Resilience of Digital Protection Relay's Power Supplies to Powerful Nanosecond Pulses
International Journal of Research Studies in Electrical and Electronics Engineering
There are several publications that study sources of high-frequency electromagnetic pulses at power industry facilities and their influence on a DPR      . It should be noted that these publications discuss Japanese DPRs and the issues of the power industry in Japan. I could not find any information regarding European DPRs. Moreover, regardless of my personal extensive work experience in power industry, I did not come across any significant issues with a DPR protection during
... otection during operation of highvoltage switching equipment in gas-insulated substations. It is weird to read that the use of such simple tools such as ferrite filters on control cables and additional absorbing capacitors on input terminals of a DPR and the printed circuit board of CPU  solved the problem of DPR's resistance to this kind of electromagnetic impact. One can assume that a Japanese DPR does not have any electromagnetic filters and circuits which suppress noise. Another Abstract: The article presents the results of testing the resilience of power supplies of digital protection relays to the effects of short high-voltage pulses. A strange fenomenon of the sensitivity of one of the relay types to standard nanosecond pulses5/50 ns with 1kV amplitude (EFT) and simultaneous resistance to more powerful standard microsecond pulses 1.2/50 µs with amplitude 6 kV µs was detected. By using standard EMC filters, it is not possible to increase the stability of this digital relay to EFT.