Environomic Design of Vehicle Integrated Energy System - Application on a Hybrid Electric Vehicle Energy System

With the increasing trend of mobility of the human population, vehicles have to face the problem of primary energy resources scarcity. The vehicles need higher efficiency and better adaptation to the alternative energy sources. The need to improve the efficiency of the vehicle energy system motivates to search for innovative solutions during the design process. The main design criteria for modern sustainable development of vehicle powertrain are the high energy efficiency of the conversion system, the competitive cost and the lowest possible environmental impacts. These objectives are most of the time antagonistic. To cope with this challenge the automotive engineers need a structured optimization methodology. A multi-objective optimization methodology is being applied as search for the best powertrain design solutions. This kind of approach named "multi-objectives optimization" is based on genetic algorithms, which are based on the process of natural selection. An innovative decision- making methodology, using this optimization technic is currently under development at PSA Peugeot Citroen. The idea is to obtain simultaneously a population of possible design solutions corresponding to the most efficient energy system definition for a vehicle. These solutions are optimal from a technical, economic and environmental point of view. In this article the methodology is applied on a hybrid electric vehicle study in order to define the powertrain configuration of the vehicle, estimate the cost of the powertrain equipment and show the environmental impact of the technical choices on the lifecycle perspective of the vehicle. For that a physical model of a hybrid electric vehicle is made. This model is coupled with a cost model for the vehicle and life cycle assessment (LCA) technics are used for the environmental assessment. After multi-objective optimization, the outcoming solutions from the Pareto frontiers curve are analysed.

Environomic design of vehicle energy systems for optimal mobility service

Zlatina Kirilova Dimitrova, François Maréchal

The main design criteria for the modern sustainable development of vehicle powertrains are the high energy efficiency of the conversion system, the competitive cost and the lowest possible environmental impacts. An innovative decision making methodology, using multi-objective optimization technics is currently under development. The idea is to obtain a population of possible design solutions corresponding to the most efficient energy system definition. These solutions meet technical, economic and environmental optimality. This article applies the methodology on an electric vehicle, in order to define the powertrain configuration of the vehicle, to estimate the cost of the equipment and to show the environmental impacts of the technical choices of the powertrain configurations in a life cycle perspective. A physical model of the electric vehicle is made and coupled with a cost model for the vehicle and LCA (Life Cycle Assessment) technics are used for the environmental assessment. After multi-objective optimizations with thermo-economic and environmental objectives, the solutions obtained from the Pareto frontiers curve are analyzed. Conclusions about the environomic design of the vehicle for optimal mobility service are made. The greenhouse gas emissions are calculated from a well-to-wheel perspective for different countries of use of the electric vehicle, according to their respective electricity production mixes.

Elsevier2014

Environomic design of vehicle integrated energy systems

Zlatina Kirilova Dimitrova

To meet the targets of sustainable development and greenhouse emission reduction of the future vehicles fleet, the automotive industry needs to deploy cost-competitive and efficient advanced energy conversion systems for the future commercial personal vehicles. The efficiency improvement needs induce to search new structured methodologies allowing the integration of the efficiency/cost vision for different vehicle energy technologies, in the earlier design stage of the new vehicles and their propulsion systems. The assessment of environmental impacts is also needed. In this context, the aim of this thesis is to develop a generic methodology for the design of the vehicle energy systems, which can consider on a holistic way, the âenvironomicâ criteria. To design and evaluate the competitiveness of energy integrated systems for vehicles, a systematic comparison including thermodynamic, economic and environmental considerations is required. This thesis presents the development of a systematic environomic optimization for vehicle energy systems. The efficiency, economic and environmental performances are assessed for different energy technology options and their integration in advanced vehicles powertrains. The performances indicators are compared and the trade-off are assessed to support decision making and to identify optimal energy systems configurations. The results from the energy integration studies reveal the potential of the combinations of different options of energy recovery and the integration of the energy services on the vehicle efficiency. The additional cost of the ORC installation is estimated to be 40 -55 â¬/kW. The competitiveness and the trade-off of different advanced powertrains (electric, hybrid electric and hybrid pneumatic) are assessed and optimal design configurations are pointed out. It appears that different powertrain configurations are in competition for optimal mobility service depending on the selected environomic criteria.

EPFL2015

Techno–economic design of hybrid electric vehicles and possibilities of the multi-objective optimization structure

Zlatina Kirilova Dimitrova, François Maréchal

The design criteria for modern sustainable development of vehicle powertrain are the high energy efficiency of the conversion system, the competitive cost and the lowest possible environmental impacts. In this article a multi-objective optimization methodology is applied on hybrid electric vehicles study in order to define the optimal powertrain configurations of the vehicle, estimate the cost of the power- train equipment and show the environmental impact of the technical choices on the lifecycle perspective of the vehicle. The study illustrates optimal design solutions for low fuel consumption vehicles – between 2 L/100 km and 3 L/100 km. For that a simulation model of a hybrid electric vehicle is made. This model is coupled with a cost model for the vehicle. The techno–economic optimizations are performed for two case studies, illustrat- ing the possibilities of the optimization superstructure. Firstly the life cycle inventory is written as a func- tion of the parameters of the techno–economic model. In this way, the obtained environmental indicators from the life cycle assessment are calculated as a function of the decision variables for the vehicle design. In the second example the parameters of the energy distribution function are included as decision vari- ables in the techno–economic optimization and are simultaneously optimized.

2016

Environomic design of vehicle integrated energy systems

Zlatina Kirilova Dimitrova

EPFL2015