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.

Numerical Method for the Investigation of Fault Containment and Tank Rupture of Power Transformers

Abstract: This paper presents an analysis method based on explicit dynamic analysis, enabling detailed and representative investigations of the mechanical effects of low-impedance faults in power equipment. To illustrate the effectiveness of the proposed method, a given transformer design having caused the projection of a heavy chimney/bushing assembly over a significant distance is used as a case study. A comparison about the observed projection distance of this assembly shows that the method provides representative results, thus offering the significant advantage of replacing costly and unpractical tests. The method is then used to study the retrofit measure proposed in this case to retain the chimney, further exemplifying its power to effectively study different design and retrofitting options.

Large-scale active-load modulation for angle stability improvement

Abstract: Analyses, operating experience and simulations of a large power system are used to demonstrate that active-load modulation can improve the system's dynamic performance to a large extent, with just a fraction of the base load available for control. At a time when the cost effectiveness of FACTS devices for damping interarea oscillations is constantly being questioned, it is natural to look to active-load modulation as a potential alternative method of insuring grid reliability. In developing the case, it was found that continuously modulating load stabilizers need to be fed with global signals for full efficiency. Although more difficult to design, implementation of a discontinuous control scheme shows good prospects, especially with regard to decentralization and robustness against communication delays.

Process for the destruction of toxic organic products

Abstract: There is disclosed a process for the destruction of toxic organic halogenated substances which comprises treating in a reaction chamber under a reductive atmosphere and at a temperature of from 1000° to 1600° C. a mixture of a toxic organic halogenated substance, carbon and a carbonate or bicarbonate of an alkali metal or of an alkaline earth metal whereby vapors of the alkali or alkaline earth metal are generated "in situ" to cause total degradation of the toxic organic halogenated substance into alkali or alkaline earth metal halide and carbon with the production of carbon monoxide which is subsequently oxidized into carbon dioxide.

Modeling ice growth on Canadian lakes using artificial neural networks

Abstract: [1] This paper presents artificial neural network (ANN) models designed to predict ice in Canadian lakes and reservoirs during the early winter ice thickness growth period. The models fit ice thickness measurements at one or more monitored lakes and predict ice thickness during the growth period either at the same locations for dates without measurements (local ANN models) or at any site in the region (regional ANN model), provided that the required meteorological input variables are available. The input variables were selected after preliminary assessments and were adapted from time series of daily mean air temperature, rainfall, cloud cover, solar radiation, and average snow depth. The results of the ANN models compared well with those of the deterministic physics-driven Canadian Lake Ice Model (CLIMO) in terms of root-mean-square error and in terms of relative root-mean-square errors. The ANN models predictions were also marginally more precise than a revised version of Stefan's law (RSL), presented herein. They reproduced some intrawinter and interannual growth rate fluctuations that were not accounted for by RSL. The performance of the models results in good part from a careful choice of input variables, inspired from the work on deterministic models such as CLIMO. ANN models of ice thickness show good potential for the use in contexts where ad hoc adjustments are desirable because of the limited availability of measurements and where poor data nature, availability, and quality precludes using deterministic physics-driven models.

Evalutation of Different Types of Contact Aid Components for Aluminum-to-Aluminum Connectors and Conductors

Abstract: A number of contact aid compounds commonly used for aluminum-to-aluminum connectors and conductors were evaluated on the basis of their effect on the contact resistance-force/torque relationships, stability to thermal degradation, consistency, and ability to protect the contact against fretting. The results showed that the use of the contact aid compounds markedly improves the contact properties of a joint and significantly reduces its susceptibility to fretting.