Rochdi Trigui

Université Gustave Eiffel · Laboratoire Transport et Environnement (LTE)

Battery lifetime is an important parameter in the life cycle assessment (LCA) of a plug-in hybrid-electric vehicle (PHEV). This paper aims to study the impact of various parameters on the battery aging of a PHEV. For this purpose, model-based use cases are generated, the outputs of which are the daily driven distances for a period of one year, rech...

This article deals with on the rule-based Energy Management Strategy (EMS) used for Hybrid Electric Vehicles (HEVs). Different methods are presented, with a special focus on the load following strategy. The choice of the system operations is presented for battery charge sustaining and charge depleting operations. A parallel hybrid architecture is c...

Hybrid Electric Vehicles are effective solutions to reduce energy consumption and pollution emission in the transport sector. They however present multiple energy sources and complex drivetrain structures involving numerous energy transformers. Their control is therefore complex and represents a key point to achieve the expected performance. The en...

Dear Colleagues, Urban air quality and climate change are at the heart of environmental concerns. Although internal-combustion-engine vehicles are expected to be replaced in the future by zero-emission vehicles, hybrids play a key role in the transition to all-electric vehicles. They can have many forms (sustaining hybrids, plug-in hybrids and ran...

The energy consumption of an electric vehicle is primarily due to the traction subsystem and the comfort subsystem. For a regular trip, the traction energy can be relatively constant but the comfort energy has variation depending on seasonal temperatures. In order to plan the annual charging operation of an eco-campus, a simulation tool is develope...

This paper deals with the real-time energy management of a fuel cell/battery/supercapacitors energy storage system for electric vehicles. The association of the battery and the supercapacitors with the fuel cell aims to reduce the hydrogen consumption while limiting the constraints on the fuel cell and the battery. In this paper, a real-time optimi...

Smart charging is becoming an important and indispensable asset for electric bus fleet to become economically competitive. This paper proposes an innovative approach for setting overnight charging schedules of electric bus fleet. This approach uses nonlinear programming in order to minimize both the electricity cost and the battery aging. The optim...

Electro-mobility is increasing significantly in the urban public transport and continues to face important challenges. Electric bus fleets require high performance and extended longevity of lithium-ion battery at highly variable temperature and in different operating conditions. On the other hand, bus operators are more concerned about reducing ope...

An overview of the worldwide deployment of Electric Buses (EBs) is presented with a focus on TRANSDEV strategy. The results show an important increase in the EBs sells during the last decade. Nevertheless, because of the size of their batteries, EBs fleets could have significant impacts on the grid, which requires a smart charging management. The s...

The use of electric buses (EBs) is expected to increase significantly in the coming years. Uncontrolled charging of EBs can affect not only the power grid (grid instability, harmonic pollution...) but also the operating cost. This paper introduces an optimal charging strategy based on charging schedule planning and modulation of charging power for...

The use of electric buses (EBs) is expected to increase significantly in the coming years. Uncontrolled charging of EBs can affect not only the power grid (grid instability, harmonic pollution...) but also the operating cost. This paper introduces an optimal charging strategy based on charging schedule planning and modulation of charging power for...

Energy management of multi-source vehicles is a complex task. The higher the number of sources becomes, the higher the complexity is. Moreover, the energy management strategies have to face real-time issues. As a consequence, it is important to find some testing procedures to assess the developed strategies, in real-time conditions before implement...

One of the most important research interests in the automotive sector is energy consumption and pollutant emissions reduction. Usage developments are continuing in parallel to technological evolution to maximize the efficiency of the system. One of the recent methods in usage field is eco-driving. It refers to a fuel economic driving behaviour whic...

Energy management of multi-sources vehicles is a complex task. The higher the number of sources becomes, the higher the complexity is. In this study, a decomposed energy management strategy is used for a vehicle fed by three energy sources: a fuel-cell, a battery and supercapacitors. This decomposition allows simplifying the synthesis of the Energy...

The paper deals with real-time energy management strategies for a hybrid energy storage system including a battery and supercapacitor for an electric vehicle. Besides efficiency concerns, a key issue for real-time applications is ensuring safe operations for the considered system. In such a system it is mandatory to limit the supercapacitor voltage...

Eco-driving is an efficient and economical way to reduce vehicles' energy consumption. Eco-driving techniques have been practiced for decades. However, only conventional vehicles have been deeply studied particularly by using optimization and modelling to identify the best energetically speed profiles. In this paper eco-driving of hybrid vehicles i...

Eco-driving is an efficient and economical way to reduce vehicles' energy consumption. Eco-driving techniques have been practised for decades. However, only conventional vehicles have been deeply studied particularly by using optimisation and modelling to identify the energetically best speed profiles. In this paper, eco-driving of hybrid vehicles...

A hybrid energy storage system for electric vehicle using supercapacitors and a battery is studied. Using energetic macroscopic representation formalism, an inversion-based control (IBC) can be deduced. A comparison between IBC and two other control schemes is performed within a practical aspect. Simulation and experimental tests with a reduced-sca...

Electric vehicles are facing a real challenge as they are expected to reduce drastically energy consumption and air pollution of transport. However their performances remain under users' expectation mainly concerning the range and its fluctuation. "Eco-behavior" use like eco-driving could help to reduce range weakness. This paper proposes an approa...

This paper deals with energy management for electric vehicle using SuperCapacitors (SCs) and battery. SCs are connected to the DC bus through a converter whereas battery is directly connected to the DC bus. Using the inversion-based rules of Energetic Macroscopic Representation (EMR), a systematic control structure can be deduced. Some differences...

A way to improve the existing hybrid vehicles is the global optimal design of their components when related to their actual use. This paper proposes a global optimal design method for Power-Split Hybrid Electric Vehicles (PS-HEVs) equipped with an Electric Variable transmission. A genetic algorithm is used to optimize system parameters. The process...

Nowadays, the eco-driving technique represent one possible mean to reduce the energy consumption and the pollutants emission of vehicles. Besides the very low investment needed for such an option, its suitability to be applied even to old vehicles makes its impact important and immediate. The work presented here aims to quantify in a first approach...

The deployment of Electric Vehicles (EVs) is constrained mainly by the limited battery capacity, the limited number of charging stations and the recharging time. Our goal is to promote the use of EV by developing energy-efficient routing tools. To overcome the autonomy limitation we propose a methodology for the EV routing problem with recharging s...

The deployment of Electric Vehicles (EVs) is constrained mainly by the restricted autonomy, the lack of charging stations, the battery recharge time and recuperation capability (e.g. braking phases or downhill). In this study we aim to develop a green routing tool to encourage the use of EV. To overcome the autonomy limitation we propose a methodol...

Abstract-The deployment of Electric Vehicles (EVs) needs an optimized and cost-effective implementation of charging stations. As a decision support tool for network design, we define a methodology to allocate charging stations in a real network. This study uses trip OD matrix information from household travel survey coupled with a dynamic vehicle m...

This paper deals with inversion-based control of EVs with Hybrid Energy Storage System based on battery and supercapacitors. Using inversion rules of Energetic Macroscopic Representation (EMR), a systematic control structure can be deduced. However, it points out the possibility of an algebraic loop issue. Furthermore, it may result in computation...

L'éco-conduite des véhicules représente aujourd'hui un des moyens pour réduire la consommation d'énergie et limiter les émissions de CO2 dans l'atmosphère. En plus du coût d'investissement très faible de cette option, son application possible à des véhicules anciens rend son impact important et immédiat.Les travaux exposés ici visent à quantifier d...

In this work the trade-off between economic, therefore fuel saving, and ecologic, pollutant emission reducing, driving is discussed. The term eco-driving is often used to refer to a vehicle operation that minimizes energy consumption. However, for eco-driving to be environmentally friendly not only fuel consumption but also pollutant emissions shou...

Automotive engineers and researchers have proposed different topologies for series–parallel hybrid electric vehicles (SP-HEVs). The Toyota Hybrid System (THS) is the best known SP-HEV-based vehicle, but alternative solutions, such as electric variable transmission (EVT), have been also proposed. An efficient comparison between these different solut...

This paper presents a methodology to optimally design the drive train of an Extended Range Electric Vehicle (EREV) according to the use specifications from European mobility surveys. At first the analysis of car uses is carried out, and a process aiming to classify the car use profiles into different clusters is proposed. Clusters that could fit ty...

Energy storage systems are a key point in the design and development of electric and hybrid vehicles. In order to reduce the battery size and its current stress, a hybrid storage system, where a battery is coupled with an electrical double-layer capacitor (EDLC) is considered in this paper. The energy management of such a configuration is not obvio...

This paper questions the relevance of microscopic traffic models for estimating the impact of traffic strategies on fuel consumption. Urban driving cycles from the ARTEMIS database are simplified into piecewise linear speed profiles to mimic the classical outputs of microscopic traffic flow models. Fuel consumption is estimated for real and simplif...

A hybrid energy storage system (HESS) composed of electrochemical batteries and supercapacitors is considered. The supercapacitors aim to manage the peak power and thus increase the lifetime of the battery. A control scheme of this HESS is obtained by inversion of its energetic macroscopic representation. This control scheme enables different energ...

This paper presents the control of a Permanent Magnet Electric Variable Transmission (PM-EVT) for Hybrid Electric Vehicles (HEVs). Consisting of two electric machines, the EVT realizes the power split function in an electromagnetic way rather than in a mechanical way. A specific PM-EVT has been designed for Toyota Prius II. The control scheme of th...

Customer acceptance of Battery Electric Vehicles (BEVs) depends strongly on the performance of the Energy Storage System (ESS). Energy density, power density and lifetime of ESSs are three key parameters to be optimized in a BEV. For this purpose the use of a hybrid energy source on board of electric vehicles has been proposed and analyzed in liter...

Evaluating and estimating vehicle energy consumption has always been an important issue while determining CO2 emissions. Several studies have focused on the energy consumption of various types of vehicles (thermal, hybrid or electric) with the aim of reducing consumption. Eco-routing is our first concern and our work aims to develop energy-efficien...

Evaluer et estimer la consommation énergétique des véhicules a toujours été un élément important lors de la détermination des émissions de CO2, gaz responsable de l'effet de serre. Plusieurs études se sont intéressées à l'évaluation de la consommation de tout type de véhicule (thermique, hybride ou encore électrique) avec comme objectif la réductio...

In this work potential gains in fuel consumption due to eco-driving will be discussed. A vehicle model and numerical optimization methods are used to identify optimal vehicle operation. To advice the driver of the realistically optimal velocity trajectory for a given trip, road and traffic constraints have to be taken into account. Most prior work...

Eco-driving is an immediately applicable way to reduce fuel consumption in road vehicles by changing vehicle operation such that system efficiency is maximised. In order to identify the maximum potential of eco-driving a numerical method that computes the optimal velocity profile for a specified mission is presented here. An inverse vehicle model i...

Optimizing traffic management systems requires the development of dynamic traffic flow models capable of estimating environmental externalities. However, such models only produce simplified trajectories. Therefore they cannot be directly coupled with traditional emission models based on real trajectories, i.e. observed experimentally. The main obje...

Due to environmental concerns and scarcity on non-renewable fossil fuels researchers are currently looking for new, more fuel efficient solutions in the transportation sector. With its ability to regenerate kinetic energy while braking the electric vehicle is an attractive solution. In addition the electrification gives flexibility for the source o...

Hybrid vehicles are found to be one solution to reduce fuel consumption in the transportation sector. Eco-driving is a concept that is immediately applicable by drivers to improve the efficiency of their vehicle. In this work the potential of eco-driving for hybrid drive train vehicles is discussed. The operation of hybrid vehicles is strongly depe...

In our effort to assess battery usage in transportation applications, we analyzed the anticipated battery duty profile of traction batteries in the context of an urban heavy-duty passenger trolleybus. Propulsion-wise, trolleybuses rely on grid-provided electrical power as well as an onboard high power diesel generator for out-of-trolley-network ope...

This paper presents the application of optimal control to two series-parallel hybrid architectures. The dynamic programming method is applied to Toyota Hybrid System (THS) and a hybrid vehicle with Electric Variable Transmission (EVT). First the theoretical approach of dynamic programming and its application to SP-HEVs is presented. The way to take...

Hybrid vehicles are complex systems using more than one energy source. Different topologies have been developed and can satisfy the dynamic specifications with more or less energy efficiency. The fuel economy potential comparison between different topologies is not an obvious task because of the diversity of the hybrid solutions and the strong infl...

Hybrid vehicles are complex systems using more than one energy source. Different topologies have been developed and can satisfy the dynamic specifications with more or less energy efficiency. The fuel economy potential comparison between different topologies is not an obvious task because of the diversity of the hybrid solutions and the strong infl...

This paper focuses on an analysis of technical requirements for the design of a permanent-magnet-type electric variable transmission (PM-EVT), which is a novel series-parallel hybrid electric vehicle (HEV) powertrain concept. Similar to the planetary gear train used in Toyota Prius II, the EVT also realizes the power-split function. However, it is...

The six papers in this special section focus on state-of-the-art research and development, as well as future trends in modeling, design, control, and optimization of advanced power and propulsion systems for modern transportation systems.

Nowadays, no electrochemical energy system presents a competitive operation if compared with internal combustion engine, which is the reason for combining electrochemical energy systems to obtain a hybrid energy storage system. This paper presents a fuel cell-battery-ultracapacitor system for vehicle application. The objective of this paper is to p...

To reduce fuel consumption in the transportation sector research focuses mainly on the development of more efficient drive train technologies and alternative drive train designs. Another and immidiately applicable way found to reduce fuel consumption in road vehicles is to change vehicle operation such that system efficiency is maximized. The conce...

As a novel series-parallel hybrid powertrain, the electric variable transmission (EVT) has gained much attention last years. With EVT, a power split function can be realized by changing its torque and speed in an electromagnetic way. Various machine types can be introduced into the concept of EVT. This paper will present a permanent magnet EVT (PM-...

The modelling of a clutch in a power train transmission is a delicate process because of its non-linear behaviour. Two different states have to be taken into account: when the clutch is locked and when the clutch is slipping. Moreover the clutch has often to be controlled automatically in parallel hybrid electric vehicles (HEVs). An energetic macro...

Real-time energy management of HEVs is a key point for performing effective fuel economy optimization. Offline methods have been developed for energy management optimization when the drive cycle is known. Online real-time methods can provide good results but can only ensure suboptimal management. In this study it is assumed that information about t...

Hybridization, that is adding one or more electric machines powered by a battery to a conventional powertrain, is a promising way to achieve fuel consumption and pollutant emission reduction. Several mechanical arrangements can be considered. A control strategy is required to choose, at each sampling time, the power split between the engine and the...

ADVANCED electric drive traction systems are being developed in order to ensure better energy efficiency for the emerging and future transportation systems such as electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), fuel cell vehicles (FCVs), as well as electrified and advanced tractions and propulsio...

This paper focuses on a permanent magnet (PM) machine based electric variable transmission (PM-EVT) for HEV applications. The basic idea of EVT is firstly given as well as a state-of-the-art. To choose an appropriate PM-EVT structure, a detailed description of possible architectures is presented and the specifications are defined based on the well-...

Using different approaches, modeling for different HEVs has been studied. Generally, considering the different combinations of components, each architecture has its own modeling. The modeling and control design of different HEVs could be achieved in a general way, despite the fact that HEVs can be very different from each other in terms of structur...

Silicon carbide (SiC) power semiconductor devices are known to have potential benefits over conventional silicon (Si) devices, particularly in high power applications such as hybrid electric vehicles (HEVs). Recent literature studying the use of SiC JFETs in HEV inverters indicate a substantially increased gas mileage. This paper further investigat...

The energy storage is a key issue for traction applications like Electric Vehicles (EVs) or Hybrid Electric Vehicles (HEVs). Indeed, it needs a higher power and energy density, a right size, a long lifetime and a low cost. A Hybrid Energy Storage System (HESS) using batteries and supercapacitors seems to be an appropriate device to fulfill these co...

This paper presents a comparison between two offline optimisation methods for energy management applied to electrical vehicle with one electrical machine and fed by a hybrid storage system composed of batteries and ultra-capacitors. After a short presentation of the two methods, they are applied and compared to the case of an electric micro bus.

Hybrid electric vehicles (HEVs) would contribute to energy saving and greenhouse effect reduction if they were to be massively launched on the market. A notable effort has been done in simulation to optimize energy consumption and component sizing. Power-hardware-in-the-loop (PHIL) simulation could be a further step to obtain more realistic perform...

The control strategies of hybrid electric vehicles (HEV) consist of determining an optimal power split between different energy sources. The objective is to improve fuel economy and reduce pollutant emissions of the vehicle. In this paper a global optimization algorithm based on Lagrange formalism is recalled. This algorithm is then embedded within...

The energy storage is key issue for traction applications like electric vehicles (EVs) or hybrid electric vehicles (HEVs). Indeed, it needs a higher power and energy density, a weak bulk and size, a long lifetime and a low cost. A hybrid energy storage system (ESS) using batteries and super capacitors, seems to be a good device to answer to these c...

An offline optimized energy management of a plug in series hybrid microbus is used for optimal component sizing and CO2 versus cost analysis. Comparison between fixed-rate battery discharge management and a global trip optimization are first performed. Then a parametrical study on components sizing is presented and give some elements concerning the...

An energetic macroscopic representation (EMR) is used to establish the global modeling of different hybrid vehicles. EMR is a graphical modeling tool to describe electromechanical systems using causal modeling or functional modeling. It has helped in modeling a series-parallel hybrid vehicle using a planetary gear and the model is used to describe...

In this paper, we describe the global approach that has been developed at INRETS-LTE for hybrid powertrain sizing, consumption gain evaluation, and optimal control. The procedure is described in the particular case of a two clutch parallel hybrid architecture, but could apply to any other configuration. Firstly the context and the common issues rel...

La concentration de CO2 dans l'atmosphère est passée de 280 ppm au milieu du 18e siècle à 383 ppm en 2007 avec un taux de croissance soutenu durant les dernières décennies. D'après les dernières estimations de l'AIE, les émissions mondiales en 2006 dues à l'énergie sont en hausse de 3,5 % par rapport à 2005 avec un total de 28 Gt de CO2 (1). Au niv...

Un calculateur capable d’optimiser la consommation d’énergie tout en ménageant les batteries dans les moteurs hybrides. C’est le résultat des travaux de l’équipe "Véhicules électriques et hybrides", au Laboratoire Transport Environnement, et du Laboratoire des Technologies Nouvelles.

To optimize the operation of internal combustion engine (ICE), maximize fuel economy, and minimize emissions, many novel traction schemes have been developed. Among those, an electromechanical converter known as electric variable transmission (EVT) was presented in, which enables a continuously variable transmission (CVT), starter, and generator. I...

Après le premier volume de Paroles de chercheurs, paru en 2005 et consacré à la sécurité routière "Sur la route... la sécurité", l'INRETS a recueilli d'autres points de vue de chercheurs sur le thème de la mobilité. Pourquoi et comment nous déplaçons-nous ? Quels sont les grands enjeux de la mobilité aujourd'hui et demain ? Comment les systèmes de...

Hybrid vehicles use two energy sources for their propelling. Usually an internal combustion engine (ICE) is used with one or more electric machine(s) (EM). The problem is then to split the driver power demand between the ICE and the EM in order to minimize a criterion, usually the fuel consumption. A global optimization algorithm based on optimal c...

A hybrid electric vehicle is a combination of two power sources: one unidirectional power source based on an internal combustion engine (ICE), and the other bidirectional based on batteries or electric energy storage, plus electric machines (EM). Different ways of combination lead to different vehicle architectures. But these hybrid vehicles have t...

Urban buses must deal with the challenge of decreasing local nuisances such as air pollution and noise. Hybrid driveline could be a technological response to these requirements. In this context, the Transport and Environment Lab of the INRETS is collaborating with a French body manufacturer with the aim to develop and optimize a plug-in series hybr...

Certain difficulties arise when attempting to model a clutch in a power train transmission due to its nonlinear behavior. Two different states have to be taken into account-the first being when the clutch is locked and the second being when the clutch is slipping. In this paper, a clutch model is developed using the energetic macroscopic representa...

Hybrid vehicles use two energy sources for their propelling. In order to investigate an optimal splitting of the power flows between the engine and the electric machine, an optimal control algorithm is recalled. A new formulation using maps allows a very fast solving this problem which then may be used in real time control. In the particular case o...

For hybrid vehicles, it is difficult to obtain realistic component models and actual interaction between subsystems without carrying out experiments. INRETS has performed a coupled approach associating simulation using its in house VEHLIB software together with experimental validation. This paper highlights the evaluation and modelling of the Toyot...

This paper presents a backward approach for HEVs modelling with a global optimization method. This method allows to determine the maximal potential gain in terms of CO2 emission for a given HEV. It is then applied to size and compare two hybrid architectures and conventional vehicles. Finally a comparison on measurement, classical forward approach...