ON SITE ASSESSMENT OF THE INSULATING CONDITION IN HIGH VOLTAGE ELECTRICAL EQUIPMENTS USING HIGH VOLTAGE AT VERY LOW FREQUENCY

摘要

This article describes a new programmable cable and electrical equipment test and diagnostics system with an integrated dissipation factor (DF) and partial discharge (PD) measurement and several field test results for the assessment of the insulating material condition. Based on a very low frequency (VLF) 80 kV HV sinusoidal source the system is capable of producing an integral assessment of the condition of the insulation and on the other hand the detection and location of single defects in the tested equipment at a nondestructive test voltage level. Defects can be measured in their magnitude of partial discharges and located with the time domain reflectometry method. The HV dielectric test, the dissipation factor and partial discharge measurement is displayed with time sensitive evaluation as diagnostic parameters and is all integrated into a single test apparatus.