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.

Wind and solar curtailment

Abstract: High penetrations of wind and solar generation on power systems are resulting in increasing curtailment. Wind and solar integration studies predict increased curtailment as penetration levels grow. This paper examines experiences with curtailment on bulk power systems internationally. It discusses how much curtailment is occurring, how it is occurring, why it is occurring, and what is being done to reduce curtailment. This summary is produced as part of the International Energy Agency Wind Task 25 on Design and Operation of Power Systems with Large Amounts of Wind Power. Keywords-wind; solar; curtailment; transmission congestion

Effects of the development of a newly created spawning ground in the Des Prairies River (Quebec, Canada) on the reproductive success of lake sturgeon (Acipenser fulvescens)

Abstract: Summary In the fall of 1996, the surface area of an existing spawning ground located downstream of a power dam on the Des Prairies River was expanded. More than 8000 m2 of appropriate substrate were then added to the largest lake sturgeon spawning ground in the lower St. Lawrence River system. The impact of this enhancement project was monitored 3 years before (1994–1996) and 7 years after (1997–2003) habitat modification. Four hypothesis were tested: (i) the newly created spawning ground was utilized by lake sturgeon for egg laying, (ii) the utilization of the newly spawning bed improved the reproductive success of lake sturgeon, (iii) the improvement of the reproductive success increased the lake sturgeon larvae production, and (iv) the increase of larvae production increased the recruitment of lake sturgeon. After the new spawning area was developed, the sampling station located in this new section was one of those most used for egg deposition, under both high (1997) and low (1998–1999) flows conditions. Absolute annual numbers of drifting larvae varied between 1.2 million (1996) and 12.8 million (2003). The mean survival rate of the estimated number of laid eggs compared with drifting larvae was 0.88 and 0.93% in 1995 and 1996, respectively, relative to 5.6% in 1997, 3.82% in 1998 and 2.41% in 1999. These results indicate that the new area had a positive impact on the reproductive success of lake sturgeon in the Des Prairies River. From 1994 to 2003, strong cohorts in the lower St. Lawrence system were related to high larval drift in this river. However, high larval production did not necessarily lead to a strong cohort, and year-class strength determination also appeared affected by environmental factors, with the strongest year classes all associated with high June flow rates (over 1150 m3 s−1) in the Des Prairies River. The information gathered during this study enabled us to refine previous observations on the management of sturgeon spawning grounds and the planning of their design, surface area, substrate and location, as well as other physical parameters.

Analysis and validation of a real-time AC drive simulator

Abstract: This paper presents the analysis and validation of a real-time AC drive simulator. Real-time simulation has been used for over a decade in power systems engineering to test controllers thoroughly, efficiently, and safely. The development and testing of large DC drives could benefit from this type of simulation, but real-time power system simulators have modeling restrictions preventing stable and accurate simulation of isolated drives switching at high frequencies. These restrictions can be overcome by combining in a single model both the power converter and motor models. After discussing the salient issues related to the real-time simulation of DC drives, a prototype real-time simulator for drives is described. Its ability to accurately emulate the behavior of large drives is demonstrated through two case studies. A first case study demonstrates the feasibility of simulating a drive of typical complexity in real-time. The second case study demonstrates how the controller for a PWM VSI fed induction motor, switching at 4 kHz, is designed, implemented in a microcontroller and tested in real-time using a simulated inverter, motor and load. Comparisons against results obtained with another simulation tool, which uses extremely accurate variable-step integration algorithms, demonstrates the validity of our approach.

Multilayer material, method for making same and use as electrode

Abstract: A multilayer material includes a solid substrate and at least two superimposed solid layers containing particles of an electrochemically active material, the first solid layer adhering to the solid substrate and the second solid layer adhering to the first solid layer. The multilayer material has a constant thickness of upper layer not less than 95% and a depth of penetration of the second layer into the first layer which is less than 10% of the thickness of the first layer, and enables as electrode constituent, generators having a low risk of overload degradation to be prepared.