Novel Calibration systems for the dynamic and steady-state testing of digital instrument transformers

Within the frame of the European project 'Future Grid II-Metrology for the next-generation digital substation instrumentation', several partners developed traceable calibration systems which allow the calibration of conventional or non-conventional instrument transformers (IT) even with a sampled value (digital) output according to IEC 61869-9. Different setups are prepared to allow the calibration with complex test waveforms to emulate steady state, dynamic or temporary events during the assessment of the ITs. The laboratory calibration setups for either current transformers or voltage transformers are briefly described. Several results obtained for different kind of voltage or current transformers are presented

The T.O.S.C.A. Project: Research, Education and Care

Despite recent and exponential improvements in diagnostic- therapeutic pathways, an existing “GAP” has been revealed between the “real world care” and the “optimal care” of patients with chronic heart failure (CHF). We present the T.O.S.CA. Project (Trattamento Ormonale dello Scompenso CArdiaco), an Italian multicenter initiative involving different health care professionals and services aiming to explore the CHF “metabolic pathophysiological model” and to improve the quality of care of HF patients through research and continuing medical education

H-infinity robust displacement velocity control of a UAV based upon optical flow estimation

[EN] The design of a displacement velocity controller is presented for a six rotor aerial vehicle. H–infinity control is proposed in order to achieve robust performance in presence of dynamic model uncertainty. It is assumed that a considerable amount of uncertainty is due to time delays introduced by the algorithms employed. The estimation of the vehicle’s displacement velocity is carried out on-board through an optical flow sensor implemented employing a camera and a high level processor a s w ell a s t he H–infinity controller. Through experimental data, the system’s identification procedure used to obtain a description of the plant as a family of models with global dynamic uncertainty is also presented as part of the design process. The implemented optical flow estimation methods are also presented as well as the tuning procedures employed which may affect the results of the system’s identification and the control performance. Experimental results are presented with details regarding the implementation phase.[ES] Se presenta el diseño del control para la velocidad de desplazamiento de un vehículo aéreo de seis rotores. La técnica de diseño utilizada es el control óptimo en H–infinito con el objetivo de conseguir rendimiento robusto ante la incertidumbre en el modelo de la dinámica de la velocidad de desplazamiento. Se considera que buena parte de la incertidumbre es atribuible a retardos de tiempo inciertos que introduce el propio algoritmo que se utiliza para estimar la velocidad de desplazamiento. El vehículo realiza a bordo la estimación de esta última a través de un sensor de flujo óptico implementado con una cámara y un procesador de alto nivel en el cual además se implementa la ley de control. Junto con el diseño del control, se muestra el procedimiento de identificación de sistemas utilizado para conseguir una descripción de la dinámica a través de una familia de plantas con incertidumbre dinámica global a través de la toma de datos experimentales. Finalmente se exhiben resultados experimentales con la implementación del sistema de control completo. Los autores agradecen la tarea de los revisores del trabajo. Sus observaciones y correcciones han contribuido a la introducción de significativas mejoras en el mismo. Este trabajo ha sido realizado parcialmente gracias al apoyo de la Universidad de Buenos Aires a través del proyecto UBA-PDE2019 y de la Universidad Tecnológica Nacional a través del proyecto CCUT-7731TC.Ghersin, A.; Giribet, J.; Luiso, J.; Tournour, A. (2021). Control robusto H-infinito para la velocidad de desplazamiento de un UAV en base a estimación de flujo óptico. 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Compensation of Current Transformers' Non-Linearities by Means of Frequency Coupling Matrices

Current transformers (CTs) are the most commonly installed current transducers in power systems, at all voltage levels. Therefore, the measurement of harmonics, and power quality in general, which is an essential task in the new context of Smart Grids, are strongly influenced by the performance of CTs. It is well known that CTs can exhibit a nonlinear response and, therefore, in order to accurately measure harmonics with CTs, suitable non-linear mathematical models have to be used. In this paper the complex ratio of the CT is modelled using a frequency domain model based on frequency coupling matrices. An accurate measurement setup has been built to characterize the CTs performance in distorted conditions. Some preliminary results of the proposed compensation technique are presented and discussed for a commercial CT of accuracy Class 0.5

Assessment of the high frequency emissions of low-voltage electronic equipment under different supply conditions

Assessing the emissions of low-voltage electronic equipment in the high frequency (HF) range (2-150 kHz) is an important ongoing research topic required to better understand the long term implications of HF distortion. Such studies can be conducted by supplying the load directly from the Mains network, from a programmable Power Source or via a defined impedance stabilization network. However, a standardized measurement procedure and source specification is still missing in literature. This paper presents a comparative study of background voltage distortion and emitted currents of two different electronic loads using the three different measurement set-ups deemed suitable for assessing the HF emissions of electronic equipment. The results highlight the difficulties in systematic testing of HF distortion and show that the supply configuration has considerable impact on the obtained results

Monitoring a DC Train Supplied by a Reversible Substation

European energy policy has been supporting a gradual shift towards an efficient energy management in order to reduce the railway transport emissions by 50 % within 2030. One of the most promising solutions to reduce emissions is the recovery of braking energy: it is possible to convert kinetic energy back to the electrical form and reinject it back to the grid. Currently, because of the unidirectional nature of the substation, the receptivity of the supply network is limited and only a small part of the traction energy is sent back to the catenary. The remaining part is usually wasted on the train braking rheostats. In this scenario, new installations of reversible substations in DC railway systems, can improve energy savings. In this paper, in order to evaluate the impact of this innovative technology, a preliminary analysis of the data acquired during a measurement campaign conducted jointly with Metro de Madrid (train and substation owner) and HitachiRail (train manufacturer) is presented. Energy exchanged between train and supply line and real-time power quality events survey can be valuable tools to make an estimation of the impact of the reversible substation. © 2020 IEEE