The feedfroward plus decoupling control design for TITO system

Proportional-Integral-Derivative (PID) controllers are commonly used controllers in industry for their relative ease of use and it also provides the satisfactory performance in industrial processes. It exploits in case of tight performances by employing additional functionalities such as antiwindup, set-point weight, feedforward action. These functionalities are developed for Single-Input-Single-output (SISO) systems. A system with multi inputs and multi outputs are alloyed as MIMO system. Industrial systems like Chemical reactors, Heat exchangers and Distillation column etc. are the best examples of MIMO systems. To perform an operation in SISO system is easier than the operation in MIMO system. The cause of this complication occurs due to the coupling or interactions in between the input and output variables. Hence to minimize the interactions, in this paper we are going to discuss about Decoupling for a TITO system. And the feedforward controller is used for following the set-point

Design of Decoupler and Performance Analysis of A Distillation Column

The main aim of this thesis is to control the basic parameters of distillation column .The distillation column is basically a MIMO process that means all the inputs and outputs are coupled to each other. It is very difficult to control such type of process so, we have to reduce or eliminate the interaction between the inputs and outputs. Therefore the process can be converted to a single input and single output system (SISO).In order to convert the MIMO system to SISO system it is necessary to design a decoupler which will eliminate the interaction among all the inputs and outputs.My focus is here to design that decoupler, which is very difficult to design when the process variables are more. It is easy when we consider TITO system. When we consider a ‘three input and three input’ and ‘four input and four output’ system it is necessary to follow some methods like RGA and RNGA methods. After getting those parameters we have to follow the ETF method so that the decoupler will be designed. After designing the decoupler, our aim to be controlled the distillation process. Here I am using PID controller to control the process. In order to design the PID controller we basically emphasized on the tuning parameters of the PID. To get the tuning parameters we must follow certain methods such as Ziegler Nichols, Cohen coon and decentralized relay feedback methods, BLT methods etc. Here we are using decentralized relay feedback method in to do the tuning of the controller. After tuned the PID .We will get the desired output what we actually want to get.The result was obtained and shown that implemented work is successfully done. Finally the interactions are rejected and the process was controlled.Here all the simulations are done by the MATLAB tool and Microsoft window 7operating syste

Experimental investigation and control of a hot-air tunnel with improved performance and energy saving

The paper is focused on the identification, control design, and experimental verification of a two-input two-output hot-air laboratory apparatus representing a small-scale version of appliances widely used in the industry. A decentralized multivariable controller design is proposed, satisfying control-loop decoupling and measurable disturbance rejection. The proposed inverted or equivalent noninverted decoupling controllers serve for the rejection of cross-interactions in controlled loops, whereas open-loop antidisturbance members satisfy the absolute invariance to the disturbances. Explicit controller-structure design formulae are derived, and their equivalence to other decoupling schemes is proven. Three tuning rules are used to set primary controller parameters, which are further discretized. All the control responses are simulated in the Matlab/Simulink environment. In the experimental part, two data-acquisition, communication, and control interfaces are set up. Namely, a programmable logic controller and a computer equipped with the peripheral component interconnect card commonly used in industrial practice are implemented. A simple supervisory control and data acquisition human-machine interface via the Control Web environment is developed. The laboratory experiments prove better temperature control performance measured by integral criteria by 35.3%, less energy consumption by up to 6%, and control effort of mechanical actuator parts by up to 17.1% for our method compared to the coupled or disturbance-ignoring design in practice. It was also observed that the use of a programmable logic controller gives better performance measures for both temperature and air-flow control.Tomas Bata University in Zlin [RVO/CEBIA/2020/001]RVO/CEBIA/2020/001; Univerzita Tomáše Bati ve Zlín

Evaluation of modern control system design techniques for a multivariable electro-hydraulic system.

An experimental apparatus has been developed with the object of providing a test plant, based on commercially available electro-hydraulic components, for the investigation of multivariable control system design methodologies. A mathematical model has been produced for this experimental plant and a preliminary analysis of the plant carried out.A selection of controller design techniques has been investigated. Designs have been produced for two state feedback controllers in which the feedback coefficients were based on LQR theory, one of which used a full order estimator based on a Kalman Filter, the other using a reduced order observer whose poles were chosen arbitrarily. In addition, forward path compensators have been developed using the Characteristic Locus and the Hinfinity/Mixed Sensitivity methods. These controller designs were based on computations and simulations utilising Matlab and a selection of its control engineering toolboxes and Simulink. The completed designs were implemented in digital form and tested on the actual plant.A series of tests were carried out to assess the robustness of the various controllers in the presence of plant uncertainty. The physical plant was modified and the controllers based on the nominal plant model used in conjunction with this modified plant. As a design technique which enabled robustness issues to be addressed explicitly, the Hinfinity approach was used to improve the robustness of the original Hinfinity controller

Engineering Education and Research Using MATLAB

MATLAB is a software package used primarily in the field of engineering for signal processing, numerical data analysis, modeling, programming, simulation, and computer graphic visualization. In the last few years, it has become widely accepted as an efficient tool, and, therefore, its use has significantly increased in scientific communities and academic institutions. This book consists of 20 chapters presenting research works using MATLAB tools. Chapters include techniques for programming and developing Graphical User Interfaces (GUIs), dynamic systems, electric machines, signal and image processing, power electronics, mixed signal circuits, genetic programming, digital watermarking, control systems, time-series regression modeling, and artificial neural networks

International Symposium on Magnetic Suspension Technology, Part 1

The goal of the symposium was to examine the state of technology of all areas of magnetic suspension and to review related recent developments in sensors and controls approaches, superconducting magnet technology, and design/implementation practices. The symposium included 17 technical sessions in which 55 papers were presented. The technical session covered the areas of bearings, sensors and controls, microgravity and vibration isolation, superconductivity, manufacturing applications, wind tunnel magnetic suspension systems, magnetically levitated trains (MAGLEV), space applications, and large gap magnetic suspension systems

Desarrollo de un sistema de control predictivo multivariable de un generador de vapor de tubos de agua

Partiendo de la motivación de buscar medios que permitan el ahorro de energía tanto por el aspecto económico como el ecológico se desarrolló este trabajo el cual pretende diseñar un controlador predictivo basado en modelo (CPBM) para controlar un generador de vapor de tubos de agua de forma más efectiva y eficiente que los sistemas actuales Para este fin se realizó una revisión del estado del arte de los generadores de vapor y de sus sistemas de control donde se identificaron las principales variables a controlar. Debido al bajo desempeño de estos sistemas de control se propuso, luego de un análisis previo, el uso de un controlador predictivo basado en modelo para su aplicación en el generador de vapor. Para lograr este objetivo se estudió un modelo matemático no lineal multivariable de un generador de vapor reportado en la literatura, el cual posteriormente se utilizó para realizar la simulación de la planta real. Luego para el diseño del controlador se utilizó el modelo linealizado con el fin de aligerar cálculos. El diseño del controlador multivariable está basado en un controlador predictivo que es computacionalmente más eficiente que el controlador predictivo convencional. Para la aplicación de este controlador se consideraron restricciones en la señal de control y durante las pruebas simuladas en Matlab/Simulink se le introdujo señales ruidosas y perturbaciones alcanzando buenos resultados en eficiencia energética y de control superando al sistema actual basado en controladores PID. Finalmente se propuso la implementación práctica del controlador haciendo uso de un DSP hibrido.Tesi

Modellierung und verteilte Regelung dezentraler Energieerzeuger: ein MIMO-Ansatz

The ongoing increase of inverter-interfaced distributed energy generation based on renewable energy sources is notably changing the structure of modern power systems. Particularly in low-voltage grids, the large-scale implementation of droop-controlled distributed generation gives rise to stability issues, given the dynamic response of the power inverters and the complex coupling that arises from the inductive and resistive behavior of the power lines. This work focuses on the analysis of the small-signal stability of a low-voltage grid with distributed generation and on the design of a proper control law that assures stability independently from the chosen power droops. After a detailed introduction on the fundamentals of the operation of a low-voltage grid with distributed generation, appropriate models are introduced for the power inverters and the grid to which they are connected, followed by a discussion on their dynamics and the limits to which these models are subject. The implementation of a so-called improved droop controller on a single inverter is proposed and studied in depth, which modifies the dynamics with which a power inverter operates. The damping and stabilizing capabilities of the improved droop controller are studied at full length with the help of graphical control tools such as root-locus, Bode, and Nyquist diagrams. From this analysis, three systematical design methods are derived, which allow for the tuning of the improved droop controller in a way that enough damping can be guaranteed. Subsequently, the analysis is extended to a grid with several inverters. Although the tuning of a group of inverters is traditionally done disregarding their coupling, this work considers a low voltage grid as a whole, explicitly contemplating the interaction between power inverters. Accordingly, two methods to tune the improved droop controller for a given group of inverters are derived. Finally, a reduced-order model of the grid is derived, which captures the most significant aspects of the dynamic behavior of a low-voltage grid with distributed generation. Laboratory small-scale experiments are included to show the performance and the limits of the proposed approach.Die Struktur moderner Energiesysteme hat sich durch das laufende Wachstum der umrichterbasierten dezentralen Energieerzeugung auf Basis erneuerbarer Energiequellen enorm geändert. Besonders in Niederspannungsnetzen führt der großflächige Einsatz von verteilten Erzeugungsanlagen führt zu Stabilitätsproblemen, denn die Dynamik der Wechselrichter und die durch das ohmsche und induktive Verhalten der Stromleitungen komplexe Verkopplung können zu ungedämpften Schwingungen führen. Diese Arbeit setzt den Schwerpunkt auf die Analyse der Kleinsignalstabilität eines Niederspannungsnetzes mit dezentraler Erzeugung und auf die Auslegung eines geeigneten Regelgesetzes, das Stabilität gewährleisten kann. Nach einer detaillierten Einführung in die Arbeitsweise eines Niederspannungsnetzes mit dezentraler Erzeugung werden geeignete Umrichter- und Netzmodelle eingeführt. Darauf folgt eine Diskussion des dynamischen Verhaltens dieser Modelle und deren Grenzen. Als Regler wird ein so genannter improved-droop Regler vorgeschlagen, der als PDT-Regler auf die Wirkleistungsstatikkennlinie des Umrichters wirkt. Das Dämpfungs- und Stabilisierungsvermögen des PDT-Reglers werden in vollem Umfang mit Hilfe von Wurzelortskurven, Bode- und Nyquist-Diagramme untersucht. Aus dieser Analyse werden drei Design-Methoden abgeleitet, die die systematische Auslegung des Reglers ermöglichen. Anschließend wird die Analyse auf ein Niederspannungsnetz mit mehreren dezentralen Umrichtern erweitert. Im Gegensatz zur traditionellen entkoppelten Reglerauslegung mehrerer Umrichter wird in dieser Arbeit deren Kopplung explizit betrachtet. Zwei solcher Verfahren zur Auslegung der PDT-Regler jeder Umrichter werden entsprechend entworfen. Schließlich wird ein Modell reduzierter Ordnung hergeleitet, das die wesentlichen Aspekte des dynamischen Verhaltens eines Niederspannungsnetzes mit dezentraler Erzeugung nachbildet. Die Leistungsfähigkeit und die Grenzen der vorgeschlagenen Ansätze werden mittels Laborversuchen demonstriert

Digital Filters

The new technology advances provide that a great number of system signals can be easily measured with a low cost. The main problem is that usually only a fraction of the signal is useful for different purposes, for example maintenance, DVD-recorders, computers, electric/electronic circuits, econometric, optimization, etc. Digital filters are the most versatile, practical and effective methods for extracting the information necessary from the signal. They can be dynamic, so they can be automatically or manually adjusted to the external and internal conditions. Presented in this book are the most advanced digital filters including different case studies and the most relevant literature