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Showing papers by "Hydro-Québec published in 2011"


Journal ArticleDOI
TL;DR: In this paper, an extended Kalman filter (EKF) technique for dynamic state estimation of a synchronous machine using phasor measurement unit (PMU) quantities is developed.
Abstract: Availability of the synchronous machine angle and speed variables give us an accurate picture of the overall condition of power networks leading therefore to an improved situational awareness by system operators. In addition, they would be essential in developing local and global control schemes aimed at enhancing system stability and reliability. In this paper, the extended Kalman filter (EKF) technique for dynamic state estimation of a synchronous machine using phasor measurement unit (PMU) quantities is developed. The simulation results of the EKF approach show the accuracy of the resulting state estimates. However, the traditional EKF method requires that all externally observed variables, including input signals, be measured or available, which may not always be the case. In synchronous machines, for example, the exciter output voltage Efd may not be available for measuring in all cases. As a result, the extended Kalman filter with unknown inputs, referred to as EKF-UI, is proposed for identifying and estimating the states and the unknown inputs of the synchronous machine simultaneously. Simulation results demonstrate the efficiency and accuracy of the EKF-UI method under noisy or fault conditions, compared to the classic EKF approach and confirms its great potential in cases where there is no access to the input signals of the system.

420 citations


Journal ArticleDOI
TL;DR: In this article, a Li-ion battery with nanoparticles of LiFePO4 (LFP) and Li4Ti5O12 (LTO) for the positive and negative electrodes is presented.

302 citations


Journal ArticleDOI
TL;DR: A review of the development of edge plasma modeling at ITER and of its interaction with the evolving divertor design is presented in this article, where the SOLPS (B2-Eirene) code has been developed for, and applied to, the evaluation and the design of the ITER divertor for the last 15 years.

223 citations


Journal ArticleDOI
TL;DR: In this paper, a comprehensive overview of the life cycle GHG emissions from wind and hydro power generation, based on relevant published studies, is presented, in order to compare with conventional fossil, nuclear and other renewable generation systems.
Abstract: This paper presents a comprehensive overview of the life cycle GHG emissions from wind and hydro power generation, based on relevant published studies. Comparisons with conventional fossil, nuclear and other renewable generation systems are also presented, in order to put the GHG emissions of wind and hydro power in perspective. Studies on GHG emissions from wind and hydro power show large variations in GHG emissions, varying from 0.2 to 152 g CO 2 -equivalents per kW h. The main parameters affecting GHG emissions are also discussed in this article, in relation to these variations. The wide ranging results indicate a need for stricter standardised rules and requirements for life-cycle assessments (LCAs), in order to differentiate between variations due to methodological disparities and those due to real differences in performance of the plants. Since LCAs are resource- and time-intensive, development of generic GHG results for each technology could be an alternative to developing specific data for each plant. This would require the definition of typical parameters for each technology, for example a typical capacity factor for wind power. Such generic data would be useful in documenting GHG emissions from electricity generation for electricity trading purposes.

209 citations


Journal ArticleDOI
TL;DR: In this paper, the electrochemical properties of submicron-sized particles of NaFePO 4 have been studied and characterized by XRD, SEM, EDX, EIS and Raman experiments.

180 citations


Journal ArticleDOI
TL;DR: In this paper, the surface of LiNi 1/3 Co 1/1/3 Mn 1/ 3 O 2 (LNMCO) particles has been studied for material synthesized at 900°C by a two-step process from a mixture of LiOH·H 2 O and metal oxalate.

124 citations


01 Jan 2011
TL;DR: In this paper, the surface of LiNi1/3Co 1/3Mn/3O2 (LNMCO) particles has been studied for material synthesized at 900 °C by a two-step process from a mixture of LiOH*H2O and metal oxalate.
Abstract: The surface of LiNi1/3Co1/3Mn1/3O2 (LNMCO) particles has been studied for material synthesized at 900 °C by a two-step process from a mixture of LiOH*H2O and metal oxalate [(Ni1/3Co1/3Mn1/3)C2O4] obtained by co-precipitation. Samples have been characterized by Xray diffraction (XRD), high-resolution transmission electron microscope (HRTEM), Raman scattering (RS) spectroscopy, and magnetic measurements. We have investigated the effect of the heat treatment of particles at 600 °C with organic substances such as sucrose and starch. HRTEM images and RS spectra indicate that the surface of particles has been modified. The annealing does not lead to any carbon coating but it leads to the crystallization of the thin disordered layer on the surface of LiNi1/3Co1/3Mn1/3O2. The beneficial effect has been tested on the electrochemical properties of the LiNi1/3Co1/3Mn1/3O2 cathode materials. The capacity at 10C-rate is enhanced by 20% for post-treated LNMCO particles at 600 °C for half-an-hour

114 citations


Journal ArticleDOI
TL;DR: In this article, the authors used the Teager-Kaiser energy operator (TKEO) to predict the instability onset time when applied to the output signals of an orthogonal filter bank and demonstrated the effectiveness of the scheme in accurately detecting and tracking the frequency and damping of oscillatory modes.
Abstract: Critical to real-time oscillations monitoring is early detection when otherwise dormant natural modes become a serious threat to grid stability. The next urgent issue is to determine the frequency and damping of the problematic modes when the signal is embedded in noise and the system contains closely spaced natural modes. The present paper addresses the detection issue using the Teager-Kaiser energy operator (TKEO) which has shown to be a fast predictor of the instability onset time when applied to the output signals of an orthogonal filter bank. In the system stability context, linear filter decomposition (LFD) is preferred rather than empirical mode decomposition (EMD), well known for its tendency to generate artificial modes with no physical meaning. A narrowband LFD with a less than 0.2-Hz bandwidth is achieved in the range 0.05 to 3 Hz through a cosine-modulated filter bank design. The effectiveness of the scheme in accurately detecting and tracking the frequency and damping of oscillatory modes is demonstrated using Monte Carlo simulations of three closely spaced modes and a detailed analysis of an actual event recorded by Hydro-Quebec's WAMS in 2006.

110 citations


Journal ArticleDOI
TL;DR: In this paper, a review of surface disorder effects, impurities, and intrinsic properties of Li-ion batteries is presented, involving sensitivity to exposure to humidity, and separate them into three categories.
Abstract: LiFePO4 has won the challenge to be the active element for the positive electrode of Li-ion batteries for electromobility. In an attempt to optimize the electrochemical performance, efforts have been made to reduce the size of the particles, so that the electrons and Li+ ions have a reduced path to travel inside the material. However, when the size decreases below 100 nm, surface effects become increasingly important, and can eventually dominate the physical and the chemical properties. The purpose of this work is to review them and their implications, involving sensitivity to exposure to humidity, and separate between surface disorder effects, impurities and intrinsic properties. This goal is achieved by the combination of different techniques to characterize the particles, including X-ray diffraction, electron microscope imaging, optical spectroscopy, and magnetism.

109 citations


Journal ArticleDOI
TL;DR: In this paper, an adaptive complex bandpass filter derived from the exponentially modulated filter bank theory has been devised, which is built from freely chosen low-pass filter prototypes that fulfill the WECC requirements.
Abstract: The steady-state performance of phasor measurement units (PMUs) is well standardized in the recently issued revised IEEE Std. C37.118. The Western Electricity Coordinating Council (WECC) has developed dynamic performance requirements for PMU filters as a means to guarantee better, uniform PMU response under dynamic conditions, such as power swings and changing harmonics. These have been endorsed by North American Synchrophasor Initiative (NASPI) for its wide-area monitoring infrastructure. The main purpose of this paper is to present a new framework for designing PMU filtering algorithms capable of meeting or exceeding the WECC/NASPI requirements, while achieving an optimum transient response time. To this end, an adaptive complex bandpass filter derived from the exponentially modulated filter bank theory has been devised. It is built from freely chosen low-pass filter prototypes that fulfill the WECC requirements. The static and dynamic performances of two specific schemes dedicated to control and monitoring with 4- and 7-cycle response-time, respectively, are ascertained under noisy waveforms and changing harmonics with system frequency varying from 40 to 80 Hz. The center-frequency adaptation approach is shown to be intrinsically superior to the frequency compensation scheme, especially under fast varying frequency and changing harmonics.

108 citations


Journal ArticleDOI
TL;DR: In this paper, the authors focused on the assessment of projected changes to selected return levels of 1-, 2-, 3-, 5-, 7-and 10-day annual (April-September) maximum precipitation amounts over Canada, using an ensemble of five 30-yr integrations each for current reference (1961-90) and future (2040-71) periods performed with the Canadian Regional Climate Model (CRCM); the future simulations correspond to the A2 Special Report on Emissions Scenarios (SRES) scenario.
Abstract: Changes to the intensity and frequency of hydroclimatic extremes can have significant impacts on sectors associated with water resources, and therefore it is relevant to assess their vulnerabilities in a changing climate. This study focuses on the assessment of projected changes to selected return levels of 1-, 2-, 3-, 5-, 7- and 10-day annual (April–September) maximum precipitation amounts, over Canada, using an ensemble of five 30-yr integrations each for current reference (1961–90) and future (2040–71) periods performed with the Canadian Regional Climate Model (CRCM); the future simulations correspond to the A2 Special Report on Emissions Scenarios (SRES) scenario. Two methods, the regional frequency analysis (RFA), which operates at the scale of statistically homogenous units of predefined climatic regions, with the possibility of downscaling to gridcell level, and the individual gridbox analysis (GBA), are used in this study, with the time-slice stationarity assumption. Validation of model simulated 20-, 50- and 100-yr return levels of single- and multiday precipitation extremes against those observed for the 1961–90 period using both the RFA and GBA methods suggest an underestimation of extreme events by the CRCM over most of Canada. The CRCM projected changes, realized with the RFA method at regional scale, to selected return levels for the future (2041–70) period, in comparison to the reference (1961–90) period, suggest statistically significant increases in event magnitudes for 7 out of 10 studied climatic regions. Though the results of the RFA and GBA methods at gridcell level suggest positive changes to studied return levels for most parts of Canada, the results corresponding to the 20-yr return period for the two methods agree better, while the agreement abates with increasing return periods, that is, 50 and 100 yr. It is expected that the increase in return levels of short and longer duration precipitation extremes will have severe implications for various water resource–related development and management activities.

Journal ArticleDOI
TL;DR: In this article, the effect of the size and quantity of silica particles on the electrical properties of the analyzed materials was examined by transmission electron microscopy, dielectric spectroscopy, conduction current and space charge measurements.
Abstract: This work deals with the study of micro and nanosilica filled epoxy resin samples carried out in the framework of CIGRE WG D1.24 cooperative test program. This program focused on chemical, electrical and electrostatic properties of epoxy based nanodielectrics for electrical engineering applications. Epoxy based samples filled with micro and/or nanoparticles of silica were characterized by transmission electron microscopy, dielectric spectroscopy, conduction current and space charge measurements. These mutually complementary techniques were used to examine the effect of the size and quantity of silica particles on the electrical properties of the analyzed materials. The analysis of charge injection, polarization, trapping and conduction phenomena has allowed the modeling of dielectric behavior of the studied materials under multiple stresses. The Schottky Injection and Space Charge Limited Current models were studied to explain conduction phenomena. A composition of micro and nano-sized silica particles accumulating the smallest amount of space charge is also proposed.

Journal ArticleDOI
TL;DR: In this paper, the SiOxgraphite electrode with polyimide binder exhibited a stable capacity of 600 mAhg−1 during high-rate charge-discharge from C/4 to 1C.

Journal ArticleDOI
TL;DR: In this article, a single-phase unified power quality conditioner (UPQC) is proposed to enhance power quality problem in single phase systems using a simple control approach and validated through simulation as well as experimental studies.
Abstract: This study is based on a single-phase unified power quality conditioner (UPQC) to enhance power quality problem in single-phase systems. A simple control approach is implemented and validated through simulation as well as experimental studies. A laboratory prototype of UPQC is designed and developed using a digital signal processor. The performance of UPQC is validated experimentally under several operating conditions. It is found that the UPQC in single-phase system effectively compensates the important power quality issues, such as the load reactive power, load current harmonics, voltage harmonics, voltage sag, voltage swell and voltage flicker. Under distorted source voltage having total harmonics distortion (THD) of 14.1% with a non-linear load producing a distorted current (THD of 30.98%), the UPQC simultaneously compensates these harmonics resulting sinusoidal source current (THD of 3.77%) and load voltage (THD of 2.54%).


Journal ArticleDOI
TL;DR: A new type of radionuclide extraction material is reported based on phosphonate functionalities covalently anchored on the mesopore surface of 3-D cubic mesoporous silica (KIT-6).

Book ChapterDOI
TL;DR: After the LGM, the Eastern Sector of the LIS evolved from a single centre into peripheral connected or detached ice masses, with ice streams in the St. Lawrence Corridor and Hudson Strait.
Abstract: After the LGM, the Eastern Sector of the LIS evolved from a single centre into peripheral connected or detached ice masses, with ice streams in the St. Lawrence Corridor and Hudson Strait. Ice over the Appalachians evolved to separate local ice caps. From 13 to 6 cal. ka, the deglaciation pattern of the main dome is roughly concentric in the southern margins, with early YD moraines. By ca. 7.5 cal. ka, the remaining Holocene glaciated area was about 0.55 × 106 km2.

Journal ArticleDOI
TL;DR: In this paper, an exhaustive simulation study performed to validate the adequacy of the equivalence method promoted by the National Renewable Energy Laboratory for modeling wind power plants by single-and multiple-machine equivalents is presented.
Abstract: This paper presents an exhaustive simulation study performed to validate the adequacy of the equivalencing method promoted by the National Renewable Energy Laboratory for modeling wind power plants by single- and multiple-machine equivalents. The main simulation results are presented for a number of steady state and transient wind turbine generator operating conditions following various faults and a typical low-voltage ride through. The impact of protection systems such as the crowbar is also taken into account. The aggregation technique has shown to be adequate for load flow, stability, and electromagnetic transient studies with limitations, as presented in the paper.

Journal ArticleDOI
TL;DR: In this article, surface water pCO2 and pCH4 measurements were taken in the boreal zone of Quebec, Canada, from summer 2006 to summer 2008 in Eastmain 1 reservoir and two nearby lakes.
Abstract: . Surface water pCO2 and pCH4 measurements were taken in the boreal zone of Quebec, Canada, from summer 2006 to summer 2008 in Eastmain 1 reservoir and two nearby lakes. The goal of this follow-up was to evaluate annual greenhouse gas (GHG) emissions, including spring emissions (N.B. gross emissions for reservoir), through flux calculations using the thin boundary layer model. Our measurements underscored the winter CO2 accumulation due to ice cover and the importance of a reliable estimate of spring diffusive emissions as the ice breaks up. We clearly demonstrated that in our systems, diffusive CH4 flux (in terms of CO2 equivalent) were of minor importance in the GHG emissions (without CH4 accumulation under ice), with diffusive CO2 flux generally accounting for more than 95% of the annual diffusive flux. We also noted the extent of spring diffusive CO2 emissions (23% to 52%) in the annual carbon budget.

Journal ArticleDOI
TL;DR: Results indicate that the new area had a positive impact on the reproductive success of lake sturgeon in the Des Prairies River, where from 1994 to 2003, strong cohorts in the lower St. Lawrence system were related to high larval drift in this river.
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.

Journal ArticleDOI
TL;DR: The reliability of the proposed approach to deal with single and multiple parameter errors in adjacent and non-adjacent branches, as well as in parallel transmission lines with series compensation, is confirmed on tests performed on the Hydro-Québec TransÉnergie network.
Abstract: This paper proposes a three-stage offline approach to detect, identify, and correct series and shunt branch parameter errors. In Stage 1 the branches suspected of having parameter errors are identified through an Identification Index (II). The II of a branch is the ratio between the number of measurements adjacent to that branch, whose normalized residuals are higher than a specified threshold value, and the total number of measurements adjacent to that branch. Using several measurement snapshots, in Stage 2 the suspicious parameters are estimated, in a simultaneous multiple-state-and-parameter estimation, via an augmented state and parameter estimator which increases the V-θ state vector for the inclusion of suspicious parameters. Stage 3 enables the validation of the estimation obtained in Stage 2, and is performed via a conventional weighted least squares estimator. Several simulation results (with IEEE bus systems) have demonstrated the reliability of the proposed approach to deal with single and multiple parameter errors in adjacent and non-adjacent branches, as well as in parallel transmission lines with series compensation. Finally the proposed approach is confirmed on tests performed on the Hydro-Quebec TransEnergie network.

Journal ArticleDOI
TL;DR: In this article, a new noise rate-based factor called the Noise rate Order Factor (NOF) is introduced for use in the effective selection of model order and noise rate estimation.

Proceedings ArticleDOI
24 Jul 2011
TL;DR: In this article, an exhaustive simulation study performed to validate the adequacy of the equivalence method promoted by the National Renewable Energy Laboratory for modeling wind power plants by single-and multiple-machine equivalents is presented.
Abstract: This paper presents an exhaustive simulation study performed to validate the adequacy of the equivalencing method promoted by the National Renewable Energy Laboratory for modeling wind power plants by single- and multiple-machine equivalents. The main simulation results are presented for a number of steady state and transient wind turbine generator operating conditions following various faults and a typical low-voltage ride through. The impact of protection systems such as the crowbar is also taken into account. The aggregation technique has shown to be adequate for load flow, stability, and electromagnetic transient studies with limitations, as presented in the paper.

Journal ArticleDOI
Alain Moreau1
TL;DR: In this article, the authors present a control strategy for water heaters that minimizes the pick-up demand when the heating elements are reactivated at the end of a load shifting period and that ensures, in all cases, the client's hot water supply.

Journal ArticleDOI
TL;DR: In this article, the throughput requirements for the ITER fuelling system were estimated considering the major system functions, including the ELM pace-making and control of the divertor power loading.

Proceedings ArticleDOI
24 Jul 2011
TL;DR: In this paper, the notion of flexibility is applied to assess the quality of a solution strategy, based on some initial criterion for a given scenario, for example reliability, and then on its success in satisfying a set of scenarios.
Abstract: This paper reviews the notion of flexibility and applies it to the problem of power system adequacy of supply and reserve computations in the face of a class of input uncertainties. It first presents some definitions given to flexibility and flexibility indices in the power systems and process control industries. This is by no means a comprehensive review, but it does highlight some of the main ideas in the field. The notion of flexibility is applied to assess the quality of a solution strategy, based on some initial criterion for a given scenario, for example reliability, and then on its success in satisfying a set of scenarios. The paper then illustrates the use of a flexibility index borrowed from the process control literature to evaluate a solution strategy that provides balancing reserves to mitigate wind generation uncertainties. The paper concludes that flexibility can only be obtained at a cost and that it could prove itself to be a useful tool for the operator in an emerging technological environment.

Journal ArticleDOI
TL;DR: In situ high-resolution transmission electron microscopy (HRTEM) studies of the structural transformations that occur during the synthesis of carbon-coated LiFePO 4 and heat treatment to elevated temperatures were conducted in two different electron microscopes.

Journal ArticleDOI
TL;DR: In this paper, the authors study mixtures of distributions with normal, gamma, and Gumbel components, where gamma mixtures are developed to model strictly positive hydrological data and gumbel mixtures for extreme variates.
Abstract: [1] Whether mixtures of distributions are employed as a flexible modeling device to estimate densities or are used to model data thought to arise from several populations, they provide an efficient tool to approximate a distribution. Indeed, mixtures of distributions can model multiple modes, different types of skewness, etc., but they can also be employed to classify observations from heterogeneous data sets. In this paper, we study mixtures of distributions with normal, gamma, and Gumbel components. Moving away from the standard normal setting, gamma mixtures are developed in order to model strictly positive hydrological data and Gumbel mixtures for extreme variates. Since the data analyzed can exhibit dependency through time, we treat both the independent and dependent cases, where the latter is modeled through a Markov process. A fairly unified approach is adopted for the different distributions and the problem is treated from the Bayesian perspective, which enables us to use marginal densities to automatically compare the adequacy of the different models for a given data set. This model-selection framework allows us to formally test the relevance of using mixture models by computing the marginal likelihoods of single distribution models and to verify the presence of a persistence in the time series by comparing independent and identically distributed (IID) and Markovian mixture models.

Journal ArticleDOI
TL;DR: The Peribonka dam construction as mentioned in this paper involved deep compaction of its foundation using vibroflotation and dynamic compaction, and surface wave testing was used, in addition to classical tests (cone pen...
Abstract: The construction of the Peribonka dam involved deep compaction of its foundation using vibroflotation and dynamic compaction. Surface wave testing was used, in addition to classical tests (cone pen...

Journal ArticleDOI
TL;DR: In this paper, the authors consider a hydrological event that took place in 2003 on the Gatineau watershed in Canada and caused management difficulties in a hydropower production context and show that with minimal post-processing of the forecasts, it is still beneficial to exploit ensemble rather than deterministic forecasts, even if the latter emerge from a more advanced meteorological model and possess superior spatial resolution.
Abstract: . Ensemble forecasts can greatly benefit water resources management as they provide useful information regarding the uncertainty of the situation at hand. However, weather forecasting systems are evolving and the cost for reanalysis and reforecasts is prohibitive. Consequently, series of ensemble weather forecasts from a particular version of the forecasting system are often short. In this case study, we consider a hydrological event that took place in 2003 on the Gatineau watershed in Canada and caused management difficulties in a hydropower production context. The weather ensemble forecasting system in place at that time is now obsolete, but we show that with minimal post-processing of the forecasts, it is still beneficial to exploit ensemble rather than deterministic forecasts, even if the latter emerge from a more advanced meteorological model and possess superior spatial resolution.