Showing papers by "Hydro-Québec published in 2016"

Wind and solar energy curtailment: A review of international experience

Abstract: Greater penetrations of variable renewable generation on some electric grids have resulted in increased levels of curtailment in recent years. Studies of renewable energy grid integration have found that curtailment levels may grow as the penetration of wind and solar energy generation increases. This paper reviews international experience with curtailment of wind and solar energy on bulk power systems in recent years, with a focus on eleven countries in Europe, North America, and Asia. It examines levels of curtailment, the causes of curtailment, curtailment methods and use of market-based dispatch, as well as operational, institutional, and other changes that are being made to reduce renewable energy curtailment.

Alkaline aqueous electrolytes for secondary zinc–air batteries: an overview

Abstract: Summary New applications and emerging markets in electromobility and large-scale stationary energy storage require the development of new electrochemical systems with higher energy density than current batteries. Rechargeable metal–air batteries, mainly lithium–air and zinc–air systems, are considered one of the most promising candidates. In contrast to lithium, zinc is abundant, inexpensive and its electrodeposition in aqueous electrolytes is relatively easy. Unfortunately, achieving a rechargeable zinc–air battery is still hindered by various technical problems related to the reversibility and lifetime of the electrodes. The most widely used electrolyte in zinc–air batteries has been the classical aqueous alkaline. In this context and with the main objective of providing a complete overview, we studied a wide number of articles starting from the beginning of the development of secondary zinc–air batteries (1970–1980s) to more recent works, with the aim of compiling all available information. It is essential to revise older papers to find relevant information that may get otherwise forgotten and not taken into account to develop new solutions. This information could also be applied in other storage systems based on zinc as nickel–zinc, zinc hybrid or zinc-ion. Copyright © 2016 John Wiley & Sons, Ltd.

Local and Wide-Area PMU-Based Decentralized Dynamic State Estimation in Multi-Machine Power Systems

Abstract: Accurate measurement of the rotor angle and speed of synchronous generators is instrumental in developing powerful local or wide-area control and monitoring systems to enhance power grid stability and reliability. Exogenous input signals such as field voltage and mechanical torque are critical information in this context, but obtaining them raises significant logistical challenges, which in turn complicates the estimation of the generator dynamic states from easily available terminal phasor measurement unit (PMU) signals only. To overcome these issues, the authors of this paper employ the extended Kalman filter with unknown inputs, referred to as the EKF-UI technique, for decentralized dynamic state estimation of a synchronous machine states using terminal active and reactive powers, voltage phasor and frequency measurements. The formulation is fully decentralized without single-machine infinite bus (SMIB) or excitation model assumption so that only local information is required. It is demonstrated that using the decentralized EKF-UI scheme, synchronous machine states can be estimated accurately enough to enable wide-area power system stabilizers (WA-PSS) and system integrity protection schemes (SIPS). Simulation results on New-England test system, Hydro-Quebec simplified system, and Kundur network highlight the efficiency of the proposed method under fault conditions with electromagnetic transients and full-order generator models in realistic multi-machine setups.

Atomic-Scale Origin of Long-Term Stability and High Performance of p-GaN Nanowire Arrays for Photocatalytic Overall Pure Water Splitting

Abstract: The atomic-scale origin of the unusually high performance and long-term stability of wurtzite p-GaN oriented nanowire arrays is revealed. Nitrogen termination of both the polar (0001¯) top face and the nonpolar (101¯0) side faces of the nanowires is essential for long-term stability and high efficiency. Such a distinct atomic configuration ensures not only stability against (photo) oxidation in air and in water/electrolyte but, as importantly, also provides the necessary overall reverse crystal polarization needed for efficient hole extraction in p-GaN.

Optimization of Layered Cathode Materials for Lithium-Ion Batteries

Abstract: This review presents a survey of the literature on recent progress in lithium-ion batteries, with the active sub-micron-sized particles of the positive electrode chosen in the family of lamellar compounds LiMO2, where M stands for a mixture of Ni, Mn, Co elements, and in the family of yLi2MnO3•(1 − y)LiNi½Mn½O2 layered-layered integrated materials. The structural, physical, and chemical properties of these cathode elements are reported and discussed as a function of all the synthesis parameters, which include the choice of the precursors and of the chelating agent, and as a function of the relative concentrations of the M cations and composition y. Their electrochemical properties are also reported and discussed to determine the optimum compositions in order to obtain the best electrochemical performance while maintaining the structural integrity of the electrode lattice during cycling.

Ambient-Air Stable Lithiated Anode for Rechargeable Li-Ion Batteries with High Energy Density

Abstract: An important requirement of battery anodes is the processing step involving the formation of the solid electrolyte interphase (SEI) in the initial cycle, which consumes a significant portion of active lithium ions. This step is more critical in nanostructured anodes with high specific capacity, such as Si and Sn, due to their high surface area and large volume change. Prelithiation presents a viable approach to address such loss. However, the stability of prelithiation reagents is a big issue due to their low potential and high chemical reactivity toward O2 and moisture. Very limited amount of prelithiation agents survive in ambient air. In this research, we describe the development of a trilayer structure of active material/polymer/lithium anode, which is stable in ambient air (10–30% relative humidity) for a period that is sufficient to manufacture anode materials. The polymer layer protects lithium against O2 and moisture, and it is stable in coating active materials. The polymer layer is gradually dis...

Can we detect Li K X‐ray in lithium compounds using energy dispersive spectroscopy?

Abstract: Lithium is the key element for the development of battery and new technology and the development of an analytical technique to spatially and quantitatively resolve this element is of key importance. Detection of Li K in pure metallic lithium is now possible in the Scanning Electron Microscope (SEM) with newly designed Energy Dispersive Spectroscopy (EDS). However, this work is clearly showing, for the first time using EDS, the detection of Li K in several binary lithium compounds (LiH, Li3 N, Li2 S, LiF and LiCl). Experimental Li K X-rays intensity is compared with a specially modified Monte Carlo simulation program showing discrepancies between theoretical and experimental Li K measurements. The effect of chemical bounding on the X-rays emission using density functional theory with the all-electron linearized augmented plane wave is showing that the emission of Li K from the binary compounds studied should be, at least, 12 times lower than in metallic Li. SCANNING 38:571-578, 2016. © 2016 Wiley Periodicals, Inc.

Recent progress in sulfide-based solid electrolytes for Li-ion batteries

Abstract: Sulfide-based ionic conductors are one of most attractive solid electrolyte candidates for all-solid-state batteries. In this review, recent progress of sulfide-based solid electrolytes is described from point of view of structure. In particular, lithium thio-phosphates such as Li7P3S11, Li10GeP2S12 and Li11Si2PS12 etc. exhibit extremely high ionic conductivity of over 10−2 S cm−1 at room temperature, even higher than those of commercial organic carbonate electrolytes. The relationship between structure and unprecedented high ionic conductivity is delineated; some potential drawbacks of these electrolytes are also outlined.

Analytical Concepts for Reactive Power Based Primary Frequency Control in Power Systems

Abstract: This paper introduces a novel idea for adding virtual inertia in power systems by controlling the frequency swing dynamics through voltage channel. The purpose is to develop a frequency-based supplementary VAR modulation to assist governor action during power imbalance events. In this aim, we propose a two-band power system stabilizer, tuned for very low-frequency common swing mode, to adaptively adjust reference voltage of a Synchronous Condenser (SC) and modulate its reactive power on a second-by-second basis. The feasibility of this idea is supported by theoretical and simulation evidences. From theoretical side, we formulate a computational procedure to measure the degree of control impact, accompanied by sensitivity analyses around varying operating points. On the simulation side, we perform extensive studies on four well-known IEEE multi-machine test systems. The results show that VAR modulation by SC has a considerable impact on the minimum post-contingency frequency (frequency nadir), even more than so-called load modulation methods in some cases, which in fact has not been given enough attention in the past. In addition, we show that the proposed method can aid governors to improve primary frequency response particularly in low inertia power systems by reducing post-event frequency settling time and bias.

Power System Dynamic Simulations Using a Parallel Two-Level Schur-Complement Decomposition

Abstract: As the need for faster power system dynamic simulations increases, it is essential to develop new algorithms that exploit parallel computing to accelerate those simulations. This paper proposes a parallel algorithm based on a two-level, Schur-complement-based, domain decomposition method. The two-level partitioning provides high parallelization potential (coarse- and fine-grained). In addition, due to the Schur-complement approach used to update the sub-domain interface variables, the algorithm exhibits high global convergence rate. Finally, it provides significant numerical and computational acceleration. The algorithm is implemented using the shared-memory parallel programming model, targeting inexpensive multi-core machines. Its performance is reported on a real system as well as on a large test system combining transmission and distribution networks.

Variability in large-scale wind power generation

Abstract: The article demonstrates the characteristics of wind power variability and net load variability in multiple power systems based on real data from multiple years. Demonstrated characteristics includ ...

Accelerated Removal of Fe-Antisite Defects while Nanosizing Hydrothermal LiFePO4 with Ca(2).

Abstract: Based on neutron powder diffraction (NPD) and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM), we show that calcium ions help eliminate the Fe-antisite defects by controlling the nucleation and evolution of the LiFePO4 particles during their hydrothermal synthesis. This Ca-regulated formation of LiFePO4 particles has an overwhelming impact on the removal of their iron antisite defects during the subsequent carbon-coating step since (i) almost all the Fe-antisite defects aggregate at the surface of the LiFePO4 crystal when the crystals are small enough and (ii) the concomitant increase of the surface area, which further exposes the Fe-antisite defects. Our results not only justify a low-cost, efficient and reliable hydrothermal synthesis method for LiFePO4 but also provide a promising alternative viewpoint on the mechanism controlling the nanosizing of LiFePO4, which leads to improved electrochemical performances.

A Colorful Blackout: The Havoc Caused by Auroral Electrojet Generated Magnetic Field Variations in 1989

Abstract: The Hydro-Quebec system is a winter-peaking system whose all-time record peak load of 39,240 MW was recorded in January 2014. Hydro-Quebec exports to neighboring systems in Canada and the United States, with an annual transaction volume of approximately 30 TWh. The current system configuration is based on the major development projects of the 1960s and 1970s. In 1965, as part of the development of the Manic-Outardes hydroelectric complex, Hydro-Quebec commissioned the world's first 735-kV lines, which had a much greater capacity than the existing 315-kV lines put into service in the late 1950s with the development of the Bersimis hydroelectric complex. In 1971, Hydro-Quebec launched what was then dubbed the "project of the century": the development of the La Grande River complex in the James Bay region at the southern end of Hudson Bay. In 1996, when the final generating station, Laforge-2, was commissioned at the end of the second phase of the project, La Grande became the largest hydroelectric facility in the world, a title it retained for a number of years.

Real-time testing platform for microgrid controllers against false data injection cybersecurity attacks

Abstract: This paper proposes a real-time hardware-in-the loop (HIL) testing platform for microgrid cybersecurity analysis. The developed platform emulates the microgrid network, the distributed energy resources (DER) and their corresponding local controllers on a real-time digital simulator (RTDS). The main microgrid controller functions are implemented on a separate digital controller. The microgrid communication network is implemented in hardware and the messages exchanged are compliant with the IEC 61850 generic object oriented substation event (GOOSE) messaging protocol. An impact assessment of false data injection (FDI) cyber-attacks on the critical microgrid control functions, specifically, loss of load due to under frequency load shedding (UFLS) has been conducted. Mitigation solutions that enhance the resilience of the microgrid to FDI attacks have been proposed. Real-time simulation results are used to quantify the attack's impact and the mitigation scheme effectiveness on the dynamic frequency response of microgrids in terms of reliability metrics, including the amount of load lost, the frequency nadir and the time needed to reach frequency stability. A 25 kV distribution system adapted from a utility feeder and reconfigured as a microgrid has been used as the benchmark test system. Applicable utility grid codes and standards are considered throughout.

A New Stray-Load Loss Formula for Small and Medium-Sized Induction Motors

Abstract: This paper proposes a new stray-load loss (SLL) formula for small and medium induction motors (IMs) based on tests data of a 182, 60 Hz IMs in the range of 1–500 hp (0.75–375 kW). They are all tested in accordance with IEEE Std 112-Method B. The proposed formula is validated by recalculating the efficiency of the same number of motors by using the proposed formula, as well as the IEEE Std 112 and the IEC 60034-2-1 standards. Another validation was done on testing 17 additional IMs that are independent of the 182-motor data. In both validations, the new formula demonstrates better accuracy. This formula shows the potential to replace the existing SLL estimation formula for this horsepower range.

Quasi-Steady-State Approach for Analysis of Frequency Oscillations and Damping Controller Design

Abstract: This paper proposes a quasi-steady-state modeling approach for an approximation of long-term frequency dynamics in power systems. A specific phenomenon of concern is an onset of frequency swings during load/generation imbalance scenarios. The effects of system voltage characteristics, system inertia, and, more importantly, damping controllers are explained and quantified using the described quasi-steady-state models. Application of the methodology to a 14-generator benchmark system demonstrates that described models are suitable for simulation of different disturbance scenarios that can trigger frequency instability. Moreover, linearization of the proposed models can provide convenient means for impact assessment and coordinated design of damping controllers. To demonstrate this, coordinated tuning of multiband power system stabilizers to improve frequency dynamics has been performed and validated through nonlinear simulations using a commercial transient stability software.

The Effect of Sodium Hydroxide Molarity and Other Parameters on Water Absorption of Geopolymer Mortars

Abstract: Objective: Durability one of the critical role effect in geopolymer serviceability. The capability of water to penetrate the mortar microstructure is mainly used to measure the durability, which also called permeability. Methods/Statistical Analysis: The influence of sodium hydroxide (NaOH) molarity, alkali Solution to Binder ratio (S:B), binder to aggregate ratio (B:A) and sodium silicate to sodium hydroxide ratio (NS:NH) on water absorption of Geopolymer Mortar (GPMs) are investigated in this article. Geopolymer mortar specimens of different NaOH molarity, S:B, B:A, and NS:NH were prepared and cured at different temperatures, 27°C and 60°C. Granulated blast furnace slag, fly ash, waste ceramic and waste glass bottle were used as a binder and mixed with river sand as fine aggregate. Findings: The results of experimental indicated that water absorption significantly affected of curing temperatures. The lower water absorption results were observed of the samples cured at ambient temperature (27°C) compared to samples cured at oven temperature (60°C). Applications/Improvements: The geopolymer specimens’ water absorption observed positively enhanced with increase concentration of alkaline solution.