Connection of HPP Dub and HPP Ustipraca (22 MVA) to the EPS of Bosnia and Herzegovina

Objective of the Study is connection of new small hydro power plants HPP Dub and HPP Ustipraca (estimated power 20MW) to the transmission network of Bosnia and Herzegovina, taking into consideration transmission development plans of 400, 220 and 110kV network until 2011 and 2013. Objected hydro power plants (HPP Dub 2x6MVA and HPP Ustipraca 2x5MVA) shall be put into operation in two stages, during 2011 and 2013. In accordance to that all analyses were performed for those two years.

Study of technical solutions and connections hydropower plants Dub and Ustipraca, located on Praca River, is made from the aspect of marketing strength and electricity in EES BH, security and respecting the criteria of least cost of building connections. Power plants will be connected to the transmission network through a common SS 110/10kV Dub.

There were analyzed three different variants of connection to the transmission network:

1. connection to the existing 110 kV OHL Visegrad - Gorazde 2 by input / output principle
2. connecting to the 110kV network with a double (on the same tower) 110kV OHLs to the SS Gorazde 2
3. connecting to the 110kV network with one 110kV OHL to the SS Gorazde 2

For each variant, load flow, voltage profile analyzes and assessments of investment costs were performed, based on which the potential variant is proposed. In other words, the proposal that meet both, the technical requirements of connecting and low investments, is given. On the basis of the proposed variant, parameters of block transformer (power, ratio, regulation) and generator power factor are defined. Calculation results pointed out to a certain level of increase in the value of short circuit and their impact on existing and new equipment of lines and transformer stations.

Static stability analyses (for small disturbances) have been performed with analysis of eigenvalues. As a result of the analysis of the stability of small disturbances, Study has provided the basic parameters of generators and block -transformer on the site of connection and an estimation of static stability and the possibility of synchronization power in the expected conditions is given.

Type of services provided:

• Definition of parameters of block transformer (power, ratio, regulation) and generator power factor
• Load flow and voltage profile studies
• Static security analyses
• Techno-economical aspects
• Short circuit analyses according to IEC 60909
• Auxiliary supply analyses
• Static stability analyses