Rubén Salas-Cabrera

State space modeling and control of the dc-dc multilevel boost converter

The dc-dc multilevel boost converter topology was recently proposed with features such as high voltage gain without using an extreme duty ratio, few components and self dc-link balancing. This paper presents the state space modeling and a linear controller based on the pole placement technique for the dc-dc multilevel boost converter. Nonlinear and linear models are derived. Simulation results obtained with the averaging model in Matlab and with the simulated circuit in Synopsys Saber software are presented to prove the principle of the proposition.

Multiplier SEPIC converter

This work introduces a set of PWM SEPIC dc-dc converters specially designed for high voltage-gain conversion, the voltage gain in the proposed converters can be adjusted by PWM and by adding diodes and capacitors in a diode-capacitor multiplier structure.

Interleaved power converter with current ripple cancelation at a selectable duty cycle

This work proposes a topology for a boost converter with the capability of canceling the input current ripple at an arbitrarily selected duty cycle.

Hybrid Voltage‐Multipliers Based Switching Power Converters

Abstract. This work presents a derivation of PWM DC-DC hybrid converters by combining traditional converters with the Cockcroft–Walton voltage multiplier, the voltage multiplier of each converter is driven with the same transistor of the basic topology; this fact makes the structure of the new converters very simple and provides high-voltage gain. The traditional topologies discussed are the boost, buck-boost, Cuk and SEPIC. They main features of the discussed family are: (i) high-voltage gain without using extreme duty cycles or transformers, which allow high switching frequency and (ii) low voltage stress in switching devices, along with modular structures, and more output levels can be added without modifying the main circuit, which is highly desirable in some applications such as renewable energy generation systems. It is shown how a multiplier converter can become a generalized topology and how some of the traditional converters and several state-of-the-art converters can be derived from the generalized topologies and vice-versa. All the discussed converters were simulated, additionally experimental results are provided with an interleaved multiplier converter.

A contribution to the dynamic modeling of switched-capacitor converters

This paper presents an analysis of the dynamics of two particular DC-DC converters that have switched-capacitors; a DC-DC Three-Switch High-Voltage Converter and a DC-DC Single-Inductor Multiplier Cuk Converter. The purpose of this paper is to explain the dynamics of the parallel connection of capacitors during the switching states of the converters. The obtained large signal models may provide a detailed description of the converters presented in this paper. The mathematical description of several dynamics of these converters may be easily extended for a wide number of power electronics devices that present similar features. The contribution in this paper represents an advantage for dynamic analysis and control design for switched-capacitor-based converters.

Observer Design for DC Electric Machines

This work deals with the experimental results of implementing an adaptive observer for a shunt connected DC motor. The observer is able to estimate the state variables and one unknown parameter. Estimated states are compared to the corresponding experimental states. Custom-made electronics designs are employed for the observer implementation and the off-line identification of some nominal parameters. A free open source Linux distribution is used as a software platform.

Dynamic Analysis of a DC-DC Multiplier Converter

Renewable energy generation systems bring the promise of providing green energy whichis highly desirable for decreasing global warming. Therefore, renewable energy systems aregaining attention among researchers.In terms of power electronics, several challenges are emerging with the advent of the greenenergy generation systems. The first issue is that renewable energy power sources such asPhoto-Voltaic PV panels, fuel cells and some wind turbine generators provide a low leveldc voltage. This voltage must be boosted and then inverted in order to be connected to thegrid. Since the level of the output voltage of these power sources depends on the weatherconditions, there should be a method to control the generated voltage.Other types of green energy power sources such as AC machine based wind generatorsprovide a low level ac voltage with amplitude and frequency depending on the wind speed. Acommon method to deal with the generated ac voltaje is to rectify it, then a DC-DC converteris used to boost it. Once the boosted DC voltage is controlled, it may feed an electric loadunder some operating range or it may be inverted for connecting it to the grid.This is a scenario of increased interest in DC-DC converters with high conversion ratios.Several converters have been proposed R. D. Middlebrook (1988), D. Maksimovic et al. (1991),B. Axelrod et al. (2008), Zhou Dongyan (1999), Leyva-Ramos J (et al 2009), however all of themare complex compared with conventional single-switch converters. Some desirable featuresof those converters are a high conversion ratio without the use of extreme duty cycles anda transformer-less topology that allows the use of high switching frequency providing highefficiency.One of the recently proposed converters is the multiplier boost converter (MBC) which isalso known as multilevel boost converter Rosas-Caro J.C. et al (2010), Rosas-Caro J.C. et al(2008), Rosas-Caro J.C. et al (2008), Mayo-Maldonado J.C. et al (2010). This topology combinesthe traditional single-switch boost converter with a Cockcroft-Walton voltage multiplier.Fig. 1 shows the Nx DC-DC Multiplier Boost Converter (Nx MBC). The nomenclatureNx is associated with the number of capacitors at the output of the converter. The mainadvantages of the MBC are (i) high voltage gain without the use of extreme duty cycles andtransformer-less, (ii) self balancing, in other words the multiplier converter maintains the

On the real time estimation of the wind speed for wind energy conversion systems

This paper presents the experimental results of the real time estimation of the wind speed for a wind turbine. In order to estimate the wind speed, an adaptive observer is employed. A wind turbine emulator was designed for validating the theoretical results. The wind turbine emulator is able to simulate the dynamics of a real wind turbine. For emulation purposes the wind speed is considered as a known input. On the other hand, for the adaptive observer the wind speed is considered as an unknown parameter. A free Linux-based real time platform was used for the experimental setup.

Two-switches-based AC-link three-phase voltage regulator

This paper presents a topology for a PWM controlled three-phase voltage regulator which uses only two driven switches giving high reliability and making the switching stage simpler and cheaper compared with other available configurations. The proposed topology is suitable for voltage regulation on the distribution power system and able to regulate the steady state voltage and to reject voltage variations such as flicker or sags caused by big motors start, the compensator is free of energy storage elements.

An experimental setup for teaching dynamic systems

In this work an experimental tool is presented for teaching the most important features of continuous n-dimensional linear time-invariant dynamic systems. This tool consists of a combination of analog/digital electronics hardware and software. An analog electronics-based dynamic system is used as the experimental plant to be studied. A free Linux-based real-time software is used to implement a linear observer and a linear state feedback. The digital set up is composed by the mentioned real-time software, a commercial data acquisition board and a personal computer. Experimental results are presented.