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.

Surface conductivity of epoxy specimens subjected to partial discharges

Abstract: The surface conductivity of epoxy specimens was found to increase appreciably with the exposure time to partial discharges, the change being most pronounced during the initial stages on the exposure. No definite tendency could be detected in the mean partial discharge pulse amplitude with time. Surface degradation of the epoxy was characterized by the commonly observed occurrence of pitting and deposition of droplets and crystals. >

Cellulose chemical markers in transformer oil insulation Part 1: Temperature correction factors

Abstract: The concentrations of cellulose chemical markers, in oil, are influenced by various parameters due to the partition between the oil and the cellulose insulation. One major parameter is the oil temperature which is a function of the transformer load, ambient temperature and the type of cooling. To accurately follow the chemical markers concentration trends during all the transformer life, it is crucial to normalize the concentrations at a specific temperature. In this paper, we propose equations for the normalization of methanol, ethanol and 2-furfural at 20 °C. The proposed equations have been validated on some real power transformers.

Hydro-Quebec multiple SVC application control stability study

Abstract: A report is presented on the SVC (static VAR compensator) control stability studies undertaken as part of an overall system improvement project. It is shown that for an all-shunt network, a regulator setting of T/sub r/=0.5 s would be stable for many contingencies, but some contingencies would require gain-supervisor action and transfer-trip automatisms to ensure system security. The transfer-trip automatisms would be complex and require much study to identify. Thus, from the perspective of SVC voltage regulator stability, the all-shunt option is the least desirable. For a mostly series network, a regulator setting of T/sub r/>0.25 s provides good stability margin for all system contingencies. This means that system security is not dependent upon a complex set of transfer-trip automatisms. A few new design considerations for the power system have been identified, due to adding series compensation. The major new phenomenon is a low-frequency oscillation between shunt reactors and the series capacitors, which has very little natural damping. The SVC voltage regulators will decrease the damping of these modes, and may cause them to become unstable. To insure against such instability, it is proposed that high-pass filters with a break frequency of 20 Hz be applied to all SVCs. >

Application aspects of multiterminal DC power transmission

Abstract: Four practical multiterminal DC systems are described. Two are already in commercial operation: Nelson River (double-bipole four-terminal), and Sardinia-Corsica-Italy (two-terminal monopolar tapped to become three-terminal). Two others are expansions of existing systems and are under construction: Pacific HVDC (high-voltage DC) Intertie (bipolar four-terminal) and Hydro-Quebec/New England (bipolar five-terminal). All of the systems are able to shift to a stable operating point following a disturbance (e.g., loss of a converter station). Application aspects of each system are presented, with emphasis on the attention required to make each system practical. >