Achieving the Dispatchability of Distribution Feeders through Prosumers Data Driven Forecasting and Model Predictive Control of Electrochemical Storage

We propose and experimentally validate a control strategy to dispatch the operation of a distribution feeder interfacing heterogeneous prosumers by using a grid-connected battery energy storage system (BESS) as a controllable element coupled with a minimally invasive monitoring infrastructure. It consists in a two-stage procedure: day-ahead dispatch planning, where the feeder 5-minute average power consumption trajectory for the next day of operation (called \emph{dispatch plan}) is determined, and intra-day/real-time operation, where the mismatch with respect to the \emph{dispatch plan} is corrected by applying receding horizon model predictive control (MPC) to decide the BESS charging/discharging profile while accounting for operational constraints. The consumption forecast necessary to compute the \emph{dispatch plan} and the battery model for the MPC algorithm are built by applying adaptive data driven methodologies. The discussed control framework currently operates on a daily basis to dispatch the operation of a 20~kV feeder of the EPFL university campus using a 750~kW/500~kWh lithium titanate BESS.Comment: Submitted for publication, 201

Advanced models and algorithms to provide multiple grid services with battery storage systems

Battery energy storage systems (BESSs) are expected to play a major role in the power grid of the near future. These devices, capable of storing and returning electrical energy, are valuable assets to a grid that integrates more and more distributed, intermittent and renewable generation. Compared to renewable energy sources, however, battery storage systems are still in an early stage of deployment and the way to exploit them in an optimal way is still subject of research. In this respect, this thesis develops two lines of investigation to reach an optimal utilisation of these devices. In its first part, the thesis proposes a control framework to operate a utility-scale BESS connected to a distribution feeder. This control framework allows to provide a set of services: dispatch of the operation of such feeder, load levelling, frequency response. It is structured in a period-ahead and a real-time phase. The former plans the BESS operation for a given time horizon through the solution of optimization problems. These take into account the BESS state of energy as well as forecast scenarios of quantities such as the feeder prosumption and of the BESS energy needs due to the frequency response service. The real-time phase determines the BESS power injections a resolution as fast as 1 second and, in the case of the dispatch, relies on model predictive control. Moreover, the thesis proposes the formulation of a framework for the simultaneous deployment of multiple services. The objective of this is to maximise the BESS exploitation in the presence of uncertainty. All the proposed methods are validated experimentally, on the 560 kWh/720 kVA BESS installed on EPFL campus. This extensive validation demonstrates their effectiveness and deployability. In its second part, the thesis discusses the integration of electrochemical models in the control of BESSs. Such models, compared to more conventional equivalent circuits or empirical ones, can provide deeper insight in the processes occurring within Li-ion cells - the founding elements of BESSs - and by consequence a more effective operation of BESSs. The thesis proposes a method to identify the parameters of one of such models - the single particle model - and, again, validates it experimentally. Moreover, in its final chapter, the thesis provides a proof-of-concept by simulations of the advantages of the integration of electrochemical models in the control framework proposed in its first part and, in general, in BESS control

Nuevos complejos de Ga(III): síntesis, identificación estructural y propiedades biológicas

En la búsqueda de nuevos compuestos que reduzcan las limitaciones terapéuticas de las sales de Ga(III), se abordó la síntesis, caracterización estructural y el estudio de algunas propiedades biológicas de nuevos compuestos de coordinación de Ga(III), utilizando semi- y tiosemicarbazonas como ligandos. Usando disolventes polares próticos, tiempos moderados de reacción y calentamiento a reflujo se sintetizaron las semicarbazonas de los ácidos pirúvico (H2PSC), 2-cetobutírico (H2CBSC), 3-metil-2-oxo-butanóico (H2IPSC), benzoilfórmico (H2BFSC), α-oxo-furanacético (H2αOFSC) y 3-indolglioxílico (H3INSC); la semicarbazona del salicilaldehído (H2SSC), del 2,4-dihidroxibenzaldehído (H3XSSC), del 2-hidroxi-1-naftaldehído (H2NAFSC), de la di-2-piridilcetona (HBIPSC), y las bis-semicarbazonas del 4-tert-butil-2,6-diformilfenol (H3DBZSC) y de la 2,6-diacetilpiridina (H2DAPSC). Del mismo modo, se obtuvieron las tiosemicarbazonas del ácido α-oxo-furanacético (H2αOFTSC), del ácido 3-indolglioxílico (H3INTSC), del salicilaldehído (H2STSC), del 2,4-dihidroxibenzaldehído (H3XSTSC), 2-hidroxi-1-naftaldehído (H2NAFTSC), de la 2-acetilpiridina (HAPTSC), y las bis-tiosemicarbazonas del 4-tert-butil-2,6-diformilfenol (H3DBZTSC) y de la 2,6-diacetilpiridina (H2DAPTSC). Estos compuestos fueron caracterizados por análisis elemental, espectroscopia IR y resonancia magnética nuclear de 1H y 13C. Además, se obtuvieron cristales adecuados para su estudio por difracción de rayos X de monocristal en el caso de los compuestos H2PSC, H2CBSC, H2IPSC, H2αOFSC, H2αOFTSC, H3INSC, H2SSC, H2STSC, H3XSSC, H3XSTSC, H2NAFSC, HBIPSC, H2DAPSC, HAPTSC y H2DAPTSC. En condiciones similares a las utilizadas para obtener los ligandos, y con una relación molar ligando/metal 1:1 con las sales Ga(NO3)3·H2O, GaCl3 y GaCl(ACO)2, se sintetizaron los compuestos Ga(HPSC)(PSC), Ga(HBFSC)2Cl, Ga(HBFSC)(BFSC), Ga(HBFSC)Cl2, Ga(HαOFSC)2Cl, Ga(HαOFTSC)2(NO3)·3H2O, Ga(H2INTSC)2Cl, Ga(H2XSSC)(HXSSC), Ga(H2XSSC)2Cl·4H2O. Además, se obtuvieron en forma de cristales adecuados para su estudio por difracción de rayos X de monocristal los complejos [Ga(HαOFSC)(bipy)H2O](NO3)2·1.6H2O [Ga(HCBSC)(CBSC)], [Ga(HαOFSC)(H2O)2Cl]Cl, [Ga(HαOFSC)(αOFSC)], [Ga(H2INSC)2]NO3·2EtOH·1/5H2O, [Ga(HαOFTSC)(αOFTSC)]·(H2O), [Ga(HSSC)2]NO3·MeOH, [Ga(HSSC)2]Cl·H2O, [Ga(H2XSSC)2]NO3·EtOH, [Ga(H2DBZSC)2]Cl·H2O, [Ga(HNAFSC)2]Cl·2.25H2O, (H2BIPSC)2 [GaCl4]Cl, [Ga(HDAPSC)(H2O)2](NO3)2·H2O, [Ga(APTSC)Cl2], [Ga(APTSC)2]NO3, [Ga(H2DBZSC)(HDBZSC)]·H2O y [Ga(1,10-fen)2Cl2]Cl·3H2O. Su caracterización se completó mediante análisis elemental, espectroscopia IR y RMN 1H y 13C. Para algunos de los ligandos y compuestos de coordinación se realizaron pruebas de citotoxicidad con la línea celular HeLa-229

Quantification of Primary Frequency Control Provision from Battery Energy Storage Systems Connected to Active Distribution Networks

In this paper, we consider the provision of primary frequency control by using battery energy storage systems (BESSs). In particular, we use a standard droop-based frequency control for a BESS where the control action (i.e. the BESS power output) consists in the contribution of two additive terms: the regulating power, proportional to the frequency deviations, and an offset term computed to manage the BESS State-of-Energy (SOE). In the context of such a control scheme, we propose a method to forecast the BESS energy for regulation needs and we show that the inclusion of such a forecast can increase the regulating power provision. Finally, we demonstrate the performance of the proposed approach by means of a real-scale experimental setup composed by a grid-connected 720 kVA/560 kWh BESS installed at the EPFL campus in Lausanne, Switzerland

1,3,5-Triaza­adamantan-7-amine

The title compound, C7H14N4, represents the first structurally characterized, isolated triaza­adamantane. In the crystal structure, weak inter­molecular N—H⋯N hydrogen bonds link the mol­ecules into columns about the crystallographic fourfold axis

Battery Storage System Optimal Exploitation Through Physics-Based Model Predictive Control

Traditionally, the safe operation of a battery energy storage system (BESS) is achieved by imposing conservative constraints on its DC bus current and voltage. By using a computationally efficient single particle model (SPM), we propose to replace these constraints with the battery internal ion concentrations and electrical potentials in order to avoid these quantities to exceed hazardous limits. Indeed, the in-depth knowledge of the BESS internal states provided by the SPM, enhances the awareness of a control action and allows for a better exploitation of the BESS energy and power capabilities, while maintaining safe operational conditions. The target application is composed by a model predictive control (MPC) applied to a MW-class grid-connected BESS responsible to dispatch the operation of a medium voltage (20 kV) feeder interfacing heterogeneous loads and distributed generation. The performance of the proposed MPC are assessed and compared with respect to a traditional approach constraining the BESS DC bus current and voltage

Assessment of Battery Ageing and Implementation of an Ageing Aware Control Strategy for a Load Leveling Application of a Lithium Titanate Battery Energy Storage System

The manuscript describes a method to embed into a battery energy storage system (BESS) control strategy the performance degradation associated with the battery operation. In particular, the proposed method aims at minimizing the degra- dation of the BESS electrochemical cells. A load leveling strategy is described as a case study and the ageing effects associated with the battery current extraction are embedded as constraints into the optimization problem. The main contributions of the work, compared to the existing literature are: i) the degradation process is formulated as a weighted energy throughput, thus taking into account the C-rate effect on the degradation phenomena; ii) the performance of the proposed control strategy has been applied to a large scale lithium-titanate BESS of 280 kWh interfaced to a 20 kV active distribution network

Improvement of Dynamic Modeling of Supercapacitor by Residual Charge Effects Estimation

The paper presents a set of experimental investigations related to the dynamic behavior of supercapacitors. The experimentally observed results are then used as inputs for the development of an improved version of one of the most common supercapacitor RC-equivalent circuit models. The key improvement concerns the accurate modeling of the diffusion phenomenon of the supercapacitor residual charge during charging/discharging and rest phases. The experimental procedure needed for evaluating the parameters of the proposed model is also given. The accuracy of the obtained model is, then, experimentally validated for different cycles characterized by different dynamics