Coupling Characteristics of Active and Reactive Power in Power System with Renewable Integration

A universal functional method to express the coupling characteristics of active and reactive power is proposed in this paper using the coordinated dispatch model and polynomial fitting. The coordinated dispatch model of active and reactive power, as a more accurate operation model, is introduced to calculate the active and reactive power flow in multiple scenarios to show the global feature of the power system under the uncertainty of renewable generation. The polynomial fitting analyzes the active and reactive power flow data from coordinated dispatch and extracts a universal functional form to describe the coupling characteristics of active and reactive power in the power grid, which is applicable in any network with different structures and different resource configurations. This universal function is also validated in an IEEE-39 system.