37. саветовање CIGRE Србија (2025) СИГУРНОСТ, СТАБИЛНОСТ, ПОУЗДАНОСТ И RESILIENCE ЕЛЕКТРОЕНЕРГЕТСКОГ СИСТЕМА МУЛТИСЕКТОРСКО ПОВЕЗИВАЊЕ У ЕНЕРГЕТИЦИ И ПРИВРЕДИ – C4-06
АУТОР(И) / AUTHOR(S): Ana Vuković, Mila Drajić
DOI: 10.46793/CIGRE37.C4.06
САЖЕТАК / ABSTRACT:
In a power system, voltage is a quantity that has a narrow range of permissible variations under normal operating conditions. The upper and lower limits most often vary from ±5% to ±10%, depending on the voltage level which is being observed. This ensures voltage stability and reliable power transfer in the power systems. Reactive power is a quantity directly linked to voltage and responsible for its regulation. Most grid codes in the world define reactive power capability requirements at the connection point which power plants must comply with in both inductive and capacitive regimes. In traditional power systems, voltage regulation was carried out mainly by synchronous generators. The increase in penetration, and in certain power systems, the dominance of renewable energy sources has caused a change to the sources and the methods carrying out voltage regulation. Solar and wind power plants are nowadays being developed and implemented with the ability to independently regulate reactive power and voltage conditions at the connection point. To help inverter-based resources meet the reactive power requirements, the capability of power plants can be enhanced by adding specialized devices such as capacitor banks or STATCOMs. The aim of this paper is to assess the capability of a large PV plant (750MW) connected to a 132kV transmission system to meet the reactive power requirements at the connection point under various operating conditions. Base case will represent the assessment of P-Q characteristics of the PV plant at ambient temperature characteristic for the observed geographical region (46°C), assuming the voltage of the inverters can be at the maximum values guaranteed by the equipment manufacturer (1.1pu). Sensitivity analysis will be carried out in two cases: in other ambient conditions (outdoor temperature of 52°C) and for the inverter voltage lower than maximum (1.05pu). For each of the three cases mentioned above both inductive and capacitive operating modes will be considered at nominal and extreme voltage values at the connection point. The analysis will be conducted in the DIgSILENT PowerFactory software tool, including the detailed modeling of the observed PV plant and its elements. The results will give an assessment of the reactive power capabilities of a large PV plant to support the power system in critical operating regimes. The influence of ambient conditions on the inverters’ power production will also be assessed, as well as the impact of limiting the inverter voltage to values less than the maximum in order to extend the lifetime of the observed equipment.
КЉУЧНЕ РЕЧИ / KEYWORDS:
PV plant, reactive power, capability curve, P-Q diagram, DIgSILENT PowerFactory, software tools
ПРОЈЕКАТ / ACKNOWLEDGEMENT:
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