In order to investigate the electrical characteristics of the voltage-current and the morphologic development of secondary arc

we built a low-voltage simulative experimental platform of secondary arc for UHV transmission lines without compensation.On the basis of the experimental platform

the electrical characteristics of the voltage and current were analyzed

involved with development rules of transient process

discharge power

and discharge energy of the secondary arc.When the secondary arc current is 10 A and 30 A

the maximum range of discharge power is in the range of 2

3

MW and its duration is about 0.27

0

.38 s.When the discharge is over

the discharge energy of 10 A or 30 A secondary arc is greater than 9×10

9

J.In addition

binary mask image was processed

and the centroid

the arc length and the arc radius of the secondary arc were also analyzed.The centroid trajectory quantitatively describes the movement of the arc column

on the basis of the centroid trajectory and the force analysis of current element in cascaded chain model for secondary arc

the secondary arc shifts overall horizontally under the effect of the electromagnetic force and rises vertically mainly under the effect of the thermal buoyancy.By comparing the experimental results and computational results

the arc length does not exceed the corresponding maximum computation value of the arc length at arc extinction time.The experimental results of the arc radius is also consistent to its computation results in the order of magnitude.