PRELIMINARNA PROCENA GUBITAKA ELEKTRIČNE ENERGIJE U VETROELEKTRANAMA

Abstract

If you are involved in acquiring or investing in wind energy projects, it is crucial for you to estimate the Annual Energy Production (AEP). Thereby, the actual (net) AEP of a Wind Power Plants (WPP) is usually less than the theoretical (gross) AEP, due to several reasons such as: downtime for repairs, curtailment to protect the grid, inefficiencies of the rotor and drivetrain due to ageing, lower wind speeds compared to the expected wind speeds, wake effects (turbulance) of wind behind tubine, shutdowns due to lightning and icing, ect. This paper takes into consideration the electrical energy losses during estimated annual WPP production. The electrical losses preliminary evaluation is based on a power flow method for radial networks with representation of distributed Wind Turbine Generators (WTG) as an equivalent single-machine system. Accordingly, the electrical energy losses include the electrical infrastructure on-site of WTGs and the substation infrastructure up to the point of connection WPP to the grid. As specific of presented approach is in estimation of middle voltage (MV) cable losses which is based on thermo-electric model of cable losses (IEC 60287-1). Besides, in the order to quantify the annual losses in electrical energy, the applied methodology of electrical energy losses calculation is at normal operating voltage, unity power factor and WTG’s rated current, but based on estimated operating (equivalent) hours per year. In fact, the number of equivalent hours provides the number of hours (equivalent from the energy viewpoint) for which the WTGs are operational at its nominal power during one year. The electrical losses of WPP are usually limited in advance defined Employer Requirements. Later on, they must be estimated in WPP conceptual design phase, guaranteed in WPP construction phase and finally confirmed by Balance of Plan (BoP) Contractor in WPP taking over phase by Employer. The presented methodology can be used for those purposes.