CIGRÉ e IEEE tienen un papel importante en la gestión dinámica de conductores ACSR, ya que proporcionan dos procedimientos alternativos pero similares para calcular tanto su capacidad máxima como la temperatura. Una vez implementado el sistema de gestión dinámica a través de los algoritmos propuestos por CIGRÉ e IEEE, es importante validar su precisión. Para ello, se han aplicado los algoritmos planteados por CIGRÉ e IEEE en una línea área de alta tensión de 30 km, que cuenta con un sistema de medida distribuida de la temperatura (DTS) basado en la instalación de una fibra óptica en uno de los conductores de fase (optical phase conductor –OPPC‐). Esta línea de estudio cuenta con un sistema de 6 estaciones meteorológicas ubicadas en diferentes apoyos de la misma para aumentar la resolución espacial con respecto a la monitorización a través de una sola estación.

La ocurrencia del fenómeno de la ferroresonancia en transformadores de tensión en redes eléctricas de distribución con neutro aislado puede ocasionar daños a la aparamenta eléctrica y dar lugar a situaciones potencialmente inestables. Entre las causas más frecuentes que estimulan las condiciones necesarias para su aparición se encuentran las faltas a tierra y la operación no simétrica de los interruptores. En este trabajo se estudia la ferroresonancia en transformadores de tensión en redes eléctricas de distribución de neutro aislado y el efecto de las características del sistema eléctrico de distribución en la ocurrencia del fenómeno. Se presentan diversas estrategias de detección aplicables que permitan determinar la aparición de las condiciones necesarias para su ocurrencia y, en el caso de que ésta se produzca, verificar su presencia. El trabajo presenta varios casos de estudio sobre modelos de simulación y de casos reales correspondientes a una red de neutro aislado en media tensión.

Dynamic line rating is a technique that is becoming more and more important in order to increase the capacity of existing overhead lines without upgrading the infrastructure in a significant way. This paper summarizes the methodology and the most important results related to the project DYNELEC. In this project VIESGO Distribution has developed this technology from scratch, not only including the technical design but also the legal approval for this kind of operation by government agencies. One of the novelties of this research project is related to the fact that since January 2015 the Dynamic Thermal Rating (DTR) is computed using the new CIGRE TB601 “Guide for Thermal Rating Calculations of Overhead Lines” that was published in December 2014. Currently, there has been a successful pilot project running since 2012. In 2015 this project obtained the final approval from the government.

CIGRE TB601 guide for thermal rating calculations recommends the use of ultrasonic anemometers over mechanical devices. This paper aims to compare the mechanical and ultrasonic wind speed measurement technologies for the purpose of dynamic ampacity rating. The comparison consists of applying the measurements of both anemometers (placed in the same spot) to the computation of ampacity in the same overhead line, and evaluating the diferences at different speed ranges.

In the last 20 years, installed wind power capacity in North of Spain has grown from 24 to more than 1,650 MW. In this geographical region, wind energy farms are located in places that are far away from the transmission networks so they have to be integrated into distribution networks. Build new overhead lines dedicated for a distribution energy is not the best way to increase the evacuation energy of the wind farms because the cost is quite strong. So, the aim to solve these issues, is by means of an increase in the capacity of existing lines using the dynamic management of the network. This paper is devoted to show the difference of the conductor temperature between the parameter of solar radiation measured by a pyranometer and the use of the theoretical solar radiation which is explained in CIGRE TB601 [1] and IEEE Std. 738-2012 [2] algorithms.

The grid integration of renewable energy supposes an important problem to deal with for Distributor System Operators (DSO). Distributor and transmission system operators have been using static rates for a long time to manage electric systems. Currently operators deal with one, annual, static rate or four, seasonal, static rates. This paper is devoted to the analysis of a real case of ampacity management in a 132 kV overhead line for the purpose of stablishing new static rates based on different temporal intervals.

The grid integration of renewable energy, and particularly in Spain, supposes an important problem to deal with for Distributor System Operators (DSO). Most of the times Wind Energy Farms are located in places that are far away from the transmission networks so they have to be integrated into distribution networks that are frequently next to their static rate. Current regulations make almost impossible to build new overhead lines so the increase of the capacity of the existing lines is a new target for the DSO. One of the developed options to solve this issue is the dynamic management of the network. This paper is devoted to the analysis of a real case of ampacity management in a 132 kV overhead line placed in a high-wind generation area. The obtained results show that this approach can increase the lines capacity in a significant percentage.

This paper describes a preliminary experience with the installation and use of a no-gap power quality meter network along a distribution grid in the North of Spain. No-gap power quality meters record all cycles of voltage and current waveform for all the monitored channels. This approach extends the analysis further than the classical approach provided by other power quality meters that records only survey data and events triggered according predefined rules. A comparison with the classical approach is discussed and the results of a two year power quality survey are also provided.

Ampacity techniques have been used by Distributor System Operators (DSO) and Transport System Operators (TSO) in order to increase the static rate of transport and distribution infrastructures, especially those who are used for the grid integration of renewable energy. One of the main drawbacks of this technique is related with the fact that DSO and TSO need to do some planning tasks in advance. In order to perform a previous planning it is compulsory to forecast the weather conditions in the short-time. This paper analyses the application of the neural network to the estimation of the ampacity in order to increase the amount of power produced by wind farms that can
be integrated into the grid.

Ampacity techniques have been used by Distributor System Operators (DSO) and Transport System Operators (TSO) in order to increase the static rate of transport and distribution infrastructures, especially those who are used for the grid integration of renewable energy. One of the main drawbacks of this technique is related with the fact that DSO and TSO need to do some planning tasks in advance. In order to perform a previous planning it is compulsory to forecast the weather
conditions in the short-time. This paper analyses the application of the neural network to the estimation of the ampacity in order to increase the amount of power produced by wind farms that can be integrated into the grid.

This paper is devoted to the development of a methodology suitable to be used to determine the impact of the grid integration of wind farms in distribution networks that are also supplied with other classical generation facilities based on thermal and hydraulic energy. The methodology is based on an automated analysis system that varies the level of the electric generation for both the hidraulic and thermal generators by using PSS, Phyton and Matlab. The user can define multiple scenarios considering wind, thermal and hydraulic generators so the line capacity can be computed and compared in order to know where the system bottleneck is located and which situations occur. All the results computed can be analysed in a single or compared way by using tables and plots and considering the static rate of the distribution lines. The developed system can also be applied to the computation of the sensitivity of the power flow to the variation of the parameters that define the power system.

The grid integration of renewable energy, particularly in Spain, supposes an important problem to deal with for Distributor System Operators (DSO). Most of the times Wind Energy Farms are located in places that are far away from the transmission networks so they have to be integrated into distribution networks that are frequently operating close to their static rate. Current regulations make almost impossible to build new overhead lines so the increase of the capacity of the existing lines is a new target for the DSO. This paper is devoted to the analysis of a new methodology and monitoring system that have been developed to overcome the existing static rates by moving the operation point of the overhead lines close to their dynamic rate. This new rate is computed by using both the IEEE and CIGRÉ algorithms and a local weather forecast. The obtained results show that this approach can increase the capacity of the lines in a significant percentage.

This research work is devoted to the study of the Power Quality (PQ) impact of small wind energy conversion systems (SWECS) connected to the low voltage grid. A common coupling point (CCP) has been monitored using a PQ meter that fulfils the standard IEC 61000-4-30 class A. The PQ survey has been conducted with and without the SWECS and the results were compared with the limits defined by the standard EN 50160.

Power quality disturbances like voltage sags and harmonics are an important cause of many ill effects and economic losses in industrial productive processes. Among others problems, production down times, equipment malfunctions and/or destruction of devices and even quality defects in final products can be originated by voltage dips. Power quality surveys and electromechanical device testing are previous steps for achieving an effective mitigation solution. This paper discusses a power quality survey conducted in an automotive company. In addition, a portable test platform for evaluating voltage dip immunity of industrial robots and components is presented. The results obtained from this survey and the immunity test may be useful for improving the power quality of this type of installation [3,4,6].

The decomposition of voltage, current and power is presented in order to determine the responsibility of the distribution company and the electrical energy consumer for the harmonic distortion measured at the point of common coupling, PCC. This way, three types of variables should be managed, namely fundamental frequency, frequencies associated with the distribution system distortion and frequencies associated with the consumer distortion. These magnitudes can be also measured in relation to power factor compensation and harmonic elimination problems in power distribution systems. Moreover, the power factors resulting from the new decomposition are also analyzed. The algorithm of the decomposition will be implemented on a measurement platform based on a digital signal processor, DSP.

Wave energy conversion can be done by using several technologies and oscillating bodies constitute an important class of wave energy converters, especially for offshore deployment. This research work focuses on the development of a Matlab toolbox able to analyze the performance of this class of converters considering specific wave conditions

This research work is devoted to the comparison of some proposed high-frequency (HF) models of transformers and their application to power quality (PQ) studies. The models are classified according their structure, physical description and experimental methodology and set-up facilities needed to obtain the parameters.

Thermal solar energy offers a huge opportunity to reduce fuel dependency and environmental impact created by fossil fuel consumption. One of the main disadvantages of this renewable energy is its intermittence which decreases thermal solar power plants performance. In order to reduce cost electricity is necessary to create thermal solar plants which include thermal storage. There are different options of thermal storage: sensible, latent and chemical heat. It has been demonstrated that latent heat could store large amount of energy per unit mass. Moreover, latent heat storage could store fusion heat at a constant temperature which is the phase transition temperature of the phase change materials (PCM). However, these materials have a critical limitation that needs to be resolved in order to reduce operation cost of solar plants. This limitation is their low heat conductivity. This paper gathers the main solutions that are being analyzed in order to increase the possibilities to use PCMs in a high temperature thermal storage that is essential to develop optimum thermal solar power plants.

This research work is devoted to the development of a set-up facility for testing Permanet-Magnet Synchronous-Machines (PMSM) used in small wind energy generators. The developed test system can be used not only for PMSM parameters characterization but also for the study of the performance of the power electronic associated to the electrical machine.

This paper develops the comparison of two cogeneration systems that are suitable to perform heat energy recovery of the smoke produced by a casting process.

The paper analyzes the propagation of voltage sags through the distribution network of an industrial company. For this, power quality is monitoring in high voltage, 44kV, and low voltage, 400V. The theory of M. Bollen is used for the study of the sags recorded by the meters at different points of the installation. It is necessary to know the connection of transformers in order to determine the transmission of the sags.

This research work is devoted to the critical evaluation of the role of the dc-bus in the behavior of threephase adjustable-speed drives with voltage sags. In particular, the dc-link voltage variation under voltage sag and its dependence on bus capacity, dc-link resistance and inductance and source impedance. The analysis can be used to introduce additional capacitance in the dc-link in order to increase the ride-through capability of the ASD. Both an electromagnetic transient model and a set-up facility have been introduced. This test platform can be used in order to study the sensitivity of ASD to different disturbances.

This research work introduces the architecture of a low-cost advanced metering infrastructure (AMI) named DANCA with the ability to record up to six different current channels with the same voltage. This watt-hour meter can send the recorded power and energy data in real-time to a web server using both an ethernet wired and an IEEE 802.11b WiFi wireless connection. The server stores the data measured by the meters and can elaborate reports with useful data for the users. The clients can access the data in real-time using a web browser. From a instrumentation point of view the developed system can measure the power and energy consumption of clusters of loads in residential and small industrial applications. From the point of view of the connectivity the system can communicate with the server using the domestic internet access point. The amount of data to be transmitted is very low so the impact of the system in the network bandwidth can be considered negligible.

A stochastic linear model have been developed to analyze the Generation Expansion Planning in 2013-2032, through the programming language specific to the application GAMS. In this model the nuclear technology has been considered as generation option in several scenarios of costs of the fossil fuels. Also, two of clean coal technologies have been taken into account. The evolution of supply security has been assessed by means the determination of the vulnerability and degree of independence of the generator system with respect to primary energy sources. On the other hand, the determination of the reserve margin and the percentage of the capacity with regulation capability have allowed to analyze the evolution of its reliability. Lastly, the generation mix of smaller total cost and with less emissions of CO2 has also been determined. The final conclusion would be that a generator system should have the biggest possible number of types of generation.

This paper analyzes the energy potential which waste from the forestry eucalyptus globulus in Cantabria, with particular reference to their potential for direct combustion in power plants. This has made a software in which introducing the values for the various parameters that affect combustion, provides results in flame temperature and electrical performance.

The supply security of the primary energy sources (coal, natural gas, enriched uranium…) and the reliability of the system in terms of the oscillations of the frequency and voltage are two aspects to assess in the Generation Expansion Planning. In this article, for the first criterion, the evolution of vulnerability and degree of independence of the generator system with respect to primary energy sources has been assessed by the indexes of Shannon-Weiner and energy independence, espectively. For the second approach, the evolution of the reserve margin by means the coverage index and the progression of the inertia and regulation capacity by means of its percentage regarding the total installed capacity. These four indexes have been applied on the obtained results of a stochastic lineal model developed with the software GAMS. In this model the nuclear technology has been considered as generation option in several scenarios of costs of the fossil fuels, coal and natural gas. Also, two of clean coal technologies with greater possibility of putting into service have been taken into account. The final conclusion would be that each technology carries out several functions in the generator system but not all them. That is, a generator system should have the greatest possible number of types of generation to be reliable and have supply security.