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

2 1 The innovative transport systems and the CityMobil project 10 1.1 The research questions 10 2 The state of art in the field of automatic transport systems 12 2.1 Case studies and demand studies for innovative transport systems 12 3 The design and implementation of surveys 14 3.1 Definition of experimental design 14 3.2 Questionnaire design and delivery 16 3.3 First analyses on the collected sample 18 4 Calibration of Logit Multionomial demand models 21 4.1 Methodology 21 4.2 Calibration of the “full” model. 22 4.3 Calibration of the “final” model 24 4.4 The demand analysis through the final Multinomial Logit model 25 5 The analysis of interaction between the demand and socioeconomic attributes 31 5.1 Methodology 31 5.2 Application of Mixed Logit models to the demand 31 5.3 Analysis of the interactions between demand and socioeconomic attributes through Mixed Logit models 32 5.4 Mixed Logit model and interaction between age and the demand for the CTS 38 5.5 Demand analysis with Mixed Logit model 39 6 Final analyses and conclusions 45 6.1 Comparison between the results of the analyses 45 6.2 Conclusions 48 6.3 Answers to the research questions and future developments 52

The European commission

Renewable energy sources like wind, sun, and hydro are seen as a reliable alternative to the traditional energy sources such as oil, natural gas, or coal. Distributed power generation systems (DPGSs) based on renewable energy sources experience a large development worldwide, with Germany, Denmark, Japan, and USA as leaders in the development in this field. Due to the increasing number of DPGSs connected to the utility network, new and stricter standards in respect to power quality, safe running, and islanding protection are issued. As a consequence, the control of distributed generation systems should be improved to meet the requirements for grid interconnection. This paper gives an overview of the structures for the DPGS based on fuel cell, photovoltaic, and wind turbines. In addition, control structures of the grid-side converter are presented, and the possibility of compensation for low-order harmonics is also discussed. Moreover, control strategies when running on grid faults are treated. This paper ends up with an overview of synchronization methods and a discussion about their importance in the control

/pdf/overview-of-control-and-grid-synchronization-for-distributed-2nx31ovpe9.pdf

Overview of Control and Grid Synchronization for Distributed Power Generation Systems

DC and AC Microgrids are key elements to integrate renewable and distributed energy resources as well as distributed energy storage systems. In the last years, efforts toward the standardization of these Microgrids have been made. In this sense, this paper present the hierarchical control derived from ISA-95 and electrical dispatching standards to endow smartness and flexibility to microgrids. The hierarchical control proposed consist of three levels: i) the primary control is based on the droop method, including an output impedance virtual loop; ii) the secondary control allows restoring the deviations produced by the primary control; and iii) the tertiary control manage the power flow between the microgrid and the external electrical distribution system. Results from a hierarchical-controlled microgrid are provided to show the feasibility of the proposed approach.

/pdf/hierarchical-control-of-droop-controlled-dc-and-ac-26q2w9lpco.pdf

Hierarchical control of droop-controlled DC and AC microgrids — a general approach towards standardization

The use of distributed energy resources is increasingly being pursued as a supplement and an alternative to large conventional central power stations. The specification of a power-electronic interface is subject to requirements related not only to the renewable energy source itself but also to its effects on the power-system operation, especially where the intermittent energy source constitutes a significant part of the total system capacity. In this paper, new trends in power electronics for the integration of wind and photovoltaic (PV) power generators are presented. A review of the appropriate storage-system technology used for the integration of intermittent renewable energy sources is also introduced. Discussions about common and future trends in renewable energy systems based on reliability and maturity of each technology are presented

/pdf/power-electronic-systems-for-the-grid-integration-of-4s5cxjhatl.pdf

Power-Electronic Systems for the Grid Integration of Renewable Energy Sources: A Survey

Energy production based on the use of renewable sources has a huge potential The needed technology is available and it benefits of continuous improvement due to academic and industrial research activity Another mayor issue is the knowledge transfer to industry on the basis of international conferences/workshops and educational programs Selected issues related to renewable energy systems technology and knowledge transfer are discussed in the panel session This summary introduces them: energy conversion, storage and transportation, control, monitoring and communication, technical committees activity and educational programs

Industrial electronics for renewable energy

Resonant andrepetitive controllers arewellsuited forsingle-phase photovoltaic systems duetotheoptimumtracking andharmonics rejection capability. Inthispapertheeffects of non-linear inductance ontheperformance ofcurrent controllers basedontheIMP areinvestigated. Whentheinductance isnon- linear adistorted current waveform isproduced; itcontain only oddharmonics ifthesaturation issymmetric. A detailed time- varyingmodelofnon-linear inductor hasbeendeveloped considering two different non-linearities: saturation forhigh currents andalight non-linearity whichoccurs inthefirst portion ofthemagnetization curveforverylowcurrents. Therobustness ofthecurrent controllers hasbeentested. Experimental results havebeenobtained withtwodifferent inductors oftwomain families: powdered metalcoreandferrite core. Ithasbeenproven thattheresonant andrepetitive controllers areabletomitigate harmonicdistortion introduced by thenon-linearities andto ensure theIEEE929standard compliance.

Studyoftheeffects ofnon-linearinductance on the performanceofresonant and repetitive controllers

Bidirectional converters enable vehicle-to-grid (V2G) operations in electric vehicle (EV) charging stations. In this context, dual-active bridge (DAB) DC-DC converter is a preferable solution due to galvanic isolation and reduced volumes compared to other systems. Single-phase DAB (1ph-DAB) and three-phase DAB (3ph-DAB) topologies are usually compared in terms of efficiency and performances with the same rated power. Conversely, this paper focus on a comparison concerning device losses and stresses, medium-frequency transformer (MFT) design and capacitor filter sizing for the same power per switch, considering DABs and batteries coupled in a V2G application. Thereby, the impact of the battery state-of-charge (SoC) variation relative to the grid-side DC voltage is studied. Theoretical analysis and simulations results reveal that, in some respects, 1ph-DAB performance is superior to that of the 3ph-DAB with the proposed comparison approach. While, the main advantage of 3ph-DAB over 1ph-DAB is the reduced size of filter capacitors.

Comparative Study of Single-phase and Three-phase DAB for EV Charging Application

This paper investigates the influence of a constant carrier phase shift on the DC-link capacitor harmonic current of cascaded converters used in fuel-cell and mild-hybrid electric vehicles. In these applications, a DC-DC converter can be adopted between the battery and the motor drive inverter in a cascaded structure, where the two converters share the same DC-link. Since the DC-link capacitor of such a system represents a critical component, the optimization of the converter operation to limit the current stress and extend the lifetime of the capacitor is an primary objective. This paper proposes the use of a carrier phase shift between the modulations of the two converters in order to minimize the harmonic current of the DC-link capacitor. By harmonic analysis, an optimal carrier phase shift can be derived depending on the converter configuration. Analytical results are presented and validated by hardware-in-the-loop experiments. The findings show that the pulse width modulation carrier phase shift between the interleaved boost converter and the voltage source motor drive inverter has a significant influence on the DC-link capacitor current and thus on its lifetime. A case study with two-cell and three-cell interleaved boost converters shows a possible DC-link capacitor lifetime extension of up to 390%.

/pdf/common-dc-link-capacitor-harmonic-current-minimization-for-2qh75j5x.pdf

Marco Liserre

Papers

Industrial electronics for renewable energy

Studyoftheeffects ofnon-linearinductance on the performanceofresonant and repetitive controllers

Comparative Study of Single-phase and Three-phase DAB for EV Charging Application

Common DC-Link Capacitor Harmonic Current Minimization for Cascaded Converters by Optimized Phase-Shift Modulation

Optimization of EV-Fast Charging Station Placement for Grid Support