High Current Arc Phenomena in Transmission and Distribution Lines and their Countermesures

Pressure Rises Due to Arc under Insulating Oil in Closed Vessel—Pressure Fluctuation of Depth Direction in Oil

“…Third, after that, oil flows on top of the arc according to the bubble behavior (expansion and contraction), and pressure in air and liquid phases fluctuates at a low frequency. This pressure fluctuation was reported under different names, such as "piston motion" [9] and "oil piston" [11]. These spike pressure and piston motion can be attributed to insulating oil flux.…”

“…Initial peak of these pressure pulses is proportional to primary arc power and is observed at a delay time corresponding to the sound velocity in the insulating oil and distance to the pressure sensor [7]. This pressure fluctuation was reported under different names, such as "piston motion" [9] and "oil piston" [11]. Second, on top of this, insulating oil around the arc decomposes into gases, thus a big pressure rise, referred to as "spike pressure" [9] or "dynamic pressure" [10] occurs in liquid phase.…”

“…From previous studies [7,[9][10][11], we conclude that pressure rise phenomena in a closed vessel, from arc ignition through its extinction, can be divided into three main types. First, high-frequency pressure pulses are observed in air phase at the moment of arc ignition.…”

“…First, high-frequency pressure pulses are observed in air phase at the moment of arc ignition. Second, on top of this, insulating oil around the arc decomposes into gases, thus a big pressure rise, referred to as "spike pressure" [9] or "dynamic pressure" [10] occurs in liquid phase. Therefore, one can assume that these pressure pulses pertain to pressure propagating in insulating oil rather than being related to oil flux.…”

“…Therefore, one can assume that these pressure pulses pertain to pressure propagating in insulating oil rather than being related to oil flux. Second, on top of this, insulating oil around the arc decomposes into gases, thus a big pressure rise, referred to as "spike pressure" [9] or "dynamic pressure" [10] occurs in liquid phase. Third, after that, oil flows on top of the arc according to the bubble behavior (expansion and contraction), and pressure in air and liquid phases fluctuates at a low frequency.…”