43 research outputs found
Demand flexibility enabled by virtual energy storage to improve renewable energy penetration
The increasing resort to renewable energy distributed generation, which is needed to mitigate anthropogenic CO2 emissions, leads to challenges concerning the proper operation of electric distribution systems. As a result of the intrinsic nature of Renewable Energy Sources (RESs), this generation shows a high volatility and a low predictability that make the balancing of energy production and consumption difficult. At the same time, the electrification of new energyâintensive sectors (such as heating) is expected. This complex scenario paves the way for new sources of flexibility that will have more and more relevance in the coming years. This paper analyses how the electrification of the heating system, combined with an electric flexibility utilisation module, can be used to mitigate the problems related to the fluctuating production of RES. By using PowerâtoâHeat (P2H) technologies, buildings are able to store the overproduction of RES in the form of thermal energy for endâuse according to the principle of the soâcalled Virtual Energy Storage (VES). A contextâaware demand flexibility extraction based on the VES model and the flexibility upscale and utilisation on districtâlevel through grid simulation and energy flow optimisation is presented in the paper. The involved modules have been developed within the PLANET (PLAnning and operational tools for optimising energy flows and synergies between energy NETworks) H2020 European project and interact under a unified coâsimulation framework with the PLANET Decision Support System (DSS) for the analysis of multiâenergy scenarios. DSS has been used to simulate a realistic future energy scenario, according to which the imbalance problems triggered by RES overproduction are mitigated with the optimal exploitation of the demand flexibility enabled by VES
Co-simulation Management Algorithm for Distribution System Operation with Real-Time Simulator
This article presents a co-simulation framework consistent with the real-time simulation for operational analysis of electrical distribution networks. Realtime simulators have become a fundamental tool for testing and optimising control strategies in a safe and controlled environment. The proposed methodology outlines the steps required for setting up, controlling, and monitoring an electrical grid using a real-time simulator. The framework proposes the use of the Message Queuing Telemetry Transport communication between the electrical grid module and an external coordinator. An algorithm based on the Python programming language is proposed to manage the real-time simulation, create the grid topology, and communicate with the external coordinator. The implementation of the electrical network and the validation of the real-time simulator network are also presented. The article concludes that the proposed framework can improve the performance and flexibility of co-simulation for studies on the penetration of power electronics-based renewable sources
Organically modified hydrotalcite for compounding and spinning of polyethylene nanocomposites
Organically modified hydrotalcite is a recent class of organoclay based on layered double hydroxides (LDH), which is anionically modified with environmental friendly ligands such as fatty acids. In this paper the influence of hydrotalcite compounded/dispersed by means of two different processes for production of plates and fibers of polyolefin nanocomposites will be compared. A polyethylene matrix, suitable for fiber production, was firstly compounded with various amounts of hydrotalcite in the range of 0.5â5% by weight, and then compression moulded in plates whose thermomechanical properties were evaluated. Similar compositions were processed by using a co-rotating twin screw extruder in order to directly produce melt-spun fibers. The incorporation of clay into both bulk and fiber nanocomposites enhanced the thermal stability and induced heterogeneous nucleation of polyethylene crystals. Hydrotalcite manifested a satisfactory dispersion into the polymer matrix, and hence positively affected the mechanical properties in term of an increase of both Youngâs modulus and tensile strength. Tenacity of nanocomposite as spun fibers was increased up to 30% with respect to the neat polymer. Moreover, the addition of LDH filler induced an increase of the tensile modulus of drawn fibers from 5.0 GPa (neat HDPE) up to 5.6â5.8 GPa
Fragmentation and rearrangement of carbonyl-bridged compounds. Synthesis and crystal structure of new spirocycles containing azetidine rings
Preparation and characterisation of piezoelectric poly-L-Lactide films for electrostimulated tissue regeneration
[The therapy of symptomatic and/or complicated dysontogenetic liver cysts].
Congenital hepatic cysts are a frequent disease, symptomatic in the 16-18\% of the cases. The authors report a review of the literature of the last 20 years about 135 treated surgically patients with symptomatic and/or complicated hepatic cysts. They analyse the different models of treatment both surgical and conservative, referring in special way about the alcoholization of the cysts. The authors finally report their personal experience about eight cases
Role-Oriented Code Generation in an Engine for Solving Hyperbolic PDE Systems
The development of a high performance PDE solver requires the combined
expertise of interdisciplinary teams with respect to application domain,
numerical scheme and low-level optimization. In this paper, we present how the
ExaHyPE engine facilitates the collaboration of such teams by isolating three
roles: application, algorithms, and optimization expert. We thus support team
members in letting them focus on their own area of expertise while integrating
their contributions into an HPC production code. Inspired by web application
development practices, ExaHyPE relies on two custom code generation modules,
the Toolkit and the Kernel Generator, which follow a Model-View-Controller
architectural pattern on top of the Jinja2 template engine library. Using
Jinja2's templates to abstract the critical components of the engine and
generated glue code, we isolate the application development from the engine.
The template language also allows us to define and use custom template macros
that isolate low-level optimizations from the numerical scheme described in the
templates. We present three use cases, each focusing on one of our user roles,
showcasing how the design of the code generation modules allows to easily
expand the solver schemes to support novel demands from applications, to add
optimized algorithmic schemes (with reduced memory footprint, e.g.), or provide
improved low-level SIMD vectorization support.Comment: SC19 SE-HE