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Within the “Industria 2015” Italian framework program, the HI-ZEV project has the aim to develop two high performance vehicles: one full electric and one hybrid. This paper deals with the electric energy storage (EES) design and testing of the hybrid vehicle. A model of the storage system has been developed, simulating each cell like an electric generator with more RC circuits in series. To take account of the heat transfer, a forced convection model has been used with the air speed proportional to the vehicle speed. The model had two calibration steps: the first has determined the electrical parameters of the model (open voltage circuit, internal resistances and capacitors); the second to calibrate the heat transfer model. The first calibration has been made on a climatic chamber at 23 °C discharging one single module with different constant currents from 5C (5 times the nominal capacity) to 25C and charging with currents in the range from 1C to 5C.

The adoption of composed (hybrid) lead acid battery-supercapacitor (SC) storage systems is able to improve performances (availability, durability, range) of an electric microcar. As a matter of fact, the supercapacitors extend the operation time not only by improving the energy efficiency (thanks to a higher contribution of regenerative braking), but also by reducing the power down caused by voltage drop at higher discharge rates. The integration of battery with supercapacitors requires careful analysis and calculation of the relationship between battery peak power and size of the SC bank, needed to have a balanced composition of the hybrid storage system. For this purpose, the optimization process, summarized here, is based on the combination of a conventional lead-acid battery and a commercial SC, with the vehicle running the ECE15 driving cycle.

This paper reports the results of experimental tests performed at ENEA (Italian National Agency for New Technologies, Environment and Sustainable Development) in its “Casaccia” Energy Research Center to evaluate the energetic and environmental performances of a Heavy-Duty Compressed Natural Gas (HD CNG) engine fuelled with a hydrogen-methane blend of 15% in volume. A lean burn Mercedes 906 LAG engine has been optimized properly calibrating ECU engine maps regarding both ignition advance and air to fuel ratio (AFR). It was therefore possible to correct ignition advance to take into account the faster combustion speed given by the hydrogen content of the fuel mixture. Equivalence ratio (Lambda) has instead been modified in order to minimize the NOx emissions. All the tests were performed on a steady engine test-bed focusing the attention on the most important parts of the engine maps.

Hybrid electric vehicles (HEVs) are worldwide recognized as one of the best and most immediate opportunities to solve the problems of fuel consumption, pollutant emissions and fossil fuels depletion, thanks to the high reliability of engines and the high efficiencies of motors. Moreover, as transport policy is becoming day by day stricter all over the world, moving people or goods efficiently and cheaply is the goal that all the main automobile manufacturers are trying to reach. In this context, the municipalities are performing their own action plans for public transport and the efforts in realizing high efficiency hybrid electric buses, could be supported by the local policies. For these reasons, the authors intend to propose an efficient control strategy for a hybrid electric bus, with a series architecture for the power-train.

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 showed a fair improvement of the efficiency and CO2 emissions as well as an overall improvement regarding local pollutants.

ENEA is studying innovative vehicles such as pure electric and hybrid-electric vehicles, aiming to increase their energy efficiency and to reduce pollutant emissions. As part of such activities, a quite large demonstration project for verifying technical and economical viability of hybrid buses under real public transport operation conditions, has been carried out. Furthermore, a controller for an electric hybrid vehicle has been developed that allows to achieve a further 30% fuel economy improvement. The results of such activities are the input information of the TREMOVE model to investigate the potential impact of electric hybrid vehicle deployment in an Italian city, as a case study. The positive effects of new hybrid vehicle introduction for freight transport in terms of fuel saving and emission reduction, have been also investigated.

Among the research and development subjects of ENEA (Italian National Agency for New Technology, Energy and Environment) an important theme is the study of innovative vehicles with high energy efficiency and low emissions. ENEA has set up an infrastructure in order to execute research and development activity for hybrid and electrical vehicles. The paper deals with features and working methods throughout the testing campaign on the ALTRA minibus drive-train, a 6m. series hybrid developed by IVECO and ANSALDO. The test demonstrated that the energy consumption is strong correlated to the power management strategy. Subsequently, a testing work was carried on with a controller developed by ENEA and University of Pisa, by using the roll bench of ENEA, while the IVECO tested on the road an other control system. All these tests convalidates the need of a controller to achieve fuel economy.

Among the research and development subjects of ENEA (Italian National Agency for New Technology, Energy and Environment) an important theme is the study of innovative vehicles with high energy efficiency and low emissions. Our programs are aimed at designing and setting up innovative vehicles with electric propulsion. These vehicles will be of two main types: battery-powered (pure- electric) and hybrid (fuel cell/battery and diesel/battery). At the moment, the fuel-cell technology applied to engines for vehicular applications displays broad margins of convenience over any known alternative engine for what concerns the compliance with any present and foreseeable environmental and energy saving regulations. On the other hand, the use of hydrogen, produced on board from fuels or stored as a liquid or a gas, raises new problems from the point of view of safety regulations and standards both in the design and use of vehicles and in the fuel production and distribution.