The book is an enhancement of the 1st HV Power Lines Regulation: published years ago.
The text is supplemented by an annex to the characteristics of many type of electrodes, different configurations and at different burial depths, far surpassing the old text of UNESA method that included reference tables.
1. Physical Fundamentals of grounding systems.
2. Characterization of the grounding electrodes.
3. Calculation of ground currents.
4. Requirements for the design of grounding.
5. Draft a facility grounding.
6. Application Examples.
7. measures grounded in high voltage installations.
Annex I. Calculation sequence impedances.
Annex II. Characteristic parameters of type configurations calculated using the Load Simulation Method (LSM)
After a thorough investigation and written by Industrial Engineering Doctor Jorge Moreno Mohíno and his collaborators, the book has recently seen the light "Earthing Systems in High Voltage Utilities. Design Calculation and Verification ", An excelllent work that fills an important gap in line with the current documentary legal regulations, which actually did not cover the needs of different professionals. So far, they should be referred to document UNESA "Method of calculation and installation project ground to processing centers connected to networks of third category," published in 1989 and generally used for the calculation and design start grounding of high voltage electrical installations.
The new book has been published with the push of Iberdrola Electricity Diistribution and the FFII (F²I²) "Foundation for the Promotion of Industrial Innovation", along with the investigations carried out and results obtained within the "Tabón" project, an initiative of R&D financed by the mechanism of the European Economic Area (EEA-Grants) with financial contribution of Iberdrola SA, Iberdrola Electrical Distribution and ATISAE.
Born in Yepes (Toledo), Spain, PhDr. Moreno holds a degree in Industrial Engineering from the Polytechnic University of Madrid (UPM) in 1989, and PhDr in Industrial Engineering in 1995.
With solid experience in university education field, between 1989 and 1995 as a professor in the Electrical Engineering Department at the UPM. Since 1995, he assumed the Palacios Bregel Laboratory of Magnetic Measurements UPM University CEO responsibility. He is also expert project evaluator for the Accreditation Agency for Research, Development and Technological Innovation (Aidit). His research interests include magnetic measurements and analysis of earth fault systems.
The significance of the publication is given by the importance of safety in the field of high voltage deployments commissioning systems. In fact, one of the risks of the electricity distribution activity are earth faults produced, among other reasons, due to the aging of insulating materials, unexpected breakdowns, or any other incidences. It is in these circumstances that the correct design, implementation and verification of grounding systems provides a guarantee of safety for both people (workers, users and passersby or third parties) to the facilities themselves.
As noted above, to date there was no text to gather updated theoretical and practical aspects, such as distinguishing between ground default current and rounding current In this book the current distribution by the several grounding systems is also treated with great practical sense when they are interconnected through screens underground cables, which will undoubtedly facilitate the implementation of projects of facilities commissioning ground in an urban environment, without resorting to unnecessary derivatives oversizing of an incorrect approach.
The book is particularly aimed towards engineering and senior cycle students, designers, engineers, professionals, installers and energy distribution companies. All they will have a suitable tool that fits Regulations Power Lines High Voltage (RLAT), published in March 2008 and Regulation of Electrical Installations High Voltage, later updated on June 2014, which have led to major changes for the design, calculation and verification of earthing in high voltage electrical facilities.
Seven chapters and two annexes
Jorge Moreno and his colleagues have structured their work in seven chapters and two appendices. In the first one the physical foundations of the grounding system, delving into the theoretical aspects required to understand obtaining parameters that characterize the different types of electrodes are described, as well as the methods used in practice for obtaining these parameters (method Howe and the Load Simulation Method LSM).
The following method applies Howe as the LSM method for obtaining the characteristic parameters of the electrodes, making a comparison between them and the existing commercial software.
The third chapter details the calculation methodology for solving the fault currents and ground by the electrodes, specifying the calculation for different earth network configurations (isolated neutral, impedance, etc.) as well as for different high voltage installations (support cable airline without ground wire, transformers and substations).
Meanwhile, the fourth includes regulatory requirements for the design of the grounding, its constitution, safety requirements, sizing and shows some of the electrodes commonly used by Iberdrola Electricity Distribution in its high voltage facilities.
In the fifth chapter describes the procedure used to project a grounding installation, first by investigating the terrain, the determination of the maximum off earth currents and leakage time of the defect current and the preliminary design for a detailed installation. It also describes the calculations of system resistance grounding, the step voltage and touch voltage that occurred in the system, the step voltage and touch voltage that are supported in the installation and its comparison with previous and obtained voltages outside transferable.
As for the sixth chapter, it presents seven fully solved examples, which serve as much help to the designers of such facilities. Notably design grounding of transformer type "Lonja" where obtaining current grounding is a determinant to meet regulatory requirements factor. the design of the ground support airline ground wire without ground wire, transformer fed from a network with impedance neutral, isolated neutral, isolated neutral with excess ballast and ends with the contemplated design grounding of a substation.
It is noteworthy in this context the design example grounding of a transformer belonging to a distribution network with isolated neutral endowed with an internal ballast zig-zag, at the head of substation, typical of the distribution network medium voltage used in the Canary Islands. In this method actual ground currents that occur in the processing center are determined, justifying why the use of simpler electrode (buried conductor stakeless) without oversizing the grounding installation.
The seventh chapter is entitled "Measurement of earthing in high voltage installations" and is intended for professionals who will carry out the checks and inspections on the premises grounding (accredited professionals, official institutions, installers, HV installers and energy distribution companies).
As its author states, in this chapter it places special emphasis on safety precautions to take into account not only during the measurements grounding the high voltage but also in pre-measures operations and during procedures for execution. With special editorial care, the book illustrates didactically each example:
#1.- The soil resistivity measurement
#2.- Also, the different methods used for measuring the resistance of the grounding system, depending on the type of installation (airline support without ground wire and ground wire, transformers and substations) are specified.
#3.- As well as measurements to be considered in the case of touch voltages and step voltages.
Towards the end of the work, the author has reserved us as an annex, a section that includes the calculation of sequence impedances of both airlines without ground wire with a ground wire and two ground wires as underground lines with grounded at one end, at both ends and Cross-Bonding screens. These impedances are necessary to establish the calculations of ground fault currents in different HV facilities, calculations referred to in the third chapter.
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