A novel single-phase shunt active power filter based on a current-source converter with reduced Dc-Link

Nowadays, the majority of electronic equipment behave as nonlinear loads, introducing Power Quality (PQ) problems into the Power Grid (PG), namely, current harmonics and low power factor. These PQ problems contribute to the reduction of the efficiency of the transmission and distribution PG, as well as induce the malfunctioning of sensitive loads connected to the PG. Therefore, the development of equipment able to mitigate these PQ problems is extremely important. In this context, this paper presents a novel single-phase Shunt Active Power Filter (SAPF) based on a current-source converter, where the key differencing factor, when compared with the conventional approach, is the reduced dc-link. As the proposed topology requires a reduced dc-link, it represents a relevant advantage, since a typical current-source converter needs an inductor with a high inductance in dc-link, which results in higher losses, costs and component sizing. The proposed SAPF with reduced dc-link is introduced in detail along the paper and a comprehensive comparison with the conventional SAPF is established based on computer simulations. Besides, an experimental validation was carried-out with a developed laboratory prototype, validating the main advantages of the proposed SAPF with reduced dc-link.This work has been supported by FCT – Fundação para a Ciência e Tecnologia with-in the Project Scope: UID/CEC/00319/2019. This work has been supported by the FCT Project QUALITY4POWER PTDC/EEI-EEE/28813/2017, and by the FCT Project newERA4GRIDs PTDC/EEI-EEE/30283/2017

QCD and strongly coupled gauge theories : challenges and perspectives

We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.Peer reviewe