Adaptability Analysis of Directional Element for Inverter Interfaced System Considering Fault Control Strategy

Due to the fragility of power electronic devices and controllability of grid-connected inverters, photovoltaic power plants change the fault current characteristics of transmission lines, resulting in adaptability problems for various directional relays based on traditional synchronous power supply fault characteristics. In this paper, the phase Angle variation of the side sequence impedance of a photovoltaic power station is deduced by considering the control objective of negative sequence suppression. Its influence on the directional element based on the sequence component is analyzed. Set up a photovoltaic power station in the PSCAD/EMTDC simulation platform, test and verify sequence impedance Angle changes on the traditional direction element adaptive problems.