high current performance was demonstrated, and small-scale bow wave tests. The work reported here includes applying the previous results to full-scale models, refining sump design, developing a stability control/flotation system and integrating these subsystems in a pre-prototype model for testing at OHMSETT.

scholarly journals Modeling of a Heaving Buoy Wave Energy Converter With Stacked Dielectric Elastomer Generator

2014 ◽  
Author(s):  
Giacomo Moretti ◽  
Marco Fontana ◽  
Rocco Vertechy
Keyword(s):  
Wave Energy ◽  
Control Strategies ◽  
Mechanical Energy ◽  
Wave Climate ◽  
Dielectric Elastomer ◽  
Wave Energy Converter ◽  
Climate Data ◽  
Energy Converter ◽  
Design And Optimization ◽  
And Control

This paper introduces a novel architecture of Wave Energy Converter (WEC) provided with a Dielectric Elastomer (DE) Power Take–Off (PTO) system. The device, named Poly–Buoy, includes a heaving buoy as primary interface, that captures the mechanical energy from waves, and a DE Generator (DEG), made by stacked layers of silicone elastomer, that converts mechanical energy into electricity. A mathematical model of the Poly–Buoy is proposed, which includes analytical electro–hyperlastic equations for the DEG and a linear model for wave-buoy hydrodynamics. Procedures for the design and optimization of different layouts and control strategies for the DE–PTO are introduced that specifically consider single–DEG and dual–DEG architectures. A numerical case study is also reported for specific geometrical dimensions of the buoy and specific wave climate data.

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