DIAGNOSTIC METHOD AND DIAGNOSTIC DEVICE FOR DETERIORATION OF HIGH-VOLTAGE POWER CABLE

摘要

PPROBLEM TO BE SOLVED: To provide a method for diagnosing a deteriorated condition of a high-voltage power cable by detecting a weak higher-harmonic current caused by water tree deterioration. PSOLUTION: This diagnostic method has: a physical quantity detecting means 2 for obtaining a physical quantity correlated with a zero-phase current superposed with the higher-harmonic current flowing through the high-tension power cable 1 in three-phase collective current measurement; a zero-phase current component removing means 3 for removing a component correlated with a zero-phase current flowing through the high-tension power cable 1 out of the physical quantities obtained by the physical quantity detecting means 2; and a current measuring means 4 for finding the higher-harmonic current flowing through the high-tension power cable 1, based on the physical quantity from which the component correlated with the zero-phase current flowing through the high-tension power cable 1 is removed by the zero-phase current component removing means 3. PCOPYRIGHT: (C)2007,JPO&INPIT