Improving Voltage Stability by Utilizing Reactive Power Injection Capability of Variable Speed Wind Turbines

N.R. Ullah and T. Thiringer (Sweden)


Renewable generation, variable speed wind turbine, power system stability, reactive power, ULTC.


The impact that wind turbines have on the voltage stabil ity is investigated in this paper. In particular, the effect of utilizing the reactive power injection capability of modern wind energy converters is investigated. It is found that reac tive power injection from the wind turbine can increase the voltage stability of the power grid substantially, as well as moderately increase the steady-state power transfer limit. For a high wind speed situation, where the wind turbine converter is fully utilized, it is found that it is worth reduc ing the active power production from the wind turbine in order to make room for reactive power injection, from a voltage stability point of view. An interesting observation is that a modern variable speed wind turbine constantly op erating at maximum power factor does not provide much voltage stability improvement compared to a traditional fixed-speed system under its usual operating condition, i.e. at lower wind speeds. The finding is that the worst case to handle, from a voltage stability point of view, is the case where there is a high load demand, irrespective of the wind speed situation.

Important Links:

Go Back