Roberto Villafáfila

IEC 61850 as a flexible tool for electrical systems monitoring

In the last decades there have been great advances in electronic, information and communication technologies. Up to date, any of these advances have been implemented in electrical systems, but some difficulties have been encountered, particularly regarding to the integration of intelligent electronic devices from different manufactures into a centralized system. With the aim of solving the above mentioned problem, the standard IEO 61850 was developed to specify communication networks in substations. In addition to control and protection functions, the information model created around IEO 61850 series can help the development of other applications related with electrical monitoring systems. Monitoring can be used to achieve a variety of benefits for utilities, including maintenance prediction, failure prevention, active control, improved commissioning tests and more accurate end of life assessments. Examples of application that could be highly benefited by the adoption of IEC 61850 as standard for communications in the power electrical industry are power quality monitoring and condition based maintenance.In this paper, the new standard IEC61850 and the new opportunities that it can offer to the electrical industry are presented. Firstly, a brief presentation of IEC61850 and the main benefits it provides are described. Finally, a more detailed description of the possibilities that IEC61850 can offer in the field of power quality monitoring and condition based maintenance (CBM) is highlighted.

Study of power fluctuation from dispersed generations and loads and its impact on a distribution network through a probabilistic approach

In order to assess the performance of distribution system under normal operating conditions with large integration of renewable energy based dispersed generation (DG) dispersed generation, probabilistic modeling of the distribution system is necessary in order to take into consideration the stochastic behavior of load demands and DG units such as wind generation and combined heat and power plant generation. This paper classifies probabilistic models of load demands and DG units into summer and winter period, weekday and weekend as well as in 24 hours a day. The voltage results from the probabilistic load flow based on Monte Carlo method and those from the statistical measurement data are compared. Simulation results from the probabilistic model show good agreement with those from the statistical measurement data.

Development and implementation of a condition monitoring system in a substation

Maintenance is a key activity for utilities in order to assure the proper operation of their networks. And it implies a huge amount of human and economic resources. Saving maintenance costs means that it is needed to invest in innovation. In order to improve the effectiveness of the maintenance in the electrical utilities, a transformation from preventive maintenance based on time (TBM) to preventive maintenance based on condition (CBM) is taking place. The core element of the CBM strategy is the implementation of a condition monitoring system. This work treat about the development and implementation of a condition monitoring system in a pilot plant of an electric utility consisting in a 66/25 kV, 30 MVA power transformer and 66 kV and 25 kV circuit breakers. The system was implemented by using the monitoring functions of commercial protection relays equipped with IEC61850 communication capabilities. In this work, first a description of the monitoring system is presented, followed by the description of the pilot plant where the system has been installed and finally, the conclusions and further works are presented.

Assess the impact of photovoltaic generation systems on low-voltage network: software analysis tool development

The integration of photovoltaic generation systems into power networks can cause both benefits and drawbacks. However, utilities have to control and operate their systems properly, in order to assure the availability and quality power supply to the users. Therefore, utilities should consider technical constraints and existing regulation in order to assess the impact of photovoltaic systems and limit their integration. On the other hand, regulation includes few operation constraints and they are not implemented in current software analysis tools. In the present paper a tool for assessing the impact of PV integration on low-voltage networks is described. The voltage fluctuation, the inversion of the power flow and the increase of short-circuit capacity are the problems considered in the proposed tool. Further work will focus on harmonics distortion.

Probabilistic assessment of wind power production on voltage profile in distribution networks

Distribution power networks are accommodating more and more generation and most of them are based on renewable sources, like wind power. Then, this new generation, generally known as distributed generation (DG), has a stochastic power production that affects technically the network in different ways. However, availability and power quality must be kept within standard limits. Deterministic approach can not cope with this issue and a probabilistic assessment is needed. Wind power has a high level of integration around the world. Then, its impact of voltage profile in a distribution network is analyzed.

Selection criteria of high-power static Uninterruptible Power Supplies

Non-stop interruption-free applications in home, office and industry demand for a high quality and reliability power supply. Uninterruptible power supply (UPS) manufactures offer a great deal of solutions, but each application requires a particular solution. Selecting the best static UPS for an application is a cumbersome task for many customers. This paper reviews the IEC 620400-3 standard regarding static UPS performances and tests requirements and also proposes some new test not included in the standard. Moreover, general criteria for selecting a high power static UPS are depicted.