Experimental Analysis of a Zebra Battery Based Propulsion System for Urban Bus under Dynamic Conditions

Abstract In this paper preliminary results on a Zebra battery based propulsion system for urban bus applications are presented. The analysis is carried out with the support of a laboratory 1:1 scale test bench, focusing the attention on a 65 kW electric drive, specifically designed for urban bus applications, supplied by two 20 kWh Zebra batteries working in parallel. The electric power train is connected, through a fixed ratio gear box, to a 100 kW regenerative electric brake provided with speed and torque controls, in order to evaluate the propulsion system performance in steady state and dynamic operative conditions. On the base of the architecture of a urban bus, powered by the same electric propulsion system studied in laboratory, a Matlab-Simulink model has been carried out to assess the dynamic behavior of the full electric urban bus and also other possible hybrid configurations, working on standard and real driving cycles, taking into account the resistant forces represented by proper vehicle/road/aerodynamic parameters. For the above configurations an evaluation of the expected real vehicle performance, in different operative road conditions, can be validated through the laboratory dynamic test bench

Laboratory Bench to Test ZEBRA Battery Plus Super-Capacitor Based Propulsion Systems for Urban Electric Transportation

Abstract In this paper a laboratory 1:1 scale test bench to perform experimental analysis on a Zebra battery plus super-capacitor based propulsion systems for electric urban transportation means is presented. The analyzed case study is focused on a 70 kW electric drive, specifically manufactured for electric urban road applications, supplied by a parallel of two 550 V - 38 Ah Zebra batteries and a 63 F super-capacitors bank. The electric power train is connected, through a fixed ratio gear box, to a 100 kW regenerative electric brake provided with speed and torque controls, in order to evaluate the propulsion system performance in steady state and dynamic operative conditions. The two different storage systems can be tested when working together and providing the required power to the electric drive, with different contributions by each storage device in terms of electric energy and power. In addition, different control strategies can be experimentally evaluated, depending on the tested driving cycle and with reference to a specific vehicle under study. For the above configuration, an evaluation of the real vehicle performance, in various operative road conditions, can find a validation through this laboratory dynamic test bench. Finally, this experimental procedure to characterize and study electric power trains supplied by different kinds of storage systems highlights the real potentialities for manufacturers of electric vehicle in taking advantage of laboratory experimentations on the electric power-train, in order to support their design processes. The content of this paper represents a knowledge base to carry out experimental results, which are object of following studies

Integration between Super-capacitors and ZEBRA Batteries as High Performance Hybrid Storage System for Electric Vehicles

Abstract This paper presents experimental evaluations on the performance of a hybrid energy storage system to supply urban electric vehicles. The paper starts with a description of nickel chloride batteries and electric double layer capacitors with details on their related advantages. Then, a laboratory test bench is presented to experimentally evaluate the performance of the realized hybrid storage system, obtained through a controlled DC/DC bidirectional power converter, supplying an electric power-train in real operative conditions on standard driving cycles. The main results of this study shows the importance of using that power converter to take advantage of the power characteristics of the super-capacitor and to easily implement on board energy management strategies to increase the whole vehicle performance

New light on bacterial carbonic anhydrases phylogeny based on the analysis of signal peptide sequences.

Among protein families, carbonic anhydrases (CAs, EC 4.2.1.1) are metalloenzymes characterized by a common reaction mechanism in all life domains: the carbon dioxide hydration to bicarbonate and protons (CO2+H2O HCO3(-)+H(+)). Six genetically distinct CA families are known to date, the alpha-, beta-, gamma-, delta-, zeta- and eta-CAs. The last CA class was recently discovered analyzing the amino acid sequences of CAs from Plasmodia. Bacteria encode for enzymes belonging to the alpha-, beta-, and gamma-CA classes and recently, phylogenetic analysis revealed an interesting relationship regarding the evolution of bacterial CA classes. This result evidenced that the three bacterial CA classes, in spite of the high level of the structural similarity, are evolutionarily distinct, but we noted that the primary structure of some beta-CAs identified in the genome of Gram-negative bacteria present a pre-sequence of 18 or more amino acid residues at the N-terminal part. These observations and subsequent phylogenetic data presented here prompted us to propose that the beta-CAs found in Gram-negative bacteria with a periplasmic space and characterized by the presence of a signal peptide might have a periplasmic localization and a role similar to that described previously for the alpha-CAs

DC Charging Station for Electric and Plug-in Vehicles

AbstractThis paper is focused on the evaluation of theoretical and experimental aspects related to the different operation modes of a laboratory power architecture, which realizes a micro grid for the charging of road electric and plug-in hybrid vehicles. The analyzed power configuration is based on a DC bus architecture, which presents the main advantage of an easy integration of renewable energy sources and buffered storage systems. A first phase of simulations is aimed to evaluate the main energy fluxes within the studied architecture and to identify the energy management strategies, which optimize simultaneously the power requirements from the main grid and charging times of different electric vehicles. A second phase is based on the experimental characterization of the analyzed power architecture, implementing the control strategies evaluated in the simulation environment, through a laboratory acquisition and control system. Then the experimental results coming from the laboratory prototype are compared with the simulation results, in order to achieve a better parameter setting of the simulation model for the analyzed structure. This preliminary analysis makes possible other simulations to be carried out on more complex architecture of micro-grids, taking into account the integration of renewable energy sources and high power buffer storage systems. Particular attention is also given to the analysis of ultra-fast charging operations and the related performance in terms of total efficiency, charging times, total power factor and power requirements from the main grid. This study represents a further step toward the new concept of smart grid scenario for electric vehicles

Design of a Hybrid Propulsion Architecture for Midsize Boats

Abstract This paper presents preliminary evaluations on the design of hybrid propulsion architectures related to midsize boats. The analysis is carried out for the case study of a retrofit operation proposed for an oceanographic ship, which is used by the researchers of the National Research Council of Italy for experimental campaigns in the Mediterranean Sea. Starting from the information obtained on the existing architecture by means of various on-board inspections, an experimental set-up is proposed for the monitoring and acquisition of the main electrical and mechanical parameters of the ship, during her navigation campaigns. Different possible hybrid configurations are also proposed, identifying the main advantages and drawbacks of each configuration for the considered application. The proposed set-up allows obtaining experimental information, about the behaviour of the ship in a large variety of operative conditions, which will be useful to support the choice of a proper hybrid propulsion architecture and the optimal design of components

optimal control strategy of ultra capacitors in hybrid energy storage system for electric vehicles

Abstract This paper describes a novel Energy Management Strategy (EMS) for hybrid energy storage systems, when used to supply urban electric vehicles. A preliminary off-line procedure, based on nonlinear programming, is performed in order to optimize the battery current profile for fixed working cycles. Hence, a suitable control strategy, which is based on a constrained minimization problem, is tailored for real-time applications. This control strategy exploits the off-line solution of a proper isoperimetric problem and aims to dynamically optimize the battery durability by reducing peak charging/discharging current values. The main advantage of the analysed EMS consists in the easy on-board implementation through the use of one single parameter, which can be quickly identified through a simple off-line numerical procedure. The proposed strategy is evaluated in simulation environment, through the use of a Matlab-Simulink model, for the case study of an urban electric vehicle running on a ECE 15 driving cycles. Simulation results have confirmed the good performance of the above strategy in reducing the battery peak charging/discharging current through the proper management of the hybrid energy storage system

Charging Architectures Integrated with Distributed Energy Resources for Sustainable Mobility

Abstract This paper introduces a study on the charging infrastructures, integrated with distributed energy sources, showing their ability to support the electric and hybrid mobility in a smart grid scenario. This analysis starts from a description of the main AC and DC architecture and then goes through the advantages derived by the integration of renewable energy sources within the existing electric power network. A section of this paper is then dedicated to the main technologies of energy storage systems, which allow and support the integration of unpredictable energy sources into the grid. Finally, the power on-board and off-board vehicle charging devices are analyzed with specific focus on PWM control schemes, for the regulation of AC/DC and DC/DC power converters, and on grid operations (V2G) related to different aggregation schemes

Protonography, a new technique for the analysis of carbonic anhydrase activity.

All proteolytic enzymes, which are able to renature and reacquire the proteolytic activity on a copolymerized substrate, can be analyzed by zymography upon removal of sodium dodecyl sulfate (SDS). Protonography, the new technique described in this study, unlike zymography, allows the detection of a different protein, not a protease, i.e. of the carbonic anhydrase (CA, EC 4.2.1.1) activity on a SDS polyacrylamide gel electrophoresis gel. CAs are zinc-containing enzymes that catalyze the reversible conversion of carbon dioxide to bicarbonate and protons. Hydrogen ions produced during the catalyzed reaction are responsible for the change of color that appears on the gel around the CA band. For this reason, we named the new technique "protonography". The following four salient features characterize this new technique: (a) on the basis of molecular weight markers, recombinant or native CAs with different molecular weights can be detected and quantified rapidly on a single gel; (b) the hydratase activity can be reversibly inhibited by SDS during electrophoresis and recovered by incubating the gel in aqueous Triton X-100; (c) it is possible to separate active oligomeric forms of CAs on the gel enabling their activities to be determined independently of one another. This feature is not possible when using solution assays; and (d) it can be a useful tool to establish if a putative or a newly identified CA in a genome is expressed and enzymatically active. This article outlines the general principles employed in protonography, providing an easy procedure to implement it in laboratories working with CAs. It also presents an overview of its development and current research applications through specific examples