Abstract: A high gain, low distortion and high noise immunity high frequency current transformer, (HFCT) partial discharge sensor device allows obtaining a high measurement accuracy, with a self-check system for fixed monitoring of high voltage equipment and installations. The device includes a ferrite core; a first measurement coil wound to the ferrite core; and a first coaxial cable welded to the first measurement coil. The sensor device further includes a second auxiliary check coil wound to the ferrite core; an electrical resistance in series with the auxiliary check coil; a second coaxial cable welded to the electrical resistance; and an outer coating of resin.

Abstract: Method for evaluating and qualifying of the functional characteristics of PD measuring and diagnostic instruments, which comprises the following stages: generation (1) either from a scale HV testing setup (100) or from an arbitrary function generator of at least one PD reference pulse test series characteristic of a type of electrical defects representative of HV grids, generation of at least one electrical noise signal (9), superposition (14) without galvanic connection of one or more of the series of PD reference pulses generated corresponding to a specific functional characteristic of the measuring and diagnostic instrument for discrete values of charge and of the generated electrical noise signal(s), and Evaluation and qualification (15) of said functional characteristic of the measuring and diagnostic instrument, supplying the superposition of signals and reading to compare with the expected values.

Abstract: A method specially designed for detecting events associated with partial discharges (PDs) in high voltage cables includes the identification of the location and the evaluation of the amplitude and rate of repetition per period of the grid voltage, with the possibility of identifying different sources producing PD signals as a function of the location thereof and recognising the type of defect associated with PDs in the same location. Generated electric signals are measured and the discriminated in relation to the background noise. A system for carrying out the method includes devices for discriminating the noise in relation to the transient waveform of the PD, determining the parameters associated therewith, determining the map of sources of PDs along the length of the cable, graphically representing the sources, and identifying the patterns of the sources of PDs separated as a function of the location thereof along the length of the cable.

Abstract: A method for detecting events associated with partial discharges (PDs) in high voltage equipment and installations diagnoses insulation conditions in real time by using PD signal noise discrimination by the parallel use of multiprocessors, which are additionally used for the discrimination, in real time, of different PD sources located in a single position or in different positions. In order to identify the various PD sources, three-dimensional clusters are formed using the coordinates of three parameters characteristic of each pulse: the parameter associated with the front time of the impulse, the parameter associated with the tail time and the parameter associated with the pulse frequency. The diagnostic method can be performed with grid voltage or independent generators as a voltage source, and the invention particularly relates to a novel voltage source designed therefor. A system for the implementation of the method captures PDs, and performs the necessary analysis and measurement.

Abstract: A method specially designed for detecting events associated with partial discharges (PDs) in high voltage cables includes the identification of the location and the evaluation of the amplitude and rate of repetition per period of the grid voltage, with the possibility of identifying different sources producing PD signals as a function of the location thereof and recognising the type of defect associated with PDs in the same location. Generated electric signals are measured and the discriminated in relation to the background noise. A system for carrying out the method includes devices for discriminating the noise in relation to the transient waveform of the PD, determining the parameters associated therewith, determining the map of sources of PDs along the length of the cable, graphically representing the sources, and identifying the patterns of the sources of PDs separated as a function of the location thereof along the length of the cable.