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Charge dynamics of partial discharges explored applying a chopped sequence

Florkowski Marek

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 5

art. no. e138817

EN

Diagnostic methodologies are of fundamental importance for operational strategies of electrical devices, both in the power grid and in industrial applications. This paper reports about a novel approach based on partial discharge analysis applied to high voltage electrical insulation. Especially dynamics of charges deposited by partial discharges is explored applying a chopped sequence. The applications refer to microvoids occurring inside solid insulating systems or at the interfaces, such as delaminations at the electrodes. The experiments were carried out on embedded voids having distinctive wall dielectric materials. The underlying physical phenomena of post discharge charge transport are analyzed. The assessment is performed using phase-resolved partial discharge patterns acquired applying a chopped sequence. The chopped partial discharge (CPD) method provides quantitative insight into post discharge charge decay processes due to deposited and accumulated charges fluctuations. The assessment indicator is based on comparing partial discharge inception angle between chopped sequence and continuous run. The experiments have shown that materials with distinctive surface conductivity revealed adequately different charge decay time dynamics. The detailed analysis yields time constant of walls charge decay for insulating paper equal to 12 ms and cross-linked polyethylene 407 ms. The CPD method may be further used to investigate streamer physics inside bounded cavities in the form of voids. The presented method provides a quantitative approach for charge non-invasive decay assessment and offers high potential in future diagnostics applications.

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Szacowanie czasu propagacji fal dźwiękowych w ośrodkach materialnych za pomocą metody Dijkstry

Perkowski Z., Gozarska K.

Roczniki Inżynierii Budowlanej

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2012

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z. 12

43--48

EN

A proposition of method enabling an estimation of wave propagation time from point to point (but without refection) in material media is presented in the work. The calculating procedure is based on Fermat’s principle and Dijkstra’s algorithm and it is relatively quick and easy for its implementation by means of individual computer code. It can be used effectively in optimization methods oriented on reconstruction of damage state in engineering structures basing on time-of-flight measurements for mechanical waves.

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Wyznaczanie parametrów sygnału okresowego w przenośnym systemie tomografii impedancyjnej pni drzew

Sikora A., Kryla P., Zmyślony W.

Elektronika : konstrukcje, technologie, zastosowania

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2010

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Vol. 51, nr 9

81-83

PL

W artykule przedstawiono wyniki porównania dwóch systemów detekcji przesunięcia fazowego sygnałów pomiarowych, zaimplementowanych na potrzeby realizacji projektu przenośnego systemu tomografii impedancyjnej. Zaprojektowane i uruchomione moduły poddano próbom w celu oceny możliwości zastosowania ich w przenośnym urządzeniu do tomografii impedancyjnej pni drzew.

EN

In this article the comparison result of the phase shift detection systems was presented. Those systems were implemented in order to be applied in mobile impedance tomography system. Developed modules were tested with view of being applied in mobile topographic system for tree trunks diagnostics.