Apparatus and method for measurement of moisture of transformer by using Return Voltage MeasurementRVM and characteristics of dielectric substance

摘要

A device and a method for measuring moisture using RVM(Return Voltage Measurement) and dielectric characteristics are provided to measure an internal moisture density or moisture concentration of a transformer reliably by measuring the characteristic of the transformer while changing the frequency of power or duty ratio in charging or discharging. A moisture measuring device using RVM and dielectric characteristics is composed of measuring electrodes(700,710) comprising plural pairs of inner and outer components of a transformer(900); a power supply unit(300) supplying power to the measuring electrodes; high-voltage relay switching units(600,610) switched on or off by the power of the power supply unit to charge the electrodes for the predetermined time and forcibly discharge the electrode in order by using the power fed from the power supply unit; a computer control unit(100) commanding short-off during a forcible discharge process and measuring the return voltage characteristic; a duty ratio regulating unit connected with the high-voltage relay switching unit to regulate the charging and discharging time; a dielectric characteristics measuring unit connected with the high-voltage relay switching unit to measure the dielectric characteristics while changing frequency of the power; and a PCI(Programmable Communication Interface) unit(200) connecting the output of the computer control unit to the high-voltage relay switching unit.