Next Generation HEV Powertrain Design Tools: Roadmap and Challenges

Hybrid electric vehicles (HEVs) represent a fundamental step in the global evolution towards transportation electrification. Nevertheless, they exhibit a remarkably complex design environment with respect to both traditional internal combustion engine vehicles and battery electric vehicles. Innovative and advanced design tools are therefore crucially required to effectively handle the increased complexity of HEV development processes. This paper aims at providing a comprehensive overview of past and current advancements in HEV powertrain design methodologies. Subsequently, major simplifications and limits of current HEV design methodologies are detailed. The final part of this paper defines research challenges that need accomplishment to develop the next generation HEV architecture design tools. These particularly include the application of multi-fidelity modeling approaches, the embedded design of powertrain architecture and on-board control logic and the endorsement of multi-disciplinary optimization procedures. Resolving these issues may indeed remarkably foster the widespread adoption of HEVs in the global vehicle market

Reducing the energy consumption of electric buses with design choices and predictive driving

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Assessing lightweight layouts for a parallel Hybrid Electric Vehicle driveline

The presence of multiple power sources and the several possible architectures that can be designed when referring to hybrid electric vehicle (HEV) powertrains complicate the identification of an optimal HEV configuration. Among the diverse parameters that can be chosen in design and sizing processes of a parallel full HEV, the number of gears and the gear ratios in the transmission are considered as fulcra of this case study. For this scope, five different transmissions have been sized while assessing drivability and acceleration performance along with the fuel economy capability. A dynamic programming-based approach algorithm has been utilized for controlling the HEV, thus providing reliable outcomes and enhancing the consistency of the study. The results obtained in the sizing process suggest that the presence of an electric machine may mitigate the effect of the lower number of gears and enhance the fuel consumption efficiency even when reducing the number of gears in the transmission to 2 or 3. More precisely, even though they might be associated to slightly higher fuel consumption and, in turn, operative costs compared with the other considered configurations, these drawbacks can be overcome by the higher savings in production costs, thus suggesting parallel full HEVs with a reduced number of gears as an appealing design option

Design and testing of the WVU Challenge X competition hybrid diesel electric vehicle

The WVU Challenge X Team was tasked with improving the fuel economy of a 2005 Chevrolet Equinox while maintaining the stock performance of the vehicle. A through-the-road-parallel hybrid diesel-electric was implemented to accomplish this goal. The greatest potential for improvement to hybrid electric vehicle technology is in energy storage in terms of cost, size, lifespan, and efficiency. Currently, battery cost is limited by the expense of the base materials. The characteristically low power density of electrochemical energy storage rather than energy density is responsible for the size of current hybrid energy storage systems. A limited lifespan is inherent in electrochemical energy storage. The WVU Challenge X Team sought to produce a hybrid electric vehicle with a high power, efficient energy storage system with an extended lifespan and costs not limited by the base materials used in manufacture. The team selected an ultracapacitor pack with an effective energy storage of 0.17 kWh to accomplish those goals. The work presented analyzed this energy storage system, the powertrain architecture associated with it, and the unique control strategy developed to control it. The fuel economy of the stock vehicle was compared with the diesel powertrain only as well as the complete hybrid electric powertrain selected by the team. Road load was calculated over the course of the competition drive cycle and was compared to the power capability for the electric motors. The cycle energy and power were calculated for each braking and power event and the statistics compared with the capabilities of the energy storage system, hybrid electric system, and the actual performance during the 2007 Challenge X competition. The small effect of a 20% reduction in the size of the selected energy storage system and its efficiency were also discussed. Finally, suggestions for improvement to the architecture, design and control strategy were discussed

Modeling, Simulation, and Concept Studies of a Fuel Cell Hybrid Electric Vehicle Powertrain

This thesis focuses on the development of a fuel cell-based hybrid electric powertrain for smaller (2 kW) hybrid electric vehicles (HEVs). A Hardware-in-the-Loop test rig is designed and built with the possibility to simulate any load profile for HEVs in a realistic environment, whereby the environment is modeled. Detailed simulation models of the test rig are developed and validated to real physical components and control algorithms are designed for the DC/DC-converters and the fuel cell system. A state-feedback controller is developed for the DC/DC-converters where the state-space averaging method is used for the development. For the fuel cells, a gain-scheduling controller based on state feedback is developed and compared to two conventional methods. The design process of an HEV with regard to a given load profile is introduced with comparison between SuperCaps and batteries. The HEV is also evaluated with an introduction to different powermanagement concepts with regard to fuel consumption, dynamics, and fuel cell deterioration rate. The powermanagement methods are implemented in the test rig and compared

ME-EM 2013-14 Annual Report

Table of Contents Human-Centered Engineering Enrollment & Degrees Graduates Faculty & Staff Alumni Donors Contracts & Grants Patents & Publicationshttps://digitalcommons.mtu.edu/mechanical-annualreports/1005/thumbnail.jp

Electric Vehicle Efficient Power and Propulsion Systems

Vehicle electrification has been identified as one of the main technology trends in this second decade of the 21st century. Nearly 10% of global car sales in 2021 were electric, and this figure would be 50% by 2030 to reduce the oil import dependency and transport emissions in line with countries’ climate goals. This book addresses the efficient power and propulsion systems which cover essential topics for research and development on EVs, HEVs and fuel cell electric vehicles (FCEV), including: Energy storage systems (battery, fuel cell, supercapacitors, and their hybrid systems); Power electronics devices and converters; Electric machine drive control, optimization, and design; Energy system advanced management methods Primarily intended for professionals and advanced students who are working on EV/HEV/FCEV power and propulsion systems, this edited book surveys state of the art novel control/optimization techniques for different components, as well as for vehicle as a whole system. New readers may also find valuable information on the structure and methodologies in such an interdisciplinary field. Contributed by experienced authors from different research laboratory around the world, these 11 chapters provide balanced materials from theorical background to methodologies and practical implementation to deal with various issues of this challenging technology. This reprint encourages researchers working in this field to stay actualized on the latest developments on electric vehicle efficient power and propulsion systems, for road and rail, both manned and unmanned vehicles

Computational fluid dynamics modelling of a polymer electrolyte membrane fuel cell under transient automotive operations

A polymer electrolyte membrane (PEM) fuel cell is probably the most promising technology that will replace conventional internal combustion engines in the near future. As a primary power source for an automobile, the transient performance of a PEM fuel cell is of prime importance. In this thesis, a comprehensive, three-dimensional, two-phase, multi-species computational fuel cell dynamics model is developed in order to investigate the effect of flow-field design on the magnitude of current overshoot/undershoot and characteristics of current response when the cell is subjected to different voltage change patterns representing an automotive operation. The meshing strategy specific to PEM fuel cell modelling is studied in a systematic manner and employed in all analyses presented in this thesis. The predicted results compare very well with experimental data under both steady-state and transient operations. Two computational domains are used – the straight single-channel and practical-scale square cells with parallel, single-serpentine, and triple-serpentine flow-fields. The results from the straight single-channel cell suggest that the magnitude of current overshoot/undershoot increases with the voltage change rate. The behaviour of a current response curve is the result of complex interplay between water content at both sides of the membrane. It is also found that current overshoot/undershoot is amplified with the presence water flooding in the cell. The results from the square cell reveal that current overshoot/undershoot is caused by non-uniformity of local current density over the active area confirming the effect of flow-field geometry on transient response of the cell. By comparing the transient performance between the three flow-fields, a direct relationship between degree of water flooding in the cell and magnitude of current overshoot/undershoot has been found. A conclusion has been drawn which states that a cell with superior water removal ability will experience smaller current overshoot/undershoot