Suppression Method of Voltage Flicker by Automatic Adjustment of Feedback Gain in Frequency Feedback Method with Step Injection of Reactive Power of PCSs

Voltage flicker has been increasingly observed due to the large-scale integration of photovoltaic generation. This voltage flicker is occurred often due to the frequency feedback method with step injection of reactive power which is one of the islanding detection methods of PCS (Power Conditioning System). In this paper, the method is implemented in multiple experimental inverters to replicate voltage flicker. Furthermore, a voltage flicker suppression method is proposed in which the feedback gain is automatically adjusted according to the frequency deviation, and its effectiveness is verified through case studies. In addition, the authors verify the optimal placement and number of PCS units incorporating the proposed method.