A distributed reactive power optimization method for multi-area interconnected power grid

This paper presents a distributed optimization method to solve the optimal reactive power flow (ORPF) problem of multi-area interconnected power grid. An external network reduced equivalent model is used to implement the ORPF calculation of each sub-grid. And the inter-area coupling constraint can be transformed into the injection power modified equation of external boundary bus afterwards. Therefore, the distributed solution of multi-area ORPF problem can be realized through updating of boundary bus equivalent injection power and voltage phasors. The proposed method avoids the tedious process of network equivalence and reduces the dependence on the coordination layer. Furthermore, it accords with the local feature of reactive power optimization and control properly as well. The numerical simulation results of several IEEE cases show that the proposed method is effective and suitable for online application.