Patent ID: 9037438
Filing Date: 2015-05-19
Classification: G01R

Abstract:
1. A device for detecting and processing signals relating to partial electrical discharges in an electrical apparatus powered by a square-wave voltage modulated by a modulating wave in such a way as to form an alternating voltage of predetermined frequency, comprising: a sensor connectable to the apparatus for detecting a discharge signal representing the electrical pulses generated by the partial discharges; a processing unit connected to the sensor to receive the discharge signal and derive the detection instants of each of the pulses detected with respect to a predetermined time reference, wherein the device comprises: a synchronization module, designed to receive an electrical synchronization signal representing the power supply voltage and equipped with a filter configured for extracting from said power supply signal a signal representing the modulating wave, wherein the synchronization signal received from the synchronization module has a first contribution, relative to a square-wave voltage, and a second contribution, relative to the modulating wave and providing an alternating signal at said predetermined frequency lower than the frequency of the square-wave voltage, wherein the filter is configured for extracting said second contribution at said predetermined frequency; a voltage divider connected across the power supply and the filter, wherein the processing unit is configured for associating with the pulses detected the values of a phase parameter representing the phase of the modulating wave at the pulse detection instants.