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Inductive power transfer (IPT) systems offer a promising solution to multiple major hurdles associated with electric vehicles, such as the lack of widespread charging infrastructure, driving range anxiety, and significant charging time. With the aid of IPT systems, dynamic wireless charging enables electric vehicles to be charged when running over the IPT power pads. The objective of this study is to minimise the overall cost of charging infrastructure by optimising the deployment of IPT transmitters and the battery size required to support charging for electric buses. A mixed-integer linear programming model is proposed and solved using the commercial solver Gurobi. Bus route information and the characteristics of electric buses, such as weight, drag coefficient and frontal area, are used as input to run the traffic simulation in SUMO to get time-varying velocity and acceleration data during bus operations. A bus route in Auckland, New Zealand, is used as a case study in the presented numerical experiments. A strong correlation between the velocity of the bus and the state of charge is identified. The largest cost component is the charging pad, followed by the battery. [ABSTRACT FROM AUTHOR]

This study quantifies the spatio-temporal distribution of electric buses' (EBs) electricity consumption characteristics and identifies the most electricity-saving operations from both instantaneous movements and driving conditions considering road types and bus routes. First, the real-world EB operating data collected from four EBs are divided into segments. Factors that influence the value of two energy consumption indexes (electricity consumption rate, ECR, and electricity consumption factor, ECF) are assessed. The study finds that an increasing average speed of a bus leads to a lower value of ECF, suggesting a less aggressive and a more efficient driving style. Further, ECFs are clustered into four states (very low/low/medium/high) to identify the energy-saving situation. The result shows that the most energy-saving speed ranges for expressways, arterial roads, and local roads during peak hours are 45–50 km/h, 35-40 km/h and 25-30 km/h, respectively. Findings from this study can be applied for eco-driving suggestions to drivers in order to improve the efficiency of EB operation system. [ABSTRACT FROM AUTHOR]

In the Greater Houston Area, mobile sources contribute to the highest share of NOx emissions and the second-highest share of VOC emissions. The Houston METRO system that operates public buses is a key element of Houston's infrastructures that could reduce the emissions of criteria air pollutants (CAPs) and greenhouse gases (GHGs), thus improving the regional air quality. We used life-cycle assessment (LCA) and life-cycle cost analysis (LCCA) to evaluate the environmental sustainability of electric buses and compared it to diesel buses. The LCA simulations demonstrate that life-cycle emissions of GHGs, VOCs, NOx, and black carbon associated with electric buses are lower than conventional diesel and diesel hybrid buses. These lower emissions are mainly attributed to the fact that natural gas currently makes up about 50% of the fuel used to generate electricity in Texas. However, other emissions such as PM10, PM2.5, SOx, N2O, and primary organic carbon are higher and would lead to the higher environmental cost of electric buses than diesel buses. The environmental cost analysis estimates that the annual cost savings of electric buses in 2040 would significantly support the long-term goal of environmental sustainability in the Greater Houston area. [ABSTRACT FROM AUTHOR]

Electric buses are growing in numbers in Sweden, which contributes to the development of a fossil fuel free society and a reduction of emissions. Earlier studies of bus systems have identified a need to further investigate societal costs, total cost of ownership, energy use on a yearly basis to account for seasonal variations, and noise during acceleration. Addressing those needs was the purpose of this study. Investigations were made in five cities in Sweden that have recently implemented different electric buses in their respective public transport system. Based on results from these investigations and earlier studies, new and developed models where designed and applied on electric buses on route 1 in Karlskrona, as a representative example. It was found that there were significant savings in societal costs and total cost of ownership when compared to diesel and biogas powered buses, mainly due to decreased noise, no emissions in the use phase, and decreased energy use. [ABSTRACT FROM AUTHOR]

Since Electric Auxiliary Systems (EAS) accounts for a large proportion of electric bus energy consumption, in order to reduce EAS energy consumption and improve bus driving range, the working principles of EAS have been studied. The number of passengers, bus interior and exterior temperature can have great influence on EAS energy consumption, it is important to dynamically manage EAS working status according to the changes of bus driving conditions for saving energy, then an integrated control method for EAS is proposed for better meeting the real demands of EAS. The proposed method takes EAS as a whole and can manage EAS working status mainly according to the changes of bus passengers. For verifying the effectiveness of the proposed method, an electric bus model including EAS has been built and simulated by co-simulation in different platforms. Compared with common control method, the experimental simulation results shows that EAS energy consumption can be effectively reduced by dynamically managing EAS working status according to the changes of bus driving conditions, energy consumption proportion of each subsystem in EAS also has been discussed. The proposed method gives new way for saving EAS energy and has great application value for electric buses. [ABSTRACT FROM AUTHOR]

This paper designs a refueling system for battery electric buses (BEBs) by applying battery-swapping technologies together with a local charging system. The service capability of battery-swapping stations (BSSs) is restricted by the number of installed swapping robots. Depleted batteries are charged at BSSs which is equipped with a local charging system having a number of standby batteries and chargers in various types. This study intends to answer four fundamental questions: How many BSSs should be installed? Where should they be? How to assign the depleted electric buses to BSSs? What is the service capability of the BSS? An integer linear program is first formulated to represent the problem with deterministic demand. A two-stage stochastic programing model is then formulated to handle the demand uncertainties, which is then solved by a customized gradient algorithm. The test on a real network of the southeast region of Melbourne in Australia verifies the feasibility of the proposed model and draws managerial insights for the location and configuration of BSSs. [ABSTRACT FROM AUTHOR]

We investigate the economic and technological potential for adoption of Electric Vehicles (EVs) in Abu Dhabi through a parametric assessment, a public attitude survey, and a diffusion model. Abu Dhabi, similar to fossil-fuel-rich countries in its region, features a car-dependent society and energy subsidies while being situated in hot, desert environment challenging to EVs. We compare conventional vehicles and EVs in the region accounting for the higher use of air-conditioning (AC) in the actual climatic and driving pattern conditions of Abu Dhabi developing an EV AC consumption penalty model. Average annual AC penalty in fuel consumption over normal testing conditions is 16% for conventional vehicles and 25% for EVs based on hourly weather and vehicle utilization patterns. For 250 days per year, the expected EV range is higher than 75% of the nominal value. During the five hottest days of the recorded year, it can drop to 60% but still covering the average daily driving of the majority of users with a single charge with a 25kWh battery. With partial subsidies offered for both fuel and electricity, EV adoption impacts the state in terms of opportunity costs for these fuels in addition to environmental externalities. We calculate the state and user benefits in a parametric analysis dependent on driving distance and battery costs. If the battery cost is $325/kWh, direct and internalized benefits and costs are balanced when the EV is driven 60 km/day. A diffusion scenario of 5% by 2030 results in cumulative net savings of 6.4 million barrels of oil, a reduction of 517.000 tonnes of CO2, and a cumulative net benefit of $127 million. [ABSTRACT FROM AUTHOR]

The deployment of battery-powered electric bus systems within the public transportation sector plays an important role in increasing energy efficiency and abating emissions. Rising attention is given to bus systems using fast charging technology. This concept requires a comprehensive infrastructure to equip bus routes with charging stations. The combination of charging infrastructure and bus batteries needs a reliable energy supply to maintain a stable bus operation even under demanding conditions. An efficient layout of the charging infrastructure and an appropriate dimensioning of battery capacity are crucial to minimize the total cost of ownership and to enable an energetically feasible bus operation. In this work, the central issue of jointly optimizing the charging infrastructure and battery capacity is described by a capacitated set covering problem. A mixed-integer linear optimization model is developed to determine the minimum number and location of required charging stations for a bus network as well as the adequate battery capacity for each bus line. The bus energy consumption for each route segment is determined based on individual route, bus type, traffic, and other information. Different scenarios are examined in order to assess the influence of charging power, climate, and changing operating conditions. The findings reveal significant differences in terms of required infrastructure. Moreover, the results highlight a trade-off between battery capacity and charging infrastructure under different operational and infrastructure conditions. This paper addresses upcoming challenges for transport authorities during the electrification process of the bus fleets and sharpens the focus on infrastructural issues related to the fast charging concept. [ABSTRACT FROM PUBLISHER]

This paper describes an integrated chassis control framework for a novel three-axle electric bus with active rear steering (ARS) axle and four motors at the middle and rear wheels. The proposed integrated framework consists of four parts: (1) an active speed limiting controller is designed for anti-body slip control and rollover prevention; (2) an ARS controller is designed for coordinating the tyre wear between the driving wheels; (3) an inter-axle torque distribution controller is designed for optimal torque distribution between the axles, considering anti-wheel slip and battery power limitations and (4) a data acquisition and estimation module for collecting the measured and estimated vehicle states. To verify the performances, a simulation platform is established in Trucksim software combined with Simulink. Three test cases are particularly designed to show the performances. The proposed algorithm is compared with a simple even control algorithm. The test results show satisfactory lateral stability and rollover prevention performances under severe steering conditions. The desired tyre wear coordinating performance is also realised, and the wheel slip ratios are restricted within stable region during intensive driving and emergency braking with complicated road conditions. [ABSTRACT FROM PUBLISHER]