Insulation strength test method for long-distance power cables in particular
Very Low Frequency (VLF) Hipot Test is a specialized insulation strength test method for high-voltage cables, especially long-distance power cables. It uses an extremely low frequency AC voltage (typically 0.1 Hz, i.e., a sine wave, cosine square wave, or sine square wave with a period of 10 seconds) to replace the traditional power frequency (50/60 Hz) AC withstand voltage test or DC withstand voltage test. The following is a core analysis of the VLF hipot test: 1. Why is VLF testing needed? (Background and Pain Points) In power cable testing, traditional methods have obvious drawbacks: Power frequency AC withstand voltage (50Hz): For long cables, the capacitance is very large. According to the formula
