Hydro-Québec

About: Hydro-Québec is a government organization based out in Montreal, Quebec, Canada. It is known for research contribution in the topics: Electric power system & Dielectric. The organization has 2596 authors who have published 4433 publications receiving 100878 citations.

Occupational and residential 60-Hz electromagnetic fields and high-frequency electric transients: exposure assessment using a new dosimeter.

Abstract: One problem that has limited past epidemiologic studies of cancer and exposure to extremely low-frequency (0–100 Hz) electric and magnetic fields has been the lack of adequate methods for assessing personal exposure to these fields. A new 60-Hz electromagnetic field dosimeter was tested to assess occupational and residential exposures of a group of electrical utility workers and a comparison background group over a 7-day period. Comparing work periods only, utility workers' exposures were significantly higher than background levels by a factor of about 10 for electric (E) and magnetic (B) fields and by a factor of 171 for high-frequency transient electric (HFTE) fields. When overall weekly time-weighted averages combining work and nonwork exposures were compared, ratios of the exposed to background groups were lower. B and HFTE exposure ratios remained statistically significant, with values of 3.5 and 58, respectively, whereas the electric field exposure ratio was no longer significant, with a value of 1....

Nanoscopic scale studies of LiFePO4 as cathode material in lithium-ion batteries for HEV application

Abstract: We present a review of the structural properties of LiFePO4. Depending on the mode of preparation, different impurities can poison this material. These impurities are identified and a quantitative estimate of their concentrations is deduced from the combination of X-ray diffraction analysis, Fourier transform infrared spectroscopy, Raman spectroscopy, and magnetic measurements. An optimized preparation provides samples with carbon-coated particles free of any impurity phase, insuring structural stability and electrochemical performance that justify the use of this material as a cathode element a new generation of lithium secondary batteries.

Some Observations on the Character of Corona Discharges in Short Gap Spaces

Abstract: Corona discharge results, obtained with a number of gases under atmospheric pressure using plane-parallel metallic and dielectric electrodes placed between 0.05 and 9.00 mm apart, are discussed. With short gap spacings, deviations from the pulse or spark-type discharge mechanism are observed to occur in particular when dielectric surfaces are involved; the deviations are characterized usually by the appearance of pseudoglow discharges, which exhibit properties that are common to both pulse and glow discharges. The practical significance of pseudoglow discharges in relation to corona measuring techniques, utilizing conventional pulse discharge detectors, are considered both on a short-and long-term test basis.

Thin electrode supported on electronically conductive sheet and process of manufacture

Abstract: Process of manufacturing thin electrodes, supported on an electronically conductive sheet, the electrodes being made from an element selected from lithium, lithium alloy, or doped lithium, whose melting point does not differ from the melting point of lithium by ±50° C. and whose thickness is constant, from a roller of the sheet and a source of the element. According to the invention, there is provided a bath of the element in molten state, the sheet is continuously unrolled, a constant quantity of the molten element is continuously applied on one of the two faces of the sheet, so as to produce a film on the sheet, whose thickness is constant and between about 0.1 and about 40μ and whose surface is homogeneous and uniform. The process is carried out in such a manner that the molten element is prevented from solidifying while in contact with the sheet, and the solidification of the element on the sheet takes place after formation of the film on the sheet. Electrode made of a sheet coated with a layer of lithium whose thickness is 0.1 to 40μ.

A Commentary on Partial Discharge Measurement and Detection

Abstract: A critical review is presented on the various electrical methods available for partial discharge detection and measurement in terms of their chronological development and application on cable, capacitor, transformer, and machine insulation specimens. A substantial portion of the effort is devoted to corona pulse detection techniques, because these constitute the most popular forms of corona measurement. It is pointed out, however, that under some conditions discharges may assume a pulseless or pseudo-glow type character and that in such circumstances pulse detection procedures become ineffective and must be replaced by appropriate bridge methods.