Technical report - Task 7 : Europe-centric Light Duty Test Cycle and Differences with Respect to the WLTP Cycle

The Worldwide harmonized Light duty Test Cycle (WLTC) has been designed on the basis of the in-use driving databases provided by Europe, India, Japan, Korea and USA. These databases have been merged by applying a weighing factor to each of them, obtaining the “Unified” database. In order to verify the representativeness of the Unified database and the resulting WLTC with respect to the European driving behavior, a comparison between the Unified and the European database has been carried out, which has shown a high level of resemblance for the most important parameters (i.e. speed distribution, acceleration distribution, speed* acceleration, etc.). The drivability tests carried out over the WLTC in several laboratories have shown levels of CO2 emissions similar to those obtained with NEDC. Possible explanations of such results are presented.JRC.F.8-Sustainable Transpor

Durability demonstration programme for EURO6 passenger cars: thermal load to after-treatment systems

The thermal aging of emission control devices is the most important cause of vehicles' emissions deterioration. This report compares the thermal load generated by the Standard Road Cycle (SRC) with that generated by the Worldwide-harmonized Light-duty Test Cycle (WLTC) on 2 gasoline and 2 diesel vehicles, confirming that the SRC is fit for the purpose.JRC.C.4-Sustainable Transpor

Fuel consumption and CO2 emissions of passenger cars over the New Worldwide Harmonized Test Protocol

AbstractIn 2014 the United Nations Economic Commission for Europe (UNECE) adopted the global technical regulation No. 15 concerning the Worldwide harmonized Light duty Test Procedure (WLTP). Having significantly contributed to its development, the European Commission is now aiming at introducing the new test procedure in the European type-approval legislation for light duty vehicles in order to replace the New European Driving Cycle (NEDC) as the certification test.The current paper aims to assess the effect of WLTP introduction on the reported CO2 emissions from passenger cars presently measured under the New European Driving Cycle and the corresponding test protocol. The most important differences between the two testing procedures, apart from the kinematic characteristics of the respective driving cycles, is the determination of the vehicle inertia and driving resistance, the gear shifting sequence, the soak and test temperature and the post-test charge balance correction applied to WLTP. In order to quantify and analyze the effect of these differences in the end value of CO2 emissions, WLTP and NEDC CO2 emission measurements were performed on 20 vehicles, covering almost the whole European market. WLTP CO2 values range from 125.5 to 217.9g/km, NEDC values range from 105.4 to 213.2g/km and the ΔCO2 between WLTP and NEDC ranges from 4.7 to 29.2g/km for the given vehicle sample. The average cold start effect over WLTP was found 6.1g/km, while for NEDC it was found 12.3g/km. For a small gasoline and a medium sized diesel passenger car, the different inertia mass and driving resistance is responsible 63% and 81% of the observed ΔCO2 between these two driving cycles respectively, whereas the other parameters (driving profile, gear shifting, test temperature) account for the remaining 37% and 19%

Impact of ethanol containing gasoline blends on emissions from a flex-fuel vehicle tested over the Worldwide Harmonized Light duty Test Cycle (WLTC)

AbstractRegulated and unregulated emissions from a Euro 5a flex-fuel vehicle tested with nine different hydrous and anhydrous ethanol containing fuel blends at 23 and −7°C over the World harmonized Light-duty vehicle Test Cycle and the New European Driving Cycle, were investigated at the Vehicle Emission Laboratory at the European Commission Joint Research Centre Ispra, Italy. The experimental results showed no differences on the regulated and unregulated emissions when hydrous ethanol blends were used instead of anhydrous ethanol blends. The use of E85 and E75 blends (gasoline containing 85% and 75% of ethanol, respectively) resulted in a reduction of NOx emissions (30–55%) but increased the emissions of carbon monoxide, methane, carbonyls and ethanol compared to E5, E10 and E15 blends (gasoline containing 5%, 10% and 15% of ethanol, respectively). The increase of the acetaldehyde and ethanol emissions (up to 120% and 350% at 23°C and up to 400% and 390% at −7°C, for acetaldehyde and ethanol, respectively) caused a severe increment of the ozone formation potential. Most of the studied pollutants presented similar emission factors during the tests performed with E10 and E15 blends. The emission factors of most unregulated compounds were lower over the NEDC (with ammonia as an exception) than over the WLTC. However, when taking into consideration only the cold start emissions, emission factors over the WLTC were observed to be higher, or similar, to those obtained over the NEDC. Low ambient temperature caused an increase of the emissions of all studied compounds with all tested blends

Joint Research Centre 2017 light-duty vehicles emissions testing

This report summarises the results of the pilot study on the market surveillance of light-duty vehicles. The emission performance and the CO2 emissions of 15 vehicles are presented. The methodology for vehicle compliance checks defined in the Guidance note published by the European Commission was applied and discussed.JRC.C.4-Sustainable Transpor

Particle Number PEMS: Inter-Laboratory: Comparison Exercise

This report summarizes the results of the Inter-Laboratory Comparison Exercise for the PN-PEMS equipment that took place between September 2015 and January 2016. The accuracy and precision of PN measurement with two different PN-PEMS was assessed with one selected Golden Vehicle in seven different laboratories across Europe, providing indications for drafting the third package of the RDE regulation. The differences of the PN-PEMS to the reference system at the CVS were between -40% and +40%; similar to those between the reference system at the tailpipe and the CVS. The accuracy and precision of the PN-PEMS, as estimated by comparing them with the reference system at the tailpipe were 10.4% ± 11.9% for the diffusion charger based PN-PEMS and -8.0% ±9.5% for the CPC-based PN-PEMS. The larger differences compared to the reference system at the CVS can be explained by particle transformations between the vehicle tailpipe and the CVS and calibration uncertainties of the reference systems at the CVS. On road tests showed that the PN-PEMS were stable and measuring as in the laboratory. For the tested vehicle technology, there were not significant deviations between the PN emissions measured in the laboratory and the PN emissions measured under real driving conditions at ambient temperatures between 3°C and 25°C.JRC.C.4-Sustainable Transpor

Optimized Driving Cycle Oriented Control for a Highly Turbocharged Gas Engine

The article is focused on a 1-D drive dynamic simulation of a highly turbocharged gas engine. A mono fuel CNG engine has been developed as a downsized replacement of the diesel engine for a medium size van. The basic engine parameters optimization is provided in a steady state operation and a control adjustment is applied to a dynamic vehicle model for a transient response improvement in highly dynamic operation modes of the WLTC (world light duty test cycle), selected for investigation. Vehicle simulation model with optimized control system is used for driving cycle fuel consumption and CO2 emissions predictions compared with the basic engine settings

Characterization of laboratory and real driving emissions of individual Euro 6 light-duty vehicles – Fresh particles and secondary aerosol formation

Emissions from passenger cars are one of major sources that deteriorate urban air quality. This study presents characterization of real-drive emissions from three Euro 6 emission level passenger cars (two gasoline and one diesel) in terms of fresh particles and secondary aerosol formation. The gasoline vehicles were also characterized by chassis dynamometer studies. In the real-drive study, the particle number emissions during regular driving were 1.1–12.7 times greater than observed in the laboratory tests (4.8 times greater on average), which may be caused by more effective nucleation process when diluted by real polluted and humid ambient air. However, the emission factors measured in laboratory were still much higher than the regulatory value of 6 × 10^(11) particles km^(−1). The higher emission factors measured here result probably from the fact that the regulatory limit considers only non-volatile particles larger than 23 nm, whereas here, all particles (also volatile) larger than 3 nm were measured. Secondary aerosol formation potential was the highest after a vehicle cold start when most of the secondary mass was organics. After the cold start, the relative contributions of ammonium, sulfate and nitrate increased. Using a novel approach to study secondary aerosol formation under real-drive conditions with the chase method resulted mostly in emission factors below detection limit, which was not in disagreement with the laboratory findings

Intercomparison of real-time tailpipe ammonia measurements from vehicles tested over the new world-harmonized light-duty vehicle test cycle (WLTC)

Four light duty vehicles (two diesels, one flex-fuel and one gasoline vehicle) were tested as part of an intercomparison exercise of the World harmonized Light-duty vehicle Test Procedure (WLTP) aiming at measuring real-time ammonia emissions from the vehicles’ raw exhaust at the tailpipe. The tests were conducted in the Vehicle Emission Laboratory (VELA) at the European Commission Joint Research Centre (EC-JRC) Ispra, Italy. HORIBA, CGS and the Sustainable Transport Unit of the JRC, took part in the measurement and analysis of the four vehicles exhaust emissions over the World harmonized Light-duty vehicle Test Cycle (WLTC) class 3, version 5.3 using a HORIBA MEXA 1400 QL-NX, a CGS BLAQ-Sys and the JRC FTIR, respectively. The measured ammonia concentrations and the emission profiles revealed that these three instruments are suitable to measure ammonia from the vehicles raw exhaust, presenting no significant differences. Furthermore, results showed that measurement of ammonia from the vehicle exhaust using online systems can be performed guaranteeing the reproducibility and repeatability of the results. While no ammonia was detected for any of the two diesel vehicles (even though, one was equipped with a SCR system) average ammonia emission factors 8-10 mg/km (average concentrations 20-23 ppm) and 10-12 mg/km (average concentrations 22-24 ppm) were estimated for the flex-fuel and gasoline vehicles, respectively.JRC.F.8-Sustainable Transpor

Active thermal management for Interior Permanent Magnet Synchronous Machine (IPMSM) drives based on model predictive control

This paper proposes an active thermal management scheme for Interior Permanent Magnet Synchronous Machine (IPMSM) drives based on the model predictive control concept. The proposed control scheme can adaptively set torque limit based on the thermal state of the machine to limit the machine winding and end-winding temperatures. The proposed control scheme is assessed by experiments on a laboratory machine drive system and simulated for traction drives over Worldwide Harmonized Light-duty Test Cycle (WLTC). Compared with conventional traction control scheme, the proposed scheme can effectively reduce peak temperature and hence thermal stress of the machine for improving its lifetime