Walter Lhomme

Design and Control of a supercapacitor storage system for traction applications

The storage system in this paper is made of supercapacitors. The main goal is to ensure an efficient energy management in a series hybrid vehicle, even if braking resistors are still needed. Design considerations are discussed. In particular the influence of the inductor resistance on the system stability is described. A maximum control structure is then deduced from the energetic macroscopic representation of the storage system. Comparisons between experimentation and simulation are presented in order to highlight the influence of the inductor resistor. Experiments are then carried out on a normal operating cycle.

Switched Causal Modeling of Transmission With Clutch in Hybrid Electric Vehicles

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 representation, which is, in turn, used in the modeling of complete hybrid electric vehicles (HEVs). Two different models are used, and a specific condition defining the commutation between both models with respect to the physical energy flow is proposed. A Petri net is employed to activate one of the models, depending on the clutch state (locked or slipping). This model allows us to implement without difficulty a simulation of the clutch with a relatively short computation time.

Hardware-in-the-loop simulation of electric vehicle traction systems using Energetic Macroscopic Representation

A hardware-in-the-loop (HIL) simulation of an electric vehicle traction system is developed for experimental validations of electrical drives. Energetic macroscopic representation is used to organize the numerous blocks required. A classical 2-driven-wheels traction is studied with an induction machine. The HIL is based on a controlled DC drive, which imposes the same behavior of the mechanical power train to the induction machine. A flexible and dynamical model of the whole system is used and experimental results are provided

Different models of a traction drive for an electric vehicle simulation

Various simulations of Electric Vehicles (EVs) or Hybrid Electric Vehicles (HEVs) are achieved for different objectives. In this paper, the influence of the electrical drive model is studied for simulation of an EV. Indeed, the electric machine with its associated converter can be modelled in three different ways: dynamic, static and quasi-static modelling. The studied electric machine is an induction machine. The aims of this paper are to show different effects of each model on an EV simulation and to study when each model should be used.

Influence of an Energy Storage System on the Energy Consumption of a Diesel-Electric Locomotive

This paper studies the influence of an energy storage system (ESS) on the fuel consumption of a diesel-electric locomotive. First, an energetic model of a diesel-electric locomotive is established using energetic macroscopic representation (EMR). An inversion-based control is deduced, and the model is validated by experimental results on a real locomotive. Second, from this validated model, a battery/supercapacitor ESS is added in simulation to study the benefit of hybridization before integration on the real vehicle. The simulations show that simple energy management based on a frequency approach allows for the reduction of 25% on fuel consumption on a real drive cycle.

Teaching drive control using Energetic Macroscopic Representation - initiation level

The energetic macroscopic representation (EMR) has been developed in 2000 to develop control of systems with several drives. Since 2002 this graphical tool has been introduced to teach drive control in France, then Canada and Switzerland. The University of Lille proposes two drive control units for students in electrical engineering: initiation level and expert level unit. This first paper deals with the content of the initiation level unit and describes the simulation project of an electrical vehicle using EMR.

Comparison of Control Strategies for Maximizing Energy in a Supercapacitor Storage Subsystem

Abstract A storage supercapacitor subsystem is studied for insertion in a series hybrid electric vehicle (Fig. 1). This subsystem is composed of a supercapacitor bank and a braking resistor used when the supercapacitor voltage is at its maximum value. Generally, when the maximum voltage is reached by supercapacitor, a voltage drop occurs because of the current cancellation in the series resistance of the supercapacitor. Thus the stored energy is reduced compared to the maximum value that could be reached. To overcome this drawback, new control strategies are proposed by acting on the braking resistor. Energetic Macroscopic Representation (EMR) is used to organize the numerous blocks required for modelling and control. Experiment results are provided and highlight the increase of energy storage.

Efficiency Map of the Traction System of an Electric Vehicle from an On-Road Test Drive

In this paper, the traction system modeling of a commercial electric car is studied. Experimental data acquired during an on-road test drive are used to determine an efficiency map of the traction system. Using the deduced model, simulation results are compared to experimental results. The simulation tool using the proposed efficiency map method yields less than 5 % error on energy consumption compared to experimental test drive results.

Comparison of two series-parallel Hybrid Electric Vehicles focusing on control structures and operation modes

With the aim to significantly reduce fuel consumption and exhaust emission, Hybrid Electric Vehicles (HEVs) are more and more developed. Among the different architecture, series-parallel HEVs have flexible mode operations and high efficiency. There are two basic kinds of series- parallel HEVs, one uses a planetary gear, and another uses two concentric arranged electric machines or one machine with the two rotors. Despite the advantages of seriesparallel hybrid vehicles, the systems and their controls are quite complex. This paper aims at the comparison of their control structures and their operation modes. In order to describe the two systems and organize their control structures, Energetic Macroscopic Representation (EMR) and the inversion-based control are used in this study. The same EMR and its associated control are used to describe these two kinds of series-parallel hybrid vehicles. Some simulation results are showed, discussed and compared.

Switched Causal Modeling of Transmission with Clutch in Hybrid Electric Vehicles

The modeling of a clutch in a powertrain transmission is a sensitive issue because of its non-linear behavior. Two different states have to be taken into account: clutch locked and slipping. Two different models are then used and a specific condition defines the commutation between both models with respect to the physical energy flow. An application to parallel Hybrid Electric Vehicles (HEV) is then presented. Energetic Macroscopic Representation (EMR) is used to organize the numerous blocks required. A Petri net is employed to activate a model according to clutch state (lock and slip).