다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

An overview of the self-organizing map algorithm, on which the papers in this issue are based, is presented in this article.

The Self-Organizing Map

Requirement of green supply with higher quality has been consumers’ demand around the globe The electrical power system is expected to deliver undistorted sinusoidal rated voltage and current continuously at rated frequency to the consumers This paper presents a comprehensive review of signal processing and intelligent techniques for automatic classification of the power quality (PQ) events and an effect of noise on detection and classification of disturbances It is intended to provide a wide spectrum on the status of detection and classification of PQ disturbances as well as an effect of noise on detection and classification of PQ events to the researchers, designers and engineers working on power quality More than 150 research publications on detection and classification techniques of PQ disturbances have been critically examined, classified and listed for quick reference

A critical review of detection and classification of power quality events

IEEE International Conference on Fuzzy Systems

The implementations of fuel cells (FCs) in the vehicle industry have gained great attention for the last few decades owing to simple utilization, silent operation, high efficiency and modular structure. Technological advancements show that the use of FCs in electric vehicles (EVs) will increase rapidly and cause a revolution, and will be an alternative to traditional vehicles in the future. Commercial vehicles, projects and research show that work is underway to ensure that FCEVs have sufficient performance advances for their daily transportation needs. However, the lack of a detailed study that will shed light on researchers working in this field is obvious. It aims to provide a comprehensive scientific publication on the current status and future expectations to engineers and researchers interested in this field. In the current study, numerous studies have been examined in detail and added as supplementary to the bibliography. In this context, FCEVs are classified under headings of configurations, systems components, control/management, technical challenges, marketing and future aspects. First of all, FC types and electric motors are discussed in terms of their application areas, characteristic properties and operating conditions. Power converters, which are voltage regulation and motor drive topologies used in FCEVs, are detailed according to the structural frequency of use, structure, and complexity. In the next sections, control issues for converters and technical challenges are branched for FCEVs. In final section, the current status and future aspects are reported using a large number of marketing and target data.

A review and research on fuel cell electric vehicles: Topologies, power electronic converters, energy management methods, technical challenges, marketing and future aspects

This paper proposes a novel reference signal generation method for the unified power quality conditioner (UPQC) adopted to compensate current and voltage-quality problems of sensitive loads. The UPQC consists of a shunt and series converter having a common dc link. The shunt converter eliminates current harmonics originating from the nonlinear load side and the series converter mitigates voltage sag/swell originating from the supply side. The developed controllers for shunt and series converters are based on an enhanced phase-locked loop and nonlinear adaptive filter. The dc link control strategy is based on the fuzzy-logic controller. A fast sag/swell detection method is also presented. The efficacy of the proposed system is tested through simulation studies using the Power System Computer Aided Design/Electromagnetic Transients dc analysis program. The proposed UPQC achieves superior capability of mitigating the effects of voltage sag/swell and suppressing the load current harmonics under distorted supply conditions.

A Novel Reference Signal Generation Method for Power-Quality Improvement of Unified Power-Quality Conditioner

Switching ripple filters (SRF) is one of the significant part of grid connected voltage source converters (VSC) that have been a backbone of the most of renewable energy systems for the last decade. SRFs have two main features for the grid connected VSC systems. One of these is to maintain a coupling connection and integration between grid and VSC. The other one is to prevent the penetration of switching ripple currents to the grid by filtering them. Several SRF topologies named as L, LC, LCL and LLCL type are presented in literature. In order to maintain effective switching ripple filtering, higher order SRF topologies are developed. However, these high order SRFs have resonance problems. To overcome resonance problems of higher order SRFs, passive and active damping methods are applied to SRFs. This paper presents a comprehensive review of SRFs used in grid connected VSCs. In the scope of this paper, the characteristics and the design procedures of SRFs are investigated. Also, both passive and active damping methods applied to the higher order SRFs are classified in detail with the latest studies presented in literature.

Topologies, generalized designs, passive and active damping methods of switching ripple filters for voltage source inverter: A comprehensive review

In this study, the design and analysis of a fuzzy logic (FL) controlled dynamic voltage restorer (DVR) are presented and extended to perform fast fault detection. A new control method for DVR is proposed by combining FL with a carrier modulated PWM inverter. The proposed control scheme is simple to design and has excellent voltage compensation capabilities. The proposed method for voltage sag/swell detection has the ability of detecting different kinds of power disturbances faster than conventional detection methods. Effectiveness of the proposed detection method is shown by comparison with the conventional methods in the literature. Simulation results under unbalanced supply voltage are presented to evaluate the performance of the designed DVR.

Fast sag/swell detection method for fuzzy logic controlled dynamic voltage restorer

Mathematical modeling and analysis of a unified power flow controller: A comparison of two approaches in power flow studies and effects of UPFC location

Hybrid active power filter (HAPF) consisting of passive filter and active filter in various configurations to each other has now become preferred technology for harmonic compensation in two wire, three wire and four wire ac power networks with nonlinear loads. This paper presents a detailed survey of hybrid active power filters considering converter topologies, supply system and passive filter type. In addition, the control strategies are discussed in detail. The main aim of this paper is to provide a broad perspective on the status of HAPF technology to researchers and application engineers dealing with power quality. More than eighty research papers are reviewed and classified into categories and subcategories.

Mehmet Tumay

Papers

A Novel Reference Signal Generation Method for Power-Quality Improvement of Unified Power-Quality Conditioner

Topologies, generalized designs, passive and active damping methods of switching ripple filters for voltage source inverter: A comprehensive review

Fast sag/swell detection method for fuzzy logic controlled dynamic voltage restorer

Mathematical modeling and analysis of a unified power flow controller: A comparison of two approaches in power flow studies and effects of UPFC location

Review of hybrid active power filter topologies and controllers