Experimental Study and Feature Improvement of DC Series Arc Faults with Switching Noise Interference

DC microgrids have the higher efficiency, higher flexibility, and lower cost than ac networks due to the fewer conversion stages. However, the protection of dc microgrids is still challenging because the limited ac protection technologies could be directly migrated to the dc system. For the sake of the human and equipment safety, the arc fault protection technology is one of urgently concerned aspects. In dc microgrids, arc electrical characterizations would be inevitably interfered by switching noises and higher system electric levels, making the arc fault detection more challenging.In this paper, dc series arc faults under the background of different switching noise interferences are conducted through the designed experimental platform firstly. Having analyzing arc faults with the single and multiple switching noise interference sources based on the signal separation method, the influence of switching noises on arc electrical characterizations is discussed. For arc faults with these inference factors, the existing arc fault features used in the resistive system indicate some limitations, leading to new arc fault detection difficulties. Finally, corresponding measures are taken to give the larger arc fault time discovery pulse and better separated arc fault states. The enlarged arc fault differences are of great benefit to improve the detection effectiveness in these complicated scenes.