Under
the term ‘‘damped alternating voltage’’ (DAC) (IEC 60060-3:2006), this bipolarly
oscillating voltage is successfully used for diagnostic PD measurements on
medium-voltage cable systems, but the whole test stress for the cable is a long DC
ramp (duration in the order between 1 and 100 s) followed by the much shorter
DAC voltage (duration in the order of few 100 ms).