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Background Animal pollination is an important ecosystem function and service, ensuring both the integrity of natural systems and human well-being. Although many knowledge shortfalls remain, some high-quality data sets on biological interactions are now available. The development and adoption of standards for biodiversity data and metadata has promoted great advances in biological data sharing and aggregation, supporting large-scale studies and science-based public policies. However, these standards are currently not suitable to fully support interaction data sharing. Results Here we present a vocabulary of terms and a data model for sharing plant–pollinator interactions data based on the Darwin Core standard. The vocabulary introduces 48 new terms targeting several aspects of plant–pollinator interactions and can be used to capture information from different approaches and scales. Additionally, we provide solutions for data serialization using RDF, XML, and DwC-Archives and recommendations of existing controlled vocabularies for some of the terms. Our contribution supports open access to standardized data on plant–pollinator interactions. Conclusions The adoption of the vocabulary would facilitate data sharing to support studies ranging from the spatial and temporal distribution of interactions to the taxonomic, phenological, functional, and phylogenetic aspects of plant–pollinator interactions. We expect to fill data and knowledge gaps, thus further enabling scientific research on the ecology and evolution of plant–pollinator communities, biodiversity conservation, ecosystem services, and the development of public policies. The proposed data model is flexible and can be adapted for sharing other types of interactions data by developing discipline-specific vocabularies of terms.

This paper presents an analysis of the influence of the problem of Fault Induced Delayed Voltage Recovery (FIDVR), caused by the presence of induction motors, in the operation of a doubly fed induction generator (DFIG) connected to a distribution system operating under unbalanced conditions. The aim of this analysis is to determine the effect of the FIDVR problem in the oscillations of a DFIG with a comparison among results of balanced and unbalanced conditions. It was observed that, in the operation of the induction motor under unbalanced condition, the average torque produced by the induction motor is smaller (when compared to the balanced case) due to the negative sequence component of the electromagnetic torque. Thus, the FIDVR effect is aggravated by the unbalanced conditions, and this has a direct impact on the damping of the oscillations of the DFIG. The damping and frequency of the oscillations are determined by the Prony method. The results showed a decrease in damping of the oscillations of the generator operating under unbalanced conditions when compared to the balanced condition. Furthermore, in extreme cases can lead to the loss of stability of the generator.

As the wind power penetration continues to increase, wind turbines are required to provide Low Voltage Ride-Through (LVRT) capability, thus new grid codes for wind turbines are established. Most grid codes provide the LVRT curve only for the connection to the transmission system. Only few of them include the distribution system and yet the measuring of the terminal voltage do not consider unbalanced operating conditions. This paper analyses the fulfillment of LVRT requirements under unbalanced voltage conditions for doubly-fed induction generator (DFIG) wind turbines connected to the distribution system. Three different terminal voltage measurement schemes are used and analyzed. The simulations are carried out in EMTP-RV software and the results indicate that for highly imbalanced systems all three phases must be independently analyzed.

The problem of intra-plant modes is characterized by the oscillation of the machines within a power station against each other. These modes are usually well-damped, but improper settings for the parameters for power system stabilizers (PSSs), aiming at enhancing the damping of local modes, for example, can reduce the damping of the intra-plant modes. This possibility must be avoided by a careful tuning of the stabilizers, over a model that is able to represent the intra-plant modes. This tuning process may be involved and time-consuming, requiring many hours of work from a specialist. In this paper, we present a computerized algorithm that is capable of performing this process with minimum intervention of the human designer (therefore alleviating the burden of PSS tuning for the engineer and placing most of it on the computer) and apply it to find a PSS tuning to damp both local and intra-plant modes of the same plant. As shown in the paper, the algorithm is capable of tuning PSSs for several operating conditions at once, which may also result in better tuning when compared to sequential approaches.