Evaluation of reactive power compensation on voltage stability and NTC values in the Swedish transmission network

Abstract

In this paper, the voltage stability of the Swedish grid is studied by a twofold approach. Firstly, the loads within Sweden are increased and the effect on the voltage of the tie-line buses is examined. Secondly, the exchanging of power between the two neighboring countries, Denmark and Finland, is taken into account. The main objective of this paper is to show that different reactive power compensation scenarios within the Swedish network and also in the vicinity of the tie-lines will improve the voltage stability of the whole system and also will increase the maximum power transfer on the tie-lines. With the method of this paper, we will be able to suggest the best places where the reactive power compensation can improve the voltage stability. Finally, an optimization problem for installing reactive power compensation from economic point of view is formulated. The CIGRÉ Nordic 32-A model has been used as test system and all the simulations have been done in PSS/E and Matpower.