Rated AC voltage (UN)
Maximum operating peak recurrent voltage of either polarity of a reversing type waveform for which the capacitor has been designed.
Rated DC voltage (UNDC)
Maximum operating peak voltage of either polarity but of a non-reversing type waveform, for which the capacitor has been designed, for continuous operation. Damping capacitors, for gate turn-off thyristor (GTO) can be regarded as d.c. capacitors with a ripple voltage equal to the rated d.c. voltage UNDC = Ur.
Ripple voltage (Ur) Peak-to-peak alternating component of the unidirectional voltage.
Capacitor voltage limitation