MC's PlotXY—A general-purpose plotting and post-processing open-source tool

MC's PlotXY, in the following just called PlotXY, is a free piece of software able to make line plots and bar charts from data deriving from measuring devices or simulation programs using several formats. It allows to visualize and post-process these data without the need to have on the target computer the original software that generated it. It was written from the ground-up having researchers and scientists in mind, and therefore is optimized for speed, clarity, soundness.Its special characteristic distinguishing it from the large base of existing plotting software is its flexibility: using this small piece of software, the user can do plotting and post-processing activities on the results obtained from other sources (simulation software or measuring devices) without having these sources installed on the computer where post-processing is made.Moreover, it allows reading file formats rarely available on non-specific software, such as ATP, Comtrade, LabView formats. Although the support of some of these formats is not complete, being the software open-source, anyone can contribute to expanding them, operating on just a single cpp file.It is developed using the Qt platform, which allows good GUI design, and already available for Windows, Macintosh, and Linux systems.This paper describes the software characteristics and some programming techniques used to develop it. Keywords: Line chart, Bar chart, Post-processing, Fourier series, Matlab, Lab-view, ATP, ASCI

Aging evaluation of high power lithium cells subjected to micro-cycles

A typical operating condition of storage batteries requires to deliver and absorb small currents in large intervals of time, in order of minutes or hours. However, in the last years lithium batteries have been more and more considered in "power oriented" applications, in which they are required to manage large currents in short intervals of time, typically a few seconds or tens of seconds. Unfortunately, very limited information about this kind of usage is available in literature, in terms of battery performance and aging. Therefore, the paper focuses firstly on the experimental evaluation of performance of high power and super high power lithium batteries also in comparison to other power oriented storage systems adequate for use onboard hybrid vehicles, such as supercapacitors (SCs). The evaluation has been performed through experimental tests. Results have shown that these batteries are able to guarantee significant performance, even higher than data declared by manufacturer, with slight over-temperature.Then, for high power lithium batteries aging is discussed, when they are subjected to shallow-depth charge/discharge cycles. The aim is to evaluate if the battery life corresponding to such micro-cycles can reach several hundreds of thousands that are required for applications such as hybrid vehicles and hybrid stationary generation systems. Also in this case experimental tests able to prove it have been executed. They have shown a substantially unaltered capacity fade during the execution of hundreds of thousands of micro-cycles, thus confirming the vocation of these devices for power-oriented applications

Regenerative braking in high speed railway applications: analysis by different simulation tools

Technical investigations continuously evaluate the possibility to recover significant amount of braking energy. The application normally involve conventional tramways, characterized by several stops in short-range routes. However, this possibility is becoming more and more attractive also when high-speed trains are considered. In fact, braking energy can be recovered during entry in the station, and delivered later to other trains engaged in starting acceleration. In this work, authors propose an approach based on simplified models performed with object-oriented tools as Modelica or Matlab-Simscape, which easily introduce several advantages in modelling and simulation techniques. The approach has been applied to the preliminary evaluation of one energy storage system installed along a DC line, considering a high-speed train with distributed traction power as the new Italian ETR 1000

Hybridisation of forklift trucks

In the past years, forklift manufacturers have started to hybridise their products under the worldwide interest toward electrification. This is generally made starting from existing standard products, and converting them into hybrid versions, rather than start from scratch and designing fully new vehicles. This approach involves several gaps from the inaccurate evaluation of the powertrain architecture and relative energy management strategy, up to a rough sizing of components. Therefore, this study suggests a structured methodology to follow, aimed to properly design hybrid forklift trucks. The first step is the analysis of the conventional working machine to hybridise, identifying one set of duty cycles. Then, the design of the new powertrain architecture, with a proper energy management strategy, and the definition of a numerical simulation model realised through a multiphysics object-oriented software package, to properly size the new powertrain components, and to verify energy and power flows. Finally, it is also presented a brief-cost–benefit analysis, as last verification of the proposed methodology, to verify the cost-effectiveness to bring the new products to the market. Results have shown the general feasibility of the operation since the significant reduction in fuel consumption is combined with sustainable costs of the new electrified components

La trazione ferroviaria - I sistemi a guida vincolata

Nell'ambito del volume, che affronta molteplici temi relativi alla trazione elettrica ferroviaria, il capitolo trattato dal prof. Ceraolo riguarda i sistemi di accumulo dell'energia elettrica. Si concentra prevalentemente sull'accumulo in forma elettrochimica e in supercondensatori. Fornisce elementi di confronto fra le varie tipologie e suggerimenti per la realizzazione di accumuli ibridi. Tratta anche della loro modellazione matematica e illustra di alcune applicazioni significative

Long duration simulations of railway AC Electrified lines

Simulation models must have a level of detail congruent with the prescribed goals and considered time span. Electrified railway lines require simulating trains during their typical trips, with acceleration and braking transients lasting at least several seconds or some minutes;. On the other hand, AC lines have quantities (voltages, currents) which vary much faster, e.g. at 50 or 60 Hz. This paper discusses how to model railway electric supply networks with a complexity adequate for long-run simulations, while still having good precision and details on the results. In particular, it discusses the usage of hybrid models combining the use of complex impedances for the supply system with dynamic models of trains. It also discusses the use of supply line models having a reduced number of conductors to make them smaller and faster to simulate, without loss of precision. The proposed techniques are implemented in models written in the Modelica simulation language, and results are shown, which compare precision and computational efficiency of models using the proposed technique with others built in a more conventional time-domain way