In this paper, we consider an interconnected power system, where the different Transmission System Operators (TSOs) have agreed to transferring some of their competences to a Centralised Control Center (CCC). In such a context, a recurrent difficulty for the CCC is to define decision-making strategies which are fair enough to every TSO of the interconnected system. We address this multiobjective problem when the objective of every TSO can be represented by a real-valued function. We propose an algorithm to elect the solution that leads to the minimisation of the distance with the utopian minimum after having normalised the different objectives. We analyse the fairness of this solution in the sense of economics. We illustrate the approach with the IEEE 118 bus system partitioned in 3 areas having as local objective the minimisation of active power losses, the maximisation of reactive power reserves, or a combination of both criteria.