|
|
Calculation and technical solutions earthing system of transformer substation 110/22 kV
Mašek, Jakub ; Dušek, Igor (referee) ; Bátora, Branislav (advisor)
Master's thesis deals with principles of design of earthing of a substation 110/22 kV. Specific requirements for safety have to be fulfilled when designing power installations exceeding 1kV. The aim of this paper is to design a new earthing system for reconstructed substation 110/22kV considering valid standards. Reconstruction of a property is always more or less complicated by new orders and regulations for construction. Earthing is a part of all electric equipment, therefore it is essential for the design engineer to consider a broad spectrum of requirements, even those seemingly not related to this subject, from legislative requirements to the study of reactions of a human body to electric current. The theoretical part of this work examines different approaches to earthing system's design, and analyzes the origins and earthing standards throughout history. The correctness in consideration of effects of the environment is an often neglected factor. Defining of all types of effects of the environment is a broad field, therefore this paper only summarizes the main principles. The practical part of this paper deals with the basic design of substation's earthing system and it's verification in respect of touch voltage and step voltage according to the Czech national standard ČSN 33 3201 (Power installations exceeding 1kV a.c.) and of company's energetics' standard PNE 33 0000-1 ed.4 (Protection against electric shock in distribution network and transmission system) required by the substation's distributor. This paper later quotes and takes into consideration the requirements of other standards, more or less related to listed documents, creating an interconnected body for design and testing the earthing system.
|
|
|
Project of Earthing System in 110/22 kV Transfornmation Station
Pavlík, Ludvík ; Procházka, Aleš (referee) ; Orságová, Jaroslava (advisor)
This Thesis is concerned with the concept of grounding of 110/22 kV transformer station. The aim of the Thesis is to create a ground network for grounding a specified outdoor substation. This 110 kV outdoor substation is formed according to H-scheme and encircles a wide area. In additon to this, an earth potential has to be distributed as equally as possible within the whole area of the substation. The most convenient alternative from the point of view of effective grounding and distribution of potential is a grid network. Therefore, the grid network is the means of grounding which I have chosen as a solution for this issue. In this solution, flat conductor network cables are used to cover the whole substation, with ground rods placed at the points of intersection. Parts of appliance can be then connected to this existing network, thus creating several parallel channels which provide grounding with low resistance. The network is made of common steel zinc-coated stip, size 30 x 4 mm. When proposing a concept of grounding and adjustment of ground electrodes, we have to take account of grounding requirements, stated according to ČSN standards. The proposed earthing system was created in appropriate size in order to meet all these grounding requirements. These requirements are also mentioned and described in a theoretical part of the Thesis. Second part of the Thesis consists of proposed concept of the grounding itself, together with calculated parameters. The grounding has to be carried out according to both safety regulations and electrical appliance requirements. The issue of grounding substations of power system is resolved by the ČSN standards 33 3201 (“Elektrické instalace nad AC 1kV”), 33 2000-4-41 (“Elektrická zařízení – Ochrana před úrazem elektrickým proudem”) and 33 2000-5-54 (“Elektrická zařízení – Výběr a stavba elektrických zařízení – Uzemnění a ochranné vodiče”) and by the PNE company standards 33 0000-4 (“Příklady výpočtů uzemňovacích soustav v distribuční a přenosové soustavě dodavatele elektřiny”) and 33 0000-1 (“Ochrana před úrazem elektrickým proudem v distribuční soustavě dodavatele elektřiny”). These standards apply to creating a concept of grounding and grounding of new, reconstructed or expanded electrical substations of power system.
|
guest ::
