OPTIMIZATION AND IMPROVEMENT OF VOLTAGE CONDITIONS IN THE SERBIAN POWER SYSTEM USING VARIABLE SHUNT REACTORS

Prolonged exposure to voltages exceeding permissible levels leads to a reduction in the lifespan of power system equipment, with power and measurement transformers being the most affected. Operating under excessive voltage conditions imposes additional stress on the equipment, which can result in individual outages of entire substations and permanent failures of power transformers. This issue has been extensively researched within various scientific organizations (IEEE, CIGRE), with conclusions emphasizing that nominal equipment voltage ratings must be strictly adhered to in order to prevent a reduction in lifespan and minimize the frequency of failures in the transmission system. The objective of this study is to determine the optimal locations for installing compensation devices, their installed capacities, and the technical characteristics of the voltage regulation equipment in the high-voltage network owned by EMS JSC. The primary goal is to reduce voltage levels in the transmission system during critical periods of the year while also improving the overall capability of voltage control across the system. An example of a feasibility assessment for the installation of a variable reactor in the event of high-voltage equipment being exposed to accelerated aging has been presented.