The project will start with identifying the voltage control challenges in the future Danish and Swedish power systems. The Eastern Danish power system will be particularly of interest because the grid strength is relatively low and there will be voltage issues with the future wind power development. Sweden has future challenges concerning voltage stability when the nuclear power stations will be dismantled.

Having voltage control challenges identified, a predictive hierarchical voltage control scheme will be developed to mitigate the voltage fluctuations, minimize losses, and optimize the dynamic var reserve in the system by systematic optimization and coordination of wind power plants, reactive power compensation devices and on load tap changers. The impact of the communication and coordination of different voltage control resources will be studied and a coordinated scheme will be proposed.

The stability issue of temporary over voltage and oscillation will be studied. The mechanism of the voltage instability of the future power system will be studied and the coordination and parameter tuning method will be developed to improve voltage stability in the system. The coordination of the predictive control and the control for stability will be developed to ensure there is sufficient margin for the stability control.

The proposed schemes and methods will be tested using the Eastern Denmark power system and a part of the Swedish power system. Both offline and real time simulations will be conducted to verify the effectiveness of the proposed schemes and methods.