1990 Volume 110 Issue 2 Pages 138-146
We have carried out experimental study on the recovery characteristics of horizontal rod-rod air gaps after DC arc interruption.
The experimental conditions are listed below.
Gap length: ι0(m) 0.5 to 5.
Arc current: Iarc(A) 100 to 20, 000.
Arc duration time: Tarc(s) 0.1 to 0.3.
Impulse waveform: Switching impulse (270/2, 500μs, up to 1, 340kV)
Impulse applied time after arc interruption: T1mp(s) 0.07 to 0.45
The main results are summerized as follows:
(1) In the most severe conditions such as windless, about 4, 000 A in arc current and about 0.1s in arc duration, the switching impulse withstand voltage V1mp in kV after DC arc interruptions can be discribed as;
where, αυ(kV/s) and T0(s) are experimental constants.
(2) The minimum time TRCL to be required for restarting after the arc interruption of 4, 000 A on the 500kV DC line can be simulated as;
wher, Tυ(s) is a constant determined by the line voltage to ground and the gap length and τ (s) is a starting time constant settled in the DC system, for an example TRCL=0.1s in a 500kV line.