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IEEE/PES Transmission and Distribution Conference and Exposition: Latin America

作者： R. T. de Souza E. G. da Costa A. C. de Oliveira W. de V. Sousa T. C. M. de Morais Industry Academic Unit Paraiba Federal Institute Brazil Department of Electrical Engineering Campina Grande Federal University Brazil Post-Graduate Program in Electrical Engineering - PPgEE - COPELE - DEE Campina Grande Federal University Brazil Encrgisa Paraiba Brazil

Static resistance measurement of circuit breakers has been a crucial technique to assess the state of contacts, supporting maintenance procedures. However, in many cases, the obtained results do not provide accurate data for correct diagnosis, since the test examines only the main contact. This article discusses the application of the contact dynamic resistance measurement (DRM) in the evaluation of main and arcing contacts. The DRM is a contact resistance test, and the resistance is determined during the opening of contacts, analyzing the main and arcing contacts. The research objective is to get the DRM parameters that can assist in the contacts diagnosis. The obtained results indicate that DRM has presented more qualitative parameters than the static resistance test in the evaluation of contacts. The resistance tests were performed applying a direct current with 300 A of ***.

关键词： Resistance Circuit breakers electrical resistance measurement Current measurement Voltage measurement Contacts Oscilloscopes

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Hybrid Open-End and NPC AC Six-Phase Machine Drive Systems

Hybrid Open-End and NPC AC Six-Phase Machine Drive Systems

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IEEE Energy Conversion Congress and Exposition

作者： Victor F. M. B. Melo Cursino B. Jacobina Nady Rocha Post-Graduate Program in Electrical Engineering - PPgEE - COPELE - UFCG Campina Grande Paraiba Brazil Electrical Engineering Department - Federal University of Campina Grande - UFCG Campina Grande Paraiba Brazil Federal University of Paraiba - UFPB Joao Pessoa Paraiba Brazil

ISBN: (纸本)9781479957774

This paper presents two machine drive system based on a six-phase machine (SPM) and three-leg converters. The machine is composed of two three-phase groups. For the first configuration, one of the groups is connected to a three-leg converter and the other is connected to other two three-leg converters in an open-end winding configuration (see Fig. 4). For the second configuration, one of the groups is connected to a three-leg converter (similar to first one) and the other group is connected to a three-level NPC converter (see Fig. 5). Since the machine two groups are fed differently, the system topology is considered to be hybrid. The purpose of these topologies is to be an alternative configuration, being midway between the conventional six-leg inverter system (see Fig. 1) and the NPC six-leg inverter system (see Fig. 2) and Conventional twelve-leg Open-end inverter system (see Fig. 3). Compared with the conventional six-leg system, the proposed systems permits reducing the power processed by the semiconductor switches and their ratings, the dc-link voltage and the harmonic distortion. On the other hand, the proposed systems constitute less complex alternatives, compared with the open-end and NPC counterparts (see Fig. 3). PWM and control strategies are discussed. Simulation and experimental results are also presented.

关键词： drive train Figs Thyristors Converters machine six-phase Midway Inventors Harmonic distortion

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Shunt Active Power Filter With Open-End Winding Transformer and Series Connected Converters

Shunt Active Power Filter With Open-End Winding Transformer ...

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IEEE Energy Conversion Congress and Exposition

作者： G. A. de A. Carlos C. B. Jacobina E. C. dos Santos E. L. L. Fabricio N. Rocha Department of Control and Industrial Process Federal Institute of Alagoas (IFAL) Post-Graduate Program in Electrical Engineering - PPgEE - COPELE Department of Electrical Engineering Federal University of Campina Grande (UFCG) Department of Electrical and Computer Engineering Purdue School of Engineering and Technology (IUPI) Department of Electrical Engineering Federal University of Paraiba (UFPB)

ISBN: (纸本)9781479903375

This paper presents a shunt active power filter based on the concept of open-end winding (OEW) transformers. The proposed configuration is constituted of two converters with three legs each series connected throughout a three-phase OEW transformer. Model PWM strategy and control scheme are presented as well. The main advantage of the proposed system lies on the multi-level waveform generation, which allows reduction of either harmonic distortions or switching losses. This proposed topology is suitable for medium voltage (MV) distribution systems. Simulation and experimental results validate the theoretical study.

关键词： OEW multi-level MV active power filter Transformer power filters multilayers Converters winding (process) shunt Shunts (electrical) Multiple Virtual Storage Theoretical Study

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Comparison of new techniques based on EMD for control of a SSVEP-BCI

Comparison of new techniques based on EMD for control of a S...

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IEEE International Symposium on Industrial Electronics (ISIE)

作者： Richard M. G. Tello Sandra Mara Torres Müller Teodiano Bastos-Filho Andre Ferreira Post-Graduate Program of Electrical Engineering (PPGEE). UFES Vitoria Brazil Department of Computer and Electronics (CEUNES) Sao Mateus Brazil

ISBN: (纸本)9781479924004

This paper presents the comparation of three different feature extraction techniques based on the Empirical Mode Decomposition (EMD) for a SSVEP-BCI. This approach based on the characterization of the signal by EMD, is proposed as a novel alternative to other techniques and it was demonstrated that it exceeds both in accuracy rate and Information Transfer Rate (ITR). The experiments were performed in an offline way, and seven volunteers participated of the study. The stimulis were generated both by LCD and LEDs. The frequencies used were 8, 11, 13 and 15 Hz. The results here reported such represent the average of the seven participants, achieving a success rate of 81% and ITR of 23.32 bits/min of the total set of cases analyzed. It is further confirmed that the highest success rates and ITRs were obtained for stimulation by LEDs.

关键词： Electrodes

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One and Two Dc-Links Universal Active Power Filter Without Series Isolation Transformer

One and Two Dc-Links Universal Active Power Filter Without S...

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IEEE Energy Conversion Congress and Exposition

作者： P. L. S. Rodrigues C. B. Jacobina G. A. de A. Carlos M. B. R. Correa M. A. Vitorino Post-Graduate Program in Electrical Engineering - PPgEE - Copele Federal University of Campina Grande (UFCG) Campina Grande - 58429-900 - Paraiba - Brazil Department of Electrical Engineering Federal University of Campina Grande (UFCG) Campina Grande - 58429-900 - Paraiba - Brazil

ISBN: (纸本)9781479957774

This paper presents two universal active power filter (UAPF) configurations for reactive power and harmonic compensation without series isolation transformer. The proposed systems combine both series and shunt compensation, by using converters with one (configuration I) or two (configuration II) dc-links. They are suitable for applications in which size, weight and cost associated with transformers becomes a critical issue. The PWM techniques and complete control of the systems are developed. Simulation and experimental results are shown for validation purposes.

关键词： isolation transformer active power filter power filters shunt compensation harmonic compensation series (mathematics) Reactive power Transformer Converters Universal

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Single-phase to three-phase induction generation system with two parallel single-phase half-bridge converters

Single-phase to three-phase induction generation system with...

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Brazilian Power Electronics Conference, COBEP

作者： Nady Rocha Ely C. de Menezes Ítalo A. Cavalcanti de Oliveira Cursino B. Jacobina Electrical Engineering Department (DEE) Federal University of Paraíba (UFPB) Cidade Universitária - João Pessoa PB Brazil Post-Graduate Program in Electrical Engineering - PPgEE - COPELE Federal University of Campina Grande (UFCG) Campina Grande PB Brazil

This paper presents a generation system based on the induction generator for wind energy application. The induction generator is connected to single-phase grid through an ac-dc-ac single-phase to three-phase converter. The single-phase converter is composed of two parallel single-phase half-bridge converters. Suitable modelling, including the circulation current, and control strategy are developed. The control of generator is based on the field oriented control. A pulse width-modulation (PWM) technique using a single and double carriers PWM is presented. Proposed topology permits to improve the harmonic distortion. Beside, it can reduce the power losses in the converter. Finally, simulation and experimental results are presented.

关键词： Pulse width modulation Topology Estimation Induction generators Inductance Harmonic distortion

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Hybrid multilevel inverter system for Open-End Winding (OEW) induction motor drive based on Double-Star Chopper-Cells (DSCC) converter

Hybrid multilevel inverter system for Open-End Winding (OEW)...

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Annual IEEE Conference on Applied Power Electronics Conference and Exposition (APEC)

作者： Italo Roger F. M. P. da Silva Cursino B. Jacobina Alexandre C. Oliveira Gregory A. de Almeida Carlos Maurício B. de R. Corrîa Post-graduate Program in Electrical Engineering PPgEE/COPELE Department of Electrical Engineering (DEE) Federal University of Campina Grande (UFCG) Campina Grande PB Brazil Department of Control and Industrial Process Federal Institute of Alagoas (IFAL) Palmeira dos Indios AL Brazil

ISBN: (纸本)9781479967360

This paper proposes a hybrid multilevel topology for Open-End stator Winding (OEW) induction motor drive based on Modular Multilevel Cascade Inverter (MMCI) with Double-Star Chopper-Cells (DSCC) and 2-Level Voltage Source Inverter (2L-VSI). An efficient Voltage Reference Technique is proposed to generate the pole voltages of both inverters. As a result, the DSCC inverter is commanded in high-switching frequency, while the 2L-VSI operates at the fundamental frequency. A voltage-balancing control of the floating DC capacitors of the DSCC is presented to ensure the energy balance. At last, to investigate the proposed system and control strategy, experimental results are presented.

关键词： Voltage control Inverters Induction motors Topology Capacitors Inductors Logic gates

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Three-phase four-wire inverters based on cascaded three-phase converters with four and three legs

Three-phase four-wire inverters based on cascaded three-phas...

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IEEE Energy Conversion Congress and Exposition

作者： Joao P. R. A. Mello Cursino B. Jacobina Mauricio B. R. Correa Post-Graduate Program in Electrical Engineering (PPgEE/COPELE) Federal University of Campina Grande (UFCG) Campina Grande - 58429-900 - Paraiba - Brazil Department of Electrical Engineering (DEE) Federal University of Campina Grande (UFCG) Campina Grande - 58429-900 - Paraiba - Brazil

ISBN: (纸本)9781509007387

This paper presents three-phase converter topologies for four-wire systems. The converters are series connected by three-phase transformers with accessible neutral. They possess a common dc-link, which is the power supply of the system, and two or more converters, where one of them is connected directly to the ac system, and the others cascaded through three-phase transformers. The three-phase transformers have turn ratios that are calculated in order to maximize the number of levels produced by the inverters. The Level-Shifted Pulse Width Modulation technique is developed for two and three cascaded converters, and a control system is used to set the electrical grid currents on desired values. Simulation and experimental results are exposed for configurations with two cascaded converters, each one with either three or four legs.

关键词： three phase transformers Converters AC SYSTEMS cascades phase convertors Phase transformers Electric Power Source Inventors control systems three-phase four-wire Leg grid current

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Performance of Cognitive Spectrum Sensing Based on Energy Detector in Fading Channels

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Procedia Computer Science 2015年 65卷 140-147页

作者： Fabrício B.S. de Carvalho Waslon T.A. Lopes Marcelo S. Alencar Post-Graduate Program in Electrical Engineering – PPgEE – COPELE Federal University of Campina Grande Department of Electrical Engineering Campina Grande-PB 58429-900 Brazil Federal University of Paraíba Department of Electrical Engineering João Pessoa-PB 58051-970 PO BOX 5115 Brazil Institute of Advanced Studies in Communications (Iecom) Campina Grande-PB 58109-970 Brazil

Spectrum scarcity and the inefficient use of the electromagnetic spectrum motivated the development of Cognitive Radio (CR), which aims to extend the spectral efficiency, with opportunistic access to the available frequency bands. Energy Detection (ED) is the most adopted spectrum sensing technique for cognitive radio applications due to its simplicity. However, fading effects are usually simplified or discarded when evaluating the energy detector performance in spectrum sensing. This paper presents the performance evaluation of cognitive spectrum sensing, based on energy detector, for fading channels. The objective is to analyze how the use of various fading models affect the spectral detection in cognitive networks. Rayleigh, Rice, Nakagami-m and Lognormal fading channels are considered, and the results favor the use of ED when the channel is subject to Lognormal fading.

关键词： Cognitive Radio Spectrum Sensing Energy Detector Fading Channels

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A low cost power quality meter over the internet

A low cost power quality meter over the internet

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International Conference on Harmonics and Quality of Power

作者： Eddy L. Medeiros Edson G. Costa George R. S. Lira Alex C. R. Alves Caio V. A. Diniz Post-Graduate Program in Electrical Engineering - PPgEE Federal University of Campina Grande - UFCG Campina Grande Brazil COPELE UFCG Department of Electrical Engineering - DEE Federal University of Campina Grande - UFCG Campina Grande Brazil DEE Federal University of Campina Grande - UFCG Campina Grande Brazil UFCG

ISBN: (纸本)9781509037933

This paper proposes a low cost three-phase power quality meter. Due to its characteristics, the meter can be applied for residential or small businesses use. The proposed device uses the power definitions from IEEE Standard 1459-2010. Moreover, it calculates the true rms value, the individual harmonics, and the voltage unbalanced factor. In order to validate the power quality meter, simulations and experimental results are presented. The results are presented on a web page that can be accessed by any device with internet access.

关键词： Voltage measurement Harmonic analysis Power quality Reactive power Current measurement Pollution measurement Internet

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