This report focuses on the impacts of traffic generated as a result of the windmill on pavement structures. The wind energy industry is a fast growing sector of the U.S. economy. Lately concerns have been raised over the transportation of heavy windmill components on the pavement infrastructure. This report analyzes the impacts of windmill traffic on two pavement structures in Texas: 1) rural interstate facility, and 2) rural collector roadway facility. Windmill traffic was disaggregated by windmill component and categorized into eight vehicle classes. Two traffic scenarios were developed and a damage ratio for pavement rutting was developed. Based on the rutting damage ratio, results showed that windmill traffic has a significant impact on rural collector facilities when compared against normal truck traffic activity. Meanwhile, impacts on rural interstate facilities were determined to be insignificant when compared to normal truck traffic activity. / text

Galloping of structures such as transmission lines and bridges is a classical aeroelastic instability that has been considered as harmful and destructive. However, there exists potential to harness useful energy from this phenomenon. The study presented in this paper focuses on harvesting wind energy that is being transferred to a galloping beam. The beam has a rigid prismatic tip body. Triangular and D-section are the two kinds of cross section of the tip body that are studied, developed and tested. Piezoelectric sheets are bonded on the top and bottom surface of elastic portion of the beam. During galloping, vibrational motion is input to the system due to aerodynamic forces acting on the tip body. This motion is converted into electrical energy by the piezoelectric (PZT) sheets. A potential application for this device is to power wireless sensor networks on outdoor structures such as bridges and buildings. The relative importance of various parameters of the system such as wind speed, material properties of the beam, electrical load, beam natural frequency and aerodynamic geometry of the tip body is discussed. A model is developed to predict the dynamic response, voltage and power results. Experimental investigations are performed on a representative device in order to verify the accuracy of the model as well as to study the feasibility of the device. A maximum output power of 1.14 mW was measured at a wind velocity of 10.5 mph. / text

Στην εργασία μελετάται η ανάλυση και ο έλεγχος μετατροπέων αιολικής ενέργειας (ανεμογεννήτριες) και συγκεκριμένα μία ανεμογεννήτρια η οποία χρησιμοποιεί σύγχρονη γεννήτρια με 2 τριφασικά τυλίγματα στο στάτη και με διασύνδεση συνεχούς ρεύματος. Παρουσιάζεται η μοντελοποίηση της γεννήτριας, του ανεμοκινητήρα και της διασύνδεσης συνεχούς ρεύματος. Στη συνέχεια σχεδιάζονται διάφοροι τρόποι ελέγχου ώστε να είναι δυνατή η σύνδεση της ανεμογεννήτριας σε ασθενή δίκτυα μέσης τάσης, σε απομονωμένα φορτία αυτόνομα και σε συνεργασία με υδροηλεκτρικό σταθμό. / In this thesis, the analysis and control of wind energy conversion systems is studied. The chosen wind energy converter consists of an horizontal-axis three-blade pitchable wind turbine, a six-phase synchronous generator and an AC/DC/AC link. The operation is based on a variable-speed constant-frequency scheme that is achieved through two different AC/DC/AC topologies and the appropriate pulsation of the IGBT converters. The aerodynamic torque on the wind turbine is modeled by a special non linear equation, which also includes the pitch angle as an extra variable for the control of the aerodynamic power. The simulation program SIMULINK has been used for the modeling and the study of the various systems under large variations of the wind speed.

In response to energy crisis and power quality concerns, three different methodologies to integrate the concept of active filtering into the alternators are proposed. Wind energy, due to its free availability and its clean and renewable character, ranks as the most promising renewable energy resource that could play a key role in solving the worldwide energy crisis. An Integrated Doubly-fed Electric Alternator/Active filter (IDEA) for wind energy conversion systems is proposed. The proposed IDEA is capable of simultaneous capturing maximum power of wind energy and improving power quality, which are achieved by canceling the most significant and troublesome harmonics of the utility grid and power factor correction and reactive power compensation in the grid. The back-to-back current regulated power converters are employed to excite the rotor of IDEA. The control strategy of rotor-side power converter is based on position sensoreless field oriented control method with higher power density. Analysis and experimental results are presented to demonstrate the effectiveness of the proposed IDEA. In next step, an integrated synchronous machine/active filter is discussed. The proposed technology is essentially a rotating synchronous machine with suitable modification to its field excitation circuit to allow dc and ac excitations. It is shown that by controlling the ac excitation, the 5th and 7th harmonics currents of the utility are compensated. The proposed method is cost effective because it can be applied to existing standby generators in commercial and industrial plants with minimal modification to the excitation circuits. To boost the gain of harmonic compensatory, an advanced electric machine is proposed. An Asymmetric Airgap Concentrated Winding Synchronous Machine (AACWSM) with ac and dc excitation was designed and employed. It is shown that the AACWSM with its unique design, in addition to power generation capability, could be used to compensate the most dominant current harmonics of the utility. The proposed AACWSM can compensate for the 5th and 7th harmonics currents in the grid by controlling the ac field excitation. In addition, the 11th and 13th harmonics currents are also significantly reduced. This system can be used at medium and low voltages for generation or motoring mode of operation.

Due to growing concerns over climate change, more and more countries are looking to renewable energy sources to generate electricity. Therefore, wind turbines are increasing in popularity, along with doubly-fed induction machines (DFIGs) used in generation mode. Current grids codes require DFIGs to provide voltage support during a grid fault. The fault ride-through (FRT) capability of DFIGs is the focus of this thesis, in which modifications to the DFIG controller have been proposed to improve the FRT capability. The static synchronous compensator (STATCOM) controller has been applied with proposed method to study its influence on the voltage at the point of common coupling (PCC). The proposed method was also compared with other FRT capability improvement methods, including the conventional crowbar method. The simulation of the dynamic behaviour of DFIG-based wind turbines during grid fault is simulated using MATLAB/Simulink. The results obtained clearly demonstrate the efficacy of the proposed method.

Sandhill Crane (Grus canadensis) migratory populations use wetland ecosystems on northern Vancouver Island for their breeding habitat. With wind energy development being proposed for the area, an ecosystem-based management approach is being used to maintain Sandhill Crane breeding habitat and biological diversity within the bog wetland complex of the Nahwitti Plateau at the northern tip of the island. Shelter, forage and nesting habitat suitability were identified and rated with a six-class scheme from April to October over a two-year period. Vegetation surveys and crane inventories were carried out in 2006 and 2007 to spatially map the structure and patterns of bog ecosystems used by migrating cranes. The highest-rated Sandhill Crane nesting habitat consisted of sedge and low shrub dominated blanket bog wetlands with vegetated mounds. Riparian features and bog forests were also determined to be important habitats for forage, shelter, and living habitat. Based on the analysis, three Wildlife Habitat Areas were proposed to maintain Sandhill Crane nesting habitat and connected ecological services that support ecosystem-based management objectives, including promoting human well-being.

In the last fifty years, Nunavut has developed a deep dependence on diesel for virtually all of its energy needs, including electricity. This dependence has created a number of economic, environmental and health related challenges in the territory, with an estimated 20% of the territory’s annual budget being spent on energy, thereby limiting the Government of Nunavut’s ability to address other essential infrastructure and societal needs, such as education, nutrition and health care and housing. One solution to address this diesel dependency is the use of renewable energy technologies (RETs), such as wind, solar and hydropower. As such, this thesis explores energy alternatives in Nunavut, and through RETScreen renewable energy simulations, found that solar power and wind power are technically viable options for Nunavut communities and a potentially successful means to offset diesel-generated electricity in Nunavut. However, through this analysis it was also discovered that accurate data or renewable resources are often unavailable for most Nunavut communities. Moreover, through qualitative open-ended interviews, the perspectives of Nunavut residents with regards to developing RETs in Nunavut were explored, and it was found that respondents generally supported the use of renewable energy in their communities, while acknowledging that there still remains a knowledge gap among residents regarding renewable energy, stemming from a lack of communication between the communities, government and the utility company. In addition, the perceived challenges, opportunities and gaps that exist with regards to renewable energy policy and program development were discussed with government policy-makers through further interviews, and it was discovered that often government departments work largely independently of each other rather than collaboratively, creating gaps and oversights in renewable energy policy in Nunavut. Combined, the results of this thesis were used to develop a number of recommended policy actions that could be undertaken by the territorial and federal government to support a shift towards renewable energy in order to develop a sustainable and self-sufficient energy plan in Nunavut. They include: gathering accurate renewable resource data in Nunavut; increasing community consultations on the subject of renewable energy; building strong partnerships with universities, colleges and industry; developing a knowledge sharing network; and finally increasing accessibility to renewable energy programs and policies in Nunavut. / Thesis (Master, Environmental Studies) -- Queen's University, 2011-09-29 23:47:11.775

As a cost-effective test method, a vehicle-based test rig can be utilized in small wind turbine experimental work to facilitate turbine performance tests under a range of controlled wind speeds, as well as to validate turbulent flow models. The instrumentation of a custom trailer-based mobile wind turbine test rig has been modified to provide a platform for full rotor speed control. A control system coupled to an electric vehicle controller with regenerative braking technology was developed in five steps, namely: system modeling in Simulink, system identification, control system design and analysis, control system implementation in LabVIEW, and Proportional-Integral-Derivative (PID) controller tuning in real-time. A custom Graphical User Interface (GUI) was also developed. Furthermore, a Computational Fluid Dynamics (CFD) analysis was conducted to assess the potential impact of towing vehicle’s disturbance on the free stream available to the rotor disc. This trailer rig will allow up to a 1kW wind turbine. It can be towed behind a vehicle to conduct steady state tests or it can be parked in an open area to collect unsteady field data. It has been tested in a towed scenario and the Blade Element Momentum (BEM) predictions were compared with the obtained aggregate performance curve. / Graduate / 0548 / 0791 / 0544 / khorsand@uvic.ca

This thesis develops a framework to investigate and design novel optimization methods for two important problems: computational advertising (particularly, sponsored search) and wind farm turbine-layout planning. Whereas very different in specifics, both problems share some common abstractions. The existing solution in sponsored search is based on a greedy pay-per-click auction and is suitable only for advertisers seeking a direct response. It does not apply to advertisers who target certain numbers of clicks in a predefined time period. To address this new challenge, we introduce a unified optimization framework combining pay-per-click auctions and guaranteed delivery in sponsored search. Our new method maximizes the revenue of the search engine, targets a guaranteed number of ad clicks per campaign for advertisers willing to pay a premium, and enables keyword auctions for all others. Results combining revenue to the search engine and click rates for the advertisers show superior performance over strong baselines. The proposed framework is based on linear programming with delayed column generation for computational tractability at scale. We design a game theoretic approach to optimize the strategy for individual advertisers, i.e. to optimize their choices between auctions and guaranteed delivery, and analyze the behavior of the new market formed by our framework. Specifically, we introduce a new method for computing the approximate Nash equilibrium where an exact computation would prove computationally intractable. We rely on approximations of complex utility functions, a combination of simulated annealing and integer linear programming as our principled approach. Wind farm layout optimization is the selection of optimal locations for placement of large wind turbines taking into account factors such as topographical features, prevalent but non-constant wind direction and turbine-wake interference. Existing approaches are deficient in their inability to consider long distance turbine interference, changing wind speed and direction and multiple types of wind turbines in optimization. The dissertation develops an optimization framework based on a scalable divided-and-conquer strategy that enables scalability to real-world wind farm scales taking into account the aforementioned complexities in the optimization process. Essentially the process optimizes in a hierarchical manner at different levels of granularity. This hierarchical decomposition approach to optimization is common to both search-advertisement and wind-farm layout challenges.

Wind energy industry has been growing fast during last years, and the demand for operation and maintenance (O&M) services has been increasing rapidly. As wind turbine manufacturing companies have been focusing more on selling rather than after sales services, this created problems in O&M, which started to influence the overall profitability of wind energy projects. In the current conditions, business model innovation in O&M services is needed. While initial step in business model innovation is identifying what is valuable for customer (customer value), it is not clear what is of customer value in B2B context, how to identify it and what is valuable for industrial customers in O&M overall and in wind energy industry in particular. Therefore, the purpose of our research was to explore customer value as an input in the process of business model innovation in B2B context. In order to reach the goal of our research, inductively based approach was used for multiple case study of O&M services customers in wind energy industry in Sweden. Semi structured interviews were conducted with a representative from each company. The parts of their business models connected to wind turbine O&M were mapped, as well as customer value was outlined. The connection between customer value and business model components was analyzed within each case and then the results were compared across the cases. The main findings of our study are as follows. Business model in B2B context serves as the frame of reference for customer value formation. Characteristics of business model components, in particular key activities and key resources, as well as the intentions for further business model development become more specific underlying criteria of value proposition assessment. In wind energy industry in Sweden there is a core customer value to get the highest possible energy production, shared by all studied cases. Differences in customer value among O&M customers were identified in their perceptions of customer value of O&M service (contracts, SCADA system, reports, and education) and relationship with service providers. Such business model related criteria as competence, characteristics of fleet, involvement in O&M activities, and intention for development of O&M involvement explain why customer value differs among the studied customers of O&M services in wind energy industry in Sweden. Customer business model should be used by managers in both wind energy industry and other contexts for understanding customer value in a holistic way. Further customer segmentation should be done based on customer business model related criteria, and in the context of wind energy industry the criteria identified in this study can be used. What is more, O&M service providers should allow more flexibility in contracts and give additional attention to customer relational mechanisms in their business models as the source of customer value. / Business model innovation: A case study of maintenance services for the wind power industry