抄録
The developing mechanisms of the positive corona streamers on the insulation surface affected due to the nanosecond rise time of impulse voltage wave have been studied by using the dust figure method. By applying short rise time of impulse voltage of 12 to 120ns to a needle point where a glass plate is sandwiched in between the needle and plate electrodes, the diameters of the discharge pattern were measured against the relation between rise time and applied voltage. From the experimental results, it is found that irrespective of the positive applied voltage maintaining a constant of peak value the size of circular discharge patterns reduces with increasing the rise time of 12 to 120ns,and also that irrespective of the applied peak voltage being increased from 6 to 12kV the size of circular discharge patterns holds a constant in the range of the rise time of 12 to 120ns. It is concluded that the experimental results are strongly depending on the Fractal character because the circular discharge patterns recorded are decided due to the charge quantities accumulated at the tip of needle just before the initiation of corona streamer.
