An indirect procedure for real-time monitoring the neutral conductor condition in three-phase distribution networks, based on watching over the growth of a novel parameter (∆τ), has been described in this paper. The parameter ∆τ has been defined as the relationship between the neutral-displacement power and Buchholz’s apparent power measured at the fundamental frequency in the loads of the distribution networks for any condition of the neutral conductor and in its nominal conditions. The effectiveness of this procedure has been compared with other traditional indirect procedures, such as the surveillance of the RMS values of the line-to-neutral load voltages or their zero-sequence component. The practical application on a real distribution network reveals that the growth of the parameter ∆τ in the early stages of the breaking process of the neutral conductor follows a straight line whose equation is known for each length and section of that conductor, regardless of the loads and the voltage regulation of the transformer of the distribution network. This characteristic of the ∆τ parameter shows that the proposed procedure is suitable for monitoring neutral conductor deterioration and can be used for preventive maintenance of distribution networks.

A procedure for improving the energy, economic and environmental sustainability of the transformation houses in low-voltage distribution networks is described in this paper. This procedure is based on the reduction of the transformer consumption, copper and core losses. Likewise, the procedure distinguishes between transformation houses with old and new transformers. The reduction of core losses, replacing transformers with others of lower power or that are more efficient, achieves significant improvements in energy and environmental aspects. The reduction of copper losses, and applying reactive compensation techniques, such as harmonic filtering and load balancing, applied in old and new transformation houses, have a greater impact on cost savings, especially when there are capacitive consumptions, as the Circular 3/2020 of the National Markets and Competition Commission of Spain determines. The procedure has been applied to an industrial transformation house, which has an old 1600 kVA transformer, resulting in significant economic savings and CO₂ reductions of more than 60%, after replacing the current transformer with a more efficient one.

Short-circuit resistances are transformer parameters that characterize the electrical load losses and correct operation of these machines. However, the traditional concept of short-circuit resistance, independent of the harmonic frequencies, has been superseded by present transformer standards. Hence, new expressions for short-circuit resistances of three-phase transformers have been developed in this article based on the IEEE Standard C57.110-2018 and are presented jointly with the losses that these resistances characterize. These refer to the secondary effective short-circuit resistance of each phase ($R_{cc,z}$), of each harmonic ($R_{cc,h}$), and the non-fundamental frequency combined harmonics ($R_{cc,Hz}$). Likewise, the harmonic loss factor (${HLF}_z\%$) has been established to determine the importance of the harmonics in each phase’s load losses. The application of these short-circuit resistances to the calculation of the load losses for a 630 kVA transformer from an actual residential distribution network has shown that the same values are obtained as with the IEEE Standard C57.110-2018, and they are 48.75% higher than those recorded with the traditional short-circuit resistances when the current distortion rates are 36.47%.

In an agrivoltaic plot, the hourly panel tracking angle governs electricity, on-site economics, avoided carbon dioxide, irrigation demand and crop yield. Operating for photovoltaic output alone discards that space, and does so when a midday kilowatt-hour has lost its value: 715 h of the studied season carried a non-positive export price, 517 of them at midday. This work formalizes the electrical operating layer of a mechanistic hourly simulator as nine panel-orientation modes, each a constrained program solved deterministically by sequential quadratic programming, a dense angular scan, or both. Two modes keep an energy-proportional objective non-degenerate through an adaptive clean-grid switch and an economics–carbon weighting anchored on the crop. The catalog is a framework, demonstrated over a 153-day season on a 66 kWp single-axis sage (Salvia officinalis) plot near Valencia, Spain. Seasonal photovoltaic energy ranged from 57.0 to 31.9 MWh, plot-mean relative yield from 95% to 109%, and worst-plant protection from 61% to 94%. Energy maximization sits at a flat extreme of the frontier: the Pareto mode gained 11.4 yield points and 31 worst-plant points for 1.1% less energy. Avoided carbon dioxide varied by 2.1% across the nine modes, so a carbon objective is degenerate with energy without an interior term.

Most agrivoltaic (APV) models assemble stand-alone tools ex post and optimize panel orientation for energy alone. It remains an open question whether the energy resource of an APV plot (its generation, storage, and shiftable demand) can instead be optimized at the resolution of the individual module while still guaranteeing that crop needs are met. This paper addresses that question with a mechanistic, hourly, spatially resolved framework in which the panel-orientation optimizer is embedded inside the hourly loop, ahead of the radiation sub-model, so every candidate orientation is evaluated through the full geometric chain it would produce rather than from cached values. Four operating modes (pure energy, energy under a crop-yield floor, pure yield, and yield under an energy floor) make the energy–yield trade-off an explicit decision variable that can be posed against a regulatory yield threshold. Over a full growing season (1 May–31 October 2021) for a Citrus limon orchard in Valencia, Spain (39.47391° N, 0.37966° W), the modes span 45.0–85.3 MWh of generation and 74.8–100.5% relative crop yield, with Land Equivalent Ratios of 1.37–1.48 and LCOE of 0.097–0.183 EUR/kWh.