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-order black-box models for control system design in large power systems

Abstract: The paper studies two multi-input multi-output (MIMO) procedures for the identification of low-order state space models of power systems, by probing the network in open loop with low-energy pulses or random signals. Although such data may result from actual measurements, the development assumes simulated responses from a transient stability program, hence benefiting from the existing large base of stability models. While pulse data is processed using the eigensystem realization algorithm, the analysis of random responses is done by means of subspace identification methods. On a prototype Hydro-Quebec power system, including SVCs, DC power lines, series compensation, and more than 1100 buses, it is verified that the two approaches are equivalent only when strict requirements are imposed on the pulse length and magnitude. The 10th-order equivalent models derived by random-signal probing allow for effective tuning of decentralized power system stabilizers (PSSs) able to damp both local and very slow inter-area modes.

A photochemical diode artificial photosynthesis system for unassisted high efficiency overall pure water splitting.

Abstract: The conversion of solar energy into chemical fuels can potentially address many of the energy and environment related challenges we face today. In this study, we have demonstrated a photochemical diode artificial photosynthesis system that can enable efficient, unassisted overall pure water splitting without using any sacrificial reagent. By precisely controlling charge carrier flow at the nanoscale, the wafer-level photochemical diode arrays exhibited solar-to-hydrogen efficiency ~3.3% in neutral (pH ~ 7.0) overall water splitting reaction. In part of the visible spectrum (400–485 nm), the energy conversion efficiency and apparent quantum yield reaches ~8.75% and ~20%, respectively, which are the highest values ever reported for one-step visible-light driven photocatalytic overall pure water splitting. The effective manipulation and control of charge carrier flow in nanostructured photocatalysts provides critical insight in achieving high efficiency artificial photosynthesis, including the efficient and selective reduction of CO2 to hydrocarbon fuels. A major challenge facing solar-to-fuel technologies is the integration of light-absorbing and catalytic components into efficient water-splitting devices. Here, the authors construct a photochemical diode array to harvest visible light and split pure water at high solar-to-hydrogen efficiencies.

Computation of Dynamic Operating Balancing Reserve for Wind Power Integration for the Time-Horizon 1–48 Hours

Abstract: A challenge now facing utilities is how to adjust reserves in the operations-planning horizon of 0 to 48 hours ahead to mitigate the effects of wind variability and forecast uncertainties, in addition to those of load uncertainties and unavailability of generation. Reserves are maintained to ensure a high level of reliability and security to the system. They are subdivided into two groups: those responding within an intrahourly time horizon to regulate power imbalances, and those responding over a 1-48 hours ahead time horizon addressing the net forecast uncertainties. In this paper, we present a methodology for calculating reserves in the latter category, referred to as balancing reserves (BRs), following the integration of wind generation in a power system. Their computation is based on maintaining a predefined level of risk. The novelty here is that wind forecast error distributions are adjusted as a function of wind generation forecast levels. Gamma-like distributions with time-varying parameters, estimated from real data, were chosen to approximate the wind generation forecast errors. It is shown that this improved modeling significantly modifies the values of required balancing reserves and associated risk. The methodology developed is based on a clear criterion, namely risk, and it demonstrates the imperativeness of considering dynamic balancing reserves as a function of the imminent wind generation forecast.

Nanostructured Hybrid Materials for the Selective Recovery and Enrichment of Rare Earth Elements

Abstract: The importance of rare-earth elements (REEs) in the global economy is booming as they are used in numerous advanced technologies. Industrially, the extraction and purification of REEs involve multiple liquid–liquid extraction (LLE) steps as they exhibit very similar complexation properties with most common ligands. In order to substantially improve this process and provide a greener alternative to LLE, functional porous hybrid materials, demonstrating enhanced selectivity towards heavier REEs compared to commercially-available products, are proposed. In addition, because of the grafting procedure used in the synthesis, the proposed materials demonstrate a higher degree of reusability, increasing their marketable potential.