Showcasting the use of big data for policy purposes

[¶EN] While the availability and accessibility of large data sources is a rich field for statisticians, economists, econometricians and forecasters, it has been relatively unexploited for producing substainable and reliable statistics for policy purposes. It is of particular interest if such large sources could help to detect trends and turning points within the economy, thereby providing supplementary and more timely information compared to the “traditional” toolkit of policy makers. These supplementary statistics may provide further insights contributing to guiding policy actions as well as to assessing the subsequent impact and associated risks of these policy decisions on the financial system and real economy. Big data sources could assist policy makers in obtaining a nearly real-time snapshot of the economy as well as providing early warning indicators. This may be particularly welcome in the light of the shortcomings observed in the run-up to the financial crisis. In particular regulators have been keen to expand the data collection so as to better monitor financial intermediaries, financial risks and vulnerabilities. The way forward may therefore be to develop and apply a structural approach for piloting the use of big data. While it may be reasonable to expect that “big data” suppliers have different business and data models, it is important to assess their usefulness according to a standardised set of five key criteria following a production cycle; “Input”, “Quality”, “Production”, “Results” and “Assessment” as part of exploring its relevance for producing substainable and reliable statistics for policy making purposes.Nymand-Andersen, P. (2016). Showcasting the use of big data for policy purposes. En CARMA 2016: 1st International Conference on Advanced Research Methods in Analytics. Editorial Universitat Politècnica de València. 118-118. https://doi.org/10.4995/CARMA2016.2015.4247OCS11811

Model Predictive Controllers With Capacitor Voltage Balancing for a Single-Phase Five-Level SiC/Si Based ANPC Inverter

Employing both high bandwidth (HBW) controller and wide bandgap (WBG) devices in the structure of converters improve the system size, performance, and efficiency. In this paper, HBW model predictive controllers (MPCs) are proposed, with both fixed and unfixed switching frequencies, to control a single-phase five-level hybrid active neutral-point-clamped (ANPC) inverter. A hybrid modulation technique is considered in this paper, in which some of the switches are modulating with high frequency. Therefore, Silicon-Carbide (SiC) MOSFETs are employed in the converter structure to increase the switching frequency and consequently reduce the filter size and increase converter power density. To have the functionality of multilevel output voltage, some restrictions are defined in the adopted MPC with unfixed switching frequency. In the MPC with the constant switching frequency, predefined switching sequences are employed for all sectors. Moreover, to control the neutral point (NP) voltage, the applied times of both small voltage vectors are sets through a cost function. Finally, the simulation and experimental results prove the ability of both proposed methods to control the voltages of the load and NP.This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/This work was supported by the APETT project, funded by Innovation Fund Denmark.fi=vertaisarvioitu|en=peerReviewed

Litteratursøgning

Litteratursøgemuligheder

Operation and Efficiency Analysis of a 5-level Single-Phase Hybrid Si/SiC Active Neutral Point Clamped Converter

The ability to improve both the size and efficiency of multilevel single-phase converters is a key to uplift them as an attractive solution for industries, while the high number of switches and complex modulation techniques understandably make them unattractive. 5-level active neutral point clamped converter, due to its inherent advantages such as employing different switching frequencies and using different switch technologies, presents an ideal candidate for study. This paper performs a comprehensive analysis of the converter to highlight the advantages of it. This analysis results in a modified hybrid modulation that effectively regulates the neutral point (NP) of the dc-link. Consequently, the combination of the topology and the modified modulation make the converter ideal to utilize two different switch technologies- in this paper Silicon Carbide (SiC) and Si MOSFET. To evaluate the analysis and the effectiveness of modulation, a 2kW hybrid 5-level ANPC is built. Analyzing of the behavior of the converter current, power loss in the filter and switches are, therefore, calculated. The efficiency measurement is performed and compared with the calculated efficiency. There is a close coherency between the measurement and the calculated results and a peak efficiency of 98.4% is achieved.© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.fi=vertaisarvioitu|en=peerReviewed

Litteratursøgning

Litteratursøgemuligheder

Perception of drug teratogenicity among general practitioners and specialists in obstetrics/gynecology:a regional and national questionnaire-based survey

Cover letter to participants and online questionnaire. (DOC 27 kb