Luis I. Silva

Vehicle dynamics using multi-bond graphs: Four wheel electric vehicle modeling

This work addresses the development of a 4-wheels vehicle model capable to reproduce the complete dynamical behavior. The modeling task is firstly performed by the separated 3-D representation on the Dymola environment of the chassis, suspensions, tires and joints using the library for multi-bond graphs in 3-D mechanics. Secondly, these parts are connected to form the complete vehicle model. The compactness and resemblance with a real vehicle assembling is shown.The main contribution of this paper is to provide a model applicable to electric or hybrid vehicles where the complete dynamics can be simulated. The simulation results obtained illustrate ordinary situations where the inclusion of traction control and ABS are essential for the vehicle safety and stability.

Multi-Domain Model for Electric Traction Drives Using Bond Graphs

In this work the Multi-Domain model of an electric vehicle is developed. The electric domain model consists on the traction drive and allows including faults associated with stator winding. The thermal model is based on a spatial discretization. It receives the power dissipated in the electric domain, it interacts with the environment and provides the temperature distribution in the induction motor. The mechanical model is a half vehicle model. Given that all models are obtained using the same approach (Bond Graph) their integration becomes straightforward. This complete model allows simulating the whole system dynamics and the analysis of electrical/mechanical/thermal interaction. First, experimental results are aimed to validate the proposed model. Then, simulation results illustrate the interaction between the different domains and highlight the capability of including faults.

Multi-domain modeling of electric traction drives using Bond Graphs: Application to fault diagnosis

In this work a dynamic model of the induction machine that considers the thermal behavior is developed using bond graphs (BG). The thermal model is based on considering the slots and teeth as independent elements with their own temperature. It corresponds to a real motor used in the tractive wheel of an electric vehicle. The model of the vehicle is also obtained in BG and is coupled to the motor. The complete model allows simulating the whole dynamics in a single model and the analysis of electrical/mechanical/thermal interaction is performed. Simulation results are intended to illustrate this interaction under faulty and healthy conditions in the stator winding. The impact on the mechanical and thermal domain produced by a fault in the electrical domain is also analyzed.

Modeling of electric vehicles dynamics with Multi-Bond Graphs

The construction of a model that represents the behavior of an Electric Vehicle is studied in detail. The contribution of this work is twofold. On one hand an efficient and compact way to model dynamical systems is introduced. On the other hand, the power interchange between the electrical and mechanical sub-models allows a deep understanding of the dynamics involved in electrically driven vehicles. The approach used to model the mechanical parts (chassis, suspension, wheels) and the induction motors is the Multi-Bond Graph based in models discussed in recent literature. Then these models are integrated in order to form the complete model that simulates the whole system dynamics. Simulation results are aimed to illustrate the electromechanical interaction (ABS, regenerative braking, etc) as well as the evolution of certain variables during a risky situation. Conclusions are obtained based on these results.

A Novel Approach for Simulating the Control of the Traction System of an Automatic Subway

The present paper deals with the simulation and control design of the traction system of the VAL subway. The traction system is ensured by two DC machines connected in series. A common chopper supplies the armature windings and a double-chopper supplies the field windings. The novelty consists on modeling the physical system using Bond Graph, a structural formalism, whereas the control structure is deduced from the Energetic Macroscopic Representation which is a functional formalism. The combination of Bond Graph and Energetic Macroscopic Representation in the same simulation environment allows exploiting the advantages of both approaches. Simulation results are provided in order to illustrate the proposal and to analyze the performance of the closed-loop system.

Simulation of Electric Vehicles Combining Structural and Functional Approaches

In this paper the construction of a model that represents the behavior of an Electric Vehicle is described. Both the mechanical and the electric traction systems are represented using Multi-Bond Graph structural approach suited to model large scale physical systems. Then the model of the controllers, represented with a functional approach, is included giving rise to an integrated model which exploits the advantages of both approaches. Simulation and experimental results are aimed to illustrate the electromechanical interaction and to validate the proposal.

Modeling and control of an electric vehicle combining bond graph and Energetic Macroscopic Representation

The present work addresses the modeling and control of an electric vehicle. The novelty is the utilization of both functional and structural approaches in the same simulation environment. On the one hand, it is deduced the Bond Graph model (structural approach) from the physical system, thus the system and its model present a direct correspondence. On the other hand, the control structure is easily deduced from the Energetic Macroscopic Representation (functional approach) of the vehicle using a systematic procedure. The Bond Graph model and its control are combined in the same simulation environment in order to analyze the behavior of the vehicle and its control. Simulation results illustrate the close loop control performance of the proposal.

Modeling an Electric Vehicle Lithium-Ion Battery Pack Considering Low Temperature Behavior

This paper deals with the modeling and simulation of an electric vehicle lithium-ion battery pack considering low temperature behavior. The initial part is focused on the impact of considering the thermal dynamics. To this end, experimental data is used to evaluate the parameters behavior due to the operation at low temperatures. The second part is devoted to study the thermal distribution in the complete pack. In this analysis, the advantage of using a structural approach such as Bond Graph becomes crucial. The complete thermal model is obtained graphically thus creating a direct correspondence between the topology of the system and its representation. Simulation results are provided in order to illustrate the importance of considering the thermal dynamics and the degradation produced when the cells within the battery pack are not equalized.

Bond graphs representation of a Brushless DC motor and inverter driver

This paper present a proposal of Bond Graphs representation of a Brushless DC motor and an inverter used to drive it. The representations were developed based on previously known models. The model representations were evaluated by a simulation of reference tracking and energetics behavior. This paper provides an energetic analysis of the Bond graphs Model representation and an evaluation of the proposed models for inverter and brushless motor.

Multi-domain model of induction motor with stator core faults

In the present work a multi-domain model of an induction machine with stator core fault is presented. Its electromagnetic behavior as well as the thermal dynamics are modeled with Bond Graph. This complete model is used to obtain simulation results aimed to illustrate the thermal impact of different fault severities. Experimental results are provided to validate the proposed model.