Comparison of Insulation Cable Voltage Withstand Testing Requirement Using Very Low Frequency Test Methods According to IEC and IEEE Standards

The voltage withstand testing of cables insulation used in the electrical systems of the Provincial Electricity Authority (PEA) after installation is a crucial part of cable testing. It ensures the reliability and safety of cable usage and enhances the stability of the electrical system. Currently, the voltage withstand testing of cable insulation in high voltage distribution systems of 22 kV and 33 kV can be performed using AC testing known as Very Low Frequency (VLF) testing, according to international standards. The standards specifying the use of VLF for cable testing are IEC 60502-2:2014, IEC 60060-3:2006, and IEEE 400.2:2013. Additionally, VLF testing can measure the dielectric loss factor (tan $\delta$) to assess the condition of the cable insulation and partial discharge levels. Consequently, VLF testing for cable insulation voltage withstand has been widely accepted by many electrical utilities. This article presents a significant comparison between IEC standards (IEC 60502-2:2014, IEC 60060-3:2006) and IEEE standards (IEEE 400.2:2013), which are international standards referenced for voltage withstand testing of cable insulation in 22 kV and 33 kV high-voltage distribution systems using Very Low Frequency (VLF) testing methods. It compares the differences between the two standards by analyzing various requirements including voltage waveforms, voltage levels, and testing duration for different scenarios. Additionally, the article provides VLF cable testing requirements to help cable testers select the appropriate testing method for various cases.