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Title Probabilistic Analysis of Reactive Power Control Strategies for Wind Farms
Author Hethey, János
Leweson, Sofie
Supervisor Nielsen, Arne Hejde (Electric Power Engineering, Department of Electrical Engineering, Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark)
Holmstrøm, Ole (DONG Energi A/S)
Negra, Nicolas (Dong Energy A/S)
Institution Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark
Thesis level Master's thesis
Year 2008
Abstract The increasing wind power penetration in electrical power systems across Europe has led to rising grid code requirements concerning reactive power control by wind farms in order to meet the upcoming challenges for system stability, control and operation. Some of the important factors for the reactive power control strategy are the stochastic variations of wind and grid voltage which affect both the reactive power capabilities of wind farms and the reactive power support demanded by the grid code. This master’s thesis concentrates on developing a method for probabilistic analysis of reactive power control strategies for wind farms with the aim to analyse the impact of different strategies with respect to the expected annual energy losses, number of tap changer operations of tap changing transformers and voltage profiles within wind farms. Based on a literature study the different options for a probabilistic analysis were identified and a sequential and non-sequential Monte Carlo simulation and a so-called enumeration method were studied in further detail in a case study. For this purpose both the necessary data analysis and modeling have been carried out, and a model of a generic offshore wind farm was built in the power system simulation tool DIgSILENT PowerFactory. The investigations revealed important advantages of the numeration method with the main issues being reliable results for both annual energy losses and tap changes, the option to include data from several years as opposed to a time sweep simulation and by far the shortest simulation time. The proposed method was applied to analyse different reactive power control strategies, regarding the usage of different reactive power sources such as wind turbines, FACTS and reactors. This revealed differences on annual energy losses and number of tap changes and illustrated the importance of reactive power control strategies. These kind of studies are useful for analyzing future wind farms and their design with respect to reactive power control.
Admin Creation date: 2009-05-15    Update date: 2009-05-15    Source: dtu    ID: 242955    Original MXD