A Simple and Effective Hardware-in-the-Loop Simulation Platform for Urban Electric Vehicles

This paper deals with hardware-in-the-loop simulation of urban electric vehicles. The proposed platform, which is expected to be used for electric vehicle prototyping, is very simple and effective. Indeed, the induction motorbased powertrain is coupled to DC machine-based load torque emulator taking into account the electric vehicle mechanics and aerodynamics. Experiments are carried-out using the New European Driving Cycle (NEDC) to show that the proposed hardware-in-the-loop simulation system is effective and provides a simple configuration for prototyping electric vehicles

Optimal energy management of HEVs with hybrid storage system

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 obvious and the optimal operation concerning the energy consumption and battery RMS current has to be identified. Most of the past work on the optimal energy management of HEVs only considered one additional power source. In this paper, the control of a hybrid vehicle with a hybrid storage system (HSS), where two additional power sources are used, is presented. Applying the Pontryagin's minimum principle, an optimal energy management strategy is found and compared to a rule-based parameterized control strategy. Simulation results are shown and discussed. Applied on a small compact car, optimal and ruled-based methods show that gains of fuel consumption and/or a battery RMS current higher than 15% may be obtained. The paper also proves that a well tuned rule-based algorithm presents rather good performances when compared to the optimal strategy and remains relevant for different driving cycles. This rule-based algorithm may easily be implemented in a vehicle prototype or in an HIL test bench

Performance comparison of three storage systems for mild HEVs using PHIL simulation

HEVs would contribute to the energy saving and GHE reduction if they are launched massively on the market. A notable effort has been done in simulation in order to optimize the energy consumption and the component sizing. PHIL simulation could be a further step in order to obtain more realistic performance and to compare different solutions including economic aspects. This paper deals with the implementation on a high dynamic test bench of a diesel Mild-hybrid parallel HEV using PHIL technique. Three configurations, corresponding to different energy storage systems, have been tested in the same conditions. Power, energy, consumption and pollutant emission performance, measured on the test bench, are compared and discussed

Performance comparison of three storage systems for mild HEVs using PHIL simulation

HEVs would contribute to the energy saving and GHE reduction if they are launched massively on the market. A notable effort has been done in simulation in order to optimize the energy consumption and the component sizing. PHIL simulation could be a further step in order to obtain more realistic performance and to compare different solutions including economic aspects. This paper deals with the implementation on a high dynamic test bench of a diesel Mild-hybrid parallel HEV using PHIL technique. Three configurations, corresponding to different energy storage systems, have been tested in the same conditions. Power, energy, consumption and pollutant emission performance, measured on the test bench, are compared and discussed

Design, Modelling and Verification of Distributed Electric Drivetrain

The electric drivetrain in a battery electric vehicle (BEVs) consists of an electric machine, an inverter, and a transmission. The drivetrain topology of available BEVs, e.g., Nissan Leaf, is centralized with a single electric drivetrain used to propel the vehicle. However, the drivetrain components can be integrated mechanically, resulting in a more compact solution. Furthermore, multiple drivetrain units can propel the vehicle resulting in a distributed drive architecture, e.g., Tesla Model S. Such drivetrains provide an additional degree of control and topology optimization leading to cheaper and more efficient solutions. To reduce the cost, the drivetrain unit in a distributed drivetrain can be standardized. However, to standardize the drivetrain, the drivetrain needs to be dimensioned such that the performance of a range of different vehicles can be satisfied. This work investigates a method for dimensioning the torque and power of an electric drivetrain that could be standardized across different passenger and light-duty vehicles. A system modeling approach is used to verify the proposed method using drive cycle simulations. The laboratory verification of such drivetrain components using a conventional dyno test bench can be expensive. Therefore, alternative methods such as power-hardware-in-the-loop (PHIL) and mechanical-hardware-in-the-loop (MHIL) are investigated. The PHIL test method for verifying inverters can be inexpensive as it eliminates the need for rotating electric machines. In this method, the inverter is tested using a machine emulator consisting of a voltage source converter and a coupling network, e.g., inductors and transformer. The emulator is controlled so that currents and voltages at the terminals resemble a machine connected to a mechanical load. In this work, a 60-kW machine emulator is designed and experimentally verified. In the MHIL method, the real-time simulation of the system is combined with a dyno test bench. One drivetrain is implemented in the dyno test bench, while the remaining are simulated using a real-time simulator to utilize this method for distributed drivetrain systems. Including the remaining drivetrains in the real-time simulation eliminates the need for a full-scale dyno test bench, providing a less expensive method for laboratory verification. An MHIL test bench for verification of distributed drivetrain control and components is also designed and experimentally verified

Approche systémique pour la modélisation, la gestion de l'énergie et l'aide au dimensionnement des véhicules hybrides thermiques-électriques

The Hybrid Electric Vehicle is a complex system made up of several sources and the arrangement of its transmission can appeal to several components. The possibility of having different sizes of the battery compared to the combustion engine, coupled with the various possible topologies, represent as many degrees of freedom that can be exploited for its energy optimization. The first chapter of this paper exposes this diversity by presenting the different common classifications of hybrid electric vehicles. Apart from a few applications that are intended to increase the dynamic performance of the vehicle (speed and acceleration), the goal of hybridization is mainly the reduction of energy consumption and emissions of pollutants. It is the energy target that is considered in this work. To achieve this goal, optimizations are needed on different plans. For a given use, the energy performance of the hybrid vehicle depends on three strongly interdependent aspects which are i) topology (series, parallel, dual) ii) the sizing of components iii) energy management strategy to share the instantaneous power demand. To understand these different dimensions and their coupling, a systemic approach based on modelling was implemented with the Electric and Hybrid Vehicle team members. This approach has led to the development of a simulation tool, VEHLIB, that allowed to capitalizing different modelling works. This tool, which is presented in the second chapter, has then been used to serve the objectives of the energy management optimization and support the optimal design of hybrid vehicles. Under the MEGEVH network[1] , an opening towards the Energetic Macroscopic Representation (EMR, developed by the L2EP) showed the undeniable contribution of the EMR to the systematic synthesis of complex systems' control. Chapter III, dedicated to energy management, presents a State of the art of the methods developed these past ten years, and our contribution in this area. The latter was initially in the use and improvement of the rule based methods. Then two theses under my supervision proposed the optimization of the energy management in terms of fuel consumption. All these works relied on an approach using modeling, as well as experimentation on a test bench in an emulated vehicle configuration (Hardware In the Loop - HIL - simulation). Was also highlighted for the hybrid electric vehicles the problem of the relative size of the battery and electrical machines compared to the size of the combustion engine. Indeed, for a given dynamic specifications, several sizing may qualify. A help to the optimal sizing procedure has been implemented in the team and has been the subject of work described in Chapter 4. Theoretically, the general definition of hybrid vehicles is not limited to thermal - electric version which was the subject of the majority of our contributions so far. Other possibilities for association of sources (fuel cell, supercapacitors, flywheel, ...) are being considered and are the subject of recent work. We can speak in this case of multi-source vehicle. Either at topology level or at the level of the energy management and components' sizing, research is still needed to try to generalize the concepts already developed for the hybrid electric vehicle. The use of structuring formalisms like the EMR would help to understand the growing complexity and achieve the articulation between the different levels of control, local and global. On these different dimensions, perspectives and opportunities are detailed in the last chapter of this report.Le véhicule hybride est un système complexe constitué de plusieurs sources et dont l'agencement de sa transmission peut faire appel à plusieurs composants. La possibilité d'avoir des dimensionnements différents de la batterie par rapport au moteur thermique, couplée aux diverses topologies possibles, représentent autant de degrés de liberté qui peuvent être exploités pour son optimisation énergétique. Le premier chapitre de ce mémoire expose cette diversité en présentant les différentes classifications usuelles des Îhicules hybrides. Mises à part quelques applications qui visent à augmenter les performances dynamiques des Îhicules (vitesse et accélération), l'objectif de l'hybridation est principalement la réduction de la consommation énergétique et des émissions de polluants. C'est l'objectif énergétique qu'on considère dans ces travaux. Afin d'atteindre cet objectif, des optimisations sont nécessaires sur différents plans. Pour un usage donné, les performances énergétiques du Îhicule hybride dépendent de trois aspects fortement interdépendants qui sont i) la topologie (série, parallèle, mixte) ii) le dimensionnement des composants iii) la stratégie de gestion de l'énergie entre les différentes sources. Pour appréhender ces différentes dimensions et leur couplage, une approche systémique s'appuyant sur la modélisation a été mise en place avec les membres de l'équipe Véhicules électriques et hybrides du LTE. Cette approche a abouti au développement d'un outil de simulation, VEHLIB, qui a permis de capitaliser les différents travaux de modélisation. Cet outil, présenté dans le deuxième chapitre, a été utilisé ensuite pour servir les objectifs d'optimisation de la gestion de l'énergie et d'aide au dimensionnement optimal des Îhicules hybrides. Dans le cadre du réseau MEGEVH , une ouverture vers la Représentation Energétique Macroscopique (REM, développée au L2EP) a permis de démontrer l'apport incontestable de la REM pour la synthèse systématique de la commande des systèmes. Le chapitre III, consacré à la gestion de l'énergie, présente un état de l'art des méthodes développées ces dix dernières années, ainsi que notre contribution dans ce domaine. Cette dernière a consisté dans un premier temps en l'utilisation et l'amélioration des méthodes à base de règles expertes. Ensuite deux thèses ont proposé l'optimisation de la gestion de l'énergie de point de vue de la consommation de carburant. Tous ces travaux se sont appuyés sur une démarche utilisant la modélisation, ainsi que l'expérimentation sur banc d'essai à l'échelle 1 dans une configuration de Îhicule émulé (Hardware In the Loop - HIL - simulation). Il s'est posé également, pour le Îhicule hybride, le problème de la taille relative de la batterie et des machines électriques vis-à-vis de la taille du moteur thermique. En effet, pour un cahier des charges dynamique donné, plusieurs dimensionnements peuvent être admissibles. Une procédure d'aide au dimensionnement optimal a été mise en oeuvre dans l'équipe et a fait l'objet de travaux exposés dans le chapitre 4. En théorie, la définition générale du Îhicule hybride ne se limite pas à la version thermique - électrique qui a fait l'objet de la plus part de nos contributions jusqu'ici. D'autres possibilités d'association de sources (Pile à combustible, supercondensateurs, volent d'inertie, ...) sont envisagées et font l'objet de travaux récents. On peut parler dans ce cas de Îhicule multi-sources. Tant au niveau des topologies, qu'au niveau de la gestion de l'énergie et du dimensionnement, des travaux de recherches sont encore nécessaires pour tenter de généraliser les concepts déjà développés pour le Îhicule hybride thermique-électrique. L'utilisation de formalismes structurants à l'image de la REM permettrait d'appréhender la complexité croissante et de réaliser l'articulation entre les différents niveaux de commande, locale et globale. Sur ces différentes dimensions, des ouvertures et des perspectives sont détaillées dans le dernier chapitre de ce mémoire