Impact of non Coordinated MVAr Scheduling Strategies in Multi Area Power Systems

Interregional reactive power flows are rarely a decisive issue for transmission system utilities operating on interconnected systems. However, economic constraints and increasing stress on interconnection lines may lead to recurrent conflicts, which could be avoided with a better inter-utility coordination. This paper exposes a method for evaluating the impact of multi-utility MVAr scheduling. This method is illustrated with an IEEE 118 bus system with 2 separately controlled regions, whose MVAr scheduling objective is different. The regional scheduling process is described and the state of the interconnected power system is compared with a global optimization. Differences from global optimal solution are highlighted for active power losses and reactive power reserves.