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Air quality standards and legislations
Published in Abhishek Tiwary, Ian Williams, Air Pollution, 2018
The NEDC regulatory emissions testing framework covering vehicular air pollution from diesel engines came under heavy criticism for the gaps between real-world and laboratory test emissions. In response, the European Commission introduced the Real Driving Emissions (RDE) test procedure, and there is a series of initiatives underway to improve and harmonise the test standards up to mid-2020. The proposed RDE testing using some form of onboard portable emissions measurement systems (PEMS) is meant to overcome the shortcomings of measurements taken under chassis dynamometer. The RDE testing marks the transition from the existing NEDC regulations to the Worldwide Harmonised Light Vehicle Test Procedure (WLTP). The latter developed was under the UNECE is expected to take over NEDC entirely from 2021 onwards. The RDE conditions have introduced more stringent testing parameters, including ambient temperature, altitude, speed, driver aggression levels and gradient. The NEDC and WLTP driving cycles have similar profiles but differ in terms of speed, duration and profile regularity. The NEDC has a total 780 s urban driving cycle with an average speed of 18.35 km h−1, and four identical cycles of speeding up and slowing down (it also has an EUDC of 400 s with speeds reaching 120 km h−1). On the other hand, the WLTP has four sections representing low, medium, high and extra high speeds. The test cycle used depends on the vehicle power but can last up to a total of 1800 s, reaching speeds of 130 km h−1.
Lubricant Contribution to Energy Efficiency
Published in Don M. Pirro, Martin Webster, Ekkehard Daschner, Lubrication Fundamentals, 2017
Don M. Pirro, Martin Webster, Ekkehard Daschner
In Europe, the New European Driving Cycle is used to quantify vehicle emissions. The test method uses a complete vehicle that is run on either a flat road or a stationary roller test system capable of simulating aerodynamic drag. The test is started using a cold vehicle (20–30°C), which is then driven through a sequence of four urban driving cycles followed by an extra urban driving cycle. The test sequence captures the warming up effects associated with a relatively cold start and has been shown to favor use of lower viscosity lubricants. Since the test was originally conceived, vehicle power and driving styles have changed, and there have been concerns raised on the ability of the procedure to reproduce results relevant to current vehicle use. A harmonized world light vehicles test procedure (WLTP) is under development as a likely replacement.
Energy conservation of electric vehicles by applying multi-speed transmissions
Published in Lin Liu, Automotive, Mechanical and Electrical Engineering, 2017
Xiaoxiao Wu, Peng Dong, Xiangyang Xu, D.A. Kupka, Yanqin Huang
Different driving cycles can be selected in the forward driving simulation, e.g. the New European Driving Cycle (NEDC), which is supposed to represent the typical usage of a passenger car in Europe. In this paper, a Worldwide Harmonised Light-Duty Test-Cycle (WLTC) is applied in the simulation. The WLTC represents real driving scenarios more accurately than the NEDC. The load transients of the WLTC are more frequent. It will replace the NEDC from 2017. The WLTC is divided into three classes according to the vehicle power-weight ratio: Class 1: low-power vehicles with power-weight ratio smaller than 22 W/kgClass 2: medium-power vehicles with power-weight ratio between 22 W/kg and 34 W/kgClass 3: high-power vehicles with power-weight ratio higher than 34 W/kg
Plug-in hybrid electric vehicle observed utility factor: Why the observed electrification performance differ from expectations
Published in International Journal of Sustainable Transportation, 2022
Seshadri Srinivasa Raghavan, Gil Tal
In the United States two test cycles are used, the Urban Dynamometer Driving Schedule (UDDS) and Highway Fuel Economy Test (HWFET) cycle. In the EU, only one test cycle, namely the Worldwide Harmonized Light-duty vehicle Test Cycle (WLTC) and its associated Worldwide Harmonized Light-duty vehicle Test Procedure (WLTP) are used (European Commission, 2018, 2016a). Prior to the introduction of WLTP in 2017, New European Drive Cycle (NEDC) was used as the test cycle for type approval (Ligterink et al., 2016) but was phased out in favor of the WLTP to reduce the gap between on-road and type approval energy consumption and emission estimates. Realistic driving behavior, inclusion of diverse driving situations (urban, suburban, main road, and motorway), representing high speed and propulsion power demand, and stringent testing conditions are some of the notable benefits of the WLTP compared to the NEDC (ACEA, 2017). The CD range estimated based on the NEDC is reduced by 25% under the WLTP (European Commission, 2016b). Measurements using the WLTP also considers optional equipment and add-ons for comfort, luxury, and performance that impacts the rolling resistance, vehicle aero-dynamics, and mass (European Commission [EC], 2017).
Energy management strategy for FCEV considering degradation of fuel cell
Published in International Journal of Green Energy, 2023
Yan Sun, Changgao Xia, Bifeng Yin, Haiyu Gao, Jiangyi Han, Jing Liu
The model in the loop (MIL) is realized based on AMESIM (SIEMENS®) and MATLAB/Simulink (Mathworks®). The performance of the proposed EMS is explored under three driving cycles, namely, World Light Vehicle Test Procedure (WLTP), Urban Dynamometer Driving Schedule (UDDS), and New European Driving Cycle (NEDC). WLTP is a new global standard for defining the levels of pollutants and fuel consumption of vehicles. Figure 6(a)/(b)/(c) shows the WLTP/UDDS/NEDC driving cycles and their corresponding requested power curves. The negative output power represents the driving state, and the positive power represents the braking state.
Impact of an emissions-based car tax policy on CO2 emissions and tax revenue from private cars in Ireland
Published in International Journal of Sustainable Transportation, 2022
Vera O’Riordan, Fionn Rogan, Brian Ó'Gallachóir, Hannah Daly
The tax policy also highlights the pitfalls of setting an environmental policy based on laboratory-based manufacturer specified measurements that cannot be continually monitored on the road. The manufacturer specified emissions used to set the Irish car tax rate were subject to “gaming” in what is now known as the “Diesel-gate” scandal. While emissions of nitrous dioxides (NOx) and sulfur dioxides (SOx), rather than CO2, were in the spotlight throughout the scandal, the growth of the CO2 on-road factor in Ireland over the period of 2008 − 2018 as highlighted in Table B1 contributed to CO2 emissions being higher than they otherwise would have been. This also impacted the tax revenue collected by the Irish government as cars were increasingly in lower taxation classes than they would be if they were rated according to real-world driving. As internal combustion engines are emitting more than the tax policy specifies, the relative tax benefit of switching to a no-emission car, such as an electric car, is subsequently reduced. Increasing the relative difference between the emissions bands, combined with the new World Harmonized Light Vehicle Test Procedure (WLTP), would result in a stronger price signal for switching to super low emission cars such as EVs (Electric Vehicles) could be helpful toward Ireland’s 2030 EV uptake and sustainable transport targets. Retrospectively updating taxation rates on higher emission cars are also an option to be considered, as current updates to the taxation policy only focus on cars registered after the date of implementation. An iterative approach to taxation policy allows for continual monitoring of tax revenue from the new taxation schemes and prevents the revenue losses suffered because of the 2008 car tax rate changes.