Infrastructure facilities

Donji Andrijevci SS 110/20(10) kV

Donji Andrijevci SS 110/20(10) kV is located north of the Donji Andrijevci – Čajkovci road and connected to the transmission network via the 110 kV transmission line Donji Andrijevci - Slavonski Brod and 110 kV transmission line Donji Andrijevci - Đakovo. Those transmission lines are two-system transmission lines. Free space has been provided for the possibility of additional construction of two more 110 kV transmission bays.

At the 110/20(10) kV Donji Andrijevci SS, in the 20 kV plant, 11 20 kV cable bays have been built: two 20 kV cable bays for the connection of 20/0.4 kV transformer substations along the motorway, six 20 kV cable bays for the connection of 20/0.4 kV transformer substations of Hrvatska elektroprivreda, and three back-ups.

The 110 kV plant is of a semi-high construction. High voltage devices and power transformers are located in the open space of an arranged plateau, while the corresponding secondary equipment is located in relay kiosks. The plants were constructed with two busbar systems.
The 110 kV busbars will be constructed with two main busbars systems (W1 + W2), ranging seven bays, with 450 mm2 Al/St rope.

The 110/20 kV power transformers have the power of 20 MVA each, with the regulation of voltage under load, reduced losses structure, with X and C tertiary ends, YNd5 connection group, transmission ratio 1100x1.5%/21(10.5) kV. The neutral point of the 110 kV transformer side is directly earthed.

The connection of the power transformers to the MV switchgear has been carried out by cable, and on the high voltage plant, by an air connection using Al rope.

The earthing of the zero point of the neutral point of the 110 kV transformer side was carried out without the ground connection, but with the possibility of separating the zero point connection.

The secondary network neutral point has been grounded via a transformer for 10(20) kV neutral point formation and a regulation compensation choke for the limitation of the currents of the earth short circuit for each transformer.

On the 110 kV plant plateau, two relay kiosks have been constructed, each of dimensions 12.1 x 7.1 m, in which, among other, the secondary system equipment has been installed. Such placement reduces the need for signal cables, and most of the functional connections have been made with electromagnetic interference-resistant optical infrastructure.

ZAGREB-SISAK HIGHWAY, Jakuševec-V. Gorica South section, 10(20)/0.4 kV TRANSFORMER SUBSTATIONS

Transformer substation marked SS 10(20)/0.4 kV 1x400 kVA with 5293 HAC Jakuševec designation has been built as a stand-alone facility along the Zagreb-Lipovac motorway, near the Buzin node. The SS includes 1 transformer, and a MV and LV distribution supply room.

Ploče SS 110/20(10) kV

The 110/20(10) kV Ploče (2x20 MVA) transformer substation has been constructed for the needs of the wider area of the city of Ploče (up to now, peak load of 12 MW has been achieved), new terminal at the Port of Ploče (the total peak load of the Port of 11.5 MW is expected), and for the needs of consummption on the Zagreb - Split – Dubrovnik motorway, Dugopolje – Ploče section, and the future Ploče – Opuzen section (where the construction of as many as 7 tunnels is planned).

The SS 110/20(10) kV Ploče transformer substation consists of a building and external plateau with roads, foundations and power transformer equipment. The building houses high and medium voltage facilities, auxiliary drives equipment, and monitoring, control and communications devices.

The power plant of the transformer substation consists of the following technical and technological units:
a 110 kV armored plant with SF6 gas insulations (GIS), 20(10) kV plant with sheet metal armored switch blocks and air insulation, 20(10) kV plant for reactive power compensation, auxiliary distribution and voltage transformation 0.4 kV, 50 Hz drives, devices for the generation and distribution of auxiliary voltage 110 V DC, other devices of the control, monitoring and communication systems.

The 110 kV plant is metal-armored, SF6 gas insulated plant with single longitudinally-sectioned busbars, with three transmission line bays and two transformer bays.

The connection of the transmission line and the transformer to the plant has been performed with cables with cross-linked polyethylene insulation and silicone cable ends.

The T1 and T2 transformers have been built in the open boxes next to the building. The transformer units have nominal power of 20 MVA. The transformers have been designed to regulate the voltage under load, and have the possibility of switching (10.5-21.0 kV) in voltage-free state.

The medium voltage plant is equipped with metal-armored prefabricated switch blocks for the highest operating voltage of 24 kV. The busbars are single, insulated, longitudinally sectioned.

The control and monitoring of the 110 kV plant is carried out remotely from the dispatch center of the Split Transmission Area, and the control and monitoring of the 20 kV plant is carried out from LCC Ploče, i.e. the patch center of Elektrodalmacija Split.