This paper presents the reliability assessment of the southern part of Croatian transmission network and the influence of the wind farm on reliability indices. Croatian Electric Utility (HEP) Renewable Energy Sources with partner C.E.M.P. is developing wind farm in the region near town Knin. Wind farm will have installed capacity of 100 MW in the first phase. In the second phase additional 40 MW is planned to be installed. For the purpose of this paper, it was assumed that wind farm consist of the 50 turbine units, 2 MW each. Reliability assessment was performed, and reliability indices were computed for the case before and after construction of the wind farm. The reliability is analyzed using state enumeration method and NEPLAN software. Input data were obtained from annual reports of HEP TSO (Transmission System Operator) and statistic analysis of data was performed first. Since there are no statistical data for new cables and transformer stations that are constructed, input data for them were taken from the relevant literature. Probability of wind farm production level is taken from measured wind statistics. In reliability assessment Markov state space model of the wind generator, busbars, transformers, breakers and disconnectors was used. Load is modeled at the output substation busbars with maximum active and reactive power. The simulations are performed in order to calculate reliability indices before and after the construction of wind farm. Conclusions and comments on the results are presented at the end of the paper.

Elektrotehnika