Simulation, bifurcation, and stability analysis of a SEPIC converter controlled with ZAD

This article presents some results of SEPIC converter dynamics when controlled by a center pulse width modulator controller (CPWM). The duty cycle is calculated using the ZAD (Zero Average Dynamics) technique. Results obtained using this technique show a great variety of non-linear phenomena such as bifurcations and chaos, as parameters associated with the switching surface. These phenomena have been studied in the present paper in numerical form. Simulations were done in MATLAB

Study on Nonlinear Phenomena in Buck-Boost Converter with Switched-Inductor Structure

The switched-inductor structure can be inserted into a traditional Buck-Boost converter to get a high voltage conversion ratio. Nonlinear phenomena may occur in this new converter, which might well lead the system to be unstable. In this paper, a discrete iterated mapping model is established when the new Buck-Boost converter is working at continuous conduction current-controlled mode. On the basis of the discrete model, the bifurcation diagrams and Poincare sections are drawn and then used to analyze the effects of the circuit parameters on the performances. It can be seen clearly that various kinds of nonlinear phenomena are easy to occur in this new converter, including period-doubling bifurcation, border collision bifurcation, tangent bifurcation, and intermittent chaos. Value range of the circuit parameters that may cause bifurcations and chaos are also discussed. Finally, the time-domain waveforms, phase portraits, and power spectrum are obtained by using Matlab/Simulink, which validates the theoretical analysis results

Prototipo de seguimiento de máximo punto de potencia (MPPT) de bajo costo.

This paper presents the development of a maximum power point tracker (MPPT), for a photovoltaic system (PV), using the fractional open circuit voltage technique. The objective is to develop a low-cost prototype that allows obtaining the maximum power point of a PV generator, with the minimum requirement of software and hardware. The paper shows the simulation of the power converter used (DC / DC converter Cuk), the development of the algorithm of the control technique and the implementation of the prototype from an Arduino UNO board; Similarly, the validation of the operation through experimental tests is shown and the results are analyzed, showing the most relevant advantages of the device developed and presenting the conclusions with the most important points of the research.Este artículo presenta el desarrollo de un seguidor de máximo punto de potencia (MPPT), para un sistema fotovoltaico (FV),utilizando la técnica de voltaje fraccional de circuito abierto. El objetivo es desarrollar un prototipo de bajo costo que permita obtener el máximopunto de potencia de un generador FV, con el mínimo requerimiento de computo y hardware. En el artículo se muestra la simulación delconvertidor de potencia utilizado (convertidor DC/DC tipo Cuk), el desarrollo del algoritmo de la técnica de control y la implementación delprototipo a partir de una placa Arduino UNO; de igual forma, se muestra la validación del funcionamiento mediante pruebas experimentales yse analizan los resultados mostrando las ventajas mas relevantes del dispositivo desarrollado y presentando las conclusiones con los puntosmas importantes de la investigación

Control síncrono de potencia de un D-STATCOMde bajo costo.

This article presents the model and simulation of a D-STATCOM in the Simulink-Matlab tool, the objective is to correct the power factor of an inductive or capacitive load of a distribution system, using a proposed control technique that seeks to make the device raise the power factor of the, through a similar of control of synchronous generators; This will allow to have a low - cost device, since the topology and the control technique used are simple, favoring the reduction of losses that occur in the distribution system with a low software and hardware requirement. To validate the operation, the behavior of the device and the control technique in different load scenarios are analyzed, likewise, a harmonic content analysis is presented together with the most relevant conclusions of the research.Este artículo presenta el modelo y simulación de un D-STATCOM en la herramienta Simulink - Matlab, el objetivo es corregir el factor de potencia de una carga inductiva o capacitiva de un sistema de distribución, utilizando una técnica de control propuesta que busca que el dispositivo eleve el factor de potencia de la carga dentro de los límites permitidos, a través de un control análogo al utilizado en los generadores síncronos; esto permitirá tener un dispositivo de bajo costo, ya que la topología utilizada es simple y el control sencillo, que favorezca la reducción de las pérdidas que se presentan en el sistema de distribución, con un requerimiento bajo de software y hardware. Para validar el funcionamiento se analiza el comportamiento del dispositivo y la técnica de control frente a diferentes escenarios de carga, al igual que se presenta un análisis de contenido armónico junto con las conclusiones más relevantes de la investigación

Analysis and control of nonlinear phenomena in electrical drives

PhD ThesisElectrical motors are key to the growth of any modern society. In order to ensure optimal utilisation of the motors, the shaft speed and armature current must be controlled. Currently, the most efficient way of achieving both speed and current control in electrical motors is through power electronic switching, thus making the system both nonlinear and time varying. The combination of electric motors and control electronics is referred to as electric drives. Due to the inherent nonlinear nature of electrical drives, the system is prone to complex dynamical phenomena including bifurcations, chaos, co-existing attractors and fractal basin boundaries. The types of nonlinear phenomena that occur in some of the more common electrical drive systems, namely permanent magnet dc (PMDC) drives, series connected dc (SCDC) drives and switched reluctance motor (SRM) drives, are considered for analysis in this project. The nominal steady state behaviour of these drives is a periodic orbit with a mean value close to the reference value. But as some system parameters are being varied, the nominal orbit of the system referred to as the period-1 orbit, may lose its stability leading to the birth of new attracting orbit that is periodic, quasi-periodic or chaotic in nature. The most common technique for performing stability analysis of a periodic orbit is the Poincaré map approach, which has been successfully applied in DC-DC converters. This method involves reducing the continuous time dynamical system into a discrete time nonlinear iterative map and the periodic orbit into a fixed point. The stability of the periodic orbit then depends on the eigenvalue of the Jacobian matrix of the map evaluated at the fixed point. However, for some power electronic based system the nonlinear map cannot be derived in closed form due to the transcendental nature of the equation involved. In this project, the recently introduced Monodromy matrix approach is employed for the stability analysis of the periodic orbit in electrical drives. This method is based on Filippov’s method of differential inclusion and has been successfully applied in the stability analysis of periodic orbits in both low order and higher order DC-DC converters. This represents the first application of the technique in electrical drives. The Monodromy matrix approach involves computing the State Transition Matrix (STM) of the system around the nominal orbit including the STM at the switching manifold (sometimes referred to as the Saltation matrix). Also, by manipulating some of the parameters in the Saltation matrix, it is possible to control the instabilities and thus extend the system parameter range for nominal period-1 operation. The experimental validation of the nonlinear phenomena in a proportional integral (PI) controlled PMDC drive, which is absent in literature, is presented in this thesis. The system was implemented using dsPIC30F3010 which is a low cost and high performance digital signal controller.Petroleum Technology Development Fund (PTDF) of Nigeri

18th IEEE Workshop on Nonlinear Dynamics of Electronic Systems: Proceedings

Proceedings of the 18th IEEE Workshop on Nonlinear Dynamics of Electronic Systems, which took place in Dresden, Germany, 26 – 28 May 2010.:Welcome Address ........................ Page I Table of Contents ........................ Page III Symposium Committees .............. Page IV Special Thanks ............................. Page V Conference program (incl. page numbers of papers) ................... Page VI Conference papers Invited talks ................................ Page 1 Regular Papers ........................... Page 14 Wednesday, May 26th, 2010 ......... Page 15 Thursday, May 27th, 2010 .......... Page 110 Friday, May 28th, 2010 ............... Page 210 Author index ............................... Page XII

Modelagem e sincronização de sistemas caóticos com ênfase em sistemas financeiros

Trabalho de conclusão de curso (graduação)—Universidade de Brasília, Faculdade de Tecnologia, Curso de Graduação em Engenharia de Controle e Automação, 2013.Este trabalho estuda, com base na teoria de estabilidade de Lyapunov, o projeto de controladores robustos para sistemas hipercaóticos financeiros e caóticos unificados na presença de incerteza nos parâmetros e distúrbios limitados. Inicialmente, de modo a explicitar o problema de sincronização e apresentar os conceitos e ferramentas utilizados, uma breve revisão sobre dinâmica não linear, estabilidade, caos e análise tipo Lyapunov-like é apresentada. Na sequência, são estudados os modelos hipercaóticos e caóticos a serem utilizados. Para tanto, são analisados os trabalhos de Yu et al, 2012 e Lu et al, 2001. Estes trabalhos são fundamentais para os resultados apresentados no presente trabalho de graduação. A seguir, um esquema de controle adaptativo para sistemas hipercaóticos financeiros que assegura convergência para zero do erro residual de sincronização é estudado. O esquema é baseado em uma análise tipo Lyapunov-like e assegura convergência assintótica, mesmo na presença de erros de modelagem e distúrbios limitados. Simulações exaustivas são apresentadas com o objetivo de se avaliar a influência dos diversos parâmetros de projeto no desempenho do algoritmo. Finalmente, de modo a ressaltar a aplicabilidade da metodologia de projeto empregada, é considerado o controle adaptativo de um sistema caótico unificado. Como esperado, é mostrado que o erro residual de sincronização converge para zero na presença de erro de modelagem, distúrbios e incerteza paramétrica.The present work studies, based on the Lyapunov Stability Theory, the design of robust controllers for hyperchaotic financial and unified chaotic systems in the presence of uncertainty parameter and bounded disturbances. Initially, in order to explain the problem of synchronization and introduce the concepts and tools used, a brief review of nonlinear dynamics, stability, chaos and a Lyapunov-like analysis type is presented. In the sequel, the hyperchaotic and chaotic models are studied and then used. For this, we analyze the works of Yu et al, 2012 e Lu et al, 2001. These works are critical to the results presented in this graduate work. Following, an adaptive control scheme to a hyperchaotic financial system that assures the convergence of the residual synchronization error to zero is studied. The scheme is based upon a Lyapunov-like analysis type and assures asymptotic convergence, even in the presence of modeling errors and bounded disturbances. Exhaustive simulations are showed aiming to evaluate the influence of various design parameters on the performance of the algorithm. Finally, in order to emphasize the applicability of the design methodology employed, an adaptive control to the unified chaotic system is considered. As expected, is showed that the residual synchronization error converges to zero in the presence of modeling errors, disturbances and parametric uncertainty

Sliding Mode Control

The main objective of this monograph is to present a broad range of well worked out, recent application studies as well as theoretical contributions in the field of sliding mode control system analysis and design. The contributions presented here include new theoretical developments as well as successful applications of variable structure controllers primarily in the field of power electronics, electric drives and motion steering systems. They enrich the current state of the art, and motivate and encourage new ideas and solutions in the sliding mode control area