Purchase and installation of electrical equipment for reconstruction of PP Đurići 35/6 kV

The purchase and installation of electrical equipment for reconstruction of PP Đurići 35/6 kV was carried out from February to December 2019 at Tara Mountain, Zaovine, under investor JP EPS Beograd, Ogranak Drinsko-Limske HE Bajina Bašta (Branch of Drinsko-Limska Hydro-Power Plant Bajina Bašta). The role of PP “Đurići” is to pump the water collected in the Spajići Lake into the Zaovinsko Lake, in order to use that water later for the production of electricity in RHE “Bajina Bašta”.

Three motors of 800 kW each are used to pump water into the Zaovinsko Lake. The pumping plant is supplied from TS Metaljka located on Tara. Power is provided via a 35 kV cable. An energy transformer has been installed in the pumping plant, which transforms 35 kV voltage into 6 kV, which is suitable for connecting pumps.

The project documentation defines the basic concept for the adaptation of the 35/6 kV substation and the pumping station (3×800 kW, 6 kV). The adaptation of the Đurići pumping plant included the dismantling of existing power transformers, 35 kV and 6 kV switchyards and self-consumption equipment, the installation of new equipment consisting of a power transformer, a 35 kV gas-insulated SF6 plant, self-consumption equipment, control equipment, and 6 kV MV plant with medium voltage soft-starter device for starting pumps.

The purpose of the soft-starter is to start and to stop three motors, according to the program implemented in the control system, in accordance with the planned operation of the pumping plant.

After the installation of the new equipment, detailed adjustments of the equipment parameters, functionality tests, and implementation of remote control were performed, thus communication with the central command of the SCADA system of HPP “Bajina Bašta” has been achieved.

Due to considerable dilapidation and long-term exploitation, the reconstruction of PP Đurići is planned, where instead of the existing way of starting pump units (direct starting), a solution of “soft starting” of pump motors was introduced using a medium voltage soft-starter 6 kV, as a multi-motor starter which enabled significantly less shocks to the mains when switching on the pumps.

PP “Đurići” is located on the mountain Tara near the Zaovine Lake. In addition to the pumping plant, there is another lake called Spajići, which was formed by dividing the river Beli Rzav.