Bond Graph Methodology Research Articles

Dynamical analysis of a novel hybrid oceanic tidal-wave energy converter system

One of the current biggest hurdles to harnessing renewable energy resources is their intermittent nature. Hybrid energy conversion minimizes intermittency by diversifying energy production. This work presents a conceptual design of a hybrid energy conversion system for ocean currents and waves on a shared platform: TIWAG (Tidal-Waves Generator). The power converter consists of two turbines and a float, each connected to a Doubly-Fed Induction Generator. We use a detailed bond graph methodology to develop the mechanical and electrical systems’ dynamical modeling and apply a rotation control strategy for the hydrokinetic turbines and float. The system’s operational feasibility is analyzed numerically for different tidal current speeds and wave heights –in loco data collected in São Marcos Bay, on the coast of the state of Maranhão, Brazil. Due to the addition of the float device to the structure with two turbines, the system goes from producing 209.2 kW to 300.7 kW without an increase in the occupied area, converting 32.6% of the available energy in the ocean currents and waves into electrical power. The different energy sources in the system complement one another to reduce intermittency, increasing the stability in energy production by 20%–30%.

Modeling and Simulation of an Energy Integrated Distillation Column in a Bond Graph Approach.

The bond graph methodology for modelling an integrated energy distillation column is applied in this paper. The distillation column is built by five trays for a binary mixture. However, due to its modular construction in a bond graph, the number of trays can be increased. In order to link the analysis tools of systems modeled in the bond graph to the mathematical model given to a distillation column, a junction structure of the proposed bond graph is presented. Hence, this junction structure is a way to obtain the state space representation of the modeled column in bond graphs. Likewise, it is well known that distillation columns determine a class of nonlinear systems, so throughout this paper, these systems in a bond graph approach can be analyzed. In order to learn the behavior of the distillation column in the physical domain, simulation results using 20-Sim software are shown. In addition, with the simulation of two case studies consisting of two mixtures with different relative volatilities, the versatility of the column model in a bond graph is presented. In both cases, the increase in the feed flow, the mole fraction of the light component in the feed or the distillate reflux that enriches the concentration of light in the column determine an increase in the mole fraction of light in the distillate and in the bottom reflow. Further, the control design for a distillation column in the physical domain can be extended.

Direct Determination of Reduced Models of a Class of Singularly Perturbed Nonlinear Systems on Three Time Scales in a Bond Graph Approach

One of the most important features in the analysis of the singular perturbation methods is the reduction of models. Likewise, the bond graph methodology in dynamic system modeling has been widely used. In this paper, the bond graph modeling of nonlinear systems with singular perturbations is presented. The class of nonlinear systems is the product of state variables on three time scales (fast, medium, and slow). Through this paper, the symmetry of mathematical modeling and graphical modeling can be established. A main characteristic of the bond graph is the application of causality to its elements. When an integral causality is assigned to the storage elements that determine the state variables, the dynamic model is obtained. If the storage elements of the fast dynamics have a derivative causality and the storage elements of the medium and slow dynamics an integral causality is assigned, a reduced model is obtained, which consists of a dynamic model for the medium and slow time scales and a stationary model of the fast time scale. By applying derivative causality to the storage elements of the fast and medium dynamics and an integral causality to the storage elements of the slow dynamics, the quasi-steady-state model for the slow dynamics is obtained and stationary models for the fast and medium dynamics are defined. The exact and reduced models of singularly perturbed systems can be interpreted as another symmetry in the development of this paper. Finally, the proposed methodology was applied to a system with three time scales in a bond graph approach, and simulation results are shown in order to indicate the effectiveness of the proposed methodology.

Modular dynamic biomolecular modelling with bond graphs: the unification of stoichiometry, thermodynamics, kinetics and data.

Renewed interest in dynamic simulation models of biomolecular systems has arisen from advances in genome-wide measurement and applications of such models in biotechnology and synthetic biology. In particular, genome-scale models of cellular metabolism beyond the steady state are required in order to represent transient and dynamic regulatory properties of the system. Development of such whole-cell models requires new modelling approaches. Here, we propose the energy-based bond graph methodology, which integrates stoichiometric models with thermodynamic principles and kinetic modelling. We demonstrate how the bond graph approach intrinsically enforces thermodynamic constraints, provides a modular approach to modelling, and gives a basis for estimation of model parameters leading to dynamic models of biomolecular systems. The approach is illustrated using a well-established stoichiometric model of Escherichia coli and published experimental data.

Application and implementation of the bond graph methodology on the structural damage detection and monitoring of aeroengines

Advancements in structural safety are of prominent importance in various industrial sectors. A significant body of research has been dedicated to proposing theoretical and empirical guidelines for detecting, localizing, and assessing the severity of damage to structures. This research proposes a novel theoretical approach that employs a bond graph methodology to perform structural health assessments of aeroengine structures. In this work, a reduced aeroengine model is proposed. Using the bond graph technique, the governing dynamic equations of motion can be determined. The results obtained from the analysis can then be used to perform a structural health assessment of the aeroengine. The outcomes allow for detection and localization of any damage to the structure, based on the regions identified. In the present study, damage indicator factors have also been determined for specified aeroengine regions, which can be used to localize damage and assess the severity of its propagation in an aeroengine. The proposed theoretical structural health monitoring methodology has notable advantages over other processes proposed in the literature. The present work allows for a reduction in the cost associated with damage detection, localization, and propagation. The proposed theory offers an accurate theoretical benchmark for comparison with experimental data when assessing structural integrity. Moreover, the proposed methodology can be used to develop and implement design modifications based on design objectives, ensuring continuous and safe operation of aeroengine structures.

Transient Dynamic System Behavior of Pressure Actuated Cellular Structures in a Morphing Wing

High aspect ratio aircraft have a significantly reduced induced drag, but have only limited installation space for control surfaces near the wingtip. This paper describes a multidisciplinary design methodology for a morphing aileron that is based on pressure-actuated cellular structures (PACS). The focus of this work is on the transient dynamic system behavior of the multi-functional aileron. Decisive design aspects are the actuation speed, the resistance against external loads, and constraints preparing for a future wind tunnel test. The structural stiffness under varying aerodynamic loads is examined while using a reduced-order truss model and a high-fidelity finite element analysis. The simulations of the internal flow investigate the transient pressurization process that limits the dynamic actuator response. The authors present a reduced-order model based on the Pseudo Bond Graph methodology enabling time-efficient flow simulation and compare the results to computational fluid dynamic simulations. The findings of this work demonstrate high structural resistance against external forces and the feasibility of high actuation speeds over the entire operating envelope. Future research will incorporate the fluid–structure interaction and the assessment of load alleviation capability.

Bond Graph as a formal methodology for obtaining a wind turbine drive train model in the per-unit system

In this paper, the Bond Graph methodology is originally employed to obtain a per-unitized dynamic model for a wind turbine two-mass drive train. Bond Graph is a formal multi-domain methodology that strongly enforces the energy conserving property. A natural outcome of applying this methodology is a reliable and dimensionally homogeneous per-unit dynamic model. This methodology is utilized to address the lack of dimensional homogeneity in some drive train models that are being used in the wind energy literature.

Structured dynamic modeling and simulation of parabolic trough solar collector using bond graph approach

The present paper deals with the modeling of a solar parabolic trough collector (PTC).The system is described by a lumped parameter model; its dynamic modeling is performed using the bond graph methodology which allows having a graphical structure of the modeled phenomena where the multi-domain coupling relationships are explicitly represented. The thermal domain of the pseudo bond graph (PBG) supports all heat transfer modes established between the environment, the glass cover, the absorber tube and the fluid. The mass accumulation in the control volume is not taken into account since its dynamic effect remains largely negligible as demonstrated in this contribution. The state equation of the system is developed from the laws of the junctions, the resistance elements and capacitance elements. Numerical simulation is carried out via the Matlab software environment and the predicted results are compared with the experimental tests of the Sandia National Laboratory. For on-sun tests, the average relative errors obtained are about 0.17% for the heat transfer fluid (HTF) output temperature and about 0.96% for the energy efficiency. In the case of off-sun tests, the average relative error calculated for the predicted HTF output temperature is estimated at 0.08% and the heat losses absolute error is equal to 4.9 (W/m2). According to the previous comparisons, there is reason to affirm that the proposed model can accurately predict the thermal behavior of the collector. Finally, this work includes a case study that consists of PTC exergy performance assessment under climate conditions of three different North Africa sites.

Numerical modelling of blood clot extraction by aspiration thrombectomy. Evaluation of aspiration catheter geometry

Aspiration thrombectomy is one of the most effective systems for blood clot removal and vessel recanalization. We present the results of a study involving the modelling and extraction of blood clots in the arteries of the human body using the following computer tools: Bond-Graph methodology for the fluid domain and Multi-Body Simulation for the mechanical domain. The modelling for the mechanical domain focuses on the clot and the distal end section of an aspiration device. Our final model considers an elastic characterization of the blood clot with progressive detachment from the vessel wall. We conclude that the results of such modelling could potentially improve the effectiveness of blood clot removal by reducing the risk of clot fragmentation. Such modelling could also potentially provide an adjunct technique in improving recanalization of arteries over a range of given parameters (mechanical properties of the vessel, mechanical properties of the blood clot, blood clot length, suction pressure, catheter – clot distance, catheter shape, catheter diameter and vessel occlusion).

GMPP tracking based on model reference LPV control for a PV system with buck converter modelled on bond graph

AbstractA PhotoVoltaic (PV) system with a Linear Parametric Varying (LPV) average model of a buck converter modelled by bond graph methodology, is considered. It is assumed that the voltage generated by the PV panel is a smooth function of time under changes in atmospheric conditions. A model reference is proposed representing the PV system with buck converter operating at the Global Maximum Power Point (GMPP). An LPV control is designed, and an algorithm is proposed in a model reference tracking control configuration assuring that the PV system with buck converter tracks the proposed model reference and hence guaranteeing that this system operates at the GMPP. The proposed algorithm changes the voltage reference based on the power measurement of the PV system assuring that this reference represents the GMPP under shading conditions. The LPV control is designed for an average model of the buck converter solving a feasibility problem based on linear matrix inequalities that assure quadratic stability and minimize a quadratic criterion. The feedback system is tested under shading conditions, and its performance is compared with a standard Perturb and Observe method and with an ideal algorithm based on the irradiance measurement in each section of the PV system.

Bond Graph Modelling of Different Equivalent Models of Photovoltaic Cell

Abstract The photovoltaic (PV) generator current-voltage equation is nonlinear and need a powerful algorithm to solve it. In this paper a dynamic modelling approach of photovoltaic generator is presented by the bond graph (BD) methodology. The BD is a graphical methodology for modelling and analysis of physical systems. It’s based on decomposition of the system in subsystems and exchange energy. Therefore, using the single and double diode models representation of equivalent circuit of PV generator, the bond graph representation is derived. The mathematical model is obtained by applying the bond graph elements and rules. At the end, the simulation results of these obtained models using experimental points are plotted.

Application of the Scattering Bond Graph Methodology for Composite Right/Left Handed Transmission Lines

The approach of the metamaterials based on the theory of transmission lines has an influence on the development of the radiofrequency domain, so the types and techniques of elaboration of these artificial lines are quite diversified. This paper will present two models of Artificial Transmission Line CRLH (Composite Right Left Handed) composed of a combination of resonators OSRR (Open Split Ring Resonators) and OSCRR (Complementary Open Split Ring Resonators). This paper will also show how the Scattering Bond Graph (SBG) study methodology allows to provide electromagnetic simulation results (Scattering parameters, phase response) more conducive to Bond Graph (BG) modeling, and will prove the possibility of having the most perfect line (solved the problem of impedance adaptation) and better understanding of the behavior of radiofrequency systems.

Bond Graphs as Mechatronic Approach for Supervision Design of Multisource Renewable Energy System

This paper deals with the bond graph methodology as a decision-making tool and multiphysic approach for supervision supervision system design. The developed algorithms have been applied to a mechatronic represented by Hybrid Renewable Energy System (HRES) which consists of Solar Photovoltaic Panels (PV) and wind turbines coupled to an electrolyser for hydrogen production used an energy vector for a fuel cell.

Performance analysis of electro-hydraulic actuator based on optimal control algorithm

When designing the controller to improve the performance of the system, energy consumption are often neglected. Therefore we use the LQR control method to add energy considerations to the objective function to optimize the performance of the system. In this paper, an optimal control algorithm is proposed for Electro-Hydraulic Actuator (EHA) system. Firstly EHA system is modelled by bond-graph methodology. Then, design the controller to improve both the performance and efficiency of EHA system. The simulation results verify the optimization and stability of system by the optimal controller.

Trajectory control of a mobile manipulator in the presence of base disturbance

A mobile manipulator is typically an assembly of a mobile robot base and an on-board manipulator arm. As the manipulator arm is mounted over the mobile robot base, the controller has the additional task of taking care of the disturbances of the mobile robot due to the dynamic interactions between the mobile robot base and manipulator arm. In the present work, dynamic models for the manipulator arm and an omni-wheeled mobile robot base were developed separately and then both were combined. Two control strategies, namely only manipulator arm control (OMAC) and simultaneous manipulator and base control (SMBC) were developed for the effective control of tip trajectory. In both strategies, an amnesia recovery coupled with classical proportional integral and derivative (PID) control was used. The bond graph methodology was used for the development of the dynamic model and control for the mobile manipulator. Simulation results are presented to illustrate the efficacy of the two control strategies.

Model-based fault detection and diagnosis of complex chemical processes: A case study of the Tennessee Eastman process

Fault detection and diagnosis for industrial systems has been an important field of research during the past years. Among these systems, the Tennessee Eastman process is extensively used as a realistic benchmark to test and compare different fault detection and diagnosis strategies. In this context, data-driven approach has been widely applied for fault detection and diagnosis of the Tennessee Eastman process, by exploiting the massive amount of available measurement data. However, only few published works had attempted to deal with the dynamic behavior of the whole system including the mixing zone, circulating pumps, the reactor, the separator, the stripper, and so on, because of the difficulty of modeling physical phenomena that may occur in such complex system. In this article, an accurate model of the Tennessee Eastman process, properly tailored for fault detection and diagnosis purposes, is provided. This model shows better fault detection and diagnosis performances than all the others proposed in the literature and gives better or comparable results with the data-driven approaches. This work uses the bond graph methodology to systematically develop computational and graphical model. This methodology provides a physical understanding of the system and a description of its dynamic behavior. The bond graph model is then used for monitoring purposes by generating formal fault indicators, called residuals, and algorithms for fault detection and diagnosis. Hence, abnormal situations are detected by supervising the residuals’ evolution and faults are isolated using the nature of the violated residuals. Therefore, the dynamic model of the Tennessee Eastman process can now be used as a basis to achieve accurately different analysis through the causal and structural features of the bond graph tool.

Bond graph based control of a solar array

In this paper, the control of a solar array is proposed. The bond graph methodology is applied in order to get the structure control law for a solar array connected to the electrical network. For this, the different models of the complete system are presented. The solar array is built up by considering the individual solar panels. The inverter bond graph model is used for the development of the proposed control law. This model is inverted graphically to get the control structure. Also, the Park transformation concept is adapted to handle the control structure. This allows us to get a different control structure. Two different controls are considered in the proposed control structure, with their robustness tested for different power factors. The control law is tested using a real-time simulator. For this test, the rapid control prototyping concept is used. The obtained results demonstrate the viability of the proposed control law.

Prediction of Horizontal Axis Wind Turbine Rotor Performance: Bond Graph Approach

Modeling wind energy conversion systems is a difficult task that requires the use of a unified language gathering all aspect of energies involved such as kinetic energy, mechanical energy, and electrical energy. Bond Graph methodology is an appropriate tool to analyze wind turbine dynamic behavior since the whole system is modelled in the same frame. Herein, a methodology for HAWT's rotor modeling is proposed based on Bond Graph, aerodynamic laws and Rayleigh Beam theory. It takes into consideration the profile, chord, and twist change along the blade. The model is validated using 20-Sim software and then compared to other models from literature. Simulation results show a better value of power coefficient in comparison with works using the same tools.

Prediction of Horizontal Axis Wind Turbine Rotor Performance: Bond Graph Approach

Modeling wind energy conversion systems is a difficult task that requires the use of a unified language gathering all aspect of energies involved such as kinetic energy, mechanical energy, and electrical energy. Bond Graph methodology is an appropriate tool to analyze wind turbine dynamic behavior since the whole system is modelled in the same frame. Herein, a methodology for HAWT's rotor modeling is proposed based on Bond Graph, aerodynamic laws and Rayleigh Beam theory. It takes into consideration the profile, chord, and twist change along the blade. The model is validated using 20-Sim software and then compared to other models from literature. Simulation results show a better value of power coefficient in comparison with works using the same tools.

Representing workload control of manufacturing systems as a dynamic model

Workload control (WLC) is a methodology that aims to regulate the total workload in the production system by controlling the input and output of orders. It leads to more predictable throughput times and more accurate delivery date promising. In this paper, we propose a representation of the workload control principles by means of a dynamic model based on bond graphs, and present the modeling of this system. According to the bond graph methodology, the manufacturing entities can be associated to constitutive equations, which can be combined to generate a state model. The presented state model provides informations about instantaneous levels of work in process of the system, and can show the effect of release policies (input control) and capacity adjustments (output control) into these levels of work in process. Exploratory simulations were carried out in Simulink. The existing simulation of WLC systems usually employs open-loop descriptive models based on discrete events simulation, and the parameters of input and output control are empirically/experimentally defined. A gap was identified in the literature, specially concerning the parameter setting for output control. In the proposed model, input and output control are performed automatically, by the controllers implemented to the dynamic model (closed-loop system). Therefore, the proposed approach can bring prescriptive directions to the parameter setting of WLC, and we believe it can also bring future comparative insights to the existing simulations of this methodology.