Partial discharge

About: Partial discharge is a research topic. Over the lifetime, 13997 publications have been published within this topic receiving 102058 citations. The topic is also known as: PD.

Method of and apparatus for electrostatic fluid acceleration control of a fluid flow

Abstract: A device for handling a fluid includes a corona discharge device and an electric power supply. The corona discharge device includes at least one corona discharge electrode and at least one collector electrode positioned proximate each other so as to provide a total inter-electrode capacitance within a predetermined range. The electric power supply is connected to supply an electric power signal to said corona discharge and collector electrodes so as to cause a corona current to flow between the corona discharge and collector electrodes. An amplitude of an alternating component of the voltage of the electric power signal generated is no greater than one-tenth that of an amplitude of a constant component of the voltage of the electric power signal. The alternating component of the voltage is of such amplitude and frequency that a ratio of an amplitude of the alternating component of the highest harmonic of the voltage divided by an amplitude of the constant component of said voltage being considerably less than that of a ratio of an amplitude of the highest harmonic of the alternating component of the corona current divided by an amplitude of the constant component of the corona current, i.e., (V ac/Vdc)≤(Iac(Idc).

Estimation of partial discharge inception voltage of magnet wires under inverter surge voltage by volume-time theory

Abstract: This paper discusses a novel estimation method for partial discharge inception voltage (PDIV) of magnet wire under inverter surge voltage application. We focused on the generation probability of initial electrons, which induce PD under high electric field and short rise time of surge voltage, by means of Volume-Time theory. We applied the Volume-Time theory to PD inception phenomena in a wedge-shaped air gap of twisted pair samples composed of enameled wires, and estimated PDIV in consideration of initial electron generation probability with temporal and spatial change in electric field distribution. We could estimate PDIV under different waveforms of applied surge voltage for different specifications of enameled wires. PDIV estimated by the extended Volume-Time theory agreed well with the measured PDIV. The estimated PDIV decreased with the increase in the rise time of applied voltage waveform, which corresponded to the V-t characteristics in the time range of inverter surge voltage.

Partial discharge. XVII. The early history of partial discharge research

Abstract: For pt.XVI see ibid., vol.9, no.3, p.21 et seq. (1993). Early investigations into partial discharge (PD) phenomena are reviewed to illustrate how little has changed and how much has, in some respects, been repeated during the forty years from 1940 to 1980. The early days of PD research included studies of PD in gas-filled cavities in oil-impregnated paper insulation, broad studies of PD in high voltage apparatus and dielectric materials, and research into PD in turbine generator insulation systems. The development of PD test techniques, development of test apparatus, and development of PD-related standards are discussed. >

Continuous on-line partial discharge monitoring of generator stator windings

Abstract: The use of on-line partial discharge (PD) measurements as an indicator of stator winding insulation condition, is well known. Trending results from on-line PD measurements over time, often allows maintenance personnel to become aware of developing stator insulation problems in motors and generators, and take corrective measures before failure occurs. However, partial discharge measurements on operating rotating machines can be influenced by conditions such as humidity, temperature, terminal voltage, and load. Thus, to provide reliable data which can be trended, it is important to take readings under similar machine operating conditions. In remote plants, or on pump storage units which are frequently cycled, it can be both time consuming and costly to ensure that personnel are available to take PD readings under ideal conditions occur. This paper describes the development of an automatic partial discharge monitoring system which is permanently connected to relevant machine sensors and can be configured to collect PD data when suitable conditions are met. The operating principles of the system are described, and some results are presented from data collected to date on 30 hydrogenerators.

Fiber bragg grating sensor for hydrogen detection in power transformers

Abstract: A novel hydrogen sensor is designed on the basis of Fiber Bragg grating (FBG) sensing technique. The sensor can be arranged inside the transformer. It has several advantages, such as fast fault detection and location, immunity to electromagnetic interference, quasi-distribution measurement and real-time monitoring. The principle of the proposed FBG hydrogen sensor is based on changes of the physical properties of palladium films which absorb hydrogen. A thick palladium layer prepared by magnetron sputtering is used to achieve high sensitivity. Meanwhile, polyimide is added into the adhesive layer to improve the reliability of the sensor. Partial discharge experiments demonstrated that the wavelength shift of the FBG hydrogen sensor varies linearly with the concentration of hydrogen dissolved in the transformer oil. It is hardly disturbed by other factors. The hydrogen sensing experiment in oil at a temperature of 80°C revealed that the sensitivity of the sensor remains same as the temperature varies, ranging from room temperature to operating temperature of the power transformer. Thus, the proposed sensor can work properly under the operating temperature of power transformers.