Design and Validation of Energy Management Strategy for Extended-Range Fuel Cell Electric Vehicle Using Bond Graph Method

In view of the aggravation of global pollution and greenhouse effects, fuel cell electric vehicles (FCEVs) have attracted increasing attention, owing to their ability to release zero emissions. Extended-range fuel cell vehicles (E-RFCEVs) are the most widely used type of fuel cell vehicles. The powertrain system of E-RFCEV is relatively complex. Bond graph theory was used to model the important parts of the E-RFCEV powertrain system: Battery, motor, fuel cell, DC/DC, vehicle, and driver. In order to verify the control effect of energy management strategy (EMS) in a real-time state, bond graph theory was applied to hardware-in-the-loop (HiL) development. An HiL simulation test-bed based on the bond graph model was built, and the HiL simulation verification of the energy management strategy was completed. Based on the comparison to a power-following EMS, it was found that fuzzy logic EMS is more adaptive to vehicle driving conditions. This study aimed to apply bond graph theory to HiL simulations to verify that bond graph modeling is applicable to complex systems.

Research on Theoretical Modeling and Parameter Sensitivity of a Single-Rod Double-Cylinder and Double-Coil Magnetorheological Damper

For the single-rod double-cylinder and double-coil magnetorheological (MR) damper studied in this paper, the damping force model of the damper is established by adopting multidisciplinary domain modeling method bond graph theory. Firstly, combined with the structure of the MR damper, the bond graph model of the MR damper was established, the damping force model of the damper was derived through the bond graph theory, and the influence factors, such as the displacement, velocity, and acceleration of the damper were considered in the model. Based on the simulation of force-displacement and force-velocity characteristics of the damping force carried out by the damper theoretical model under different currents and velocities as well as the comparison with the damper bench test results, it was found that the force-displacement and force-velocity characteristic experiment curves of the damper agreed well with the simulation results. Under different working conditions, the maximum error of damping force of the MR damper was 7.2%. The damping force model of the MR damper studied in this paper was compared with that of the damper without considering the inertia force of MR fluid, and the influence of the inertia force of MR fluid on the damping force of the MR damper was analyzed. The results show that when the frequency of the damper is large, the inertial force of MR fluid has an important influence on the damping force; therefore, considering the inertial force of MR fluid in the model can greatly improve the accuracy of the model. The influence degree of key parameters on the damping force of the MR damper was studied through the theoretical model; such key parameters ranging from large to small were the channel clearance, energizing current, piston diameter, motion velocity, channel length, zero-field viscosity of MR fluid, and nitrogen pressure. This provides a basis for the adjustment of the damping force of the MR damper.

"Thermo hydraulic pseudo bond graph based modeling of a centrifugal pumppipe system with experimental analysis"

"The emergence of electrical energy is closely related to the use of power. However, the temperature of electronics could be compared to those encountered by a shuttle nose when entering the atmosphere and requires a thermal management. The technology investigated in this paper is original because able to evacuate important heat flux. The proposed system is named Biphasic Fluid Loop Mechanically Pumped (BFLMP) with a transport capacity of the thermal power up to 10 MW.m, exceeding in this way the performance of all known technologies. This paper begins with a description of the test rig of the BFLMP and its instrumentation. The second part of the paper is a detailed study of the thermo hydraulic behavior of the pump-pipe system. The proposed model is based on the bond graph theory because of its energetic approach and the multi-physics character of the studied system. A validation test is launched using water with regulation temperature at the pressurizer set at 60°C, the temperature of the secondary circuit is regulated at 37°C, a power crenel of 400 W has been applied on the evaporator. Results are discussed in a last part; the model shows up good agreement with the experimental results. The volumetric pump studied in this work is original because it was specially designed and manufactured to equip the BFLMP developed in collaboration with the research laboratory CRIStAL. This pump has been patented. Also, this centrifugal machine has been tested and has been characterized. Its performance curves are obtained and used in the model proposed in this paper. In addition, the proposed algorithm models the pump using a resistive bond graph element R."

Modal Analysis of In-Wheel Motor-Driven Electric Vehicle Based on Bond Graph Theory

A half-car vibration model of an electric vehicle driven by rear in-wheel motors was developed using bond graph theory and the modular modeling method. Based on the bond graph model, modal analysis was carried out to study the vibration characteristics of the electric vehicle. To verify the effectiveness of the established model, the results were compared to ones computed on the ground of modal analysis and Newton equations. The comparison shows that the vibration model of the electric vehicle based on bond graph theory not only is able to better compute the natural frequency but also can easily determine the deformation mode, momentum mode, and other isomorphism modes and describe the dynamic characteristics of an electric vehicle driven by in-wheel motors more comprehensively than other modal analysis methods.