Uljabuouda vindkraftpark turbinmodellering och stabilitetsanalys
Power system stabilityTransient stabilityVoltage stabilityWind turbineWind power plantDFIGDynamic simulations
This master thesis has been performed at Solvina in Gothenburg for Skellefteå Kraftand Vattenfall Eldistribution. The aim of it is to investigate the consequences of theinstallation of a wind power plant on the mountain Uljabuouda in the vicinity ofArjeplog. Especially the impacts on voltage and transient stability are examined.Furthermore, the amount of extra strain on the voltage regulation equipment and theneeds for increased regulation capabilities are looked into.The wind power plant is planned to be built by Skellefteå Kraft and connected to a130 kV grid owned by Vattenfall Eldistribution. The work comprehends the followingmain parts:- Theoretical studies aimed at wind turbines and power system stability issues.- Modelling of the type of wind turbines assumed to be built on Uljabuouda.- Simulations of different operation cases and analysis of the simulation results.The results from the simulations show that, as far as voltage stability and extraworkload on tap-changers are concerned, the wind power plant does not, in anysignificant manner, worsen the present conditions. The problem of overloading theline between Arvidsjaur and Vargfors is also minor. During the worst year for whichmeasurement results have been obtained 7,4 MWh would have had to bedisconnected, which is practically nothing in comparison with the annual hydro powerproduction in the area, 250-300 GWh.Larger problems arise when it comes to the matter of transient stability. Thesynchronous generators in the system can during deep voltage dips, depending on thecircumstances, stay synchronized approximately 0.3 seconds. However, the undervoltageprotections on the predicted type of wind turbines trips after only 0.08seconds. This sudden trip makes the plant incapable of meeting Svenska kraftnäts(The Swedish TSO?s) demands on disturbance tolerance. To be able to fulfill thosedemands the protections are required to have an operation time of at least 0.25seconds for protection levels higher than 60 %.Recommended future works are proposed in this report.The report is written in Swedish.