Dospat Vacha Hydro Power Cascade

Dospat-Vacha Hydro-Power Cascade commissioned between 1958 and 1965

During this period the Kozloduy nuclear power plant was constructed and commissioned on the Danube (1974). Its initial capacity consisted of 2×440 MW VVER-440 reactors. Later on it was extended by another 2×440 MW reactors of the same type. In 1987 Unit 5, VVER-1000 with a capacity of 1000 MW was commissioned, and in 1991-Unit 6 of the same type. Thus the total capacity of Kozloduy amounted to 1760+2000 = 3760 MW. Its annual output is presented in Table 14.

During the period reviewed here, the electric power generated by Kozloduy NPP reached 35.6% of the total power generated in the country (1989), and in the recent years its share has exceeded 40%.

The construction of a second nuclear power plant also was begun on the Danube-Belene NPP. However, after considerable progress of the construction, it was stopped and has not been continued.

The 220 kV overhead transmission line ring: Aleko-Maritsa East-Dobrudja-Gorna Oryahovitsa-Aleko was completed in 1971.

Transmission network

During that period a 400 kV transmission network was constructed-comparatively big for the scale of Bulgaria. It was developed according to the “closed loop” pattern, like the 220 kV and 110 kV networks, and was completed in 1984. At the same time, interconnection lines for such voltages were also built with the countries listed below:

Varna TPP, commissioned in 1969-overall view Varna Substation 750/400 kV, commissioned in 1987 Varna Substation 750/400 kV -transformer area Varna Substation 750/400 kV- 750 kV switchyard 750 kV overhead transmission line to Varna Substation

The related power supply substations for 220, 400 and 750 kV were also constructed, as well as a considerable number of substations for 110/10-20 kV (Table 15).Substations ft transformers diagram of the 400 kV and 220 kV transmission system in Bulgaria, 1980