Reactive Power Optimization in Regional Power Grid Considering Voltage and Reactive Power Characteristics of Boundary Buses

The power supply of regional power grid is a substation that connects the upper and lower grid. REI equivalent is applied in voltage and reactive power optimization to the problems of the conventional model. The relationship between the equivalent reactance which can effectively reflect the voltage and reactive power characteristics and the voltage/reactive power sensitivity matrix is deduced, and the time-varying characteristic of equivalent reactance is analyzed. The method, which firstly obtains the equivalent reactance according to the voltage/reactive power sensitivity matrix using local data and secondly revises the optimal voltage according to the fixity of the voltage error, is proposed. Thereby, it not only can maintain the coherence of power flow before and after the equivalent but also can reflect the voltage and reactive power characteristics effectively. By the simulations for the IEEE 9-node model combined with a real regional power grid network, it is verified that the method is effective and practical.