Engineering Papers⌕ Search

Engineering topics

Walkowicz, K.

Publications and source records attributed to Walkowicz, K..

Characterization of In-Use Medium Duty Electric Vehicle Driving and Charging Behavior: Preprint

The U.S. Department of Energy's American Recovery and Reinvestment Act (ARRA) deployment and demonstration projects are helping to commercialize technologies for all-electric vehicles (EVs). Under the ARRA program, data from Smith Electric and Navistar medium duty EVs have been collected, compiled, and analyzed in an effort to quantify the impacts of these new technologies. Over a period of three years, the National Renewable Energy Laboratory (NREL) has compiled data from over 250 Smith Newton EVs for a total of over 100,000 days of in-use operation. Similarly, data have been collected from over 100 Navistar eStar vehicles, with over 15,000 operating days having been analyzed. NREL has analyzed a combined total of over 4 million kilometers of driving and 1 million hours of charging data for commercial operating medium duty EVs. In this paper, the authors present an overview of medium duty EV operating and charging behavior based on in-use data collected from both Smith and Navistar vehicles operating in the United States. Specifically, this paper provides an introduction to the specifications and configurations of the vehicles examined; discusses the approach and methodology of data collection and analysis, and presents detailed results regarding daily driving and charging behavior. In addition, trends observed over the course of multiple years of data collection are examined, and conclusions are drawn about early deployment behavior and ongoing adjustments due to new and improving technology. Results and metrics such as average daily driving distance, route aggressiveness, charging frequency, and liter per kilometer diesel equivalent fuel consumption are documented and discussed.

25 ENERGY STORAGE↗

Medium Duty ARRA Data Reporting and Analysis (Presentation)

This project compiles medium-duty (MD) aggregated deployment data and provides the compiled detailed analyses to industry. The U.S. Department of Energy's (DOE's) American Recovery and Reinvestment Act (ARRA) deployment and demonstration projects are helping to commercialize technologies for all-electric vehicles, electrified accessories, and electric charging infrastructure. Over 3.2 million miles of in-service all-electric MD truck data from 560 different vehicles have been collected since 2011, and usage data from over 1,000 truck electrification sites have been collected since 2013. Through the DOE's Vehicle Technologies Office, NREL is working to analyze real-time data from these deployment and demonstration projects to quantify the benefits: results and summary statistics are made available through the NREL website as quarterly and annual reports; 23 aggregated reports have been published on the performance and operation of these vehicles; and detailed data are being extracted to help further understand battery use and performance.

2014 AMR↗

Medium and Heavy Duty Vehicle Field Evaluations (Presentation)

This presentation discusses field evaluations of medium- and heavy-duty vehicles performed by NREL. The project provides medium-duty (MD) and heavy-duty (HD) test results, aggregated data, and detailed analysis, including 3rd party unbiased data (data that would not normally be shared by industry in an aggregated and detailed manner). Over 5.6 million miles of advanced technology MD and HD truck data have been collected, documented, and analyzed on over 240 different vehicles since 2002. Data, analysis, and reports are shared within DOE, national laboratory partners, and industry for R&D planning and strategy. The results help guide R&D for new technology development, help define intelligent usage of newly developed technology, and help fleets/users understand all aspects of advanced technology.

2014 AMR↗

Emissions from Medium-Duty Conventional and Diesel-Electric Hybrid Vehicles; NREL (National Renewable Energy Laboratory)

This presentation discusses the results of emissions testing for medium-duty conventional and diesel-electric hybrid vehicles. Testing was based on a field evaluation approach that utilized the Fleet DNA drive cycle database and NREL’s Renewable Fuels and Lubricants (ReFUEL) Laboratory chassis dynamometer. Vehicles tested included parcel delivery (Class 6 step vans), beverage delivery (Class 8 tractors), and parcel delivery (Class 7 box trucks) vehicles, all with intended service class medium/heavy heavy-duty diesel (MHDD). Results for fuel economy and tailpipe NOx emissions included: diesel hybrid electric vehicles showed an average fuel economy advantage on identified test cycles: Class 6 Step Vans: 26%; Class 7 Box Trucks: 24.7%; Class 8 Tractors: 17.3%. Vehicle miles traveled is an important factor in determining total petroleum and CO2 displacement. Higher NOx emissions were observed over some test cycles: highly drive cycle dependent; engine-out differences may result from different engine operating point; and selective catalyst reduction temperature may play a role, but does not explain the whole story.

33 ADVANCED PROPULSION SYSTEMS↗

Fleet DNA Project Data Summary Report (Presentation)

This presentation includes graphical data summaries that highlight statistical trends for medium- and heavy-duty commercial fleet vehicles operating in a variety of vocations. It offers insight for the development of vehicle technologies that reduce costs, fuel consumption, and emission.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Statistical Characterization of School Bus Drive Cycles Collected via Onboard Logging Systems

In an effort to characterize the dynamics typical of school bus operation, National Renewable Energy Laboratory (NREL) researchers set out to gather in-use duty cycle data from school bus fleets operating across the country. Employing a combination of Isaac Instruments GPS/CAN data loggers in conjunction with existing onboard telemetric systems resulted in the capture of operating information for more than 200 individual vehicles in three geographically unique domestic locations. In total, over 1,500 individual operational route shifts from Washington, New York, and Colorado were collected. Upon completing the collection of in-use field data using either NREL-installed data acquisition devices or existing onboard telemetry systems, large-scale duty-cycle statistical analyses were performed to examine underlying vehicle dynamics trends within the data and to explore vehicle operation variations between fleet locations. Based on the results of these analyses, high, low, and average vehicle dynamics requirements were determined, resulting in the selection of representative standard chassis dynamometer test cycles for each condition. In this paper, the methodology and accompanying results of the large-scale duty-cycle statistical analysis are presented, including graphical and tabular representations of a number of relationships between key duty-cycle metrics observed within the larger data set. In addition to presenting the results of this analysis, conclusions are drawn and presented regarding potential applications of advanced vehicle technology as it relates specifically to school buses.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

In-Use and Vehicle Dynamometer Evaluation and Comparison of Class 7 Hybrid Electric and Conventional Diesel Delivery Trucks

This study compared fuel economy and emissions between heavy-duty hybrid electric vehicles (HEVs) and equivalent conventional diesel vehicles. In-use field data were collected from daily fleet operations carried out at a FedEx facility in California on six HEV and six conventional 2010 Freightliner M2-106 straight box trucks. Field data collection primarily focused on route assessment and vehicle fuel consumption over a six-month period. Chassis dynamometer testing was also carried out on one conventional vehicle and one HEV to determine differences in fuel consumption and emissions. Route data from the field study was analyzed to determine the selection of dynamometer test cycles. From this analysis, the New York Composite (NYComp), Hybrid Truck Users Forum Class 6 (HTUF 6), and California Air Resource Board (CARB) Heavy Heavy-Duty Diesel Truck (HHDDT) drive cycles were chosen. The HEV showed 31% better fuel economy on the NYComp cycle, 25% better on the HTUF 6 cycle and 4% worse on the CARB HHDDT cycle when compared to the conventional vehicle. The in-use field data indicates that the HEVs had around 16% better fuel economy than the conventional vehicles. Dynamometer testing also showed that the HEV generally emitted higher levels of nitric oxides than the conventional vehicle over the drive cycles, up to 77% higher on the NYComp cycle (though this may at least in part be attributed to the different engine certification levels in the vehicles tested). The conventional vehicle was found to accelerate up to freeway speeds over ten seconds faster than the HEV.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Navistar eStar Vehicle Performace Evaluation - 3rd Quarter 2013; Energy Efficiency & Renewable Energy (EERE)

The Fleet Test and Evaluation Team at the U.S. Department of Energy's National Renewable Energy Laboratory is evaluating and documenting the performance of electric and plug-in hybrid electric drive systems in medium duty trucks across the nation. U.S. companies participating in this evaluation project received funding from the American Recovery and Reinvestment Act to cover part of the cost of purchasing these vehicles. Through this project, Navistar will build and deploy all-electric medium-duty trucks. The trucks will be deployed in diverse climates across the country. This report covers the third quarter of 2013.

33 ADVANCED PROPULSION SYSTEMS↗