Influence of PV power plant connection on low voltage distribution network operation

Ovaj rad podijeljen je na pet cjelina koje su predstavljene poglavljima Elektroenergetski sustav, Priključenje obnovljivih izvora energije na niskonaponsku distribucijsku mrežu, Sunčane elektrane, Utjecaj sunčane elektrane na pogon niskonaponske distribucijske mreže i Utjecaj priključenja sunčane elektrane na primjeru stvarne niskonaponske mreže u računalnom programu NEPLAN. U prvom poglavlju opisan je elektroenergetski sustav, glavne podjele elektroenergetskih mreža, opisane su prijenosne i distribucijske mreže kao i vrste niskonaponskih distribucijskih mreža. U drugoj cjelini predstavljeni su i opisani koraci priključenja obnovljivih izvora energije na niskonaponsku distribucijsku mrežu, opisana su mrežna pravila, redoslijed ispitivanja sunčane elektrane prije puštanja u pogon te pokusni rad. Navedene su naponske i strujne zaštite te proračun. U trećem poglavlju opisane su sunčane elektrane sa svim dijelovima koji su potrebni za pravilan rad elektrane. Detaljno je opisan princip rada fotonaponske ćelije te su navedeni i opisani fotonaponski sustavi. Navedene su i opisane pogonske karakteristike fotonaponskoga modula i izmjenjivača sunčane elektrane „SOLEKTRA IX“ snage 999 kW. U četvrtoj cjelini detaljno je opisan princip rada sunčane elektrane „SOLARNI KROV ŠPANSKO ZAGREB“ te su opisana izvršena mjerenja kvalitete napona, vrijednosti napona, THD napona i nesimetrije napona, kao i mjerenja struje, radne i jalove snage i faktora snage. U zadnjem poglavlju pomoću računalnog programa NEPLAN simulirana je realna niskonaponska distribucijska mreža sa priključenim sunčanim elektranama, ispitan je utjecaj priključenja sunčane elektrane na naponski profil, razinu struje kratkog spoja i prikazani su tokovi snaga u mreži.This work is divided into five units, which are presented in the chapters Electric power system, Connection of renewable energy sources to the low-voltage distribution network, Solar power plants, Influence of the solar power plant on the operation of the low-voltage distribution network, and Influence of the connection of the solar power plant on the example of a real lowvoltage network in the computer program NEPLAN. In the first chapter, the power system is described, the main divisions of power networks, transmission and distribution networks as well as types of low-voltage distribution networks described. In the second part, the steps of connecting renewable energy sources to the low-voltage distribution network are presented and described, network rules are described, the order of testing the solar power plant before commissioning, and experimental work. Voltage and current protections and calculation are listed. In the third chapter, solar power plants are described with all the parts that are necessary for the proper operation of the power plant. The principle of operation of the photovoltaic cell is described in detail, and photovoltaic systems are listed and described. The operational characteristics of the photovoltaic module and inverter of the solar power plant "SOLEKTRA IX" with a power of 999 kW are listed and described. In the fourth part, the principle of operation of the solar power plant "SOLARNI KROV SPANSKO ZAGREB" is described in detail, and the measurements of voltage quality, voltage value, THD voltage and voltage asymmetry, as well as measurements of current, active and reactive power and power factor are described. In the last chapter, using the computer program NEPLAN, a realistic low-voltage distribution network with connected solar power plants was simulated, the influence of the connection of the solar power plant on the voltage profile, the short-circuit current level and the power flows in the network was examined