Coordinated reactive power control of single-phase grid-connected converter for distributed energy resources integration considering multiple functionality conflicts

To reduce the consumption of non-renewable energy in the building sector, single-phase grid-connected voltage source converter (VSC) has been widely used to integrate distributed energy resources (DERs) into the building electrical network. As the increasing penetration of DERs into the electrical power system, new grid codes require the DERs should become more interactive and flexible while operating with the utility grid. Some functionalities may include grid fault operation and support capabilities, such as fault ride through, Volt/VAr support, etc. However, these new advanced functions might bring functionality conflict with the existing functions, such as anti-islanding protention. In this paper, the behaviors of single-phase grid-connected VSC under various grid conditions, such as voltage sag and unintentional power outage, are investigated. Following the analysis, a coordinated reactive control strategy including grid status identification criteria development and reactive curve designing, is proposed to enhance the performance of the converter on descriminating various grid status with multiple functionality conflict consideration. Simulation studies are presented to demonstrate the validity of the proposed control strategy.