Mobile QR Code QR CODE : The Korean Institute of Power Electronics
Title Reactive Power P&O Islanding Detection Method using Positive Feedback
Authors Jong-Won Lee ; Sung-Youl Park ; Jae-Yeon Lee ; Se-Wan Choi
Page pp.410-416
ISSN 1229-2214
Keywords rid-connected inverter; Anti-islanding; RPV(Reactive Power Vvariation); Positive feedback
Abstract A grid-connected inverter with critical loads uses mode transfer control to supply stable voltage to the load. An islanding detection method should also be used to quickly detect the grid fault and disconnect the inverter from the grid. However using the existing islanding detection method to detect islanding is difficult due to the small fluctuation of the voltage and frequency of the point of common coupling. This study proposes a reactive power P&O islanding detection method by using the positive feedback technique. The proposed method always injects a small variation of reactive power. When a grid fault occurs, the injected reactive power accelerates the reactive power injection reference. As a result, the reactive power reference value and the sensed reactive power become mismatched, and islanding is detected. Reducing the amount of real-time injected reactive power results in high efficiency and power factor. The simulation and experimental results of a 3 kW single-phase inverter are provided to verify the proposed islanding detection method.