Study of nuisance tripping of residual current circuit breakers with electronic loads

[EN] Residual current circuit breakers (RCCBs) are often used to provide protection against indirect contacts in a grounded electrical installation. However, there are situations where the use of RCCBs presents certain problems. In circuits that feed electronic loads usually occur nuisance trips of RCCBs. This article discusses the reasons of the nuisance tripping of RCCBs in this type of circuits based in previous cases studied by the author and some tests performed in a power flexible laboratory. A theoretical circuit used to explain the phenomena is also presented.This research work has been made possible with the support of the GV/2015/068-Ayudas para la realización de proyectos de I+D para grupos de investigación emergentes.Escrivá-Escrivá, G. (2016). Study of nuisance tripping of residual current circuit breakers with electronic loads. Journal of Electrical Engineering and Electronic Technology. 4(4):1-15. https://doi.org/10.4172/2325-9833.C1.005S1154

Design and Development of a New Control System for Improving Energy Efficiency and Demand Response

Escrivá-Escrivá, G. (2020). Design and Development of a New Control System for Improving Energy Efficiency and Demand Response. Journal of Construction Research. 2(1):37-49. http://hdl.handle.net/10251/170292S37492

Electrical consumption forecast using actual data of building end-use decomposition

The calculation of electricity consumption forecast a few days ahead is a complex issue and studies about this matter are continually being performed. Advances in this field enable obtaining consumption forecasts increasingly accurate. These consumption forecasts aim to improve the knowledge of the facilities, the planning and control of consumption and the measurement and verification of energy saving measures, among others. In this study the authors present several advances related to consumption forecast using end-use (EU) approach. In the disaggregation of the total consumption process, the correlation between energy and external variables, such as mean temperature, degree days or daylight, is studied. Additionally, an extrapolation method to obtain a total consumption forecast from forecasted EUs consumption that cover approximately 60% of total consumption is developed. With this procedure, total consumption forecasts with high accuracy can be obtained. The higher accuracy in each end-use, the better results are obtained in the total consumption forecast. For this reason, the study is focused in the end-uses disaggregation and its forecast calculation. The entire methodology is illustrated and contrasted using the consumption of the Universitat Politècnica de València (UPV).This research work has been possible with the support of the Universitat Politecnica de Valencia through grant CE19990032.Escrivá Escrivá, G.; Roldán Blay, C.; Álvarez Bel, CM. (2014). Electrical consumption forecast using actual data of building end-use decomposition. Energy and Buildings. 82:73-81. https://doi.org/10.1016/j.enbuild.2014.07.024S73818

Evaluation and assessment of demand response potential applied to the meat industry

Demand response has proven to be a useful mechanism that produces important benefits for both the customer and the power system. In the context of an increasingly competitive electricity market, where prices are constantly rising and the presence of renewable energy resources is gaining prominence, this paper analyzes the flexibility potential of customers in the meat industry, based on the management of the most energy consuming process in this type of segment: cooling production and distribution. The effectiveness of the proposed actions has been successfully tested and validated in an active factory that produces cured ham in Spain, where savings of about 5% in the total annual cost of electricity have been assessed, together with power reductions in the range of 50% of the total peak demand of the studied facilities. Such results demonstrate the efficacy of these techniques, and they open the door to an innovative perspective on the evaluation of flexibility among customers which are traditionally considered rigid, providing a novel approach to the management of customer infrastructures in order to exploit their flexibility in electricity markets.This work was supported by the Spanish Government (Ministerio Ciencia e Innovacion, MICINN) under Research Project ENE2007-67771-C02-01&02/CON.Alcázar Ortega, M.; Álvarez Bel, CM.; Escrivá Escrivá, G.; Domijan, A. (2012). Evaluation and assessment of demand response potential applied to the meat industry. Applied Energy. 92:84-91. https://doi.org/10.1016/j.apenergy.2011.10.040S84919

Application of an energy management and control system to assess the potential of different control strategies in HVAC systems

[EN] The significant and continuous increment in the global electricity consumption is asking for energy saving strategies. Efficient control for heating, ventilation and air-conditioning systems (HVAC) is the most cost-effective way to minimize the use of energy in buildings. In this framework, an energy management and control system (EMCS) has been developed to schedule electricity end-uses in the campus of the Universidad Politecnica de Valencia (UPV), Spain. This paper presents an evaluation performed by using the EMCS of different control strategies for HVAC split systems. It analyzed the effect of different schedules for a common air-conditioning device and demand response strategies are tested in several situations. The economic saving is calculated taking into account the electricity contract clauses. Finally, a test is made for the control of a group of similar devices in order to reduce the maximum peak power in consumption and to obtain a flexible load shape with the HVAC loads. The studies are then extrapolated to a larger system, the whole University campus, for which energy and economic savings are quantified. (C) 2010 Published by Elsevier B.V.This research work has been possible with the support of Universidad Politecnica de Valencia (Spain) by the grant #CE 19990032.Escrivá-Escrivá, G.; Segura Heras, I.; Alcázar-Ortega, M. (2010). Application of an energy management and control system to assess the potential of different control strategies in HVAC systems. Energy and Buildings. 42(11):2258-2267. https://doi.org/10.1016/j.enbuild.2010.07.023S22582267421

The Divine Names of the Four Elements

En este artículo se realiza un análisis textual de la "doctrina de los cuatro elementos" formulada por el filósofo presocrático Empédocles de Agrigento. Para ello se examinan las cuatro figuras divinas (Zeus, Hera, Aidoneo y Nestis) con las que Empédocles se refiere a los cuatro elementos (fuego, tierra, aire y agua) que, según él, constituyen los cuatro principios fundamentales del universo. Especial atención merece la misteriosa Nestis, cuya verdadera identidad (Perséfone) y papel resultan claves para completar el análisis en su conjunto. Este análisis conduce a decantarse por una determinada correspondencia entre elementos y divinidades de entre las varias propugnadas por comentaristas de distintas épocas. Asimismo, dicho análisis revela la estructura que subyace en esta "doctrina": la articulación de dos principios masculinos y dos femeninos mediante un par de fuerzas primordiales antagónicas (amor y odio). Una elaboración de tipo mítico que permite concebir un orden y un sentido para el universo.In this article we are going to proceed to the textual analysis of the 'four elements doctrine' formulated by the pre-Socratic philosopher Empedocles of Agrigento. In order to do this we will examine the four divine figures (Zeus, Hera, Adonis and Nestis) with who Empedocles represents the four elements (fire, earth, air and water), that according to him constitute the four fundamental principles of the Universe. Special attention requires the mysterious Nestis, whose true identity (Persephone) and role are crucial to the complete analysis as a whole. This analysis leads to a determined correspondence between elements and divinities among the different ones propagated by commentators of different times. At the same time, this analysis reveals the structure that underlies in this 'doctrine': the articulation of two masculine and two feminine principles through a pair of antigenic primordial forces, love and hate. This is a kind of mythical elaboration that provides order and meaning to the universe

PSO Tuning of a Second Order Sliding Mode Controller to Adjust Active Standard Power Levels on a Single-Phase Voltage Source Inverter

[EN] Electricity management in non-conventional energy systems requires advanced control algorithms to produce and distribute electricity efficiently. Various countries worldwide have promoted policies to manage electricity from power inverters under typical voltage, current, and power values. This paper proposes a DQ control for active power regulation on a single-phase voltage source inverter (SPVSI) using a Second Order Sliding Mode Control (SMC-2). The SMC-2 tunning is performed by a metaheuristics algorithm like the Particle Swarm Optimization (PSO) to adjust the SMC-2 parameters. PSO appropriately tuns the SMC-2 through MATLAB, where the results showed lower Integral of Absolute Error value (IAE) and Integral of Square Error value (ISE) as performance indexes.This paper belongs to the project IEA.JCG.20.01 from Universidad de las Americas-EcuadorGonzales-Zurita, O.; Clairand, J.; Escrivá-Escrivá, G. (2022). PSO Tuning of a Second Order Sliding Mode Controller to Adjust Active Standard Power Levels on a Single-Phase Voltage Source Inverter. IEEE. 1-5. https://doi.org/10.1109/PESGM48719.2022.99170551

A Study on DC Limit Parameters in RCD Operation Using Capacitor

[EN] Residual-current devices (RCDs) are used to protect humans from electrical shocks. This study explores the DC limit parameters of RCDs using the capacitor. To find out the possible parameters, a common signal from the RCD in AC waveform is analyzed using a digital oscilloscope for reference. This signal is then transformed into a DC signal using a common circuit of a full-bridge rectifier, capacitor, and a voltage regulator. Finally, the signal is characterized using an oscilloscope and multimeter. The result of this work is I-V characteristic of the DC measurement obtained from the RCD. It shows two possible parameters. First is a voltage gap of 1 V which representing input current with a range from 0.4 to 64.3 mA. Second is an increasing speed of 1.06 V/s on average. These parameters could be used to overcome the nuisance trips of common RCDs.The work and publications are supported by the Faculty of Science and Technology, UniversitasAirlangga with a Young Lecturer's Research Fund Program. This article would not have been completed without the support of all the team members. Many thanks for all of the team members, as well as other colleagues for their suggestions and indirect assistance.Sutanto, E.; Ain, K.; Aziz, M.; Escrivá-Escrivá, G. (2019). A Study on DC Limit Parameters in RCD Operation Using Capacitor. Journal of Engineering Science and Technology Review (Online). 12(4):7-14. https://doi.org/10.25103/jestr.124.02S71412

Filtered Leakage Current Measurement for Various Loads

[EN] The purpose of this study was to determine the link between induction voltages from various electrical loads. We used a residual current device (RCD) circuit that operates with a capacitor as a DC voltage reading tool. The circuit reads the value of the leakage current generated by the sensing coil from the RCD. It also uses the Blynk framework as an online monitoring system and a WeMos D1-R2 microcontroller to connect to the server using Wi-Fi. Using this system, the dataset was collected in a Python server and utilized with a machine learning technique to draw a correlation between the load power and reading voltage. This will help improve the mistakes of a common RCD cut-off point, which is usually defined only at a specific induced voltage. For the different types, an LED lamp and typical electric fan were used as loads in the experiment. Meanwhile, for a similar type of load, three different LED lamps were characterized using machine learning to show the correlation. From the comparison, a threshold voltage of around 1V and three different gradients with increases of more than 10% are found for LED lamps with loads of 3W, 5W, and 9W.The results show that the relationship depends on the type of its power supply.Sutanto, E.; Nurwahyuni, S.; Yunardi, RT.; Escrivá-Escrivá, G. (2021). Filtered Leakage Current Measurement for Various Loads. International Journal of Technology. 12(2):401-411. https://doi.org/10.14716/ijtech.v12i2.4302S40141112

The boom of the superhero genre and the new global film industry

Proveniente del mundo del cómic, la figura del superhéroe debutó con éxito en el cine a finales de la década de los 70. Sin embargo, ha sido durante los últimos quince años cuando esta figura ha cobrado un extraordinario protagonismo y, en sus múltiples variantes, ha dado pie a buena parte de las franquicias cinematográficas que en la actualidad dominan las salas de cine de todo el planeta. Al hilo de este nuevo paisaje fílmico, el presente artículo se propone explorar la naturaleza del cine de superhéroes, un apabullante espectáculo audiovisual que es consumido por millones de espectadores en todo el mundo, con especial incidencia entre el público infantil y juvenil. Tal indagación conduce a examinar las narrativas desplegadas en estas series de películas, así como a analizar la propia figura del superhéroe en el contexto de un cine saturado de efectos visuales y acción trepidante. Finalmente, el artículo trata de señalar las razones de fondo que han llevado a la industria de Hollywood a apostar por el género de superhéroes como fórmula recurrente para atraer al público a las salas de cine.Coming from the field of comic books, the character of the superhero began to appear successfully in the cinema of the late 70’s. However, during the last fifteen years this type of character has taken on a very important role and, in its many variants, has given rise to much of the film franchises that currently dominate movie theatres all over the world. Following the thread of this new film landscape, this article aims to explore the nature of superhero movies, an overwhelming audiovisual spectacle that is consumed by millions of spectators around the world, with a significant impact on children and young audiences. That inquiry leads to examine the narratives unfolding in these film series, while analysing the character of the superhero within the context of a cinema saturated with visual effects and frenetic action. Finally, the article tries to point out the basic reasons that have led the Hollywood industry to focus on superhero genre as a recurring formula to bring audiences to movie theatres