Electrical breakdown strength of 5 kV XLPE cable with imperfections under combined AC-DC voltage

This paper presents data on electrical breakdown strength of 5 kV XLPE cable with imperfection under AC voltage, DC voltage and superimposed AC upon DC voltage (pulsate voltage). In the later case, the measurement was taken over a wide range of pulsate ratio, which is defined as p=Vac/Vdc. Comparison with the former measurement results for sound cables shows that the pulsate voltage can be used to detect the imperfections inside XLPE cable. Based on past research, the results obtained under combined AC plus DC voltage follow an expression which relates the breakdown voltage to the sum of the arctangent and arccotangent function of the parameter “p”