Small Hydropower Plant “Osanica 4”


Based on its characteristics, the small hydroelectric power plant “Osanica 4” is the most profitable power plant on the Osanica River. The company “Eco Energy” has won a concession to build it and has developed the project documentation. In the hydroelectric power plant, a management system has been set up that is based on programmable logic controllers and the SCADA system that allows automatic operation of the plant when unmanned, automatic and manual operation when manned, remote management and control of any point via a modem connection, remote control via GSM modem etc.

Main characteristics of the hydroelectric power plant “Osanica 4”
Drainage area: 16.7 km²
Average annual flow: 0.520 km²
Installed flow: 0.700 m³ / s
Usable flow for a given installation: 0.334 m³/s
The degree of liquidity: 0.64
The upper water height: 740.48 masl
The lower water height: 629.33 masl
Gross head: 111.15 m
Net head: 105.0 m
Installed plant power: 0.630 MW
Possible annual production of electricity: 2.5 GW

Geographical locationj
The Osanica River is located in the Goražde region and its course includes the Goražde and Foča municipalities. The river Osanica is created by the merging of the Trudanj and the Trševina streams at the elevation of 740 masl. It flows into the Drina River below the village Bogatići at 365 masl near the locality of Osanica. The total length of the flow is 16,750 meters with a vertical drop of 375 m and an average decrease of 22.5 m/km. On the river Osanica, the construction of five small hydro power plants was planned, two of which are of the cumulative-diverting type, with a total power of 3.5 MW and an annual production of 13.48 MWh.
Description of the water intake and the headrace
This is a flow diversion type of a plant. The water intake is located at the mouth of the streams Trudanj and Trševina, at the height of 740 masl, and the operator is located at the height of 629 masl. The water intake is done at the bottom, i.e. by the Tyrolean type of water-intake with a settling-tank. After settling, the water sinks to the surge tank via a derivation reinforced concrete channel of the length of 1536 m. The water is then taken from the surge tank to the powerhouse, via a penstock of the length of 290 m and a diameter of 700 m.
Electro-mechanical and hydro-mechanical equipment
A one unit solution has been adopted. Generator voltage is 0.4 kV. The connection to the electricity network is performed by connecting to a 10 kV transmission line through a transformer. The turbine is of the four jet horizontal Pelton type. The turbine controller is electro hydraulic with the following functions: speed control, steering opening, power managing, speed of management control, delay in case of emergency, monitoring, and alarm. The generator is of a three-phase asynchronous type with rotating excitation, the nominal voltage of which is 0.4 kV and the nominal power of 800 kVA, 750 r/min. The management system is based on programmable logic controllers and a SCADA system which is installed on a personal computer.
The management system is designed to allow: automatic operation of the plant when unmanned, automatic and manual operation when manned, remote control and monitoring from anywhere via a modem connection, an ordinary telephone line, a computer on which SCADA is installed, remote monitoring via a GSM modem, operation parallel to the net as well as isolated operation. Electricity metering is provided on the medium voltage. A monorail crane of 50 kN capacity has been provided in the powerhouse due to the weight and dimensions of the electromechanical equipment. In the distribution network, the plant is connected to the transmission line of nominal voltage of 10 kV, 200m away from the powerhouse.
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