Techno-economic estimation of reacitve power related additional losses inwind farms during reactive power supply

Decentralized energy sources (DER), such as wind farms, will play an increasingly important role in providing system services in the future. These include voltage maintenance through reactive power feed-in. In order to achieve an efficient reactive power provision there are already different optimization algorithms, which, among other things, take into account the resulting grid losses during reactive power supply. However, in addition to losses in the public power grid, losses also occur within generation parks, which should be considered in an economic optimization. One challenge in the loss calculation of generation parks is that the information about the topology and loss behavior is usually not available. In this work, therefore, an approach is developed which reproduces the wind farm loss behavior in a whole grid region based on publicly available information. The developed approach creates reference models for the installed lines, transformers, and inverters. With these reference models, the losses within wind farms can be estimated for a known active and reactive power feed-in and thus be considered in a higher-level reactive power optimization. The model is validated against a real existing wind park in Germany. It can be shown that the loss behavior can be estimated by an accuracy of 5-10% in the specified feed-in range of the German grid code.