Search

U završnom radu je definirana podjela uzemljenja po vrsti i načinu izvedbe. Svaki od tipova uzemljenja je objašnjen te prikazan pomoću slika. Definirane su glavne opasnosti kod zemljospoja, naponi koraka i dodira. Korištenjem programa ANSYS te izraza iz literature, izračunati su otpori uzemljenja za različite izvedbe uzemljivača. Grafički su prikazane raspodjele potencijala te ovisnost napona o udaljenosti od uzemljivača. This thesis describes different grounding techniques. Each technique is described in detail using sketches of grounding methods. Both step voltage and contact voltage, the main dangers during an occurence of an earth fault, are defined. Using mathematical terms found in literature, ground resistance for various grounding types has been caluclated. Using ANSYS, the same ground resistances have also been calculated using computer software. The results have been plotted and explained accordingly.

U diplomskom radu opisane su vrste uzemljenja prema namjeni. Objašnjen je specifični otpor tla i navedene neke od metoda za mjerenje otpora uzemljenja. Također je prikazan kako se mijenja iznos specifičnog otpora tla ovisno o tlu te raspodjela otpornosti tla na području Hrvatske. Navedene su i vrste uzemljivača te je za svaki od njih naved izraz po kojemu se računa otpor uzemljenja. Prilikom projektiranja uzemljivačkog sustava bitno je pridržavati se važećih normi I propisa. This Master's thesis describes the types of grounding by application. The soil resistivity is explained and some of the methods for measuring ground resistance are mentioned. It also shows how the amount of soil resistivity changes depending on the soil and distribution of soil resistivity on the Croatian territory. In this thesis are also mentioned different types of grounding and for each of them the term by which is calculated grounding resistance. When designing the grounding system is essential to comply with the applicable norms and regulations, it is essential.

U diplomskom radu prikazan je utjecaj različitih modela tla na proračun uzemljenja. Prvi dio rada obrađuje osnovne četiri vrste uzemljenje (pogonsko, zaštitno, gromobransko i združeno), vrste uzemljivača te pojmove dodirni napon, napon koraka i raspodjela potencijala. Specifični otpor tla osnovna je karakteristika tla na koju utječe niz parametara (temperatura, vlaga, sadržaj soli). Obrađene su osnove metode mjerenja specifičnog otpora tla: Wenner-ova metoda, Schlumberger-ova metoda, Opća metoda, Metoda 3-sonde i Dipol-Dipol metoda. Na osnovu mjerenja specifičnog otpora tla izrađuju se modeli tla (jednoslojni, dvoslojni horizontalni, višeslojni horizontali i ostali). Simulacijama u programskom paketu CDEGS (moduli RESAP i MALT), usporedbom dva modela tla, prikazan je utjecaj modela tla na otpor rasprostiranja uzemljivača, raspodjelu potencijala zemljišta, dodirni napon i napon koraka. In this thesis influence of different soil models on grounding calculation was presented. The first part of this thesis deals with four basic types of grounding systems (working, protective, lightning and combined), grounding types and terms such as: touch voltage, step voltage and potential distribution. Soil resistivity is the basic characteristic of soil which affects a number of parameters (temperature, humidity, salt content). Basic methods of measuring soil resistivity, which were presented in this thesis, are: Wenner method, Schlumberger method, General method, Driven rod (3-probe) method and the Dipole-Dipole method. Soil resistivity measurements are used to obtain an equivalent soil model (uniform model, two-layer horizontal model, multi-layer horizontal model and others). With the simulations in the CDEGS software package (both the RESAP and MALT modules were used) on two different soil models, the resulting affect of soil model on the grounding resistance, potential distribution at the surface, touch and step voltage were shown.