Nuclear Magnetohydrodynamic EMP, Solar Storms, and Substorms

In addition to a fast electromagnetic pulse (EMP), a high altitude nuclear burst produces a relatively slow magnetohydrodynarnic EMP (MHD EMP), whose effects are like those from solar storm geomagnetically induced currents (SS GIC). The MHD EMP electric field E < 10^-1 V/m and lasts < 10^2 sec, whereas for solar storms E > 10^-2 V/m and lasts >10^3 sec. Although the solar storm electric field is lower than MHD EMP, the solar storm effects are generally greater due to their much longer duration. Substorms produce much smaller effects than SS GIC, but occur much more frequently. This paper describes the physics of such geomagnetic disturbances and analyzes their effects.Comment: 29 pages, 14 figures, 5 table

Grounding Performance under Lightning Surges in High Voltage Substations

Postponed access: the file will be accessible after 2019-05-31To achieve electromagnetic compatibility (EMC) and sufficient protection against lighting transients in the power transmission system, understanding of the grounding system transient behavior becomes crucial when deviating from international design standards and recommendations. To consider design deviations the present work is focused towards developing a method of integrating simplified grounding system models in transmission systems and perform lightning transient analysis on both parts to evaluate a particular design case. Firstly, the grounding system models for substation grounding grids, with a variety of configurations and sizes, is implemented. The characteristic transient response of the grounding system is visualized through simulations to study the sensitivity of configurations and modified soil parameters during current injections. The method of implementation allows for a detailed view and pre-processing of large data-sets from simulations. The advantages of this method is used to extract overall measured values to create a tool for EMC analysis and in addition processing different parameters and functions of the grounding system. Secondly, the grounding system model is integrated into transmission systems using a newly released interfacing application. The application allows for co-simulation between the development software of the grounding system and a specialized tool for the transmission system. The innovation of this modeling approach is given as a contribution to an international conference by submitting a paper. Finally, the integrated grounding models and transmission system are studied with two substation design cases; a short and long cable between surge arrester and transformer. The short cable case follows well-known design standards where the long cable case is a design deviation which is common in larger domestic hydropower plants. Even though the long cable case is deviating from design recommendations, the results show a less negative impact on the grounding system compared to the short cable case.Masteroppgave i energiMAMN-ENERGENERGI39

Improving lightning performance on high voltage overhead shielded networks by reducing tower footing earthing resistance.

Master s Degree. University of KwaZulu-Natal, Durban, 2019.Abstract available in pdf

Analysis of Lightning Strike Impulse Strategies in Electricity Distribution Channels Utilizing Mixed Lines

To ensure the operational security of these systems and to give higher quality electricity to all users, it is important to assess the transient behavior of electric power transmission and distribution systems when they are challenged to varied forms like lightning discharges, which in this research is focused to determine the effect by utilizing the mixed line configuration on the impulse voltage of lightning strike on the 20 kV distribution line. This experiment was carried out using sources of data through channel documentation on Makassar City Polda Feeders with an airway length (SUTM) of 7.8 km and a cable channel length (SKTM) of 2 km obtained from PT. PLN (Persero) Makassar Branch and then input into the ATP-EMTP simulation process with either a simulation of 20 and 50 kA strikes at distances of 2.5, 4.5 and 6.5 km with lightning impulses of 1.2/50 and 8/20 µs. configuration of lines at the transition point and also the end of the cable channel depending on the magnitude of the lightning current, the location of the strike, and the lightning impulse. Lightning peak current is proportional to the voltage response at the transition point and the end of the cable, and the effect on lightning impulse peak voltage is generated at the transition point and the end of the cable. According to research results of initial research, the use of mixed channel lines can decrease the impulse voltage is 20 kV distribution lines

Lightning Modeling and Its Effects on Electric Infrastructures

When it comes to dealing with high voltages or issues of high electric currents, infrastructure security and people’s safety are of paramount importance. These kinds of phenomena have dangerous consequences, therefore studies concerning the effects of lightning are crucial. The normal operation of transmission and distribution systems is greatly affected by lightning, which is one of the major causes of power interruptions: direct or nearby indirect strikes can cause flashovers in overhead transmission and distribution lines, resulting in over voltages on the line conductors. Contributions to this Special Issue have mainly focused on modelling lightning activity, investigating physical causes, and discussing and testing mathematical models for the electromagnetic fields associated with lighting phenomena. In this framework, two main topics have emerged: 1) the interaction between lightning phenomena and electrical infrastructures, such as wind turbines and overhead lines; and 2) the computation of lightning electromagnetic fields in the case of particular configuration, considering a negatively charged artificial thunderstorm or considering a complex terrain with arbitrary topograph

Outdoor Insulation and Gas Insulated Switchgears

This book focuses on theoretical and practical developments in the performance of high-voltage transmission line against atmospheric pollution and icing. Modifications using suitable fillers are also pinpointed to improve silicone rubber insulation materials. Very fast transient overvoltage (VFTO) mitigation techniques, along with some suggestions for reliable partial discharge measurements under DC voltage stresses inside gas-insulated switchgears, are addressed. The application of an inductor-based filter for the protective performance of surge arresters against indirect lightning strikes is also discussed

Selected Papers from 2020 IEEE International Conference on High Voltage Engineering (ICHVE 2020)

The 2020 IEEE International Conference on High Voltage Engineering (ICHVE 2020) was held on 6–10 September 2020 in Beijing, China. The conference was organized by the Tsinghua University, China, and endorsed by the IEEE Dielectrics and Electrical Insulation Society. This conference has attracted a great deal of attention from researchers around the world in the field of high voltage engineering. The forum offered the opportunity to present the latest developments and different emerging challenges in high voltage engineering, including the topics of ultra-high voltage, smart grids, and insulating materials