Amt für Städtebau

This document explores how switchgear and protective devices in transformer stations can be optimized to ensure reliable protection against malfunctions, with a particular focus on mitigating switching failures. The goal is to implement protective measures and to propose a new standard concept for transformer stations. The paper examines various protection concepts, comparing options such as fuse switch-disconnectors and circuit breakers with secondary protection. It considers regulatory requirements, including the Heavy Current Ordinance Art. 47 [1] and ESTI 407, alongside operational needs like transformer tripping, protection coordination, and selectivity. The findings underline the significance of robust protection strategies and provide key insights for enhancing safety and reliability in transformer station operations, serving as a foundation for the selection of an optimal protection concept.

Current earth fault distance measurement based on symmetrical components does not work very well in compensated systems because the steady-state currents through the fault location are significantly smaller than the load currents. It is not possible to distinguish between load current and fault current. It has also been assumed that the fault impedance, including the arc, is a linear impedance. However, this is not the case in the real world, especially for faults in the cable section of a line. The air gap creates an additional layer of insulation with increased and variable ignition voltage. This non-linearity affects the current waveform, voltage waveform, and frequency of the low-current arc. With the new modified method, it is now possible to distinguish between the fault current and the load current and to compensate for the effects of the nonlinearities of the fault impedances. The accuracy of the impedance measurement from the measuring point to the fault location is significantly improved. This paper presents the new method in detail for self-extinguishing and re-igniting earth faults in overhead and cable networks.

<strong class="journal-contentHeaderColor">Abstract.</strong> Hydromechanical soil response to moisture variations reflects complex subsurface dynamics that are critical for geoengineering, slope stability, and other soil health-related fields. While laboratory experiments have provided insights into soil behavior under varying wetness and loading conditions, field-scale observations with high spatial and temporal resolution remain limited. In this study, we present a 2 month field monitoring approach using Distributed Acoustic Sensing (DAS), which enables high-resolution, full-coverage, and continuous monitoring of a grass-covered soil slope. DAS allows for subsurface characterization and time-lapse monitoring of soil moisture dynamics using ambient noise interferometry. Furthermore, by analyzing nanostrain-scale deformation in conjunction with stress state derived from in situ soil moisture measurements, we demonstrate that DAS can track real-time volumetric changes in response to both long-term and daily cyclic moisture variations. We suggest DAS as a valuable tool for the continuous detection of moisture-driven changes in soil mechanical properties with high resolution.

Does learning political candidates’ social categories through visual cues affect voter preferences? This paper explores this question by conducting a visual conjoint survey experiment with 2324 German voters, varying whether respondents received information on candidates through explicit labels or pretested AI-generated candidate pictures. The results confirm our expectations that the way in which social categories are perceived affects preferences, with visual cues having a more significant effect on voter preferences compared to textual cues, leading to more discriminatory preferences for certain social categories. Moreover, we show that the effect of visual cues is moderated by the visibility of social categories, with visible social categories, such as gender binaries and ethnic in-/out-group, eliciting more discriminatory preferences with visual cues. The study sheds light on how visible and invisible social categories affect political candidates’ preferences and emphasizes the importance of considering the intersectionality of social categories and their relationship with ideology.

Mit der Verbreitung von Mobiltelefonen hat auch das Versenden von «Dick Pics» zugenommen. Der vorliegende Beitrag untersucht, wie das Versenden unerwünschter Fotos männlicher Genitalien strafrechtlich zu werten ist. In Frage kommen Exhibitionismus (Art. 194 StGB), Pornografie (Art. 197 StGB) und sexuelle Belästigung (Art. 198 StGB). Dabei wird sich zeigen, dass keiner dieser Tatbestände wirklich passt. Auch nach der Revision des Sexualstrafrechts ist das Problem nicht abschliessend gelöst.&#x0D; --&#x0D; L'envoi de «Dick Pics» a sensiblement augmentéavec la popularisation des téléphones portables. Notre article examine comment l'envoi de photos non désirées d'organes génitaux masculins doitêtre considérédu point de vue du droit pénal. L'exhibitionnisme (art. 194 CP), la pornographie (art. 197 CP) et le harcèlement sexuel (art. 198 CP) entrent en ligne de compte. Il sera toutefois constatéqu'aucune de ces infractions n'est vraiment adaptée. Même après la révision du droit pénal en matiè re sexuelle, le problème n'est pas définitivement résolu.&#x0D;

One of the most widely used reliability measures for the electric grid is the System Average Interruption Duration Index (SAIDI), i.e. how many minutes the average customer is without power per year. Primary substation failures may significantly increase SAIDI, since they affect a large number of customers. This may be avoided by improving the service restoration process, which requires solving complex non-convex combinatorial problems. Hence, this paper proposes an algorithm for smart, SAIDI-optimizing service restoration in meshed MV grids after primary substation failures. We first formulate service restoration as a Mixed-Integer Linear Programming (MILP) problem by using a linearization of the power flow equations that is proper for meshed grids and by applying exact Big M relaxations for linearizing other involved non-convexities. The decisions include among others the travel routes of the field crew and account for the grid security constraints. Then, we propose a low complexity heuristic iterative method that optimally solves the MILP problem. The results for a test case in Switzerland suggest that the SAIDI contribution can be reduced by more than 10% compared to the currently deployed restoration strategy at the utility. Also, they show the effectiveness of the SAIDI objective versus common objectives in the literature.

Life Cycle Assessment (LCA) is a comprehensive method for evaluating building sustainability. However, most studies have relied on generic or national LCA databases, overlooking the systematic consideration of future scenarios and sectoral developments due to data and tool constraints. Moreover, there's a gap in providing a standardized workflow for such evaluations and understanding their impact on the greenhouse gas (GHG) emissions of buildings on a national level. Addressing these gaps, our study incorporates scenarios from two Integrated Assessment Models (IAMs), considering the future developments of the electricity, cement, and steel sectors, to assess embodied GHG emissions of Swiss residential buildings from 2015 to 2055. Our findings reveal that incorporating these future considerations can lead up to a 25% GHG emissions reduction by 2055 compared to 2015, primarily due to GHG emission reductions in concrete and brick as a result of these considerations. This is much less than the emissions reduction potential of some specific construction materials and far from the goal of net zero. It also underscores the importance of exploring alternative strategies for net-zero GHG emissions at the building stock level. Consequently, we present reproducible workflows using open-source tools and future versions of the Swiss national building LCA databases, offering a blueprint for similar future studies in other countries.