Requirements for Validation of Dynamic Wind Turbine Models: An International Grid Code Review

Wind power is positioned as one of the fastest-growing energy sources today, while also being a mature technology with a strong capacity for creating employment and guaranteeing environmental sustainability. However, the stochastic nature of wind may affect the integration of power plants into power systems and the availability of generation capacity. In this sense, as in the case of conventional power plants, wind power installations should be able to help maintain power system stability and reliability. To help achieve this objective, a significant number of countries have developed so-called grid interconnection agreements. These are designed to define the technical and behavioral requirements that wind power installations, as well as other power plants, must comply with when seeking connection to the national network. These documents also detail the tasks that should be conducted to certify such installations, so these can be commercially exploited. These certification processes allow countries to assess wind turbine and wind power plant simulation models. These models can then be used to estimate and simulate wind power performance under a variety of scenarios. Within this framework, and with a particular focus on the new Spanish grid code, the present paper addresses the validation process of dynamic wind turbine models followed in three countries—Spain, Germany and South Africa. In these three countries, and as a novel option, it has been proposed that these models form part of the commissioning and certification processes of wind power plants

In search of an evidence-based strategy for quality assessment of human tissue samples: report of the tissue Biospecimen Research Working Group of the Spanish Biobank Network

The purpose of the present work is to underline the importance of obtaining a standardized procedure to ensure and evaluate both clinical and research usability of human tissue samples. The study, which was carried out by the Biospecimen Science Working Group of the Spanish Biobank Network, is based on a general overview of the current situation about quality assurance in human tissue biospecimens. It was conducted an exhaustive review of the analytical techniques used to evaluate the quality of human tissue samples over the past 30 years, as well as their reference values if they were published, and classified them according to the biomolecules evaluated: (i) DNA, (ii) RNA, and (iii) soluble or/and fixed proteins for immunochemistry. More than 130 publications released between 1989 and 2019 were analysed, most of them reporting results focused on the analysis of tumour and biopsy samples. A quality assessment proposal with an algorithm has been developed for both frozen tissue samples and formalin-fixed paraffin-embedded (FFPE) samples, according to the expected quality of sample based on the available pre-analytical information and the experience of the participants in the Working Group. The high heterogeneity of human tissue samples and the wide number of pre-analytic factors associated to quality of samples makes it very difficult to harmonize the quality criteria. However, the proposed method to assess human tissue sample integrity and antigenicity will not only help to evaluate whether stored human tissue samples fit for the purpose of biomarker development, but will also allow to perform further studies, such as assessing the impact of different pre-analytical factors on very well characterized samples or evaluating the readjustment of tissue sample collection, processing and storing procedures. By ensuring the quality of the samples used on research, the reproducibility of scientific results will be guaranteed.This work was funded by the Ministerio de Ciencia, Innovacion y Universidades of Spain and Instituto de Salud Carlos III (PI16/00528, PI16/00946, PI16/01207 and PI16/01276), co-funded by the Spanish Biobank Network (PT13/0010/0030, PT17/0015/0001, PT17/0015/0021, PT17/0015/0049, PT17/0015/0018, PT17/0015/0002, PT17/0015/0016, PT17/0015/0038, PT17/0015/0027, PT17/0015/0004, PT17/0015/0047, PT17/0015/0014, PT17/0015/0041, and PT17/0015/0006), European Regional Development Fund (FEDER) "A way to make Europe" and granted by Conselleria d'Innovacio, Recerca i Turisme del Govern de les Illes Balears (TEC/002/2017).S

A Study of Learning-by-Doing in MOOCs through the Integration of Third-Party External Tools:Comparison of Synchronous and Asynchronous Running Modes

Many MOOCs are being designed replicating traditional passive teaching approaches but using video lectures as the means of transmitting information. However, it is well known that learning-by-doing increases retention rates and, thus, allows achieving a more effective learning. To this end, it is worth exploring which tools fit best in the context of each MOOC to enrich learners' experience, including built-in tools already available in the MOOC platform, and third-party external tools which can be integrated in the MOOC platform. This paper presents an example of the integration of a software development tool, called Codeboard, in three MOOCs which serve as an introduction to programming with Java. We analyze the effect this tool has on learners' interaction and engagement when running the MOOCs in synchronous (instructor-paced) or asynchronous (self-paced) modes. Results show that the overall use of the tool is similar, regardless of the course running mode, although in the case of the synchronous mode the use of the tool is concentrated in a shorter period of time. Results also show that in the synchronous mode there is a higher percentage of accesses to the tool from registered learners (who can save their advances and continue the work later); this finding suggests that learners in the synchronous running mode are more engaged with the MOOC.The authors acknowledge the eMadrid Network, which is funded by the Madrid Regional Government (Comunidad de Madrid) with grant No. S2013/ICE-2715. This work also received partial support from the Spanish Ministry of Economy, Industry and Competitiveness, Project RESET (TIN2014-53199-C3-1-R), Project SYMBHYO-TIC (PTQ-15-07505), Project SIMLAP (RTC-2014-2811-1), Project SMARTLET (TIN2017-85179-C3-1-R), and from the European Commission through Erasmus+ projects MOOC-Maker (561533-EPP-1-2015-1-ESEPPKA2-CBHE-JP), SHEILA (562080-EPP-1-2015-1-BEEPPKA3-PI-FORWARD), COMPASS (2015-1-EL01-KA203-014033), and COMPETEN-SEA (574212-EPP-1-2016-1-NLEPPKA2-CBHE-JP)

Comunidad de Aprendizaje Práctico Universitario (CAPU) para la realización de Trabajos Fin de Grado en el Departamento de Derecho Internacional

Memoria del Proyecto de Innovación Docente UCM nº 144/2022, que tiene por objeto una metodología para la realización del Trabajo de Fin de Grado de las asignaturas de Derecho Internacional Privado y Derecho Internacional Público, mediante una serie de preguntas elaboradas por el grupo de profesores sobre un conflicto o controversia internacional, de tal forma que el tema y las preguntas a responder por los alumnos esté preestablecido.Depto. de Derecho Internacional, Eclesiástico y Filosofía del DerechoFac. de DerechoFALSEsubmitte

Implementation and validation of dynamic wind turbine models for grid integration

The spectacular growth in wind power in recent years is excellent news in the current energy context. The expansion of this type of renewable energy source worldwide, which has become one of the most reliable forms of alternative energy, has brought the total cumulative capacity installed to more than 591 GW. Within this framework, Spain is positioned second in Europe and fifth in the world in terms of installed capacity, with nearly 23 GW of wind power. This situation also explains the new daily record achieved in our country: 411 GWh were generated by wind power plants on a single day in December 2019, which represents approximately 50% of the total electricity consumption on that date. However, the natural variability of wind, and in general of all renewable energy resources, brings some uncertainty to current power systems and affects their performance. This situation highlights the need to strengthen the network, ensuring the quality and continuity of electricity supply, as well as carefully assessing and quantifying the impact of the penetration of wind energy in power systems. In this sense, Distribution System Operators (DSO) and Transmission System Operators (TSO) in each country are the main entities entrusted with the proper operation of the grid and maintenance of its infrastructures at every level. Conducting dynamic simulations may therefore help DSOs and TSOs to predict the behavior of power systems when an increasing number of Wind Power Plants (WPP) are integrated. In this sense, the assessment of the behavior of Wind Turbines (WT) and WPPs when facing grid events, such as loss of generation or voltage dips, is particularly important. In this regard, the first WT simulation models were developed by WT manufacturers, and are thus private, complex, very detailed and represent only one specific model of an actual WT. Faced with this situation, the International Electrotechnical Commission (IEC), through Standard IEC 61400-27-1, developed sufficiently generic WT simulation models to represent the vast majority of actual WT models within the same topology. These publicly available generic models are studied by conducting Root Mean Square (RMS) transient stability analyses and may be implemented in any simulation software tool. Moreover, in order to demonstrate the usefulness, applicability and accuracy of the generic WT models, the IEC also developed its own validation methodology. In this context, and given the lack of scientific studies related to the validation of generic WT models using specialized software tools, the first main objective of the present Doctoral Thesis is the complete implementation, simulation and validation of the Doubly Fed Induction Generator (DFIG) WT model defined by IEC 61400-27-1 in one of the most powerful software tools in the fields of electrical engineering and power systems: DIgSILENT PowerFactoryTM (PF). It is to be noted, also, that each country usually has its own technical requirements to be complied with by WPPs connected to the national network. In Spain, Operation Procedure (PO) 12.3 is the grid code that established the requirements for fault ride-through capability of WPPs, i.e., the response that this type of installation must have under voltage dips. In addition, a specific Procedure for Verification, Validation and Certification (PVVC) was developed, which sets out the guidelines to be followed in order for Spanish WPPs to fulfill PO 12.3 requirements. In general, the procedure to certify a wind power installation following the PVVC involves the validation of the WT simulation model corresponding to the actual WT model installed at the WPP. This implies, first, conducting different field tests on the actual WT, second, the simulation of the WT model by using the field measurements of those tests, and third, the application of the PVVC validation procedure. In light of the above, in the same line of generic WT simulation models and given that these are able to faithfully represent the behavior of most actual WTs, the second objective of the current Doctoral Thesis is to submit, for the first time, the Type 3 or DFIG WT simulation model defined by both the IEC and the Western Electricity Coordinating Council (WECC) to the requirements established by a national grid code, Spanish PO 12.3. The PVVC validation methodology is applied to these generic WT models, and some modeling modifications are proposed to improve their behavior. These analyses allow, on the one hand, the scope of application of international IEC and WECC guidelines with regard to the generic WT models to be expanded, and on the other hand, the limitations of these to be determined. Currently, another main concern in the wind power industry is that of the aging of WTs, given that the first WPPs were commissioned many years ago. This situation leads to several negative scenarios, such as long downtimes of the machines due to the increased number of failures, costly maintenance operations or low production of energy. Under this framework, and given that these old WPPs are located at sites with excellent wind resources, one of the most logical solutions being introduced is the replacement of old WTs with newer designs, thus allowing a WPP's energy production and power performance to be notably increased. As a consequence, in addition to the dynamic analyses of the WT models that will be part of a repowered WPP, which will also help the owner make a decision on the matter, the estimation of the technical and the economic feasibility of the project plays a key role. However, regarding the latter point, there is a lack of scientific works related to the assessment of real repowering projects, and thus the third and final main objective of the present Doctoral Thesis consists of conducting a comprehensive techno-economic analysis of a real repowering experience carried out at the Malpica WPP, located in the northwest of Spain. Likewise, the profitability of the project is estimated, and the uncertainties affecting the performance of the WPP are assessed using a sensitivity analysis

Electromagnetic Torque Transient Control System of a Generic DFIG Wind Turbine Model

The Standard IEC 61400-27-1 intends to cover the current needs of power system operators regarding transient stability analysis of power systems. It provides generic wind turbine models adaptable to any vendor topology and simulation software, simple enough to work under RMS simulation. These models are developed under certain assumptions, trying to strike a balance between simplicity and accuracy. In these terms, depending on the flexibility or stability of the real topology, some behaviors or magnitudes may be dismissed, aiming to decrease the complexity of the model. Nevertheless, this is not the case for IEC Type 3 wind turbine model, which tries to emulate the behavior of magnitudes which are not usually relevant for stakeholders, such as aerodynamic response or electromagnetic torque. This work focuses on the ability of emulating the electromagnetic torque response under voltage dip conditions, illustrating its transient control possibilities in a generic Type 3 wind turbine model. The decrease of this magnitude, due to the voltage drop during the fault, as well as its recovery, can be defined in detail thanks to the complex control model. Hence, this paper may result of interest for those stakeholders involved in the development and adjustment of generic wind turbine model

Effect of Penetration Levels for Vehicle-to-Grid Integration on a Power Distribution Network

With the exponential growth of electric vehicle sales worldwide over the past years and progress in technology and actions to combat climate change by reducing greenhouse gas emissions, the trend is expected to continue with a significant increase in the deployment of electric vehicles and plug-in hybrids. Given these circumstances, it is essential to identify the constraints that this increase in the number of electric vehicle charging stations poses for the electricity system. Therefore, the analysis developed in this paper discusses the effect of integrating electric vehicle charging stations in a real distribution network with different penetration levels. For this purpose, a typical electric system in Greece, managed by the Greek distribution system operator (HEDNO), is modeled and simulated in DIgSILENT PowerFactory software, one of the most widely used simulation tools in the electricity sector. To study the feasibility of connecting electric vehicle charging stations to the network, different case studies are presented, showing changes in the quantity of electric vehicles feeding power into the network through vehicle-to-grid technology. Quasi-dynamic simulations are used to analyze and discuss the voltage profiles of the system nodes, active power flows with the external source and power losses of the distribution network to determine whether the system is capable of supporting the increase in load produced by the electric vehicle charging stations and to promote awareness of the benefits of implementing vehicle-to-grid connections

La importancia de la formación en ergonomía a todos los estamentos de la empresa. El caso de CEE Dr. Schneider

[ES] A diferencia de lo que se puede pensar "a priori", la seguridad y la salud de los trabajadores no es cuestión únicamente de los técnicos de prevención de riesgos laborales sino que deben estar implicados todos los estamentos de la empresa. El proyecto realizado en la empresa CEE Dr. Schneider ha permitido, por un lado, formar a los técnicos de prevención en la evaluación de riesgos ergonómicos y la identificación de acciones a emprender para disminuir dichos riesgos; y, por otro lado, dar a conocer al departamento de ingeniería la importancia de un diseño adecuado del puesto (tanto desde el punto de vista dimensional como organizacional) para reducir el riesgo de los trabajadores a sufrir trastornos músculo-esqueléticos.Caceres Caceres, ML.; Sanchís Almenara, M.; Oltra Pastor, A.; Marzo Rosello, R.; Ruiz Folgado, R.; Santamaría Villena, A. (2017). La importancia de la formación en ergonomía a todos los estamentos de la empresa. El caso de CEE Dr. Schneider. Revista de Biomecánica (Online). (64). http://hdl.handle.net/10251/104206S6

Implementation of IEC 61400-27-1 Type 3 Model: Performance Analysis under Different Modeling Approaches

Forecasts for 2023 position wind energy as the third-largest renewable energy source in the world. This rapid growth brings with it the need to conduct transient stability studies to plan network operation activities and analyze the integration of wind power into the grid, where generic wind turbine models have emerged as the optimal solution. In this study, the generic Type 3 wind turbine model developed by Standard IEC 61400-27-1 was submitted to two voltage dips and implemented in two simulation tools: MATLAB/Simulink and DIgSILENT-PowerFactory. Since the Standard states that the responses of the models are independent of the software used, the active and reactive power results of both responses were compared following the IEC validation guidelines, finding, nevertheless, slight differences dependent on the specific features of each simulation software. The behavior of the generic models was assessed, and their responses were also compared with field measurements of an actual wind turbine in operation. Validation errors calculated were comprehensively analyzed, and the differences in the implementation processes of both software tools are highlighted. The outcomes obtained help to further establish the limitations of the generic wind turbine models, thus achieving a more widespread use of Standard IEC 61400-27-1

Compliance of a Generic Type 3 WT Model with the Spanish Grid Code

The expansion of wind power around the world poses a new challenge that network operators must overcome, namely the integration of this renewable energy source into the grid. Comprehensive analyses involving time-domain simulations must be carried out to plan network operation and ensure power supply. In light of the above, and with the aim of extending the use of the wind turbine models developed by Standard IEC 61400-27-1 and assessing their performance according to national grid code requirements, an IEC Type 3 wind turbine model has been submitted for the first time to Spanish grid code PO 12.3. Indeed, there is a lack of studies submitting generic wind turbine models to national grid code requirements. The model’s behavior is compared with field measurements of an actual Gamesa G52 machine and with its detailed simulation model. The outcomes obtained have been comprehensively analyzed and the results of the validation criteria highlight that several modeling modifications, in the cases of non-compliance, must be implemented in the IEC-developed Type 3 model in order to comply with PO 12.3. Nevertheless, the results also show that when the transformer inrush current is not considered, the reactive power response of the generic Type 3 WT model meets the validation criteria, thus complying with Spanish PO 12.3