TS 35/10 kV “Zajecar 4”

The substation TS 35/10kV “Zaječar 4” is located on the territory of the municipality of Zaječar, on cadastral plot no. 6335/2 K.O. Zaječar and was built to increase the safety and reliability of equipment in the distribution network facilities.

Montprojekt d.o.o. Belgrade, as part of the contract for the construction of the 35/10 kV substation “Zaječar 4”, prepared complete design and technical documentation, obtained a building permit and approvals from all competent institutions in accordance with legal regulations, carried out complete architectural/construction works, and delivered and installed electrical power equipment.

The new transformer station has a voltage level of 35/10 kV, with an installed capacity of 2 x 8 MVA.

In the first phase, two power transformers with a capacity of 4 MVA, a transmission ratio of 35±2×2.5%/10.5 kV, and a Dyn5 coupling were installed.

The transformer station is built on a fenced plot and consists of:
– control and operation building – a free-standing, brick building housing 35kV, 10kV switchgear, self-consumption equipment, telecommunications equipment and equipment for measurement, protection, monitoring and control;
– outdoor part of the transformer station – two 35/10kV, 2x4MVA power transformers, foundations, transformer supports, tanks, oil pit, cable ducts, access roads and associated installations.

The 35 kV switchgear is a type-tested, air-insulated, metal-clad, metal-enclosed medium-voltage switchgear for indoor installation, with one system of sectionalized busbars, and consists of 7 free-standing metal-enclosed cells with vacuum interrupters, namely 3 water, 2 transformer, 1 coupling, 1 additional coupling cell.

The 10 kV switchgear is a type-tested air-insulated switchgear, for indoor installation, with one system of sectioned busbars, and consists of 15 free-standing cells, namely 6 outgoing cells, 2 outgoing cells (prepared for billing metering), 2 transformer cells, 2 metering cells, 1 cell with a house transformer, 1 connection cell and 1 additional connection cell. All cells are equipped with connection, switching, busbars and low-voltage compartments, equipped with vacuum circuit breakers with withdrawable parts, earthing switches, current and voltage transformers, capacitive voltage indicators, as well as microprocessor-based protection and control relays and test sockets in the LV compartments of the cells.

Two power transformers with a capacity of 4 MVA, a transmission ratio of 35±2×2.5% / 10.5 kV, Dyn5 coupling, natural air cooling, were installed and connected.