Giovanni Pede

Techniques for estimating the residual range of an electric vehicle

This paper presents an algorithm that has been developed to estimate the residual range of an electric vehicle, i.e., the distance that can still be covered with the energy stored inside the battery. The algorithm takes into account the complexity of the behavior of electrochemical batteries, with special reference to lead-acid batteries, as well as the main issues related to different driving styles. This paper also discusses some of the experimental results obtained by the use of the algorithm in several urban test trips made using two different types of electric vehicles.

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.

Compressed hydrogen fuelled vehicles : Reasons of a choice and developments in ENEA

Some recent achievements in the field of high pressure vessels and safety devices have offered a concrete chance to the application of compressed hydrogen for fleet commercial vehicles for urban use. Accordingly with this concept, ENEA has modified a Fiat Ducato van with a dual fuel engine, retaining the gasoline tank for long distance travelling and adopting the external mixture formation technique, with hydrogen injectors developed by ENEA, for non-polluting short-range duties in urban traffic. The article deals with the rationale for this choice and gives a general view of the project.

Assessment of high power HEV lead-acid battery advancements by comparative benchmarking with a European test procedure

Abstract The technical and practical suitability of lead-acid batteries for applications in vehicles with electrical drivetrains (battery-powered or hybrid electric) has been experimentally investigated in a variety of testing programmes. Under the direction and funding support of the Commission of the European Community, since early 1990s, the R&D Organisation EUCAR, a collaborative partnership of most European car manufacturers, has been conducting battery technological assessment projects, through bench tests carried out by different independent laboratories throughout Europe, using agreed test procedures. In this framework, ENEA acted as independent testing institute and tested, among others, three high power lead-acid batteries of various technologies (flat plate electrodes and spiral wound) for EV and HEV applications. In addition, different battery sizes and operating conditions have been tested at ENEA in a separate collaboration with ALTRA-IRISBUS. This paper intends to trace technological and performance improvements of high power lead-acid battery technology through the analysis of experimental data during parameter and life cycle tests, including the effects of battery sizes, charge/discharge profiles and testing procedures, with special emphasis on the reduction of the internal resistance and the variation of peak power and cycle life.

Test of blends of hydrogen and natural gas in a light duty vehicle

Hydrogen-enriched combustion has been studied by several institutions and companies over the last three decades. The purpose of adding hydrogen to conventional fuels is to extend the lean limit of combustion because hydrogen improves flame stability and allows a lower temperature combustion. Even with stoichiometric mixture, HCNG advantages had been demonstrated, since blends determine a reduction of noxious emissions. In the framework of an EU project called BONG-HY, bench tests with HCNG on a natural gas vehicle had been carried on at ENEA. Results of lab tests show a fair improvement of the efficiency and CO2 emissions as well as an overall improvement regarding local pollutants.

Design of the battery management system of LiFePO 4 batteries for electric off-road vehicles

This paper describes the design of a modular battery management system for electric off-road vehicles, where lithiumion batteries are expected to be widely used. A massive electrification of off-road vehicles can be enabled by the availability of a standard battery module, provided with an effective management unit. The design and some preliminary experimental results of the module management unit are discussed in this paper. The unit contains a high current active equalizer that enables the dynamic charge equalization among cells and maximizes the usable capacity of the battery.

Life cycles test on a lithium battery system

The topic of the paper is the life cycles test on a lithium battery system 288 V-40 Ah, 11,5 kWh. The test procedure tries to simulate the typical utilization of an electric vehicle: the batteries are discharged by means of a typical profile in urban and suburban context and charged by means of traditional charges and fast charges alternatively. In this way it is possible to simulate the utilization of a driver who uses the electric vehicle and charges the batteries at home (traditional charge) or at a public charging point (quick charge). These tests permit to identify and understand possible problems of the storage system under quick charge and discharge cycles, as well as to define how the performances decrease during the operation. The paper shows the details of the battery system under test, the complete test procedure and the results in terms of reduction of the global performances (life determination as number of cycles) and behavior of the single cells (unbalancing).

Lithium-ion starting-lighting-ignition batteries: Examining the feasibility

Rapid developments in the lithium-ion battery technology in the last decade have made it the overwhelming choice over lead-acid batteries, especially for advanced vehicles like hybrid and electric vehicles. However, for the traditional starting-lighting-ignition (SLI) application, the lead-acid technology continues to be dominant due to its low costs, despite its shortcomings. This could change in the future as a consequence of the introduction of newer, cheaper and safer lithium technologies. This paper examines the feasibility of using lithium-ion batteries for SLI application in conventional vehicles, over the lifetime of the vehicle, along with their battery management and thermal management systems and various related issues.

Energy management in hybrid electric vehicle with ICE and Ultracapacitors

This paper depicts in depth a series hybrid vehicle with a generation system based on an internal combustion engine coupled to a permanent magnets synchronous motor. A storage system with high power density, assured by the Ultracapacitors Unit (UC), is able to meet the driver peak power requests to run the vehicle and to store a part of energy from regenerative brakings as well. In this work, the vehicle energy management for a series hybrid electric vehicle is discussed with particular reference to the Generation Unit (GU) and the Electric Energy Storage (EES). The communication system is configured and remotely controlled by means of the Controller Area Network (CAN). For the purpose of obtaining the Internal Combustion Engine (ICE) better working efficiency a software supervisor has been developed to manage the GU. Further, first experimental results achieved for the prototype at roll test bench will be shown.

Implementation of the fast charging concept for electric local public transport: The case-study of a minibus

This paper shows an effective implementation of the fast charging concept in the electric local public transport context. An electric minibus powered with a lead-acid battery is considered as a case-study. Its traction battery is redesigned using 12 V standard lithium-iron-phosphate modules to benefit from the higher performance of the lithium battery technology compared to the lead-acid one. The minibus can achieve a continuous operation characterised by 20 min of traveling alternated with 10 min of standstill for fast recharging of the battery. Experiments performed on a single module of the battery show that the load profile is sustained without appreciable issues both in temperature and life degradation of the lithium cells.