Energy Storage design for Primary Frequency Control for Islanding Micro grid

International audienceThis paper presents a methodology which allows designing an energy storage device to prevent frequency instability of islanding power network. Then, energy storage will be able to stabilize frequency of the power system by limiting the frequency deviation to be within an acceptable range after occurrence of any disturbance. Principle of energy storage had been first elaborated to select a suitable model. Trials on influencing variables, such as rated power, droop value, and technology of energy storage were undertaken to find out their effects. The results show that the energy storage is likely to be an effective device for the controlling of frequency deviation. Its effectiveness is depending upon the earlier mentioned variables. However, proper calculation for a suitable value of the rated power happened to be the prime requirement of the design for an appropriate energy storage syste

Methodology of building a water heater aggregated model for evaluating energy flexibility for domestic hot water

International audienceDomestic hot water (DHW), due to their connection to the thermal energy storage, can act as an effective tool to gain the flexibility-oriented power system services such as primary frequency control, voltage balancing or power call from the grid. Its flexibility brings balance and stability to the electrical system. Thus, it is important to have an aggregated model, which represents a large number of domestic hot water systems instead of repeating a unit model of only one system. The contribution of this paper consist in developing a methodology to construct an aggregated model representing domestic hot water demand, which is equivalent to a large amount of water heater units. The objective is to assess the energy flexibility. The water heater using an electric resistance element is investigated in order to test the methodology. First, a multi-layer stratified temperature model is built and is simulated. Secondly, the mentioned methodology to provide an aggregated model is developed. Then, the results obtained are presented and show the relevance of the aggregated model behavior for a large amount of hot water heater. These results provide a first building block for the development of an energy consumption flexibility model

H infinity controller design for Primary Frequency Control of Energy Storage in Islanding MicroGrid

International audienceFor the frequency stability of microgrids assumed with storage devices, droop frequency control is generally applied for primary frequency control. However, the transient response of frequency is not quite good without any control of its performances (overtaking, time response). Moreover, many storage devices can be installed to guarantee microgrid stability, and a more centralized control may be interesting to coordinate the participation of each device. A Hinfinity controller is then proposed to improve the transient response and the robustness against any small disturbance of the frequency. A model is first proposed in accordance with the global formulation of H infinity control. Then, control specifications are defined in the frequency domain by definition of weighting functions. Finally, simulations of the system with H infinity controller allow verifying that the transient frequency response respects dynamic specification

Methodology of building a water heater aggregated model for evaluating energy flexibility for domestic hot water

International audienceDomestic hot water (DHW), due to their connection to the thermal energy storage, can act as an effective tool to gain the flexibility-oriented power system services such as primary frequency control, voltage balancing or power call from the grid. Its flexibility brings balance and stability to the electrical system. Thus, it is important to have an aggregated model, which represents a large number of domestic hot water systems instead of repeating a unit model of only one system. The contribution of this paper consist in developing a methodology to construct an aggregated model representing domestic hot water demand, which is equivalent to a large amount of water heater units. The objective is to assess the energy flexibility. The water heater using an electric resistance element is investigated in order to test the methodology. First, a multi-layer stratified temperature model is built and is simulated. Secondly, the mentioned methodology to provide an aggregated model is developed. Then, the results obtained are presented and show the relevance of the aggregated model behavior for a large amount of hot water heater. These results provide a first building block for the development of an energy consumption flexibility model

Methodology of building a water heater aggregated model for evaluating energy flexibility for domestic hot water

International audienceDomestic hot water (DHW), due to their connection to the thermal energy storage, can act as an effective tool to gain the flexibility-oriented power system services such as primary frequency control, voltage balancing or power call from the grid. Its flexibility brings balance and stability to the electrical system. Thus, it is important to have an aggregated model, which represents a large number of domestic hot water systems instead of repeating a unit model of only one system. The contribution of this paper consist in developing a methodology to construct an aggregated model representing domestic hot water demand, which is equivalent to a large amount of water heater units. The objective is to assess the energy flexibility. The water heater using an electric resistance element is investigated in order to test the methodology. First, a multi-layer stratified temperature model is built and is simulated. Secondly, the mentioned methodology to provide an aggregated model is developed. Then, the results obtained are presented and show the relevance of the aggregated model behavior for a large amount of hot water heater. These results provide a first building block for the development of an energy consumption flexibility model

Impact des principales fusariotoxines en mono et multi- contamination, sur les performances, la santé et la qualité des produits chez le canard au cours du gavage

The aim of this study was to compare zootechnical and health impact of deoxynivalenol (DON), fumonisins(FBs) and zearalenone (ZEN) and to assess their residual persistence level in edible tissues, following a mono ormulti-contamination of ducks during chronic exposure in the gavage phase. The mycotoxins were obtained byculturing toxinogenic fungal strains and incorporated in capsules distributed to ducks, to constitute the followinggroups:DON group (5 mg / kg), FBs group (20 mg / kg), ZEN group (0.5 mg / kg) and a multi-contaminatedgroup (5 mg/kg DON + 20 mg/kg FBs + 0,5 mg/kg ZEN); Ducks of control group received capsules containingflour free of mycotoxins. These capsules were given during 21 meals (2 meals/day), during the maizedistribution, to 80 ducks (MMG x PKL), 12 weeks aged, divided into 5 groups. Performance analysis revealed asignificant (P <0.05) decrease in growth in the multi-contaminated group without significant decrease in feedintake. At day 70, blood analysis showed no significant difference between groups on routine plasmabiochemistry and various markers of oxidative stress, except an elevation of sphinganine/sphingosine ratio inplasma for animals exposed to FBs compared to unexposed, without difference between single or multicontaminated groups. The search for residues revealed higher levels of FB1 in the liver than in the muscles, and no interactive effect of multi-contamination on the persistence of this contaminant.L’objectif était de comparer l’impact zootechnique et sanitaire du déoxynivalénol (DON), des fumonisines (FBs)et de la zéaralénone (ZEA) et d’évaluer leur niveau de persistance à l’état résiduel dans les produits comestibles, suite à une mono ou multi-contamination chez le canard lors d’une exposition chronique en phase de gavage. Les mycotoxines ont été obtenues par culture de souches fongiques toxinogènes et incorporées dans des gélules distribuées aux canards, permettant de constituer les groupes suivants : lot DON (5 mg/kg), lot FBs (20 mg/kg), lot ZEA (0,5 mg/kg) et lot multi-contaminé (5 mg/kg DON + 20 mg/kg FBs+ 0,5 mg/kg ZEA) ; les canards du lot témoin recevaient des gélules contenant de la farine exempte de mycotoxines. Ces gélules ont été administrées au cours des 21 repas (2 repas/jour), en milieu de gavage, à 80 canards (MMG x PKL) de 12 semaines répartis entre les 5 groupes. L’analyse des performances a révélé, sur le lot multi-contaminé, une diminution significative (P<0,05) de la croissance sans diminution notable de la prise d’aliment. A J70, l’analyse de sang n’a révélé aucune différence significative entre lots sur la biochimie plasmatique de routine et différents marqueurs de stress oxydatif. Seule une élévation significative du rapport sphinganine/sphingosine, chez les animaux exposés aux FBs par rapport aux animaux non exposés, a été observée dans le plasma, sans différence entre canards mono- ou multi-exposés. La recherche de résidus a révélé des teneurs plus élevées en FB1 dans le foie que dans les muscles, et l’absence d’effet interactif de la multi-contamination sur la persistance de ce composé

Lack of toxic interaction between fusariotoxins in broiler chickens fed throughout their life at the highest level tolerated in the european union

International audienceFusarium mycotoxins (FUS) occur frequently in poultry diets, and regulatory limits are laid down in several countries. However, the limits were established for exposure to a single mycotoxin, whereas multiple contamination is more realistic, and different studies have demonstrated that it is not possible to predict interactions between mycotoxins. The purpose of this study was thus to compare the toxic effect of deoxynivalenol (DON), fumonisins (FB) and zearalenone (ZON), alone and in combination on broiler chickens, at the maximum tolerated level established by the EU for poultry feed. Experimental corn-soybean diets incorporated ground cultured toxigenic Fusarium strains. One feed was formulated for chickens 0 to 10 days old and another for chickens 11 to 35 days old. The control diets were mycotoxin free, the DON diets contained 5 mg DON/kg, the FB diet contained 20 mg FB1 + FB2/kg, and the ZON diet contained 0.5 mg ZON/kg. The DONFBZON diet contained 5, 20, and 0.5 mg/kg of DON, FB1 + FB2, and ZON, respectively. Diets were distributed ad libitum to 70 broilers (male Ross PM3) separated into five groups of 14 chickens each reared in individual cages from one to 35 days of age. On day 35, after a starvation period of 8 h, a blood sample was collected, and all the animals were killed and autopsied. No difference between groups that could be attributed to FUS was observed in performances, the relative weight of organs, biochemistry, histopathology, intestinal morphometry, variables of oxidative damage, and markers of testicle toxicity. A significant increase in sphinganine and in the sphinganine to sphingosine ratio was observed in broilers fed FB. Taken together, these results suggest that the regulatory guidelines established for single contamination of broiler chickens fed with DON, FB, and ZON can also be used in the case of multiple contamination with these toxins

Toxicity of fumonisins, deoxynivalenol, and zearalenone alone and in combination in turkeys fed with the maximum European Union–tolerated level

International audienceSurveys of mycotoxins worldwide have shown that deoxynivalenol (DON), fumonisins (FB), and zearalenone (ZON) are the most abundant Fusarium mycotoxins (FUS) in European poultry feed, in both the level and the frequency of contamination. Previous studies reported that a combination of FUS at concentrations that individually are not toxic may negatively affect animals. However, although toxic thresholds and regulatory guidelines exist for FUS, none account for the risk of multiple contamination, which is the most frequent. The aim of this study was to compare DON, FB, and ZON toxicity, alone and in combination, in male turkey poults. Ground cultured toxigenic Fusarium strains were incorporated in corn-soybean-based feed in five experimental diets: control diet, containing no mycotoxins, DON diet (5 mg DON/kg), FB diet (20 mg FB1 + FB2/ kg), ZON diet (0.5 mg ZON/kg), and DONFBZON diet (5, 20, and 0.5 mg/kg of DON, FB1 + FB2, and ZON, respectively). Seventy male Grade Maker turkeys were reared in individual cages on mycotoxin-free diets from 0 to 55 days of age. On the 55th day, the turkeys were weighed and divided into five groups each comprising 14 birds. Each group was fed one of the five experimental diets for a period of 14 days. On the 70th day of age, feed was withheld for 8 hr, at which time a blood sample was collected, and then all the turkeys were killed, autopsied, and different tissues sampled. The weight of the different organs, analyses of performance, biochemistry, histopathology, oxidative damage, and testis toxicity revealed no significant effects attributable to FUS. Measurement of sphingolipids in the liver revealed an increase in the sphinganine to sphingosine ratio in turkeys fed diets containing FB, but had no apparent consequences in terms of toxicity. Finally, only slight differences were found in some variables and the results of this study showed no interactions between DON, FB, and ZON. Taken together, results thus suggest that the maximum tolerated levels established for individual contamination by DON, FB, and ZON can also be considered safe in turkeys fed with combinations of these FUS for a period of 14 days