Analiza nizkonapetostnega distribucijskega omrežja z gospodinjskimi odjemalci individualne gradnje

KNEZ, TADEJ (author), Čepin, Marko (mentor)

Zaradi povečevanja porabe električne energije, se distribucijsko omrežje neprestano širi, zato je ključnega pomena pravilno načrtovanje omrežja. Najprej je razložen problem padcev napetosti v omrežju, ki je eden glavnih razlogov, zakaj so analize omrežja sploh potrebne. Nato je opisana teorija pretokov moči med dvema vozliščema, kjer so izpeljane enačbe, ki se uporabljajo pri analizah pretokov moči. Analiza pretokov moči ne bi bila mogoča brez iteracijskih metod. Predstavljene so Gaussova, Gauss-Seidlova, razklopljena in hitra razklopljena metoda. Največji poudarek je na Newton-Raphsonovi metodi, ki je najprimernejša za analize v distribucijskem omrežju. Sledi pregled kriterijev načrtovanja razvoja SN in NN omrežja. Predvsem so predelani tehnični kriteriji, kot so dopustni padci napetosti, mejne obremenitve vodov in transformatorjev. Predstavljeni kriteriji za NN omrežje so relativno novi, saj upoštevajo povečevanje porabe zaradi elektrifikacije ogrevanja in prometa ter vpliv razpršenih virov. Temu sledi predstavitev delovanja programske opreme Gredos, ki je glavno orodje za načrtovanje in analize slovenskih distribucijskih podjetij. Na koncu je prikazan primer uporabe Gredosa. Izbran je bil primer dela nizkonapetostnega omrežja z 31 odjemalci, kateri je bil uporabljen pri pripravi modela v računalniškem programu Gredos. S pomočjo razvitega modela je narejena analiza obstoječega obratovalnega stanja in obratovalnega stanja ob povečani obremenitvi omrežja zaradi domačih električnih polnilnic, toplotnih črpalk in sončnih elektrarn. Analiza je pokazala, da sedanje stanje ustreza tehničnim kriterijem načrtovanja omrežja. Pri obremenitvi s 16 polnilnicami električnih avtomobilov omrežje ni ustrezalo kriterijem. Tudi pri obremenitvi s 16 električnim polnilnicami in 16 toplotnimi črpalkami niso bili izpolnjeni kriteriji načrtovanja. Previsoki dvigi napetosti so bili pri obratovanju s 16 sončnimi elektrarnami. Pri obratovalnih stanjih z drugačnimi kombinacijami obremenitve je omrežje ustrezalo kriterijem načrtovanja. Omrežje bi bilo pri prevelikih obremenitvah potrebno ojačati ali pa bi bilo potrebno v omrežje vključevati take porabnike, ki lahko konično moč prilagajajo obremenjenosti omrežja.

• Language: Slovenian
• Keywords: padci napetosti, načrtovanje distribucijskega omrežja, Gredos, električne polnilnice, toplotne črpalke, sončne elektrarne
• Work type: Master's thesis/paper
• Organization: FE - Faculty of Electrical Engineering
• Year: 2018
• PID: 20.500.12556/RUL-104804
• Publication date in RUL: 11.10.2018

Secondary language

• Language: English
• Title: Analysis of low voltage distribution network with household customers of individual construction

Abstract

Due to increasing consumption of electric energy, the distribution network is constantly expanding, so is very important that the network is properly planned. Firstly, the problem of voltage drops is explained, which is one of the main reasons why network analysis is needed. Then, a theory of power flow between two nodes is described where a derivation of the equations used in the analysis of power flow is presented. An analysis of power flow would not be possible without the iterative methods. Gauss, Gauss-Seidl, decoupled and fast decoupled methods are presented. The main focus is placed on Newton-Raphson's method, which is suited for analysis in the distribution network. Then an overview of planning criteria for medium and low voltage network development is made. Technical criteria, such as voltage drops limitations, loading of distribution lines and transformers have been described. The criteria for low voltage network is relatively new, because it takes into account increase of consumption due to electrification of heating and traffic and the impact of diffuse sources. Also Gredos software is presented, which is the main tool for network planning and analyzing in Slovenian distribution companies. Finally, an example of using Gredos is shown. An example of a low voltage network with 31 customers was selected, which was used to prepare the model in the Gredos software. Using the developed model, an analysis of the existing state of operation and state of operation with increased network load due to domestic charging stations, heating pumps and solar power stations is made. The analysis showed that the current state corresponds the technical criteria. The load with 16 electric car charging stations would not correspond the criteria. Also the load with 16 electric car charging stations and 16 heating pumps would not correspond the criteria. There were too high voltage rises in state with 16 solar power plant. In operational states with different combinations of load network corresponds the criteria. The network should be strengthened at too high loads or consumers, which can adjust their own load to network load, should be involved.

• Keywords: voltage drop, distribution network planning, software Gredos, charging stations, heating pumps, solar power stations