Research on the Effects of Voltage Support Functions on Islanding Detection Effectiveness of Distributed Energy Resources

With the rapid deployment of Distributed Energy Resource (DER), advanced inverter functions such as voltage support have been developed. However, with conflict control targets, the voltage support control is concerned to degrade the effectiveness of the islanding detection, which is yet fully investigated. Given the wide application of Slip-Mode Frequency Shift (SMS), this paper takes it as an example of islanding detection method. Firstly, the mechanism of islanded operation in a RLC island system is analyzed, and the relationship between basic electrical quantities is explored. Then the small signal model of such islanding system with the voltage support and SMS control is constructed, and its eigenvalues and sensitivity to parameter change are analyzed to investigate the influence of voltage support on the effectiveness of SMS. Finally, HIL experiments are conducted to verify the above analysis. The results show that during islanded operation, the voltage support control enhances the islanding detection and helps reduce the islanding detection time. The key affecting parameters are identified as the droop gain of voltage support control, open-loop response time and SMS coefficient.