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Telles Brunelli Lazzarin

Bio: Telles Brunelli Lazzarin is an academic researcher from Universidade Federal de Santa Catarina. The author has contributed to research in topics: Switched capacitor & Voltage. The author has an hindex of 15, co-authored 111 publications receiving 976 citations.


Papers
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Journal ArticleDOI
TL;DR: A novel transformerless high gain step-up dc–dc converter based on an active switched-inductor and a passive switched-capacitor networks that has the main advantages of the high voltage gain (>10), the reduced voltage stresses across the switches and the reduced number of components when compared to topologies that provide the same voltage gain using similar principles.
Abstract: High-gain voltage conversion is a feature required for several applications, especially for power processing of low-voltage renewable sources in grid-connected systems. In this scope, the presented paper proposes a novel transformerless high gain step-up dc–dc converter based on an active switched-inductor and a passive switched-capacitor networks. The main advantages of the proposed converter are the high voltage gain (>10), the reduced voltage stresses across the switches and the reduced number of components when compared to topologies that provide the same voltage gain using similar principles. The detailed analysis of the proposed converter and a comparison considering other topologies previously published in the literature are also presented in this manuscript. In order to verify the proposed converter performance, a prototype has been built for a power of 200 W, input and output voltages of 20 and 260 V, respectively, and switching frequency of 50 kHz. Experimental results validate the effectiveness of the theoretical analysis proving the satisfactory converter performance, which peak efficiency is around 95.5%.

272 citations

Journal ArticleDOI
TL;DR: The proposed control strategy ensures the proper sharing of the load current and avoids current circulation among the inverters during transient and steady-state operation and its design and implementation are very simple.
Abstract: This paper describes a theoretical and experimental study on a control strategy for the parallel operation of single-phase voltage source inverters (VSI), to be applied to uninterruptible power supply. The control system for each inverter consists of two main loops, which both use instantaneous values. The first (parallelism control) employs the feedback of the inductor current from the output filter to modify the input voltage of the same filter and, therefore, to control the power flow of each inverter to the load. Additionally, the second loop (voltage control) is responsible for controlling the output voltage of the LC filter, which coincides with the output voltage of the VSI. Due to the fact that there is no exchange of information among the VSIs regarding their operation points, it is easier to obtain redundant systems. Furthermore, the connection (or disconnection) of inverters in a parallel arrangement is carried out directly, without connection impedance, and can occur at any operation point of the system. The proposed control strategy ensures the proper sharing of the load current and avoids current circulation among the inverters during transient and steady-state operation. Moreover, its design and implementation are very simple. The control technique was verified through experimental results with a maximum load of 10 kVA supplied by three parallel-connected inverters.

126 citations

Journal ArticleDOI
TL;DR: In this article, the authors proposed a new ac-ac static power converter based on the switched-capacitor (SC) principle, intended to replace the conventional autotransformer in commercial and residential applications.
Abstract: This paper proposes a new ac-ac static power converter based on the switched-capacitor (SC) principle, intended to replace the conventional autotransformer in commercial and residential applications The principle of operation, a qualitative and quantitative analysis, the design methodology, and an example are described in this paper The main advantages of the proposed ac-ac converter are the absence of magnetic elements, the stress voltages in all components being equal to half of the high-side voltage, the common reference between input and output voltages, the employment of a single SC leg, the ability to be bidirectional, the high efficiency, and the high power density In order to demonstrate the performance of this converter in the laboratory, a prototype of 1-kW, 220-Vrms high-side voltage, 110-Vrms low-side voltage, and switching frequency of 100 kHz was designed and fabricated The relevant experimental results are reported herein The maximum and rated power efficiencies obtained in the laboratory were 98% and 96%, respectively

76 citations

Journal ArticleDOI
TL;DR: The principle of operation, theoretical analysis, design methodology, and a comparison of the proposed topology regarding other converters from the literature that use similar principles are approached.
Abstract: A new nonisolated high-step-up dc–dc converter based on active switched-inductors and passive switched-capacitors is proposed in this article. The main advantages of the converter are the high voltage gain (higher than 20), high efficiency, reduced voltage stresses, and reduced component count. This article approaches the principle of operation, theoretical analysis, design methodology, and a comparison of the proposed topology regarding other converters from the literature that use similar principles. Finally, the theoretical study is verified from a 200-W prototype designed to accomplish an input voltage of 20 V and an output voltage of 300 V, in which a peak efficiency of 96.2% is reached.

70 citations

Journal ArticleDOI
TL;DR: A bidirectional three-phase direct ac-ac converter, with only capacitors and switches in its power circuit and with its operation based on the switched-capacitor principle, suitable to replace the conventional three- phase autotransformer in industrial, commercial, and residential applications.
Abstract: This paper proposes a bidirectional three-phase direct ac–ac converter, with only capacitors and switches in its power circuit and with its operation based on the switched-capacitor principle. The converter presents fixed gain, it keeps the frequencies of the output and input voltages equal, and it operates in open loop with constant switching frequency and duty cycle. The main advantages of the proposed converter are the absence of magnetic elements in the power circuit, the higher efficiency, the higher power density, the higher specific power, the lower cost, and the fact that it can convert ac–ac voltages within a wide frequency range, including dc voltage. Therefore, it is suitable to replace the conventional three-phase autotransformer in industrial, commercial, and residential applications, and it can be designated as a magnetic-less three-phase solid-state autotransformer. The principle of operation, a qualitative and quantitative analysis, the design methodology, and a fabricated example are described in this paper. In order to verify the converter in the laboratory, a prototype with the following characteristics was designed and fabricated: 6 kW, 1.35 kW/kg, 380/110 V, and switching frequency of 100 kHz. The measured efficiency at rated power was 96.3%, and other relevant experimental results are reported herein.

54 citations


Cited by
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01 Jan 1992
TL;DR: In this paper, a multilevel commutation cell is introduced for high-voltage power conversion, which can be applied to either choppers or voltage-source inverters and generalized to any number of switches.
Abstract: The authors discuss high-voltage power conversion. Conventional series connection and three-level voltage source inverter techniques are reviewed and compared. A novel versatile multilevel commutation cell is introduced: it is shown that this topology is safer and more simple to control, and delivers purer output waveforms. The authors show how this technique can be applied to either choppers or voltage-source inverters and generalized to any number of switches.<>

1,202 citations

01 Jan 2016
TL;DR: This power electronics converters applications and design helps people to enjoy a good book with a cup of tea in the afternoon, instead they cope with some malicious virus inside their desktop computer.
Abstract: Thank you for downloading power electronics converters applications and design. Maybe you have knowledge that, people have look numerous times for their favorite readings like this power electronics converters applications and design, but end up in harmful downloads. Rather than enjoying a good book with a cup of tea in the afternoon, instead they cope with some malicious virus inside their desktop computer.

754 citations

Journal ArticleDOI
TL;DR: In this article, the authors present an overview of the virtual-impedance-based control strategies for voltage-source and current-source converters, and a number of practical examples are demonstrated to illustrate the feasibility of virtual impedances.
Abstract: The virtual impedance concept is increasingly used for the control of power electronic systems. Generally, the virtual impedance loop can either be embedded as an additional degree of freedom for active stabilization and disturbance rejection, or be employed as a command reference generator for the converters to provide ancillary services. This paper presents an overview of the virtual-impedance-based control strategies for voltage-source and current-source converters. The control output impedance shaping attained by the virtual impedances is generalized first using the impedance-based models. Different virtual impedances and their implementation issues are then discussed. A number of practical examples are demonstrated to illustrate the feasibility of virtual impedances. Emerging applications and future trends of virtual impedances in power electronic systems conclude this paper.

468 citations

Journal ArticleDOI
TL;DR: In this paper, the authors provide an overview of the underlying physics behind connectivity changes in highly conductive regions under an electric field, and discuss percolation model approaches and the theory for the scaling behaviors of numerous transport properties observed in RS.
Abstract: Resistive switching (RS) phenomena are reversible changes in the metastable resistance state induced by external electric fields. After discovery ∼50 years ago, RS phenomena have attracted great attention due to their potential application in next-generation electrical devices. Considerable research has been performed to understand the physical mechanisms of RS and explore the feasibility and limits of such devices. There have also been several reviews on RS that attempt to explain the microscopic origins of how regions that were originally insulators can change into conductors. However, little attention has been paid to the most important factor in determining resistance: how conducting local regions are interconnected. Here, we provide an overview of the underlying physics behind connectivity changes in highly conductive regions under an electric field. We first classify RS phenomena according to their characteristic current–voltage curves: unipolar, bipolar, and threshold switchings. Second, we outline the microscopic origins of RS in oxides, focusing on the roles of oxygen vacancies: the effect of concentration, the mechanisms of channel formation and rupture, and the driving forces of oxygen vacancies. Third, we review RS studies from the perspective of statistical physics to understand connectivity change in RS phenomena. We discuss percolation model approaches and the theory for the scaling behaviors of numerous transport properties observed in RS. Fourth, we review various switching-type conversion phenomena in RS: bipolar-unipolar, memory-threshold, figure-of-eight, and counter-figure-of-eight conversions. Finally, we review several related technological issues, such as improvement in high resistance fluctuations, sneak-path problems, and multilevel switching problems.

341 citations

Journal ArticleDOI
TL;DR: A distributed two-layer control structure for ac microgrids that regulates the active and reactive powers of CCVSIs and is verified on a microgrid test system and IEEE 34 test feeder.
Abstract: This paper proposes a distributed two-layer control structure for ac microgrids. Inverter-based distributed generators (DGs) can operate either as voltage-controlled voltage source inverters (VCVSI) or current-controlled voltage source inverters (CCVSI). VCVSIs provide the voltage and frequency support, whereas CCVSIs regulate the generated active and reactive powers. The proposed control structure has two main layers. The first layer deals with the voltage and frequency control of VCVSIs. The second layer regulates the active and reactive powers of CCVSIs. These controllers are implemented through two communication networks with one-way communication links and are fully distributed; each DG only requires its own information and the information of its neighbors on the communication network graph. The proposed control framework is verified on a microgrid test system and IEEE 34 test feeder.

221 citations