Fernando Ortenzi

This paper investigates a bidirectional power-sharing system for two mechanically coupled automated electric buses forming a convoy. The system enables dynamic energy exchange between vehicles, and between the convoy and the grid via a tramway overhead line and a ground conductor. The proposed architecture is designed to optimize onboard energy distribution, reduce peak power demands, and enhance operational resilience in urban environments. The paper presents the general functional design of the energy management system, validated through practical experiments. A dedicated simulation environment developed in MATLAB/Simulink is used to model the energy exchanges between the two buses and with the grid while the convoy travels along a realistic urban route. The simulation results illustrate the effectiveness of the power-sharing strategy under varying operating conditions. The proposed solution offers a versatile basis for cooperative electric mobility and infrastructure-integrated energy management. Using the developed simulator it was possible to assess that the initial power levels considered for the system (20 kW from the infrastructure and 5 kW for vehicle-to-vehicle sharing) are not sufficient to sustain continuous operation along the observed route, and that specifications should be set according to different route requirements (32 kW and 7 kW respectively for our case study).

Any sharing mobility service aims to make urban mobility sustainable to help reduce environmental impacts and improve the quality of life for all in cities. Many transport services are not currently self-sustainable. The Life for Silver Coast (LifeSC) opened its mobility services on 22 May 2021 and offered electric mobility services during the summer for a few cities in Tuscany. E-bikes and e-scooters can be financially neutral, and even profitable, thanks to the low costs of the vehicles, but they only see a high utilization rate in winter. Shared electric cars, meanwhile, are not profitable. A new shared service that is viable must be profitable to become widely adopted and significantly contribute to sustainability. A few key characteristics have been identified, and one has been tested with a new business model that combines ride-sharing and car-sharing. The innovative Ride Sharing Algorithm (RSA) has been tested based on data from a potential city, Monterondo, where many commuters travel daily to Rome by train. The Italian census and local survey data allowed for the simulation of the scheduling of vehicle rides and an evaluation of the economic results, which could be positive if enough interest for such a system exists among the people, as at least 400 commuters from Monterotondo go to the train station daily in the morning and return in the afternoon. Such a transport demand would justify a new commercial sharing service by using the model tested with the RSA algorithm.

The real environment impacts the fuel and energy consumption of any vehicle: technology, physical and social phenomena, traffic, drivers’ behaviour, and so on; many of them are difficult to quantify. The authors’ methodology was used to test the real impact of vehicles in “standard” urban conditions, and many generations of hybrid powertrains are compared. One of the latest performance indexes is the percentage of time the vehicle runs with zero emissions (ZEV). For example, the hybrid vehicle tested ran up to 80% with no emissions and fuel consumption below 3 L per 100 km. A few energy performance indicators were compared between five vehicles: one battery electric vehicle (BEV), two hybrid gasoline–electric vehicles (HEVs), and two traditional vehicles (one diesel and one gasoline). Their potential to use only renewable energy is unrivalled, but today’s vehicles’ performances favour hybrid power trains. This paper summarises the most sustainable powertrain for urban use by comparing experimental data from on-road testing. It also evaluates the benefits of reducing emissions by forecasting the Italian car fleet of 2025 and three use cases of the evolution of car fleets, with a focus on Rome.

Electrification and fast recharge of buses for public transportation in urban areas involve a high reliability of installed storage and recharge systems. Performed mission profiles stress the system with a relatively high mileage and repeated acceleration and braking cycles. Authors have simulated and designed different storage and recharge technologies that have been installed and tested on a fleet of revamped electric minibus. In this work, attention is focused on design and simulation of a bus equipped with high-power lithium batteries. Proposed storage is recharged by a fast station fed by a flywheel system. In this work authors describe the proposed solution and its advantages. The description of the whole activity is performed with a particular attention to implementation and to experimental results of activities performed at ENEA laboratories of Roma Casaccia (Italy).

This paper presents the performance analysis of a latest-generation hybrid vehicle (Toyota Yaris 2020) with a testing campaign in real road conditions and a comparison with the previous model (Toyota Yaris 2017). The study was conducted by applying the Real Drive Truth Test protocol, developed by the research group, validated and spread to other full hybrid vehicles: Toyota Prius IV (2016) and Toyota Yaris 2017 (2017). In the case of the 2020 tests, the co-presence on board—deemed unsafe in the usual ways given the ongoing pandemic—was achieved through precise and sophisticated remote control. An on-board diagnostic computer, video transmission and recording equipment guarantee the virtual co-presence of a technical control room and a driver. Thus, several engineers can follow and monitor each vehicle via a 4G modem (installed in each vehicle), analysing data, route and driver behaviour in real-time, and therefore even in the presence of a single occupant in the car under test. The utmost attention has also been paid to adopting anti-COVID behaviours and safety standards: limited personal interactions, reduced co-presence in shared rooms (especially in the control room), vehicle sanitising between different drivers, computers and technicians and video technicians working once at a time. The comparison between the two subsequent vehicle models shows a significant improvement in the performance of the new generation Yaris, both in terms of operation in ZEV (zero-emission vehicle) mode (+15.3%) and in terms of consumption (−35.1%) and overall efficiency of the hybrid powertrain (+8.2%).

Activities described in this paper concern the development of a newly urban transport solution which involves the revamping of electric bus and related fast-charge pantograph infrastructure. The sizing of the vehicle storage system in based on recorder mission profile and consumption acquired during real word testing, both in the real application scenarios and simulation environments. Optimal design relay on 5 Degree of Freedom vehicle model, for the purpose of estimating average consumption. These in formations are also useful to establish the size for the power and energy of the recharge infrastructures, which is equipped with flywheel inertial accumulators. Results show the accuracy of the developed model by comparing real and estimated energy consumption for several drive cycles, also concerning the effective route for the investigate bus line in the urban transport context.