Modular ESS with second life batteries operating in grid independent mode

This work is part of a bigger project which aims to research the potential development of commercial opportunities for the re-use of batteries after their use in low carbon vehicles on an electricity grid or microgrid system. There are three main revenue streams (peak load lopping on the distribution Network to allow for network re-enforcement deferral, National Grid primary/ secondary/ high frequency response, customer energy management optimization). These incomes streams are dependent on the grid system being present. However, there is additional opportunity to be gained from also using these batteries to provide UPS backup when the grid is no longer present. Most UPS or ESS on the market use new batteries in conjunction with a two level converter interface. This produces a reliable backup solution in the case of loss of mains power, but may be expensive to implement. This paper introduces a modular multilevel cascade converter (MMCC) based ESS using second-life batteries for use on a grid independent industrial plant without any additional onsite generator as a potentially cheaper alternative. The number of modules has been designed for a given reliability target and these modules could be used to minimize/eliminate the output filter. An appropriate strategy to provide voltage and frequency control in a grid independent system is described and simulated under different disturbance conditions such as load switching, fault conditions or a large motor starting. A comparison of the results from the modular topology against a traditional two level converter is provided to prove similar performance criteria. The proposed ESS and control strategy is an acceptable way of providing backup power in the event of loss of grid. Additional financial benefit to the customer may be obtained by using a second life battery in this way.

Meshing radial networks at 11kV

This project evaluates the benefits of meshing existing 11kV radial networks in order to reduce losses and maximise the connection of low carbon distributed generation. These networks are often arranged as radial feeders with normally-open links between two of the feeders; the link is closed only to enable continuity of supply to an isolated portion of a feeder following a fault on the network. However, this link could also be closed permanently thus operating the network as a meshed topology under non-faulted conditions. The study will look at loss savings and the addition of distributed generation on a typical network under three different scenarios; traditional radial feeders, fixed meshed network and a dynamic meshed network. The networks are compared in terms of feeder losses, capacity, voltage regulation and fault levels.

Reliability estimation of second life battery system power electronic topologies for grid frequency response applications

This paper is part of a project which aims to research the opportunities for the re-use of batteries after their primary use in low and ultra low carbon vehicles on the electricity grid system. One potential revenue stream is to provide primary/secondary/high frequency response to National Grid through market mechanisms via DNO's or Energy service providers. Some commercial battery energy storage systems (BESS) already exist on the grid system, but these tend to use costly new or high performance batteries. Second life batteries should be available at lower cost than new batteries but reliability becomes an important issue as individual batteries may suffer from degraded performance or failure. Therefore converter topology design could be used to influence the overall system reliability. A detailed reliability calculation of different single phase battery-to-grid converter interfacing schemes is presented. A suitable converter topology for robust and reliable BESS is recommended.

Adaptive control of hybrid battery energy storage systems under capacity fade

There is an increasing call for applications which use a mixture of batteries. These hybrid battery solutions may contain different battery types for example; using second life ex-transportation batteries in grid support applications or a combination of high power, low energy and low power, high energy batteries to meet multiple energy requirements or even the same battery types but under different states of health for example, being able to hot swap out a battery when it has failed in an application without changing all the batteries and ending up with batteries with different performances, capacities and impedances. These types of applications typically use multi-modular converters to allow hot swapping to take place without affecting the overall performance of the system. A key element of the control is how the different battery performance characteristics may be taken into account and the how the power is then shared among the different batteries in line with their performance. This paper proposes a control strategy which allows the power in the batteries to be effectively distributed even under capacity fade conditions using adaptive power sharing strategy. This strategy is then validated against a system of three different battery types connected to a multi-modular converter both with and without capacity fade mechanisms in place.

Impact of driver behaviour on availability of electric vehicle stored energy for STOR

As take up of low carbon vehicles increase, there is interest in using the energy stored in the vehicles to help maintain system frequency through ancillary services on the electricity grid system. Research into this area is generally classed as vehicle-to-grid research. In theory, the energy available from electric vehicles could be directly correlated to the vehicle's state of charge (SoC) and battery capacity during the time the car is parked and plugged in. However, not all the energy in the vehicle may be used, as some capacity is required by the driver for their next journey. As such, this paper uses data captured as part of a large scale electric vehicle trial to investigate the effect of three different types of driver routine on vehicle-to-grid availability. Each driver's behaviour is analysed to assess the energy that is available for STOR, with follow on journey requirements also considered.

Analysis and comparative study of different converter modes in modular second life hybrid battery energy storage systems

The use of ex-transportation battery system (i.e. second life EV/HEV batteries) in grid applications is an emerging field of study. A hybrid battery scheme offers a more practical approach in second life battery energy storage systems because battery modules could be from different sources/ vehicle manufacturers depending on the second life supply chain and have different characteristics e.g. voltage levels, maximum capacity and also different levels of degradations. Recent research studies have suggested a dc-side modular multilevel converter topology to integrate these hybrid batteries to a grid-tie inverter. Depending on the battery module characteristics, the dc-side modular converter can adopt different modes such as boost, buck or boost-buck to suitably transfer the power from battery to the grid. These modes have different switching techniques, control range, different efficiencies, which give a system designer choice on operational mode. This paper presents an analysis and comparative study of all the modes of the converter along with their switching performances in detail to understand the relative advantages and disadvantages of each mode to help to select the suitable converter mode. Detailed study of all the converter modes and thorough experimental results based on a multi-modular converter prototype based on hybrid batteries has been presented to validate the analysis.

Connection design without accurate LV feeder load data:an argument for LV monitoring

Since privatisation, maintenance of DNO LV feeder maximum demand information has gradually demised in some Utility Areas, and it is postulated that lack of knowledge about 11kV and LV electrical networks is resulting in a less economical and energy efficient Network as a whole. In an attempt to quantify the negative impact, this paper examines ten postulated new connection scenarios for a set of real LV load readings, in order to find the difference in design solutions when LV load readings were and were not known. The load profiles of the substations were examined in order to explore the utilisation profile. It was found that in 70% of the scenarios explored, significant cost differences were found. These cost differences varied by an average of 1000%, between schemes designed with and without load readings. Obviously, over designing a system and therefore operating more, underutilised transformers becomes less financially beneficial and less energy efficient. The paper concludes that new connection design is improved in terms of cost when carried out based on known LV load information and enhances the case for regular maximum feeder demand information and/or metering of LV feeders. © 2013 IEEE.

Globalizáció, nemzeti szuverenitás és demokrácia. Magyarország helyzete a globális világban (Globalization, national sovereignity and democracy)

Korunk új világrendjében alapvetően átrendeződik a globalizáció, a nemzeti szuverenitás és a demokrácia viszonya. Ebben az új helyzetben minden országnak, köztük hazánknak is elkerülhetetlenül szembe kell nézni azzal a körülménnyel, amit Dani Rodrik fogalmazott meg és a globális világgazdaság politikai trilemmájának nevezett, hogy e hármas egyidejűleg nem valósítható meg. E trilemmára adott válasz pedig alapvetően meghatározza azt, hogy miként alakul a világ és benne hazánk jövőbeni sorsa. A cikk e trilemma kialakulásának mozgatóerőivel, az arra adható válaszokkal foglalkozik, kísérletet téve arra, hogy Magyarországra vonatkozó tanulságokat is levonjon. / === / Our contemporary world has basically rearranged the relationship between globalization, national sovereignty and democracy. In this new situation all countries including Hungary have to face the great challenges under the political trilemma of the global economy, coined by D. Rodrik. The answers given by countries to it will determine the future development path of the whole world, and of course Hungary's one as well. The driving forces behind this dilemma and the possible answers for it are the subject of the paper.

Governance in the European Union - Applying the "trilemma of global politics"

The European Union with its sophisticated institutional system is the most important regional integration on Earth. This tight form of economic integration converges to the level that Dani Rodrik calls hyperglobalization in his model, the political trilemma of globalisation. In our paper we develop the mentioned model and then we apply it to the case of the European Integration. We argue that if we want to maintain the deep integration among member states in the EU we have to pass more and more functions of the nation states to the federation level. In case of the EMU that means that federal fiscal policy is needed which could lead to multi-speed Europe considering new member states’ reluctance to give up their specific institutions.

Nemzetgazdasági versenyképesség: elmélet, mérés, esettanulmányok = Competitiveness of National Economies: Theory, Measurement, Case Studies

Műhelytanulmányunk a nemzeti versenyképesség vállaltokon túli dimenziójával kíván foglalkozni. A felgyorsult globalizáció korának világgazdasági környezetében, ahol a nemzetköziesedett nagyvállalatok rendelkeznek az erőforrások és a közvetlen beruházások jelentős része felett és az egyes regionális piacok folyamatai gyorsan áttevődnek más régiókra, a gazdaságpolitika és tágabb értelemben az állam mozgástere és feladata megváltozott. Ez az országokra nézve azt jelenti, hogy a stabil üzleti környezet megteremtésével és az emberi erőforrás illetve a technológiai infrastruktúra, mint háttérerőforrások fejlesztésével képesek hosszútávon megalapozni a gazdasági növekedést és felzárkózást, függetlenül attól, hogy az európai gazdasági integrációs környezetben valósítják-e meg mindezt. _____ The working paper examines the dimensions of competitiveness over the corporate level. The regional positions are changing quickly and the room for manoeuvre of the economic policy in national level is narrowed for attraction of business activities in the era of quickened globalisation. The countries compete for direct investments with the level of stability in business environment, the quality of human resource, the development of technological infrastructure. The development of background factors determines the economic growth.

Gazdasági kormányzás a gazdasági és monetáris unióban - a globális politika lehetetlen szentháromsága szemszögéből (Economic governance in the economic and monetary union – applying the trilemma of global politics)

Az Európai Unió a világgazdaság egyik legfontosabb integrációja. A benne megvalósuló gazdasági integráció szorossága megfelel annak a szintnek, amit Rodrik hiperglobalizációnak nevez. Az elmélet szerint a politika szintjén egyszerre nem megvalósítható a demokratikus politikai döntéshozatal, a teljes világgazdasági integráció, illetve a nemzetállam. A trilemma a globalizáció útjában álló intézményi különbségeken alapszik. Megoldása három módon lehetséges: a demokrácia kiiktatásával a megoldás az arany kényszerzubbony, ahol a piaci mechanizmusok veszik át az állami gazdaságpolitika szerepét; a globális kormányzás megvalósulása esetén a szuverén nemzetállamok tűnnek el a nemzetközi rendszerből; végül a Bretton Woods kompromisszum esetében a globalizáció útjába állítunk akadályokat. Írásunkban a modellt az európai integrációra, egészen pontosan a Gazdasági és Monetáris Unióra alkalmazzuk. Érvelésünk szerint, ha fent kívánjuk tartani az integráció szorosságát, erősíteni kell az integráció szintjén a gazdasági kormányzást, ami pedig csak a tagállami szuverenitás rovására mehet. Ez, mely a GMU esetében leginkább a fiskális föderáció erősítését jelenti ugyanakkor, megnövelve az integráció költségeit, egy többsebességes Európa kialakulása irányába hathat. _____ The European Union with its sophisticated institutional system is the most important regional integration on Earth. This tight form of economic integration converges to the level that Dani Rodrik calls hyperglobalization in his model, the political trilemma of globalisation. In this model Rodrik assumes that from the three desired element of world politics (deep economic integration, the nation state, and democratic politics) only two can be chosen. We can either choose deep integration and the nation state but then we have to abandon democracy; or we can choose deep integration and democracy, but then we have to forfeit the nation state; or we have to circumscribe globalisation to maintain democracy and the nation state. In our paper we develop the mentioned model and then we apply it to the case of the European integration. We argue that if we want to maintain the deep integration among member states in the EU we have to pass more and more functions of the nation states to the federation level. In case of the EMU that means that federal fiscal policy is needed which could lead to multi-speed Europe considering new member states reluctance to give up their specific institutions.

Modelos flexíveis de sobrevivência com fração de cura: implementação computacional

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effetto delle condizioni ambientali nella presenza di Escherichia coli in vongole lupino (Chamelea gallina L.)

Lo scopo di questo elaborato è stato individuare una possibile correlazione tra le condizioni ambientali e la presenza di Escherichia coli in vongole lupino. I dati relativi a campioni raccolti nel periodo 2008-2015 nella zona tra Cervia e Fano sono stati messi in relazione con alcuni parametri quali salinità dell’acqua, temperatura, ossigeno di fondo, pH e livello del fiume Marecchia. Sono stati presi in considerazione oltre 350 campioni, in cui i conteggi di E. coli mediante tecnica MPN sono stati suddivisi in tre categorie: cariche basse (<50 MPN/100g); cariche intermedie (50-230 MPN/100g); cariche alte, ossia non conformi al regolamento europeo (>230 MPN/100g). L’eventuale significatività della relazione tra E. coli e le variabili considerate è stata valutata attraverso il test chi-quadrato e il test di Kruskal-Wallis. Per quanto riguarda il test chi-quadrato, eseguito in relazione ad anno, mese e stagione, si è visto che i campioni più inquinati derivano dagli anni 2010 e 2012, dai mesi novembre/dicembre e in generale dalla stagione autunnale. L’analisi della varianza tramite test di Kruskal-Wallis ha evidenziato che le frequenze dei campioni nelle tre categorie non sono significative in relazione alla salinità. Al contrario, per i parametri temperatura e livello del fiume Marecchia sono stati ottenuti risultati significativi: infatti, le cariche microbiche più alte corrispondono a temperature più basse delle acque e a periodi di maggiore portata del fiume. Questo episodio riflette sicuramente un aspetto biologico legato al ciclo vitale di Chamelea gallina, che vive la sua fase riproduttiva nella stagione più calda, diminuendo quindi la sua attività filtrante, fonte di contaminazione. Al contempo questo andamento è anche spiegabile dall’apporto di contaminanti dalle precipitazioni e dai fiumi che trascinano sostanze organiche inquinanti di natura antropica, che costituiscono fonte di nutrimento per le specie microbiche come E. coli ed altri enterobatteri.

Meiofaunal abundance, biomass, taxon richness and indices of nematode diversity of samples from the Santa Maria di Leuca Bank (southern Adriatic margin)

Deep-water coral ecosystems are hot spots of biodiversity and provide habitats and refuges for several deep-sea species. However, their role in shaping the biodiversity of the surrounding open slopes is still poorly known. We investigated how meiofaunal biodiversity varies with and is related to the occurrence of deep-water living scleractinian corals and coral rubble in two deep-sea areas (the Rockall Bank, northeastern Atlantic) and the Santa Maria di Leuca (central Mediterranean). In both areas, replicated sampling on alive and dead coral areas and from the adjacent slope sediments without corals (at the same and increasing depths) allowed us to demonstrate that sediments surrounding the living corals and coral rubble were characterised by higher meiofaunal biodiversity (as number of higher taxa, and nematode species richness) than the slope sediments. Despite the soft sediments surrounding the living coral having a higher nutritional value than those not associated with corals, with the opposite seen for coral rubble, the presence of both alive and dead corals had a significant effect on nematode assemblages. Our data suggest that, due particularly to the effects on habitat heterogeneity/complexity, both living coral and coral rubble promoted higher biodiversity levels than in surrounding slope sediments. We conclude that the protection of deep-water corals can be crucial to preserve the biodiversity of surrounding open slopes, and that the protection of dead corals, a so-far almost neglected habitat in terms of biological conservation, can further contribute to the maintenance of a high deep-sea biodiversity along continental margins.