Western Serbia – 400 kV Transmission System Upgrade

The aim of the feasibility study (FS) is to examine possible phasing options for reconstruction of transmission lines in western Serbia until 2015 and in line with long-term development plans. At this point there is no adequate network capacity and equipment is quite old. This negatively affects the transmission capacity in the region, especially taking into account the construction submarine cable between Montenegro and Italy and the expected increase in transit through the transmission network in Serbia, and the necessary reconstruction and achievement of a 400 kV voltage level is the best solution. The main activities in FS will be to review the technical analysis conducted at the Pre-feasibility Study (PFS) stage and undertake further analysis in order to fully evaluate the proposed projects from the technical perspective. In order to achieve appropriate results, it was necessary to perform the following activities:

• EMS’s model preparation which is used in the FS. All assumptions that are specified include interconnection B.Basta to Pljevlja (double circuit), Vardiste normal configuration, Bistrica new 220 kV Substation, B.Basta to Sremska Mitrovica line available including all items studied as sensitive in the PFS.
• To carry out the analysis at the level of the Pre-feasibility study which consists of modeling of 400 kV Kragujevac – Kraljevo line and 400kV new 400kV Bajina Basta - Kraljevo line.
• To identify the periods and critical regimes when OHL between B. Basta and Valjevo/Obrenovac/Beograd-3 can be switched out and what is the consequence in terms of unsupplied energy to both EMS (and EPS).
• Assess the usage of Phase-shifting transformers in Bajina Basta for 400/220kV transmission in the long term period
• Short circuit analyses in accordance to IEC 60909 standard, considering full engagement of all generation units in Serbia. This item was performed for Winter maximum 2015 regime.

Type of services provided:

• Data Collection
• Load flow analyses
• Short circuit analyses
• Techno-economical analyses
• Construction Planning