Henning Lohse-Busch

Vehicle Inertia Impact on Fuel Consumption of Conventional and Hybrid Electric Vehicles Using Acceleration and Coast Driving Strategy

In the past few years, the price of petroleum based fuels, especially vehicle fuels such as gasoline and diesel, has been increasing at a significant rate. Consequently, there is much more consumer interest related to reducing fuel consumption for conventional vehicles and hybrid electric vehicles (HEVs) than in the past. The goal of many competitions and challenges held in North America and Europe is to achieve extremely low fuel consumption. A possible strategy to reduce fuel consumption is to use the vehicle’s fuel converter such as an engine to accelerate the vehicle to a high speed and coast to a lower speed with the engine off. This method will reduce fuel flow to zero during the coast phase. Also, the vehicle uses higher power engine load to accelerate to the upper vehicle speed in a limited time, thus increasing the engine brake thermal efficiency. This strategy is known as “pulse and glide” or “burn and coast” in some references. In this study, the “pulse and glide” (PnG) method is first applied to a conventional vehicle to quantify the fuel consumption benefits when compared to steady speed conditions over the same distance. After that, an HEV is used as well to investigate if a hybrid system can further reduce fuel consumption with the proposed strategy. Note that the HEV used in this study has the advantage that the engine can be automatically shut off below a certain speed (~40 mph) at low loads, however a driver must shut off the engine manually in a conventional vehicle to apply this driving strategy.

The Measured Impact of Vehicle Mass on Road Load Forces and Energy Consumption for a BEV, HEV, and ICE Vehicle

The U.S. Department of Energy’s Office of Energy Efficiency & Renewable Energy initiated a study that conducted coastdown testing and chassis dynamometer testing of three vehicles, each at multiple test weights, in an effort to determine the impact of a vehicle’s mass on road load force and energy consumption. The testing and analysis also investigated the sensitivity of the vehicle’s powertrain architecture (i.e., conventional internal combustion

Investigating Possible Fuel Economy Bias Due To Regenerative Braking in Testing HEVs on 2WD and 4WD Chassis Dynamometers

Procedures are in place for testing emissions and fuel economy for virtually every type of light-duty vehicle with a single-axle chassis dynamometer, which is why nearly all emissions test facilities use single-axle dynamometers. However, hybrid electric vehicles (HEVs) employ regenerative braking. Thus, the braking split between the driven and non-driven axles may interact with the calculation of overall efficiency of the vehicle. This paper investigates the regenerative braking systems of a few production HEVs and provides an analysis of their differences in single-axle (2WD) and double-axle (4WD) dynamometer drive modes. The fuel economy results from 2WD and 4WD operation are shown for varied cycles for the 2000 Honda Insight, 2001 Toyota Prius, and the 2004 Toyota Prius. The paper shows that there is no evidence that a bias in testing an HEV exists because of the difference in operating the same hybrid vehicle in the 2WD and 4WD modes.

Component And Subsystem Evaluation In A Systems Context Using Hardware In The Loop

Hardware in the loop (HIL)/rapid control prototyping (RCP) is generally acknowledged to be a cost- and time-effective approach to test controllers/components/subsystems in a system context. Argonne National Laboratory has been using HIL to evaluate the potential of a plug-in hybrid battery in a vehicle (battery HIL). Argonne has also constructed a vehicle platform on wheels to evaluate different power train components on a chassis dynamometer - the mobile advanced technology testbed (MATT). This paper describes these two HIL projects and gives some preliminary results on all electric range (AER) tests conducted on both HIL platforms. These results are compared to simulation results obtained from Argonnes power train system analysis toolkit (PSAT).

An investigation into the PNGV battery model with the addition of a dynamic temperature range

The Partnership for Next Generation-Vehicles Hybrid Pulse Power Characterization (HPPC) battery model was used to develop a base-line estimation. Within the HPPC is a method to establish an estimated open circuit voltage (VOC) from a linear calculation of internal resistances and currents. The flexibility of the parameterization was tested over a changing temperature range. Algorithms were developed that predict the VOC and state of charge (SOC) based on the batterys temperature, current draw, terminal voltage, and sampling time step; therefore, increasing the accuracy of the battery parameterization estimator (BPE). Three production vehicles with lithium based battery chemistries were used in the study. A least square method is used as in the PNGV battery model to determine initial parameters; an improvement was shown over this base-line by using a non-linear algorithm. The estimates from both algorithms were compared to the measured data as verification.

Recent hybrid electric vehicle trends and technologies

In collaboration with the Department of Energys Advanced Vehicle Testing Activity, Argonne National Laboratory performs dynamometer testing and evaluation for a wide array of advanced vehicles. Using data obtained from this benchmarking, this paper discusses recently observed trends in hybrid electric vehicle technologies, discussing both overall vehicle trends as well as select component trends. This work discusses both “full” hybrids with a significant amount of electric (EV) or engine-off operation and more “mild” hybrids with a lesser amount of electric operating capability. This paper seeks to summarize some of the high-level operation trends that have been appearing in recent hybrid electric vehicles.

PHEV engine operational considerations for criteria emissions control and low fuel consumption

As one part of a large research program in plug-in hybrid-electric vehicles (PHEVs), Argonne National Laboratory has tested many conventional, hybrid-electric and plug-in hybrid-electric vehicles. Data were examined from several low-volume aftermarket PHEVs. Found in the study were trade-offs between minimizing emissions and reducing fuel consumption (by using more electrical propulsion). Key to successful emissions control is how the engine is operated during initial start, warm-up, and restart. Temperature management for engine restart is also important. Some data from charge-sustaining operation are contrasted with the charge-depleting results. The challenges in describing blended-PHEV fuel consumption are explored. This paper will examine the interesting challenges unique to blended-type PHEVs, illustrated with test data from several test vehicles.

Advanced Vehicle Performance Assessment

In order to provide answers about the performance of vehicles driven by electrified drivetrains, appropriate test procedures must be developed that are robust and compatible with the technology. In IEA-HEV-Task 17, these results are presented from vehicles tested at the Argonne National Laboratory Advanced Powertrain Research Facility under direction from the U.S. Department of Energy’s Vehicle Technologies research portfolio. Chassis dynamometer testing with controlled conditions was employed and included adoption of sophisticated instrumentation, research techniques and considerable staff expertise in testing advanced automotive vehicle technologies. This process was going on for several years, including BEV and PHEV tests with a Nissan Leaf, a PHEV-converted Prius as well as a Chevy Volt (based on the reporting year 2010). This chapter provides comparisons between the different electrified vehicles in terms of their principal configurations and operating modes, charge-sustaining and electric-only and highlights the major findings.