Bond-Graph modeling approach is constructive for the understanding and analysis of system dynamics. It allows a decomposition of a complex system into simpler subsystems. It is a formalism with a unified terminology for all physical domains, based on the analogy between phenomena, highlighting the power exchanges among subsystems and the causality simultaneously. These characteristics make Bond-Graph a powerful tool for structural analysis of the properties of the system and thus for the design of control systems. This article introduces and propose a methodology to construct Bond-Graph of simple systems and a methodology to couple Bond-Graphs with Energetic Macroscopic Representation formalism.

It is essential that electrical power systems are constructed with a reliable and resilient infrastructure. The evaluation of convergence scenarios of the load flow is a technique widely used to study the reliability of energy systems. This paper considers the classification of convergence scenarios under different loading and power generation conditions. Scenarios where the solution is not converging are evaluated using machine learning algorithms. A data set is built from power system topological representation and the simulation of load flows. Algorithms including Support Vector Machine, K-Nearest-Neighbor, and Decision Trees are evaluated and compared. The trained models can be used as a step in the contingency analysis process to be able reduce the computational time and effort in the execution of load flow calculations.

This work aims to compare the transient response of four models of wind generators present in the DIgSILENT PowerFactory software; two of them are based on the international standard IEC 61400-27-1 and the others are own templates of the program. Three types of disturbances are proposed to study wind turbine models: first, a three-phase short circuit at the terminals of the generator transformer; subsequently, a step reduction in loads; finally, a step reduction in generation. The variables observed are active and reactive power, voltage and frequency. Finally, we find to observe the advantages and disadvantages of each model studied. For the short-circuit event the models bring to the failure with reactive injection. With the modification in the load the IEC models exceed some frequency limits and disconnect, the same happens with a change in the generation only that the lower limit is passed.

Microgrids with renewable distributed generation appears to be a good alternative to provide electricity for rural areas and isolated zones. However, these microgrids presents relatively low robustness due to their distributed generation topology with lack of dominant nodes to absorb and compensate instabilities, and intermittent energy availability. This work presents a novel strategy to model microgrids in an extended graph model, generating additional model embedded information, essential for optimization processes in the quest of robustness and economy, among other objectives. The traditional impedance model of microgrid is complemented by an extended graph integrating additional information of grids elements such as saturation, current and voltage limits or energy resource availability. This paper presents the extended graph developed model, which yields to a concise representation of an entire microgrid system, as well as a set of graph metrics usable for electrical grid evaluation. The presented model and metrics show to be useful to store, in a single and simple model, valuable information for design, evaluation and operation of microgrid systems.

Achieving high speed efficient information rate transfer is a mayor challenge for visible light communications in the presence of back light, due to the difficulty in isolating signal from noise. This paper presents experimental results for communication performance tests of a Visible Light Communication (VLC) system based in a Silicon Photomultiplier (SiPM) receiver, in a relevant environment with the presence of back light and without the need of optical filters. The VLC system was tested for information transfer rate using a white led emitter to recreate environmental background lighting conditions, corresponding to standard office working conditions with lighting complying with international lighting standards for indoor working places. Results are oriented towards a VLC device design, giving useful information to determine adequate relations between emitter power, back light intensity, signal to noise ratio and transfer speed. Our findings show that the capabilities of the tested SiPM based system to operate under back light conditions overcomes the reported performance of former technologies.

This paper, presents an inertial and magnetic sensor based technological platform, intended for articular amplitude monitoring and telerehabilitation processes considering an efficient cost/technical considerations compromise. The particularities of our platform offer possibilities of a high social impact by making telerehabilitation accessible to large population sectors in marginal socio-economic sectors, especially in underdeveloped countries where, in contrast to developed countries, specialists are scarce and high technology is not available or inexistent. This platform integrates high resolution low cost inertial and magnetic sensors with adequate user interfaces and communication protocols to perform a diagnostic service through the web, or other available communication networks. Elbow amplitude information is generated by sensors and then transferred to a computing device with adequate interfaces to make it accessible to inexperienced personnel, providing a high social value at a low cost. Experimental methodology includes two different sets of tests: the first one uses flexion - extension movements on a robotic arm to validate our platform (IMOCAP) articular amplitude measurements, against the robotic positioning system. The second set of tests was carried out on human patients to test IMOCAP in real operational conditions; results were validated with an optical positioning system. This paper presents experimental results showing the platform applicability to telerehabilitation processes.