METHOD FOR DETERMINING TECHNICAL STATE OF INSULATION OF A DIGITAL TRANSFORMER BASED ON PARTIAL DISCHARGE PARAMETERS Russian patent published in 2020 - IPC G01R31/12 

FIELD: electricity.

SUBSTANCE: invention relates to high voltage engineering and can be used for diagnostics of technical state of insulation of digital transformers based on parameters of partial discharges. In the method of determining the technical state of insulation of a digital transformer based on partial discharge parameters, a digital transformer provided with a resistive voltage divider, which is arranged in an insulating body comprising a grounded lower flange of conductive material, additionally equipped with capacitive element electrode and two inductive sensors, wherein the first sensor is connected to the electrostatic screen grounding circuit, and the second sensor is connected between the capacitance element electrode and the lower grounded flange; industrial frequency voltage is recorded by a resistive voltage divider, high-frequency voltage pulses are recorded by inductive sensors, performing analogue-to-digital conversion of industrial frequency voltage and high-frequency voltage pulses, for the first half-wave of digitized high-frequency voltage pulses, polarity is determined, by a condition of heteropolarity of the first half-wave of high-frequency voltage pulses, selecting a useful voltage signal at the first inductive sensor, calculating a maximum value in the first half-wave of the useful signal voltage, number of high-frequency pulses of useful signal voltages during period of industrial frequency voltage variation, apparent charge of partial discharges, maximum value of apparent charge of partial discharges during observation, average value of apparent charge of partial discharges during observation, average current and power of partial discharges during the period of industrial frequency voltage variation, energy of partial discharges; phase characteristics of impulse voltages of useful signal relative to initial phase of industrial frequency voltage are measured, from which value of partial discharge ignition voltage is determined, value of apparent charge of partial discharges during observation is compared with threshold value, according to the comparison results conclusions are made on the insulation state of the measuring transformer.

EFFECT: technical result is timely reliable and accurate determination of current technical state of insulation of digital transformers, high reliability of digital transformers.

1 cl, 2 dwg