The following paper presents an overview of the actual forecasting methods and models used in renewable energy systems. The purpose of the study is to summarize the available forecasting tools in order to select the most efficient approach. The paper showcases the forecasting of production and consumption of electrical energy for local and global systems and also the topic associated with it.

The rapid change in human migration from rural areas towards the biggest metropolitan areas across the world implies a reorganization of the utility transport networks creating new common right-of-ways between high voltage power lines (HVPL) and metallic pipelines. In this paper, induced voltages from HVPL to metallic pipelines are calculated using different numerical approaches. The induced voltages along a metallic pipeline are computed using the wide-known circuit theory and electromagnetic field theory approaches embedded under ATP, EMTP-RV and XGSLab software packages, respectively. In order to accurately quantify the impact of different topologies on the induced voltages along the pipeline, the length of the parallel routing, as well as the separation distance, are varied during the computational domain. Moreover, the CIGRE WG 36.02 criteria regarding the equivalent parallel sections are applied when circuit theory is employed and verified using the adopted electromagnetic field method.

Assessment of very fast transient overvoltage (VFTO) requires good knowledge of the behavior of gas-insulated substation when subjected to very high frequencies. The international standards and guidelines generically present only recommendations regarding the VFTO suppression without a technical and mathematical background. Therefore, to provide an accurate image regarding the critical locations across a gas-insulated substation (GIS) from a transient response point of view, a suitable modeling technique has to be identified and developed for the substation. The paper aimed to provide an accurate assessment of the GIS holistic transient response through an electromagnetic field theory (EMF) approach. This modeling technique has always been a difficult task when it came to gas-insulated substations. However, recent studies have shown that through suitable Computer-aided design models, representing the GIS metallic ensemble, accurate results can be obtained. The paper investigated several simplifications of the computational domain considering different gas-insulated substation configurations in order to identify a suitable modeling approach without any unnecessary computational effort. The analysis was performed by adopting the partial equivalent element circuit (PEEC) approach embedded into XGSLab software package. Obtained results could provide useful hints for grounding grid designers regarding the proper development and implementation of transient ground potential rise (TGPR) mitigation techniques across a gas-insulated substation.

Leaders of subsequent strokes in negative cloud-to-ground lightning are known to produce X-ray/gamma-ray emissions detectable at distances of a few kilometers or less from the lightning channel. These leaders usually develop in decayed but still warm channels of preceding strokes. We computed electric field waveforms at different points along the path of subsequent leader as those points are traversed by the leader tip. For a typical subsequent leader, the electric field peak is a few MV/m, which is sufficient for production of energetic radiation in a warm (reduced air density) channel. We examined the dependence of electric field peak on the leader model input parameters, including the prospective return-stroke peak current (a proxy for the leader tip potential) and leader propagation speed, and compared model predictions with measurements.

An important number of major utilities infrastructure projects are adopted worldwide as a consequence of human migration, pollution, geo-political alliances which force the governments around the world to massively invest in new transport and distribution networks serving for water, electricity, gas and oil supply. Installing pipelines in energy utility corridors containing high-voltage AC transmission lines subjects the pipelines to induced AC voltages, which is a real and serious problem requiring increased attention. Through proper modelling techniques, the induced currents and voltages in the underground/aboveground metallic pipelines can be accurately computed. In the following paper two different modelling concepts, based on circuit theory and electromagnetic theory approach are developed and discussed. A common right-of-way corridor between an overhead transmission line and a metallic pipeline is considered during the proposed assessment methodology. In order to evaluate how different variations of the model affects the magnitude of the induced quantities in the metallic pipeline a parametric analysis is employed. Based on the computed results, several dependencies between the power line current loads along with the considered length of parallel routing and the induced voltage are highlighted.