Educational tool for the learning of thermal comfort control based on PMV-PPD indices

In this paper, an interactive educational tool designed for the learning of thermal comfort concepts is presented. Thermal comfort is one of the fundamental aspects of indoor environmental quality and energy savings in buildings. Comfort-based control and energy management constitute an important emergent sub-discipline of engineering studies. The developed tool allows for the definition of the thermal model of a house. Based on this model, thermal comfort is estimated through the predicted mean vote (PMV) and predicted percentage dissatisfied (PPD) indices, and energy consumption is also calculated. The tool can communicate through Modbus TCP/IP protocol, providing external connectivity and data collection from the different sensors available in a building management system (BMS). In this way, it is possible to calculate in real-time the aforementioned comfort indices and propose corrective control indications to maintain the indoor-air conditions inside the optimal comfort range. A simple control strategy that can be applied to conventional HVAC systems is also addressed. The tool is available for degree students in control engineering. A survey was performed to evaluate the effectiveness of the proposed tool

Development of an application for the study of distance measurement using UWB

[Resumen] Debido al desarrollo de la tecnología ultra-wideband en las últimas décadas dentro de los numerosos estándares de comunicación inalámbricos, en este trabajo se desarrolla una interfaz gráfica que permite realizar un análisis de esta tecnología en el campo de la medición de distancias y posicionamiento. Se utiliza para ello el módulo DWM1001-DEV, que incorpora dicha tecnología junto con diferentes modos de conexión y puertos de entrada y salida. La interfaz desarrollada permite establecer una conexión a través del puerto USB con el módulo mencionado y también de forma inalámbrica a través de una red Wi-Fi. Se plantea también el software de gestión de datos y su envío con una placa tipo Raspberry. Se muestra un conjunto de pruebas experimentales utilizando la interfaz y se realiza un estudio preliminar de la calidad de la medida de distancia entre dos módulos DWM1001-DEV.[Abstract] Due to the development of ultra-wideband technology in recent decades within the numerous wireless communication standards, this paper develops a graphical interface that allows an analysis of this technology in the field of distance measurement and positioning. For this purpose, the DWM1001-DEV module is used, which incorporates UWB technology together with different connection GPIO ports. The developed interface allows establishing a connection through the USB port with the mentioned module and also wirelessly through a Wi-Fi network. The data management software and its shipment with a Raspberry type board are also considered. A set of experimental tests using the interface is shown and a preliminary study of the quality of the distance measurement between two DWM1001-DEV modules is carried out.Universidad de Córdoba; IX Plan Propio GALILEO de Innovación y Transferenci

Interactive Tool for Frequency Domain Tuning of PID Controllers

This paper presents an interactive tool focused on the study of proportional-integral-derivative (PID) controllers. Nowadays, PID control loops are extensively used in industrial applications. However, it is reported that many of them are badly tuned. From an educational point of view, it is essential for undergraduate students in control engineering to understand the importance of tuning a control loop correctly. For this reason, the tool provides different PID tuning methods in the frequency domain for stable open-loop time-delay-free processes. The different designs can be compared interactively by the user, allowing them to understand concepts about stability, robustness, and performance in PID control loops. A survey and a comparative study were performed to evaluate the effectiveness of the proposed tool

A hybrid modeling approach for steady-state optimal operation of vapor compression refrigeration cycles

This paper presents a steady-state hybrid modeling approach for vapor compression refrigeration cycles which is intended to achieve an optimal system operation from an energy consumption point of view. The model development is based on a static characterization of the main components of the cycle using a hybrid approach, and their integration in a new optimization block. This block allows to determine completely the system stationary state by means of a non-linear optimization procedure subjected to several constraints such as mechanical limitations, component interactions, environmental conditions and cooling load demand. The proposed method has been tested in an experimental pilot plant with good results. Model validation for each identified hybrid model is carried out from a set of experimental data of 82 stationary operating points, with prediction errors below ±10%. The model is also globally validated by comparing experimental and simulated data, with a global mean relative absolute error less than 5%. The basic control structure consists of three decentralized control loops where the controller variables are the secondary fluid temperature at the evaporator inlet, the superheat, and the condenser pressure. While the secondary temperature is assumed as an imposed requirement, the optimal set-points of the other two control loops are searched offline using the proposed refrigerant cycle model. This set-point optimality is defined according to the coefficient of performance for minimizing the total electrical power consumption of the system at steady-state. This energy saving has been confirmed experimentally. The proposed method can be easily adapted for different sets of controlled variables in case of modification of the basic control structure. Furthermore, other energy efficiency metrics can be handily adopted. Considering the tradeoff between the accuracy and computational cost of the hybrid models, the proposed procedure is expected to be used in real-time applications

Adaptive Pitch Controller of a Large-Scale Wind Turbine Using Multi-Objective Optimization

This paper deals with the control problems of a wind turbine working in its nominal zone. In this region, the wind turbine speed is controlled by means of the pitch angle, which keeps the nominal power constant against wind fluctuations. The non-uniform profile of the wind causes tower displacements that must be reduced to improve the wind turbine lifetime. In this work, an adaptive control structure operating on the pitch angle variable is proposed for a nonlinear model of a wind turbine provided by FAST software. The proposed control structure is composed of a gain scheduling proportional–integral (PI) controller, an adaptive feedforward compensation for the wind speed, and an adaptive gain compensation for the tower damping. The tuning of the controller parameters is formulated as a Pareto optimization problem that minimizes the tower fore-aft displacements and the deviation of the generator speed using multi-objective genetic algorithms. Three multi-criteria decision making (MCDM) methods are compared, and a satisfactory solution is selected. The optimal solutions for power generation and for tower fore-aft displacement reduction are also obtained. The performance of these three proposed solutions is evaluated for a set of wind pattern conditions and compared with that achieved by a classical baseline PI controller

Educational software tool for decoupling control in wind turbines applied to a lab‐scale system

This paper presents an educational software tool, called wtControlGUI, whose main purpose is to show the applicability and performance of different decoupling control strategies in wind turbines. Nowadays wind turbines are a very important field in control engineering. Therefore, from an educational point of view, the tool also aims to improve the learning of multivariable control concepts applied on this control field. In addition, wtControlGUI allows for testing and control of a lab-scale system which emulates the dynamic response of a largescale wind turbine. The designed graphical user interface essentially allows simulation and experimental testing of decoupling networks and other multivariable methodologies, such as robust and decentralized control strategies. The tool is available for master degree students in control engineering. A survey was performed to evaluate the effectiveness of the proposed tool when used in educational related tasks

Software Tool for Acausal Physical Modelling and Simulation

Modelling and simulation are key tools for analysis and design of systems and processes from almost any scientific or engineering discipline. Models of complex systems are typically built on acausal Differential-Algebraic Equations (DAE) and discrete events using Object-Oriented Modelling (OOM) languages, and some of their key concepts can be explained as symmetries. To obtain a computer executable version from the original model, several algorithms, based on bipartite symmetric graphs, must be applied for automatic equation generation, removing alias equations, computational causality assignment, equation sorting, discrete-event processing or index reduction. In this paper, an open source tool according to OOM paradigm and developed in MATLAB is introduced. It implements such algorithms adding an educational perspective about how they work, since the step by step results obtained after processing the model equations can be shown. The tool also allows to create models using its own OOM language and to simulate the final executable equation set. It was used by students in a modelling and simulation course of the Automatic Control and Industrial Electronics Engineering degree, showing a significant improvement in their understanding and learning of the abovementioned topics after their assessment

Teamwork experience: design and control of a multivariable system of interconnected tanks

En este trabajo se presenta una experiencia de trabajo en grupo que pretende mejorar tanto competencias generales (organización, planificación, resolución de problemas, toma de decisiones, etc.) como específicas (modelado, diseño e implementación de sistemas de control) del alumnado implicado. Para ello, se propone el montaje e instrumentación por parte de los estudiantes de una planta experimental de tanques interconectados donde se debe controlar el nivel en los tanques actuando sobre un variador de velocidad que impulsa un caudal, y sobre una servoválvula de tres vías que reparte el caudal entre ellos. Después se debe obtener un modelo del sistema para simular y analizar su comportamiento. El proceso diseñado es un sistema de dos entradas y dos salidas que muestra interacción y ello dificulta su control. Se formaron dos grupos de trabajo en los que cada uno tiene que diseñar una estrategia de control multivariable cumpliendo unas especificaciones en el dominio de la frecuencia. Tras simular los diseños propuestos por cada grupo, se validaron con la planta experimental. Finalmente, cada grupo explicó la metodología de trabajo desarrollada. La experiencia de trabajo resultó satisfactoria, destacándose el interés por parte del alumnado en la aplicación de los conceptos teóricos a una planta real

Online Simulator of an air turbine with OpenFAST

[Resumen] La energía eólica ha alcanzado una capacidad mundial de 837 GW, y para poder seguir creciendo, se requiere seguir mejorando su eficiencia en la producción de energía, y reducir también sus costes de mantenimiento. El modelado de los aerogeneradores tanto en su propio diseño como en la implementación de sus sistemas de control es clave para maximizar la potencia generada y ahorrar costes operativos. Simuladores como OpenFAST permiten la parametrización de la turbina y el análisis de variables como la potencia generada o un estudio de las cargas a las que se somete el sistema. Debido a la complejidad de uso del simulador, para simplificar al usuario el manejo de este software se ha desarrollado una aplicación web que permite ejecutar un conjunto de simulaciones bajo OpenFAST. El programa se divide en dos partes: una parte que gestiona OpenFAST y que es manejada por Python; y la otra parte que funciona de interfaz al usuario y para la que se ha utilizado Vue. Se explican las principales características del software desarrollado y sus posibilidades de uso.[Abstract] Wind power has achieved a global capacity of 837 GW and in order to continue its growth, it needs improvements in the efficiency of energy generation and minimizing maintenance costs. Modelling these systems at the design phase and for the control systems implementation is crucial to maximize the generated power and to save operating costs. Simulators like OpenFAST allow parametrizing the wind turbine and the analysis of variables such as generated power or structural loads in the system. Because of the complex use of this software, to simplify the user interaction a web application that allows to launch simulations in OpenFAST has been developed. The application comprises two parts: one part is responsible for managing OpenFAST by using Python, and the other part works as a web interface and is developed with Vue. The main features of this software and its possible uses are explained.Ministerio de Ciencia e Innovación; PID2020-117063RB-I0