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.

Effect of overvoltage on the risetime and amplitude of PD pulses

Abstract: A two-dimensional mathematical model has been employed to characterize the pulse or spark breakdown behavior of a short gap in air. It has been established that the form or shape of a breakdown current pulse is very much determined by the overvoltage developed across the gap. Large overvoltages lead to intense space charge effects, which appreciably modify the breakdown current pulse form, leading to more rapid rise times, greater peak current amplitudes and reduced pulse widths. In so far as the overvoltage across a given cavity affects the rise time and amplitude of the pulse resulting from a spark type discharge, the response of a conventional partial discharge pulse detector is necessarily a function of the overvoltage developed across the cavity. >

A Novel In Situ Efficiency Estimation Algorithm for Three-Phase IM Using GA, IEEE Method F1 Calculations, and Pretested Motor Data

Abstract: The precise estimation of efficiency of induction motors is crucial in industries for energy savings, auditing, and management. This paper presents a novel method for in situ induction motors efficiency estimation by applying the genetic algorithm and utilizing IEEE Form F2-Method F1 calculations with pretested motor data. The method requires a dc test, full-load operating point rms voltages, currents, input power, and speed measurements. The proposed algorithm uses a sensorless technique to determine motor speed. The algorithm is not only an in situ tool; it can also be used as an on-site efficiency estimation tool that might replace the expensive dynamometer procedure. The method was validated by testing 30 induction motors.

State-of-the-art review of computer vision for the management of power transmission lines

Abstract: A review of the current state-of-the-art computer vision applied to the management of power transmission lines is presented. It covers the highest value applications for electric utilities, with a specific interest for applications dedicated on the cable system. Although robotics provides additional means of data collection, this review is not centered on specific platforms. Strategic steps that could favor the efficient introduction of computer vision in the power transmission industry are also discussed.

A study of geoelectromagnetic disturbances in Quebec. II. Detailed analysis of a large event

Abstract: For pt. I see ibid., vol.13, p.1251-6 (1998). As part of investigations of geomagnetically induced currents in the Hydro-Quebec power system, the geoelectromagnetic field was recorded at five sites in western Quebec in 1992 to 1994. A description of the measurements and some general results are presented in an accompanying paper. This paper concentrates on an analysis of a disturbance on February 21, 1994, that produced one of the largest electric fields recorded. The magnetic recordings are used to determine the intensity, location, and orientation of the auroral electrojet that is the cause of the disturbance. By tracking these parameters we show that dB/dt is due to both the changing intensity of the electrojet and due to movement of the electrojet. The resulting electric fields are found to be anti-parallel (parallel) to the electrojet when the magnetic field is increasing (decreasing).

Method for rapidly carrying out a hydrogenation of a hydrogen storage material

Abstract: Disclosed is a method for rapidly carrying out a hydrogenation of a material capable of absorbing hydrogen. It was discovered that when a powder of a material capable of absorbing hydrogen is ground under a hydrogen pressure, not at room temperature but at a higher temperature (about 300°C in the case of magnesium) and in the presence of a hydrogenation activator such as graphite and optionally a catalyst, it is possible to transform completely the powder of this material into a hydride. Such a transformation is achieved in a period of time less than 1 hour whereas the known methods call for periods of time as much as 10 times longer. This is an unexpected result which gives rise to a considerable reduction in the cost of manufacture of an hydride, particularly MgH2.