Applicability of IEC 60270 for Partial Discharge Measurements under DC Voltage - Results of a Round Robin Test

PD measurements during AC voltage stress are well known and approved since many decades and are performed today in accordance with the international standard IEC 60270. PD measurements during DC voltage stress become more and more important due to the increasing use of HVDC transmission systems, but the experience and also the information concerning this method in the IEC 60270 is less comprehensive. Therefore it is necessary to investigate the applicability of the IEC 60270 on PD measurements in the case of DC voltages. For the investigations a series of PD measurements have been done at DC as well as on AC voltages on insulators, which were made out of cast resin. The PD measurements have been performed according to IEC 60270 as a round robin test in three independent high voltage laboratories. In this paper the results of the round robin test are summarized and evaluated in order to discuss the applicability of IEC 60270 for PD measurements at DC voltage. Based on the results a discussion is started concerning possible modifications of the IEC 60270 for its use on PD measurements during DC stress.