Giovanni Lutzemberger

Experimentally-Determined Models for High-Power Lithium Batteries

Lithium batteries are increasingly being considered for installation as power sources in electric and hybrid vehicles, because of their high specific energy and power. To effectively size the vehicle Rechargeable Energy Storage System, it is very important to be able to mathematically model their behaviour. Battery modelling is also very useful for on-line management of electric and hybrid vehicles. This paper presents a dynamic model of lithium batteries based on experimental tests on high power Lithium-polymer models. The results can be adapted, with suitable parameter evaluation, to other lithium batteries as well.

High power Lithium Batteries usage in hybrid vehicles

Hybrid vehicles require an energy storage device capable of delivering or absorbing high specific powers (powers per unit of the device size), and still, in some cases, adequate levels of specific energy.

Systematic development of series-hybrid bus through modelling

With increasingly stringent regulations on fuel emissions, vehicle manufacturers have started developing hybrid and electric versions of their vehicles. This paper presents a systematic approach to developing series-hybrid version of an existing bus through power-train modelling. The approach involves accurate modelling of the conventional bus, validating it by matching the simulation results with the tests conducted on the actual bus, and then developing the hybrid version of the bus.

Use of electrochemical storage in substations to enhance energy and cost efficiency of tramways

This paper evaluates, in a case study with real data, the advantages of using regenerative braking in a tram line, both in case of non-reversible substations and substations equipped with battery energy storage. It shows that the addition of storage enhances energy efficiency a lot, and therefore this is a very cost-effective solution.

Control strategies and real time operation of storage systems integrated with MV photovoltaic plants

Nowadays the increasing share of renewable sources requires a direct participation of all form of generation to the secure operation of the electric power system, at least in terms of power balancing and voltage regulation. Resiliency, controllability and flexibility are the key factors that characterize a smart grid, compared to traditional energy systems. In this regard, storage systems can be used to provide the grid with a large range of services, such as frequency and voltage regulation, short-term power reserve and power quality. Nevertheless, persistent power modulation can originate a progressive drift of the battery State of Charge, thus reducing the real exploitability of the storage system for other scheduled energy services, like load levelling. This paper describes in a systematic approach a novel control architecture, in which an external loop aimed to compensate the SOC drift, in addition to the conventional frequency droop regulation, has been implemented and tested on an existing MV photovoltaic plant integrated with energy storage.

Modelling and simulation of electric urban transportation systems with energy storage

Electrified guided vehicles are normally equipped with regenerative braking devices, while traction lines are supplied by non-reversible substation, thus allowing braking energy recovery only if nearby other vehicles are absorbing power. To enhance the effectiveness of regenerative braking, some energy storage can be installed along the line. Evaluation of its cost effectiveness requires time domain simulations, performed creating simulation models using general-purpose or specialized simulation languages. In this paper, two simulation tools are used. Their respective characteristics compared. The results obtained from both of them are also useful to evaluate the effectiveness of energy storage in a real-life urban case study.

Cost effective storage for energy saving in feeding systems of tramways

This paper evaluates the cost effectiveness of using regenerative braking in a tram line in case of non-reversible substations equipped with battery energy storage. It shows, by the combination of results by numerical simulation model and experimental tests, how it is possible to effectively transform an existing tramway to improve its energy efficiency. Results have shown that also from the economical point of view the proposed solution can be of great interest for the transport company wishful to update its system technology.

A novel human-machine interface for working machines operation

The future of working machines winks to semi autonomy and latest technological aids to improve the quality of operations as well as the easiness of specific tasks execution. This field can take great advantage of latest human-machine interface (HMI) technologies that has been applied in the last years in field like virtual environments and robotics. The present paper discusses a novel approach for interactive operation of working machines. The approach combines traditional controls with visual/vision and haptic interactions. A wearable projection system has been introduced with the purpose of describing a wide set of localized commands recognized by the systems vision module. A preliminary setup has been developed using a simplified demonstration platform. A test session applied to a manipulation robot is presented to evaluate the performance of the proposed solutions in terms of task effectiveness, neglect tolerance, interaction effort and usability of the human-machine interface.

Impact of a large fleet of EVs on the efficiency and reliability of an electric power system

The influence of electric vehicles on the power system has been traditionally analyzed in terms of recharge infrastructures and adequacy of the electric distribution network. Nevertheless, the additional power demand due to the recharge of a large number of batteries could significantly modify the national load profile, hence the dispatching of production plants. The recent literature approaches this issue using deterministic methods or simplified probabilistic considerations. In this framework, the present paper proposes the use of a Monte Carlo probabilistic approach to assess the impact of large fleet of EVs on the efficiency and reliability of the generating park of an electric power system. A Sequential Monte Carlo simulator has been developed and applied to the hourly operation of the Italian power system. Several 2020 scenarios, diversified in terms of number of vehicles and recharge timing, have been assumed for the future fleet of EVs. The study was mainly realized within the PRIME project, funded by the Italian Ministry for the Environment.

Optimal storage operation in EV charging stations delivering grid services

This paper presents criteria for the optimal operation of an EV charging station, capable of providing the grid with regulation services such as frequency and voltage control, peak shaving, and load leveling. The presence of an additional storage device connected to the charging station is investigated; both configurations are analyzed in which the storage device of each vehicle contributes to such services and in which the charging profile is independently imposed by the vehicle charging control system.