Evaluation of a Local Fault Detection Algorithm for HVDC Systems

A great increase in the amount of energy generated from clean and renewable sources integrated in the electric power system is expected worldwide in the coming years. High Voltage Direct Current (HVDC) systems are seen as a promising alternative to the traditional Alternating Current (AC) systems for the expansion of the electric power system. However, to achieve this vision, there are some remaining challenges regarding HVDC systems which need to be solved. One of the main challenges is related to fault detection and location in HVDC grids. This paper reviews the main protection algorithms available and presents the evaluation of a local fault detection algorithm for DC faults in a multi-terminal Voltage Source Conversion (VSC) based HVDC grid. The paper analyses the influence of the DC voltage sampling frequency and the cable length in the performance of the algorithm. © 2019, European Association for the Development of Renewable Energy, Environment and Power Quality (EA4EPQ).The authors thank the support from the Spanish Ministry of Economy, Industry and Competitiveness (project ENE2016-79145-R AEI/FEDER, UE) and GISEL research group IT1083-16), as well as from the University of the Basque Country UPV/EHU (research group funding PPG17/23)

Object Control Skills Training for Children With Intellectual Disability: An Implementation Case Study

Children with intellectual disability (ID) tend to have difficulty with mastering fundamental movement skills, associated with cognitive deficits that impair skill acquisition. In this case study, motor learning evidence was transformed into an object control skills training program for children with ID in a school context. An implementation framework was used for program design, pilot, and evaluation. Research evidence on error-reduced motor learning was combined with practitioners’ insights to inform the program design. Children with ID in the participant school were allocated to a training or control group for the pilot; object control skills proficiency was the measured outcome. The lead trainer was interviewed and their notes were reviewed for process evaluation. Significant improvements in participants’ object control skills proficiency were found following training. The process evaluation confirmed fidelity and identified implementation factors. The systematically designed application was found beneficial for children with ID. Implementation criteria were identified for future iterations of an error-reduced approach to training movement skills of children with ID

Development of a new machine system for the forming of micro-sheet-products

Most of the developed micro-forming machines were based on standalone concepts which do not support efficient integration to make them fully automated and integrated. At present, material feeding in micro-forming is not of sufficient precision and reliability for high throughput manufacturing applications. Precise feeding is necessary to ensure that micro-parts can be produced with sufficient accuracy, especially in multi-stage forming, while high-speed feeding is a must to meet the production-rate requirements. Therefore, design of a new high-precision and high-speed feeder for micro-forming is proposed. Several possible approaches are examined with a view to establishing feasible concepts. Based on the investigation, several concepts for thin sheet-metal feeding for micro-forming are generated, they being argued and assessed with applicable loads and forces analysis. These form a basis of designing a new feeder

Viagem à Índia para prospecção de tecnologias sobre mamona e pinhão manso.

Viagem á Índia para prospecção de tecnologias sobre mamona e pinhão manso ; Introdução; Roteiro; Detalhamento; Sardar Krushinagar Dantiwada University; Pesquisas com mamona; Pesquisas com pinhão manso; Outras oleaginosas ; Indústria de extração de óleo de mamona ; Mercado de leilões para comercialização de produtos agrícolas ; Mini-usina de biodiesel de pinhão manso; 4º Seminário Internacional sobre semente e óleo de mamona e produtos de valor agregado ; Visita à Secretaria de Agricultura do Estado de Tamil Nadu ; Projeto MGR jatropha biodiesel ; Loco Works - Empresa operadora de ferrovias ; Exposição sobre a mini-usina de biodiesel da Empresa Loco Works ; Considerações finais; Pinhão manso ; Mamona.bitstream/CNPA/18319/1/DOC153.pd

Fault detection based on ROCOV in a multi-terminal HVDC grid

Protection of a meshed VSC-HVDC grid is a challenge due to the behaviour of DC current and voltage signals during fault conditions. Protection systems must operate in a very short time range. Since fault detection should be very fast, local measurement based algorithms are mostly used; communication based algorithms lack the needed speed as a result of the communication time delay. This way, a ROCOV algorithm is proposed in this paper. This algorithm is analysed for different fault conditions.The authors gratefully acknowledge the support from the Spanish Ministry of Economy, Industry and Competitiveness (project ENE2016-79145-R AEI/FEDER, UE), the Basque Government (GISEL research group IT1191-19), as well as from the University of the Basque Country UPV/EHU (research group funding GIU18/181)

Genetic characterization, domestication and improvement of Macrobrachium rosenbergii in the Philippines

Extensive studies in the Philippines and in adjacent countries revealed that 528 caridean prawn species are found in this region alone (Chan, 1998). Of all the known species, the giant freshwater prawn is considered the most commercially important. Except for the Philippines, culture of the giant freshwater prawn, Macrobrachium rosenbergii, has already made substantial contributions to the local aquaculture production in Southeast Asia, i.e. in Thailand, Malaysia and Indonesia. However, efforts are now being made to improve the aquaculture production of Macrobrachium rosenbergii in the Philippines, thus, optimal methods for the culture and propagation of this high value freshwater aquaculture species are being developed by the Philippine Government fishery agencies as well as other research and academic institutions. The Integrated Rural Aquaculture Program under the ASEAN-SEAFDEC Special Five-Year Program or what is presently known as the Program on the Promotion of Sustainable Aquaculture in the ASEAN Region enabled the Bureau of Fisheries and Aquatic Resources, the Mindanao State University and the Aquaculture Department of SEAFDEC to jointly conduct studies on the genetic characterization, domestication and improvement of Macrobrachium rosenbergii stocks in the Philippines in order to improve the aquaculture production of the giant freshwater prawn. Under the collaborative project which started in late 2004, specific research activities under were conducted, and an update on their results are summarized

A Mathematical Model to Optimize the Neoadjuvant Chemotherapy Treatment Sequence for Triple-Negative Locally Advanced Breast Cancer

Background: Triple-negative locally advanced breast cancer is an aggressive tumor type. Currently, the standard sequence treatment is applied, administering anthracyclines first and then a taxane plus platinum. Clinical studies for all possible treatment combinations are not practical or affordable, but mathematical modeling of the active mitotic cell population is possible. Our study aims to show the regions with the tumor’s most substantial cellular population variation by utilizing all possible values of the parameters () that define the annihilatory drug capacity according to the proposed treatment. Method: A piecewise linear mathematical model was used to analyze the cell population growth by applying four treatments: standard sequences of 21 days (SS21) and 14 days (SS14), administering anthracyclines first, followed by a taxane plus platinum, and inverted sequences of 21 days (IS21) and 14 days (IS14), administering a taxane plus platinum first then anthracyclines. Results: The simulation showed a higher effect of IS14 over SS14 when the rate of drug resistance was larger in the cell population during DNA synthesis (G1 and S) compared to cells in mitosis (G2 and M). However, if the proportion of resistant cells in both populations was equivalent, then treatments did not differ. Conclusions: When resistance is considerable, IS14 is more efficient than SS14, reducing the tumor population to a minimum

Vacuum decay in quantum field theory

We study the contribution to vacuum decay in field theory due to the interaction between the long and short-wavelength modes of the field. The field model considered consists of a scalar field of mass $M$ with a cubic term in the potential. The dynamics of the long-wavelength modes becomes diffusive in this interaction. The diffusive behaviour is described by the reduced Wigner function that characterizes the state of the long-wavelength modes. This function is obtained from the whole Wigner function by integration of the degrees of freedom of the short-wavelength modes. The dynamical equation for the reduced Wigner function becomes a kind of Fokker-Planck equation which is solved with suitable boundary conditions enforcing an initial metastable vacuum state trapped in the potential well. As a result a finite activation rate is found, even at zero temperature, for the formation of true vacuum bubbles of size $M^{-1}$. This effect makes a substantial contribution to the total decay rate.Comment: 27 pages, RevTeX, 1 figure (uses epsf.sty

Vacuum decay in quantum field theory

We study the contribution to vacuum decay in field theory due to the interaction between the long and short-wavelength modes of the field. The field model considered consists of a scalar field of mass $M$ with a cubic term in the potential. The dynamics of the long-wavelength modes becomes diffusive in this interaction. The diffusive behaviour is described by the reduced Wigner function that characterizes the state of the long-wavelength modes. This function is obtained from the whole Wigner function by integration of the degrees of freedom of the short-wavelength modes. The dynamical equation for the reduced Wigner function becomes a kind of Fokker-Planck equation which is solved with suitable boundary conditions enforcing an initial metastable vacuum state trapped in the potential well. As a result a finite activation rate is found, even at zero temperature, for the formation of true vacuum bubbles of size $M^{-1}$. This effect makes a substantial contribution to the total decay rate.Comment: 27 pages, RevTeX, 1 figure (uses epsf.sty