"HPPs ON DRINA RIVER" Višegrad

Content:
° Exploitation by the beginning of the war
° Exploitation in the war period
° Exploitation after war
° Conclusion


Exploitation by the beginning of the war

In this period, solving of problems in assembling, constructive and planning problems were continued. Major lacks on construction, assembly of turbine, GIS etc, were noticed during repairs in 1991. Something was repaired, but a part of problems remained up to now.

The first unit was put in trial work and then in operation on 25.11.1989, the second in Feb.1990, and the third one in May 1990.

The production was going on without stoppage except for maintenance and GIS damage.

Stiffening of generator guide bearing was done after having proved that ejection of unit shaft at start was far stronger than it had been expected. New alignment of al three units was done with remark that the first one could not be put in satisfactory circumference due to big inclination.

Accordance with axis of the unit 3 was improved.

Accordance with axis is a big problem because of adopted solutions, i.e. a big number of joint spots: runner shaft-generator star; generator star-shaft extension; shaft extension-oil head.

Accordance with axis of the unit 3, was improved from 300 μ to 100 μ.

A special problem in exploitation is the leaking out of the water from reservoir under the dam corpse. This problem is still present. Leaking out arose from 1,4 m3/s (1991) to 12 m3/s (2004). This is a serious problem that needs to be solved urgently as for economical as well for technical reasons.

Exploitation in the war period

When the war broke out in BiH in April 1992, deliberate destruction of transmission lines started. HPP Višegrad had main connective line of 400 kV to Tuzla and 110 kV line Vogošća-Goražde. TL Tuzla was destroyed on 11.4.1992. Since then HPP Višegrad could not produce energy and did not operate until 25.12.1992.

A war incident when all bottom outlets were open and half of one gate on spillway must be mentioned. On this occasion 6.300 m3/s of water ran out and destroyed about ten houses in Dušće. The bridge on the Drina endured in spite of the fact that water level was supposed to arise one meter more and fill all outlets under arches.

In that period, a small HPP staff made efforts to save the units from floods (Kaplan-deeply flooded), providing Rudo with electric power of 35 kV and fuel for diesel unit (which continually worked during the war). They had often to repair powergrids and to look for solution for connection to the network.

The simplest solution was to lenghten the line Višegrad-Rudo toward Potpeć and connect it with TL 110 kV Potpeć-Pljevlja.

This was done by coming with one unit into grid and was finished on 22.10.1994, when TL 220 kV Višegrad-Vardište was put in operation and fit into 220 kV line Požega. After this date complete production could be placed into system.

Voluminous repaires of the unit 1 (repair of inclination) were done from April to November 1994, in total 7 months. This was done by ten workers without suppliers presence. The unit was put in tolerance as for inclination by installing instrumental plates under cone of thrust bearing. Thrust bearing pads were brought to "Lola Korp". However their processing was inproper, and process had to be repeated. Having them repaired, the unit was put in operation (spare thrust bearing pads were fit in later).

We want to stress particuliarity of processing of the trust bearing pads. Minimum number of people worked during the war, TL often needed repairs due to war destruction, diesel units operated and there were many problems in oil supply, providing service and acquisitions of reserve parts.

Since the power plant operated with Power Utility of Serbia, needs for energy were huge and management of the units was often inadequate.

Exploitation after war

Exploitation was going on regularly solving current problems as well as old ones. Repairs were done regularly. Repair of GIS was done after another grave breakthrough. Acquisition „SCADA” system, video-supervision system and the roof of the machine hall were installed. It lasted up to bombing of FRY. Since the HPP suffered serious grounded circuits, voltage grew over 460 kV and HPP worked sometimes partially supplying consumption to Kruševac.

Another problem was a low voltage at 400 kV grid so that excitation had to go on and it had to be started by manually.

Since the beginning of its work up to 31.12.2006. HPP produced 15.211.877.757 kWh what can be seen in the survey table.

Conclusion

HPP Višegrad fulfilled all main technical-technological tasks foreseen by design solutions, what was proved through its fifteen years of sucessful work. Planned power is realized and electrical power is produced. Avialability of the plant is on a high level. The major part of obligations, defined by urbanistic-technical conditions and demands has been fulfilled, especially in waterutility and ecological sense as well as in the field of traffic infrastructure solution. In this period HPP gave and is still giving by its activity, an important contribution to entire economic and social development of this area and the Republic of Srpska.