An approach for shipping emissions estimation in ports: the case of ro–ro vessels in port of Vigo

Despite most atmospheric emissions being produced by vessels when navigating at sea, they are also important when in port because of their proximity to urban areas and their harmful effects on climate change and health. First, we carried out a bibliographical review of the nine most relevant methods to estimate the emission of ships in ports. These methods have been used to estimate the emissions of the sixteen most representatives Ro–Ro (roll-on–roll-off) ships calling at the Port of Vigo. From the results obtained, a new simplified method for estimation is proposed, which is based on linear regression curves and takes into account the number of ships and the average number of hours they remain in port annually. This simplification could be a useful tool when making preliminary assessments of the emissions from ships in port, which can also be extrapolated to other ports or types of ships.Ministerio de Ciencia e Innovación | Ref. PID2021-127876OB-I0

Magallanes project: testing the marine tidal current platform in the “Ría of Vigo”

In this study, the behavior of a platform for tidal energy is analyzed. The turbine of this platform is formed by two counter-rotating rotors aligned with the tidal current, such that one rotor is always under the wake of the upstream rotor. The platform has been tested by towing it with a tugboat to emulate tidal currents. The results of these tests are analyzed in this paper in order to estimate the generation capabilities of the platform.Peer Reviewe

Detailed energy analysis of a sheet-metal-forming press from electrical measurements

This paper presents a methodology that allows for the detection of the state of a sheet-metal-forming press, the parts being produced, their cadence, and the energy demand for each unit produced. For this purpose, only electrical measurements are used. The proposed analysis is conducted at the level of the press subsystems: main motor, transfer module, cushion, and auxiliary systems, and is intended to count, classify, and monitor the production of pressed parts. The power data are collected every 20 ms and show cyclic behavior, which is the basis for the presented methodology. A neural network (NN) based on heuristic rules is developed to estimate the press states. Then, the production period is determined from the power data using a least squares method to obtain normalized harmonic coefficients. These are the basis for a second NN dedicated to identifying the parts in production. The global error in estimating the parts being produced is under 1%. The resulting information could be handy in determining relevant information regarding the press behavior, such as energy per part, which is necessary in order to evaluate the energy performance of the press under different production conditions.Xunta de Galicia | Ref. IN854A 2020/0

Herramientas para la planificación de redes de baja tensión y media tensión urbanas

Se presenta un conjunto de herramientas que permiten diseñar las redes de distribución de baja tensión y media tensión urbanas. Para el diseño de redes de baja tensión se proponen dos herramientas: la primera basada en un algoritmo de programación dinámica permite obtener la red de baja tensión entre núcleos de población, determinando en que pueblos y ciudades se ubican los centros de transformación y cuales son los pueblos conectados a los anteriores mediante una red de baja tensión; la segunda, basada en una estrategia de evolución permite calcular la red de baja tensión interior a los núcleos de población, a partir de los datos de los clientes, tanto en el caso de núcleos rurales como urbanos. La herramienta propuesta para el diseño de redes de distribución de media tensión urbanas, permite calcular la red a partir de las posiciones y potencias de los centros de transformación y de la posición de las subestaciones. La arquitectura empleada es en bucle, con o sin centros de reflexión. En el trazado se permite ubicar en una misma zanja varios conductores. El método usado es de técnicas de estrategias de evolución

A STATCOM with supercapacitors for low-voltage ride-through in fixed-speed wind turbines

Fixed-speed wind generator (FSWG) technology has an important presence in countries where wind energy started to be developed more than a decade ago. This type of technology cannot be directly adapted to the grid codes, for example those requirements related to the immunity level under voltage dips. That behavior is typically referred as low-voltage ride through (LVRT), and it usually implies certain reactive and active power injection requirements, both during a voltage dip and during the voltage recovery. In this context, a review is presented of the LVRT exigencies present in some of the countries with the most advanced grid codes (Denmark, Germany, Spain and the United Kingdom). In this paper, the capabilities of STATCOM-based devices for fulfilling the LVRT requirements in FSWGs are analyzed. For this purpose, two technologies are considered: a STATCOM with a supercapacitor, which improves its energy storage features; and a STATCOM with a supercapacitor and a DC-DC converter, to achieve higher discharge levels.Ministerio de Ciencia e Innovación | Ref. ENE 2009-1307