Analysis of Effective Factors in Voltage Positive Feedback Islanding Detection Methods on Small-Signal Stability of Inverter-Based Distributed Generation Units

The quick islanding detection is an important issue in utilizing distributed generation (DG) systems. The main aim in using voltage positive feedback method is to make DG systems unstable underislanding-mode event. The measured parameters (voltage or frequency) in this instability become out of boundaries quickly and the protective relays simply identify the islanding mode. On the other hand, the voltage positive feedback method can lead to unwanted instability in grid-connected case. This paper analyses the effect of voltage positivefeedback method on the DG systems stability in grid-connected mode which is considering less. This work also discusses the impacts of different parameters such as DG control method (power constant or current constant), DG location and local load level.