An Improved Voltage Waveform Comparison Protection Method for Microgrid Based on EDR

Due to the structural and operational characteristics of microgrids are dissimilar to traditional distribution network, the fault characteristics of microgrids are special, and there is a large difference in fault characteristics between the two operation modes of grid-connected and off-grid. In addition, distributed power sources are affected by the control strategy, and the fault characteristics presented are also different. Aiming at these problems, this paper proposes a microgrid protection method based on voltage waveform comparison, which determines the fault location by customizing the voltage reference point, eliminating the phase difference of the waveforms by combining with the EDR algorithm, comparing the voltage waveform similarity between the measurement point and the voltage reference point. The PSCAD simulation results demonstrate that the proposed protection method can exactly distinguish between internal and external faults in microgrids, exhibiting superior operational performance.