Due to slow speed of contact movement of a disconnector, multiple restrikes/reignitions occur during switching bus charging currents by it. Typical simulated voltage wave form of the load side (capacitance) voltage is shown below. During switching off, the final trapped voltage in the capacitance is below 1 p.u. in the example. The value is affected by the electrical asymmetry of the contact (difference of discharging voltages of positive and negative polarities), speed of the contact movement, scattering of the discharging voltages, point on wave timing of the initiation of the contact movement, etc.
Huge number of simulation calculations are, generally, done to obtain the histograms of distribution density of the trapped voltages, where, parameters above shown are varied introducing also random numbers for scattering controllings. Generally, 10 thousand of simulation calculations are necessary to obtain a smooth shaped histogram.
* Bold curves in the histograms correspond to the results by equations (11)----(15)
