Voltage stability analysis of electricity networks with DFIG-based wind power plants

In recent times there has been a drive for renewable energies like wind, solar, bio fuels, geothermal and wave to be researched and developed as the next generation forms of electricity generation. Amongst these renewable energies wind has shown considerable promise and as result the amount of electric power generated by wind has grown considerably in recent history. This increase in wind power can have adverse effects on the power systems on which these wind power systems are connected to. This is due to the limited reactive power compensation of the DFIG which is widely used to generate electricity from wind resources as well as the stochastic nature of wind. In this paper a DFIG wind turbine model is developed. To test for the expected voltage stability as well as the expected power imported from the grid two algorithms are used that use the Weibull distribution to get the expected values. The two algorithms are then combined to form the wind integration factor (WIF) algorithm which is a method developed in this paper to determine the best points of integration as well as the levels of penetration without causing a loss of voltage stability. Simulations show that the algorithm is able to determine the optimum point of integration correctly but has limited capabilities in determining the optimum levels of penetration.