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.

Low Temperature Stress Corrosion Cracking of Sensitized Inconel 600 in Tetrathionate and Thiosulfate Solutions

Abstract: This paper addresses some aspects of low temperature stress corrosion cracking (SCC) in Inconel 600 steam generator tubing, a recent instance of which apparently resulted from the contamination of the primary coolant by sulfur compounds. The low temperature SCC of sensitized Inconel 600 was studied in concentrated and dilute solutions of tetrathionate and thiosulfate. The material tested was a tubing directly sensitized from the mill-annealed condition. Tests were performed using U-bends, slow strain rate, and constant extension. The results show that the propensity to SCC, especially its initiation, in thiosulfate is low and is much lower than in tetrathionate. However, when slow strain rate was applied in thiosulfate, or when the pH of the thiosulfate solution was lowered, the specimens cracked readily. Constant extension tests, where the extension was applied using dynamic straining with the solution present, caused cracking much faster than in U-bends, suggesting that U-bend cracking is initi...

Extensive evaluation of high performance protection relays for the Hydro-Quebec series compensated network

Abstract: This paper reports on an extensive study to compare the performance of 8 preselected high performance power line protection systems on the Hydro-Quebec series compensated network. The paper first presents an evaluation of the commissioning aspects and manufacturing quality of the tested relays. It then describes the simulated network, the relay testing procedure, and the laboratory test results obtained on a modern real time power system simulator. Published results of relay performance on series compensated lines are scarce and this paper provides valuable information for utility protection engineers. A total of 115,000 network disturbances were simulated and recorded on 20 different 735 kV lines; fractional test results for 84,030 cases are presented in the paper. The approach using real time power system simulation proved to be an efficient technique for evaluating protection relay performance. The laboratory test results demonstrated that the two best protection principles to be applied on the Hydro-Quebec series compensated network are those based on current differential and segregated phase comparison. The analysis does not take into account telecommunication requirements or other external constraints. >

An Experimental Evaluation of the Temperature Gradient in Solid Oxide Fuel Cells

Abstract: The use of solid oxide fuel cells SOFCs 1,2 as efficient energyconverter devices rests on their high working temperature. These ceramic fuel cells generally operate between 800 and 1000°C, although a major research effort is put forward to reduce their operation below 800°C for reducing manufacturing costs and improving cell lifetime. Depending on the selected range of temperature, a SOFC system would allow for either cogeneration or bottoming cycle, which add significantly to the overall power-generation efficiency. The high operating temperature of SOFC affords, in principle, for the direct use of hydrocarbon fuels by means of their catalytic conversion to carbon monoxide and hydrogen. The most economical way to convert these fuels is to proceed through direct internal reforming DIR, as it is observed in tubular or planar designs, or through catalytic partial oxidation CPOX, which is at the basis of the functioning of single-chamber SOFC SC-SOFC. However, both DIR and CPOX may lead to high temperature variations along the fuel cell. In the case of direct reforming of methane, a significant cooling at the inlet of the fuel cell is expected due to the fast kinetics of the endothermic reforming reaction, especially over conventional Ni– yttria-stabilized zirconia YSZ cermet. 3 It then aggravates the tem