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Halifax, Canada

Fenton G.A.,Dalhousie University | Sutherland N.,Nova Scotia Power Inc.
IEEE Transactions on Power Delivery | Year: 2011

It is well known that environmental loads, e.g., wind and ice, acting on power transmission lines are highly uncertain, as are the structural strengths of the towers supporting the lines. The design of such systems must take uncertainty into account in order to achieve acceptable reliability at a reasonable cost. The paper presents a simulation-based methodology for the optimal design of a transmission line which considers uncertainties in both environmental loads and structural resistance. The methodology is developed and illustrated for the simple problem of determining the optimal span length required for designing against tower failure. Wind, ice, and tower resistances are simulated over the extent of the transmission line and over the design life of the transmission system. Total expected system cost, along with the estimated probability of lifetime failure, are produced for a range of possible span lengths, allowing an informed decision regarding the optimum span length for the tower strength limit state. © 2010 IEEE.

Han Y.,Nova Scotia Power Inc. | Chang L.,University of New Brunswick
2nd International Symposium on Power Electronics for Distributed Generation Systems, PEDG 2010 | Year: 2010

This paper discusses the accuracy of the prediction of aggregated wind power of planned wind farms distributed in the Maritime Canada. Especially this study calculates and analyzes the aggregated regional wind power forecast error compared to single sites. Using simulated measured wind power and expected wind power from 5 planned wind farms, this research finds that the reduction of the ensemble wind power forecast error depends on the size of the region. To generate these findings, the spatial correlation function of prediction error is applied to calculate the ensemble wind forecast error based on arbitrary configurations of wind farms and wind generations, as long as the total installed wind capacity is a fixed number for selected planned wind farms. The validation of the spatial smoothing effects will provide the Maritime utilities an alternative method to reduce the regional aggregated wind power forecast errors instead of using costly wind prediction system. © 2010 IEEE.

Vercaemer B.,Bedford Institute of Oceanography | Sephton D.,Bedford Institute of Oceanography | Nicolas J.M.,Nova Scotia Power Inc. | Howes S.,Bedford Institute of Oceanography | Keays J.,Canadian Coast Guard
Aquatic Invasions | Year: 2011

Life history processes, such as reproduction, survival and growth, are known to be strongly affected in ascidians by different types of environmental factors including temperature and salinity. In a field study conducted from 2005 to 2009 in southern Nova Scotia, an area affected by invasions of Ciona intestinalis, low winter and high summer temperatures were shown to be strongly associated with intra- and inter- annual variation in larval recruitment. No clear patterns of association were seen with other environmental variables such as chlorophyll and indices of nutrient concentrations. In a 12 week challenge experiment in the laboratory, survival and growth of juvenile C. intestinalis were affected by both salinity and temperature. Individuals exposed to high temperature (25°C) and low salinity (20) did not survive the sustained exposure. In addition, Individual Specific Growth Rates were shown to decrease as salinity decreased. Temperature and salinity are factors which will subsequently influence distribution, persistence and potential for spread of adult populations. New favourable temperature and salinity conditions (e.g., potentially resulting from global climate change) will likely alter the distribution patterns of C. intestinalis. Conversely, infestation management techniques or site selection could benefit from unfavourable sustained temperature and salinity conditions.© 2011 REABIC.

Sephton D.,Bedford Institute of Oceanography | Vercaemer B.,Bedford Institute of Oceanography | Nicolas J.M.,Nova Scotia Power Inc. | Keays J.,Canadian Coast Guard
Aquatic Invasions | Year: 2011

The shellfish culture industry in Atlantic Canada has been adversely affected by the presence of non-indigenous, invasive tunicates since the mid-1990's. A Fisheries and Oceans Canada Aquatic Invasive Species (DFO-AIS) monitoring program documented the presence, establishment, and spread of five tunicate species at geo-referenced coastal monitoring stations in Nova Scotian waters from 2006-2009. Styela clava (Herdman, 1881) and Didemnum vexillum (Kott, 2002) were not found in Nova Scotia during the course of this study, despite their problematic presence in Prince Edward Island and the Gulf of Maine, respectively. Botryllus schlosseri (Pallas, 1766) was the most widely distributed species, found at more than 69% of sites monitored in all years. Ciona intestinalis (Linnaeus, 1767) was present at about half of the stations in all years, and while its populations were heaviest and most persistent in the Halifax - St. Margaret's Bay, Shelburne - Port La Tour, and Canso - Isle Madame areas, there was evidence of spread on the eastern and Fundy shores, and in Cape Breton. Botrylloides violaceus (Oka, 1927), was the least common tunicate encountered, but its distribution increased from 19% of stations in 2006 to 50% of stations in 2009. Tunicates occupied a wide variety of hard substrates (natural and artificial) in waters with 13.0 to 33.2 salinity and at oxygen saturations of 32.5 to 124.8%. © 2011 REABIC.

Cheema H.,Dalhousie University | Sidhu M.,Dalhousie University | Qabil S.,Dalhousie University | Aly H.H.,Acadia University | MacNeil R.,Nova Scotia Power Inc.
Canadian Conference on Electrical and Computer Engineering | Year: 2015

Risk profile of a working plant is one of the most important topics these days. The risk profile of plant/equipment is a kind of new method and different approach for planning and troubleshooting in the electric power industry. This paper discusses this new method of risk assessment of equipment operation in the working plants, the whole procedure is designed, developed and implemented for the equipment risk assessment, and the use of each part in the scheme is described in detail. Then, the several recommendations are proposed to increase the effectiveness of the scheme, and the scheme of the plant equipment risk assessment is summarized, the advantages and disadvantages of the scheme are explained. © 2015 IEEE.

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