Manitoba Hydro Research Articles

An overview of the NEMO modelling for the BaySys project

This article is intended as an introduction to discuss the development of a modelling framework to examine simulated climate change and river discharge regulation and their combined impact on marine conditions in the Hudson Bay Complex as a contribution to BaySys, a collaborative project between Manitoba Hydro, Hydro-Quebec, the University of Manitoba, the University of Alberta, Université Laval and Ouranos. In support of this work, a sea ice and oceanographic model was improved and then used to further study the effects of freshwater loading and ice cover on the circulation of Hudson Bay. This modelling perspective is based on the Nucleus for European Modelling of the Ocean (NEMO) ocean general circulation model coupled to version 2 of the Louvain-la-Neuve sea ice model (LIM2). The goal of the modelling was to provide a framework and tool for simulating projected changes in marine state and dynamic variables, while also enabling an integration of observations and numerical analyses. A key aspect of this work was the climate-hydrologic-ocean model integration aspect. The inclusion of a biogeochemical model and explicit tidal forcing to examine the evolution of a Canadian marginal sea with century-long integrations was also a novel aspect of the work. Overall, this work examines the NEMO modelling configuration used in BaySys, how it is set up and the experiments carried out. A broader picture evaluation of the model output is made including the BaySys mooring observations, showing that the modelling framework is suitable to examine the posed questions on the role of climate change and river regulation.

Statistical modeling of ice cover impact on flow conveyance in the Nelson River West Channel

For cold regions, an ice cover reduces channel conveyance and hydroelectricity generation potential. Therefore, predicting the impact of ice cover on a river-reservoir system is of critical importance for hydro producers. Ice impact can be described using historical records, where typical conditions are characterized by a daily median ice factor (IF) curve. The daily median IF curve works well only for past years with typical climatic conditions. Moreover, the median curve would not respond to climate-induced changes in the ice cover. In this research, a novel statistical (ST) model, named ST-IF, is developed to simulate the impact of river ice on the conveyance of the Nelson River West Channel (NRWC) as a function of daily air temperature. ST-IF uses a series of statistically based functions, including regression and threshold functions to estimate different characteristics of IF, such as its initial and peak values, and its daily distribution during ice-on period. Model performance was evaluated against historical records and the daily median value of the ice cover impact. Results showed that ST-IF significantly improved the simulation of each year-specific IF curve in NRWC compared to the daily median curve. Moreover, the model was used to predict the impact of ice cover under future climate conditions using 19 climate simulations. Results showed that, due to the predicted warmer future, ice cover is expected to take longer to fully form. This leads to longer Ice Stabilization Program duration, higher program implementation cost, and potential additional downstream stakeholder impacts. In addition, earlier ice impact peak date, shorter ice impact duration, and lower ice impact magnitude leading to overall higher winter hydroelectricity generation potential for Manitoba Hydro are expected in the future. Such future alterations intensify from near to far future time periods.

A Novel Toolbox for Induced Voltage Prediction on Rail Tracks Due to AC Electromagnetic Interference Between Railway and Nearby Power Lines

AC electromagnetic interference (EMI) between railway and nearby power lines causes serious concerns about railway personnel and equipment safety. The AC EMI analysis is usually conducted by complex computer simulation software to estimate induced voltages on rail tracks, and induced voltages can be further used for safety evaluation. However, such analysis becomes especially difficult at the transmission line routing stage when only limited information of railway and power lines is available. To overcome this challenge, a novel regression model-based toolbox is developed in this paper to predict induced voltages on rail tracks. To develop this toolbox, the dataset acquisition is critical due to very limited research done in this area. The novel dataset is produced by our newly developed AC EMI study method, where variations of several essential factors are considered, including the power line's current, the separation distance between power lines and railway, the ballast resistance, and the length of rail tracks. Two models are eventually chosen to predict induced voltages: “Gaussian process regression” with “matern 3/2” kernel function; and a tri-layered “neural network” model with “sigmoid” activation function. To improve the accuracy, hyperparameters of the regression algorithms are optimized by Bayesian optimization. The toolbox is accurate and easy-to-use, and is currently in use by Manitoba Hydro, Canada.

Looking Back inKewekapawetan: Return After the Flood. Research, Remembrance and Reclamation of a Hydro Story

This essay analyses Jennifer Dysart’s 2014 documentary film Kewekapawetan: Return After the Flood, which tells the past and present-day story of the Northern Manitoba Ithinew (Cree) community South Indian Lake and its entanglement with Manitoba Hydro. Dysart documents the history of colonial hydro policy by showcasing rare archival footage from the late 1960s and reclaims this material for the community she has roots in. At the same time, she records her search to learn about her father’s life and her efforts to reconnect with family by spending time on the land. Discussion between author and filmmaker throughout the research and writing process engages “visiting” as a methodology for studying Indigenous narrative arts. Ultimately, Dysart’s visual storytelling is a critical site of knowledge-making about the dislocation caused by large-scale resource extraction that foregrounds reconnection to family, community and land.

The Severe Multi-Day October 2019 Snow Storm Over Southern Manitoba, Canada

ABSTRACT A devastating storm struck southern Manitoba, Canada on 10–13 October 2019, producing a large region of mainly sticky and wet snow. Accumulations reached 75 cm, wind gusts exceeded 100 km h−1, and surface temperature (T) remained near 0°C (−1°C ≤ T ≤ 1°C) for up to 88 h. It produced the largest October snowfall and was the earliest to produce at least 20 cm since 1872 in Winnipeg. These factors led to unparalleled damage and power restoration challenges for Manitoba Hydro and, with leaves still largely on vegetation, the most damaging storm to Winnipeg’s trees ever recorded. The storm’s track was uncommon, and produced elevated convection related to buoyancy-driven instability and conditional symmetric instability (CSI), with a moist absolutely unstable layer (MAUL) near 500 hPa. Instabilities were released via lift through lower-tropospheric warm advection and frontogenesis, differential cyclonic vorticity advection, and jet streak dynamics. Precipitation bands, elevated convection, and lake effect snow bands enhanced local snowfall. Snow adhering to structures was not always wet but, when present, it sometimes occurred because of incomplete freezing of particles partially melted aloft in a near-surface (<100 m deep) inversion. Although other storms over the historical record have produced a similar combination of severe precipitation, temperature and wind conditions, none have done this for such a long period.

Protection Coordination Method Using Symmetrical Components in Loop Distribution System

Power utilities worldwide commonly use the radial distribution system because of its advantages of being simple in structure and having relatively inexpensive installation costs. It has a disadvantage in that its power supply reliability is low because the load side of the fault section will suffer from an outage in the event of a fault in the system. However, recently, with ICT (Information and Communication Technologies) development, system reliability is required to be high as the outage-susceptible loads increase. In addition, the increase in the connection of distributed resources such as renewable energy and electric vehicles is making it impossible to predict the power flow and reducing line utilization. Therefore, a loop power distribution system is proposed as a measure to solve this problem. Because all buses (nodes) in a loop distribution system have two or more power supply routes, they are more reliable than the radial system. It allows them to improve line utilization by connecting lines with different load peak times. However, in the case of a fault in the loop distribution system, the fault current is supplied from both directions, making it impossible to properly isolate the fault section with the protection method of the conventional distribution system. The permissive overreach transfer trip (POTT) method using communication to compensate for the limitations of conventional protection devices, and the other method using directional distance relay, is proposed. However, these methods operate by determining the direction of the fault current but have a disadvantage. It is difficult to detect a fault due to the effects of ground faults and distributed generation (DG) occurring in other lines. Therefore, in this paper, we propose a protection coordination algorithm that uses the negative-sequence component of voltage and current that occur when an unbalanced fault occurs, rather than the determination of the directionality and use of communication. To validate this, we configured a system using PSCAD/EMTDC (Manitoba Hydro International Ltd., Winnipeg, Manitoba, Canada), a system analysis program package and verified the results depending on the type of faults with the proposed algorithm.

Large-scale hybrid real time simulation modeling and benchmark for nelson river multi-infeed HVdc system

Nelson River Bipole I/II Line Commutated Converter (LCC) HVdc system has been in operation for more than 40 years and carries about 70% of total Manitoba Hydro power. The recent addition of Bipole III has formed a multi-infeed HVdc system with tightly coupled converter stations at both ends. Due to the complexity of the three Bipoles in a multi-infeed system, a large-scale hybrid real time hardware-in-the-loop (HIL) simulation model was developed with a combination of software models in Real Time Digital Simulator (RTDS) for Bipole I/II and the hardware replicas for Bipole III controls to support Bipole III commissioning and the future three-bipole planning, operation and maintenance efforts. In the paper, a RTDS modeling approach of Bipole I/II AC/DC system is introduced and discussed. This modeling approach includes the strategic design to fully utilize the library components in the page modules for AC/DC controls and the modeling structure of dividing a large HVdc system into many standalone modular systems. The paper also describes the use of a large-scale hybrid simulation model during on-site commissioning of Bipole III system. Such engineering practice has significantly reduced the technical risks, financial cost and secured the success of the Bipole III commissioning.

Incorporating Multi-Year Asset Replacement Time Into Calculation of Asset's Expected Annual Unavailability Due to End-of-Life Failure

Aging asset management requires careful consideration of end-of-life of any asset. This is particularly serious with aging infrastructure which may require complete replacement of a large asset which has a long lead time. In many current End-of-Life analysis approaches to calculate unavailability, the period of interest is sub-divided into yearly cycles with the assumption that the asset is available at the start of the year. Although this assumption is adequate if the replacement time for the asset occurs within the year, with longer lead times this can create excessively optimistic availabilities. This paper presents an improved probabilistic tool for risk assessment due to End-of-Life failure unavailability which overcomes this deficiency. The End-of-Life methodology proposed in this paper is required when aging assets have long lead times to replacement and so the capital investment decision must be made several years ahead. The method is applied to evaluate the End-of-Life unavailability of Manitoba Hydro Bipole II HVdc converters. The results are corroborated using Monte Carlo simulation. Finally, the risk of End-of-Life is incorporated into an economic cost-benefit analysis corresponding to the presented unavailability evaluation method.

Investigation of Seasonal Variations of Tower Footing Impedance in Transmission Line Grounding Systems

In the transmission line grounding system design, spatial and temporal/seasonal variations of tower footing impedance should be considered. However, in real life, only spatial variations are taken into account at the design stage, seasonal variations have not been included. In this article, seasonal variations of tower footing impedance of several types of transmission line grounding systems at Manitoba Hydro, Canada, are investigated through field measurements for a whole year. The industrial practice uses simulated tower footing impedances by the software current distribution, electromagnetic interference, grounding and soil structure analysis (CDEGS) in the design of transmission line grounding systems, however, the accuracy of simulated tower footing impedances as a critical design parameter has never been evaluated. In this article, this industrial practice is evaluated by comparing simulated and measured tower footing impedances for various transmission line grounding systems. The importance to use proper tower footing impedance for lightning conditions is also demonstrated.

Kazim AliNorthern Light: Power, Land, and the Memory of Water

Swedish, Finnish, Catalan, Norwegian, Afrikaans, and Hungarian by writers who are regarded as leading the genre’s edge in their respective countries (only Spain is represented more than once). From the collection’s first story, Italian author Luigi Musolino’s “Uironda” (a story about a divorced trucker reminiscent of the best culture-critical writing of Stephen King and the most nihilistic impulses of Thomas Ligotti), to the last, late Spanish author José María Latorre’s “Snapshot” (a macabre but humorous story of a man obsessed with snapping shots of himself in a photo booth, revealing the grim truth of what he is), The Valancourt Book of World Horror Stories is a grand guignol of horrific oddities from across the world, representing as many subgeneric impulses and terrifying plays with the genre’s possibilities as there are stories. Of particular interest and terrifying conclusion are Attila Veres’s “The Time Remaining” (Hungary), Flore Hazoum é’s “Menopause” (Ivory Coast), Marko Hautala’s “Pale Toes” (Finland), and Yvette Tan’s “All the Birds” (Philippines). Lars Ahn’s “The Collection” (Denmark), about a couple who discover they’ll do anything to prove they are right for each other, is probably my favorite of the bunch. But the range of stories presented suggests no one will be without something to love. Many of these stories are translated by Jenkins and Cagle themselves, a remarkable feat, and particular attention was paid in the anthologizing process to diversity of gender, nation, race, and colonial subjectivity . The stories come from Europe, Latin America, Asia, and Africa, some from minority languages like Catalan, and all are interested at some level in power disparities (poor/rich, men/women, colonizer/colonized ). Jenkins and Cagle have promised a second volume of The Valancourt Book of World Horror Stories, and I can only hope that future anthologies in the series Books in Review Kazim Ali Northern Light: Power, Land, and the Memory of Water Minneapolis. Milkweed Editions. 2021. 200 pages. ON A NIGHT WHEN icy winds blew south off Lake Erie and shook the windows of Kazim Ali’s house in Oberlin, he remembered the Canadian winters of his youth and searched online for images of Jenpeg—the company town he’d lived in as a child. He finds little online about Jenpeg . It’s mostly gone, the modest network of residential homes for employees at the hydroelectric dam under construction on the Nelson River. Other regional headlines piqued his interest instead. In Cross Lake, across the waters from Jenpeg and home to the First Nations Pimicikamak community, Chief Cathy Merrick had made headlines for serving eviction papers to Manitoba electric -utility giant Manitoba Hydro. Chief Merrick had contended that Manitoba Hydro, the province of Manitoba, and the federal government of Canada had not fulfilled their agreements in the Northern Flood Agreement, the 1977 treaty with five northern Bands under which Manitoba Hydro received easement rights to build the generating station. The Jenpeg Generating Station and the former town of Jenpeg where Ali lived were on Pimicikamak sovereign territory. Now, the dam his father had built was negatively impacting the Pimicikamak’s community and changing the biodiversity of their unceded lands and waters. He read more: last winter, in Cross Lake, six young people between the ages of fifteen and eighteen had died by suicide in the space of two months. The Pimicikamak had declared a mental-health emergency, and, Ali writes, “the Elders in the community had gathered and performed a sacred ceremony calling on the spirits of the land and water to assist.” In the weeks that followed, he couldn’t get Cross Lake out of his mind. The contemporary concerns in Cross Lake alarmed him and recalled the years that Ali, who is queer, Muslim, and the child of South Asian migrants, had spent traveling through the Palestinian territory in the West Bank teaching yoga and training yoga teachers. “I’d seen the impacts of occupation and political disenfranchisement up close,” Ali writes, and “the sociopolitical impacts of colonialism.” He wonders about his own family’s complicity in the dam that his father had worked on at the Jenpeg Generating Station. Reflecting on his family’s culpability in the...

Daniel MendelsohnThree Rings: A Tale of Exile, Narrative, and Fate

continue the quality of terrifying tales presented while also giving us a better look at the world of horror in Asia, Africa, and eastern Europe. Sean Guynes Michigan State University Daniel Mendelsohn Three Rings: A Tale of Exile, Narrative, and Fate Charlottesville. University of Virginia Press. 2020. 128 pages. THIS UNIQUE BOOK by memoirist and classicist Daniel Mendelsohn traces with deep learning and imagination the relation between stories and the world. It revolves, on first glance, around groups of threes. Its three chapters consider the works of three unlikely literary companions: Erich Auerbach , François Fénelon, and W. G. Sebald. All three were exiles, and all three considered or reflected in their greatly varying works questions about narrative, fiction, and reality—and the relation of all three to one another. As the reader discovers, though, other authors and books also play profound roles in Mendelsohn’s meditations: his own widely admired memoirs, The Lost: A Search for Six of Six Million and An Odyssey: A Father, a Son, and an Epic; Homer’s Odyssey; Marcel Proust’s In Search of Lost Time; and the Turkish translation of Fénelon’s Télémaque, by Kamil Pasha, to mention just a few. All are carefully examined, thoroughly or briefly , in Mendelsohn’s subtle consideration of how narrative works and how it is related to reality. Mendelsohn is especially interested in how his three main authors deploy or discuss a number of challenging narrative strategies—elaborate digressions and attention to peripheral matters crucially among them—and how those strategies both serve and challenge their representations of the world. Mendelsohn is intensely aware, though, of how differently these sundry authors regard these narrative strategies. What the reader senses early on, and what gradually becomes an explicit theme of Mendelsohn’s book, is the divide between the “optimists,” for whom narrative strategies—no matter how digressive and seemingly aimless— lead to coherence and unity, and the “pessimists ,” for whom those same strategies lead to disorientation and dead ends. Sebald exemplifies this pessimistic strain most thoroughly, as opposed to the optimist Homer. “Like Homer,” Mendelsohn concludes , ”Sebald uses ring composition to great effect. But unlike the narrative rings, circles, digressions, and wandering that we What rights and responsibilities does “being from” a place saddle a person with? Ali, who has called many places home, asks: What does it mean to have a point of origin, a community to belong to, or several? With richly layered questions about place, home, colonialism, complicity, indigenous sovereignty, and his own activism and childhood memories in mind, Ali emailed Chief Cathy Merrick. He wanted to learn more about the daily social and environmental issues facing Cross Lake and told Merrick he’d grown up in Jenpeg. Her email back was brief but generous: “It is wonderful that you would reflect on your childhood. You are more than welcome to visit our Nation.” Shortly thereafter, he boarded a plane and flew north. Northern Light is a journey story that troubles the maxim “You can never go home again.” Ali does go home, but that home, the town of Jenpeg, is gone to boreal forests growing back in the glow of Manitoba Hydro. He goes home to humble himself before the Pimicikamak community on whose ancestral lands he’d lived, unbeknownst to him, as a child. Ali returns to listen and be in dialogue with a community that has long called the waterways of the Nelson River their home. He returns to look closer and more tenderly at a place that is and is not familiar, that does and does not belong to him. His journey to Cross Lake is full of connections, burgeoning friendships, late-night hockey games, brunches honoring mothers, and school visits. Ali is a kind and attentive listener, curious , always a warm presence on the page. Always eager for more. What do we each owe to the places we call home, and what can we give back to them, and to each other? Ali’s ethical imaginary is as finely honed and illuminating as his prose. “We belong to the places of our earliest griefs, belong to where we left our dead, and belong to places where...

Impacts of a LVRT Control Strategy of Offshore Wind Farms on the HTS Power Cable

High temperature superconducting (HTS) power cables are a potential solution for the grid integration of offshore wind farms since the HTS cable can conduct bulk wind power at low voltage levels. However, the transient current through the HTS cable in cases of low voltage ride through (LVRT) operation has a negative impact on the HTS cable operation due to the quenching phenomenon. This paper analyzes the impact of LVRT control strategies on the HTS cable operation. In addition, a coordinated control of wind turbines for LVRT improvement of an offshore wind farm is proposed. The feasibility of the HTS cable application for the grid connection of offshore wind farms is also discussed in this study. The proposed controller is designed for the wind turbine generator based on a type-4 permanent magnet synchronous generator. In the proposed controller, the transient current through the HTS cable is reduced by regulating the machine side power during fault conditions. The feasibility of the proposed controller is validated in the PSCAD/EMTDC program (Manitoba Hydro International Ltd., Winnipeg, Manitoba, Canada, version 4.2.1). The effects of transient current on the cable temperatures and resistances are analyzed in this study. Simulation results show that the proposed control strategy could reduce the transient current and temperature rise of the HTS cable.

Naming Home

Naming Home Kazim Ali (bio) Click for larger view View full resolution From 1975 to 1979, my family lived in Jenpeg, north of Lake Winnipeg, in Manitoba, Canada. Manitoba Hydro had built the town for its employees to live in during the construction of the Jenpeg Generating Station, which spans the Nelson River and provides electricity to the province. I was around four when we moved there after my father took a position with Manitoba Hydro, and seven when we left. In March 2016, the Indigenous community of Pimicikamak, upon whose land the dam is built, declared a state of emergency. In the two months before, six young people in the community had died by suicide, with one hundred forty attempts in the preceding two weeks. Now, after more than forty years, I've returned north, at the invitation of the Pimicikamak government, to discover what happened in the intervening years. [End Page 19] When I say Jenpeg, I mean the old town, but when the Pimicikamak people say Jenpeg, they mean the actual dam site on the river, and the dormitory next to it where all the workers live now. This slight shift is disconcerting to me, because even if the town doesn't exist anymore, it still exists in my memory, through the shadows of the long decades between me and the boy who lived there. I find myself sad that not only might the town be really gone, but even the name I knew for it has been reassigned to another place. As the story goes that I always heard in my childhood, the town was named for two women, Jenny and Peggy, who worked in the Winnipeg-based procurement and supplies offices of Manitoba Hydro. It's morning, early in my trip, and I've asked to visit the site of the old company town. Jackson Osborne, one of the elders who has been sharing stories with me about the building of the dam and its impact on the lake's ecosystem, has asked if he can come along on the drive. My childhood romanticism, my undefined longing for some place to think of as home, will be tempered by the presence of another, but I agree. Darrell Settee, the emergency rescue coordinator for the Pimicikamak government, whom I met the day before, is going to drive us, because he has a pickup truck, which will be better than a car on the rough dirt roads between Cross Lake and Jenpeg. There was no way the child Kazim could ever have known that Darrell and Jackson lived not far away when I lived here in the north, so I am happy they are accompanying me back. When Darrell arrives, we drive to the NorthMart grocery store to pick up some water and provisions, since we won't back until late in the afternoon. It's funny that the produce in the grocery store—strawberries, blueberries—is all labeled watsonville, ca. These are the same berries I buy at home. Like me, they have traveled a long way to get here. When I lived here with my family, and there was no road between the two towns, it was only possible to fly in to Cross Lake, and many parts of the community needed improvements in infrastructure. Part of the Northern Flood Agreement, the treaty the province signed in 1977 in order to build the dam, was a commitment to build a causeway across the place where the Nelson River flows through the two arms of Cross Lake, connecting the main town with the northern portion of the reserve, which was cut off due to flooding as a result of the dam. The causeway was eventually built—after three separate appeals and further litigation—but it is now in need of repair, and its design took into account only normal cars and smaller trucks. According to Darrell, depending on the season and the water levels, school buses that cross it sometimes must pause at one end, have the students exit and follow the bus on foot, then reboard. The NFA also contained a provision to fund another bridge across the Nelson River, called by the Pimicikamak Kichi...

Behavior of Protective Relays During Subsynchronous Resonance in Transmission Line and Adaptation of Generator Out-of-Step Protection

Subsynchronous resonance (SSR) is a phenomenon in which electrical energy is exchanged between the generator and the transmission system below power frequency. SSR occurs due to the interaction of a series-compensated transmission line with a generator. It results in shaft oscillation and out-of-step (OOS) condition. During SSR, the magnitude of voltage and current is increased. It also increases probable occurrence of ferroresonance. It is obviously clear that protective relays are affected in such conditions. In this article, Manitoba Hydro electrical network is examined with series capacitors by PSCAD/EMTDC to investigate the impact of SSR on the operation of different types of protective relays. SSR is mostly concerned with transmission lines. In addition, swing characteristic of impedance during SSR causes activation of the OOS blocking (OSB) element of distance relay and OOS protection of generator. Hence, an adaptive algorithm based on subharmonic measurement and ferroresonance analysis in the time domain is proposed for OOS characteristic of generator protective relay to recognize SSR condition and make a decision on behavior of the function. Finally, the algorithm is examined in SSR condition to certify the correct operation.

Minimum Separation Distance Between Transmission Lines and Underground Pipelines for Inductive Interference Mitigation

A method to determine the minimum horizontal separation distance between transmission lines and underground pipelines for inductive electromagnetic interference mitigation under normal operation of transmission lines is proposed in this paper. The proposed method takes both AC corrosion of pipelines and a 15 V touch voltage safety limit into account. For a pipeline facility of Manitoba Hydro, soil resistivity is firstly measured at 20 locations near the pipeline; a soil model is then created for each location using the RESAP module in CDEGS software package. Two critical soil resistivity values for AC corrosion limit and 15 V voltage limit are selected for this pipeline facility. After the soil model is determined, the HIFREQ module in CDEGS is used to simulate the induced AC voltage, and a minimum separation distance can be recommended. Four voltage classes of transmission lines, 115 kV, 138 kV, 230 kV, and 500 kV, are considered. Two curves and their empirical models are created for each voltage class to determine the minimum separation distance. The modeling method is validated using two case studies with field measurements. The proposed method and guidelines can significantly improve the future line route selection process for new transmission lines.

The Bill McDermid test hall at Manitoba Hydro

The Bill McDermid test hall at Manitoba Hydro

Young professionals

I joined the Manitoba Hydro High Voltage Test Facility as an Insulation Systems Test Engineer in January 2016. As part of my regular duties, I plan, coordinate, and execute accelerated aging and diagnostic tests on generator stator coils/bars for external commercial customers and Manitoba Hydro. Since day one, my supervisor, Nathan Jacob, has recommended that I attend the Electrical Insulation Conference (EIC) and IEEE Materials Subcommittee Working Group meetings. He emphasized that attending the EIC not only benefits our Test Facility but also my professional development and future career progression.

Flow alteration impacts on Hudson Bay river discharge

AbstractThis study explores flow regulation controls on daily river discharge variations and trends into Hudson Bay from four highly regulated and 17 moderately regulated/unregulated systems over 1960–2016. These 21 rivers contribute ~70% of the total annual riverine freshwater export to Hudson Bay, with highly regulated and moderately regulated/unregulated rivers accounting for 47% and 53% of the discharge, respectively. Daily observed streamflow data from the Water Survey of Canada, Manitoba Hydro, Ontario Power Generation, and Hydro‐Québec are used. Decadal hydrographs of the mean and coefficient of variation of daily river discharge are developed to assess the changing hydrological regimes in both systems. Decadal spectral analyses reveal the dominant controls on daily river discharge input to Hudson Bay from the regulated and unregulated systems. Apart from expected peaks in spectral power on annual timescales arising from the nival regimes in both systems, a strong secondary peak emerges at weekly timescales from flow regulation due to hydropower production. Hydrographs that consider the day of the week reveal distinct weekly cycles in regulated rivers with ~10% declines in daily river discharge during weekends and statutory holidays relative to weekday averages, demonstrating the importance of regulation on the timing of freshwater into Hudson Bay.

Statistical testing for load models using measured data

This paper applies the statistical testing theory to examine the validity of different load parametric models. Traditionally measurement-based static load modeling has been performed based on a single parametric model. Commonly utilized models include: ZIP (constant-impedance–constant-current–constant-power) model, exponential model, and frequency component adjusted ZIP/exponential models. It has been conjectured that the models making use of the frequency feature should be better compared to the ones purely based on the voltage component. However, there has not been any theoretical-based justification to confirm this claim. It is a goal of this paper to provide a formal method for verifying this claim by employing the theory of statistical testing for correct parametric model specification. In particular, a class of F-tests for checking the correctness of the specific load model is employed. Our methodology is verified on the real phasor measurement unit (PMU) data describing a radial load in the Manitoba Hydro power system. The obtained results confirm the usefulness of the frequency component based models.

An Adaptive Algorithm Based on Subharmonic and Time Domain Analysis to Prevent Mal Operation of Overcurrent Relay During Subsynchronous Resonance

Subsynchronous resonance (SSR) is a phenomenon in which electrical energy is exchanged between generators and transmission systems below power frequency. It happens due to interaction of a series compensated transmission line with a generator. It results in oscillation in the shaft and power swing. In addition, SSR causes increased magnitudes of voltage and current consequently occurrence of ferroresonance. It is obviously clear that protective relays are affected in such conditions. SSR can be damped by several methods; however, protective relays must be adaptive to prevent mal operation independently. In this paper, Manitoba Hydro electrical network with series capacitor is simulated by PSCAD/EMTDC. The impact of SSR and ferroresonance on operation of overcurrent relay is analyzed. An adaptive algorithm based on subharmonic measurement and ferroresonance analysis in time domain is proposed for overcurrent relay. The algorithm detects SSR and ferroresonance, and changes setting values of the relay to prevent mal operation. Furthermore, it distinguishes protection of the hydro generator against subharmonics, which interact with natural frequencies of the rotor. Finally, the algorithm is examined in SSR condition to certify the correct operation.