<Development of a DC arc model for faults in DC equipment and DC power systems>
When a short-circuit arc or ground-fault arc (parallel arc) occurs in a DC circuit, the current value increases significantly, making detection easy. However, when a series arc occurs in a DC circuit due to loose terminals or minute wire breakage, the current value decreases only slightly, making detection difficult. To prevent public accidents caused by such arcs in DC circuits, we are conducting basic research to develop a detection technology for series arcs.
<Development of Verification Methods for Short-Circuit and Arc-Resistant Performance of DC Power Equipment>
In the IEC standard for HVDC power equipment that is currently being established, it is being considered to conduct an alternative test using AC. As a first step in studying the basic conditions for such alternative tests, we are comparing the resistance components of copper cylindrical conductors when energized by AC and when energized by DC.
*Y. Shigemura, Y. Yokomizu, M. Iwata, N. Kodama, M.S.S. Danish: “Variation of Resistance Components of a Cylindrical Conductor of AC and DC Energization —Towards Development of Verification Method for Short-Circuit Performance of Electric Power DC Equipment—”, Tokai-Section Joint Conference on Electrical, Electronics, Information, and Related Engineering, D4-5, Online, Japan (Aug.2022)