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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
691

Etude du lien entre la fréquence et les puissances actives pour le dimensionnement d'un microréseau alternatif îloté avec sources d'énergie renouvelables / Study of the link between the frequency and the active power to size an AC stand-alone microgrid with renewable energy sources

Ghanty, Yann 20 December 2018 (has links)
La qualité d’un réseau électrique se mesure notamment par sa résilience, à savoir sa capacité à continuer de fournir, de façon stable, une électricité de qualité malgré les incidents. Cette continuité d’alimentation est notamment assurée par le réglage de la fréquence, ce dernier faisant office de moyen de coopération entre les différentes sources du réseau. Les travaux de cette thèse étudient en profondeur les différentes façons d’assurer ce réglage de la fréquence sur des microréseaux alternatifs îlotés au regard des problématiques nouvelles : intégration croissante de sources d’énergie renouvelables intermittentes et baisse (voire disparition) de l’inertie inhérente aux groupes synchrones tournants. L’objectif principal est de proposer un ensemble de modèles analytiques permettant d’appréhender le comportement dynamique de la fréquence et des puissances actives transitant sur un microréseau, quelle que soit la topologie de ce dernier, afin de constituer une aide au dimensionnement. À cet objectif global s’ajoute un certain nombre de sous-objectifs qui structurent et guident l’ensemble des travaux :- Un objectif pédagogique : les couplages entre l’équilibre des puissances actives et la fréquence sur un réseau alternatif sont clairement explicités, que ces couplages relèvent de la structure et des paramètres physiques du microréseau ou qu’ils soient liés aux lois et paramètres de commande. La lecture des modèles doit ainsi permettre de comprendre analytiquement les différents liens de cause à effet entre les paramètres du système, la fréquence et les puissances,et les spécificités propres à chaque topologie de microréseau.- Un objectif de simplicité et de modularité : les modèles proposés doivent pouvoir être adaptés selon les cas particuliers de topologies, afin que tout lecteur puisse les réutiliser facilement en dehors du cadre de cette étude. Pour ce faire, ces travaux utilisent des modèles mathématiques sous forme de schémas blocs, intégrables sous Matlab.- Enfin, un objectif de modélisation « grand signal » : pour trancher avec l’approche petit signal de beaucoup de modélisations de microréseaux classiques, et pour permettre d’appréhender le comportement du microréseau sur une large plage de déséquilibre de puissance / The quality of an electricity grid is measured by its resilience, namely its ability to continue to provide electricity despite the incidents. This continuity of supply is ensured by the frequency control, acting as a means of cooperation between the different sources of the grid. This thesis examines in depth the different ways to ensure this frequency control on stand-alone microgrids with regard to new issues: increasing integration of intermittent energy sources and decreasing (or disappearing) of the synchronous rotating groups with their inertia. The main objective is to propose a set of analytical models explaining the dynamic behavior of the frequency and the active powers transiting on a microgrid, whatever the topology, in order to constitute an aid to the sizing. To this overall objective is added a number of sub-objectives that structure and guide this work:- An educational objective: the nature of the link between the balance of active powers and the frequency on an AC microgrid is clearly explained, whether this link is based on physical parameters or is related to control laws. The goal is to understand the different links of cause and effect between the paramers of the system, the frequency and the active power and thespecificities to each topology of microgrid. - An objective of simplicity and modularity: the models proposed must be adaptable to particular cases, so that any reader can reuse easily outside the scope of this study. To do this, mathematical models in the form of block diagrams which can be integrated in Matlab are used. - Finally, a "big signal" simulation objective: to decide with the small signal approach of many traditional microgrid models, and to make it possible to understand the behavior of the microgrid over a wide range of power imbalance.
692

Measuring routines of ice accretion for Wind Turbine applications : The correlation of production losses and detection of ice

Carlsson, Viktor January 2010 (has links)
Wind power will play a major role in the future energy system in Sweden. Most of the major wind parks are planned to be built in sites where the cold climate and atmospheric icing can cause serious problems. This underlines the importance of addressing these issues. The major cause of these problems is in-cloud icing of the rotor blades due to super cooled liquid droplets of clouds. The droplets freeze upon impact with the rotor blade and form hard rime ice. This rime ice causes disruption in the aerodynamics that leads to production losses, extra loads on the rotor blades and when the ice is shed it poses a safety risk to people in the near environment. This master thesis focuses on how to measure the accretion of ice and the correlation between measured ice and production losses of two wind parks in northern Sweden.   The results show a good correlation between the ice accretion on a stationary sensor and the production loss from a wind turbine. In most icing events the icing of the sensor and large production losses from the wind turbine correlated clearly. Attempts to quantify the production losses at a certain ice rate measured with the stationary sensors was done, however no clear results was produced. The reason for this is that the wind turbines often stop completely during an icing event and that the time series analyzed was too short to be able to quantify the losses at certain wind speed and ice rates.   Recommendations on the type of sensor which should be used was to be produced, however the conclusion was that no single sensor has acted satisfactory and could be recommended to measure ice accretion for wind turbine applications. Due to this, at least two sensors are recommended to increase the redundancy in the measurement system. Modeling ice accretion with standard parameters measured has been done and the results show that the time of icing could be determined quite well when the sensors was ice free, however when the sensors and especially the humidity sensors was iced the time of icing was overestimated.   The main conclusion drawn is that there is a clear relationship between the icing of a stationary sensor and the rotor blade. There is still no which fulfills all demands of measuring ice accretion for wind turbine applications, further it is possible with simple models to roughly determine when icing occurs with standard measurements.
693

Generate light with wind power

Iqbal, Fowad January 2013 (has links)
The report explain the steps taken to improve a product (SOLVINDEN), which uses sun and wind energy to generate light and is used for outdoor decoration. The research involves improvements in both designas well function. As the form follows function in the product functionality of the form is very important in selection of the form. Some of important topics which are considered are different way of using wind to charge batteries, blades profiles and shape, way of optimizing generator, ratio of the optimal solution between of how much wind power is needed tostart charging and charging efficiency. The report also includes differentway of manufacturing, testing and finalizing the right form afteroptimizing. The solar power and the batteries are not in the scope of theproject.
694

Fluid Mechanics of Vertical Axis Turbines : Simulations and Model Development

Goude, Anders January 2012 (has links)
Two computationally fast fluid mechanical models for vertical axis turbines are the streamtube and the vortex model. The streamtube model is the fastest, allowing three-dimensional modeling of the turbine, but lacks a proper time-dependent description of the flow through the turbine. The vortex model used is two-dimensional, but gives a more complete time-dependent description of the flow. Effects of a velocity profile and the inclusion of struts have been investigated with the streamtube model. Simulations with an inhomogeneous velocity profile predict that the power coefficient of a vertical axis turbine is relatively insensitive to the velocity profile. For the struts, structural mechanic loads have been computed and the calculations show that if turbines are designed for high flow velocities, additional struts are required, reducing the efficiency for lower flow velocities.Turbines in channels and turbine arrays have been studied with the vortex model. The channel study shows that smaller channels give higher power coefficients and convergence is obtained in fewer time steps. Simulations on a turbine array were performed on five turbines in a row and in a zigzag configuration, where better performance is predicted for the row configuration. The row configuration was extended to ten turbines and it has been shown that the turbine spacing needs to be increased if the misalignment in flow direction is large.A control system for the turbine with only the rotational velocity as input has been studied using the vortex model coupled with an electrical model. According to simulations, this system can obtain power coefficients close to the theoretical peak values. This control system study has been extended to a turbine farm. Individual control of each turbine has been compared to a less costly control system where all turbines are connected to a mutual DC bus through passive rectifiers. The individual control performs best for aerodynamically independent turbines, but for aerodynamically coupled turbines, the results show that a mutual DC bus can be a viable option.Finally, an implementation of the fast multipole method has been made on a graphics processing unit (GPU) and the performance gain from this platform is demonstrated.
695

Utvärdering av dataprogram för vindresursberäkningar : En jämförelse av vindresursberäkningar i kuperad skogsterräng med programmet WAsP (linjär modellering) och CFD-programmet WindSim / An evaluation of wind energy software : A comparison of wind resource calculations made with the software WAsP (linear model) and the CFD software WindSim over a hilly forested area

Johansson, Eric January 2013 (has links)
Vindkraft för generering av el har under de senaste åren vuxit kraftigt i Sverige och utbyggnaden väntas fortsätta. Ett viktigt steg när nya vindkraftsparker skall byggas är att göra en vindanalys för det aktuella området. Vindanalysen är ett viktigt underlag för att avgöra om en investering i vindkraftverk kommer vara ekonomiskt lönsamt på den aktuella platsen.      Som underlag till vindanalysen sätts vanligen mätutrustning upp i området och vindförhållandena på platsen mäts upp. Att installera och underhålla mätmaster är kostsamt och därför mäts vindarna på ett begränsat antal platser i det intressanta området. Sedan används olika beräkningsprogram för att extrapolera de uppmätta vindresurserna till positioner där mätningar saknas. För närvarande används programmet WAsP som standard av många vindkraftsprojektörer. WAsP:s beräkningsmodell är relativt enkel och tar till exempel inte hänsyn till turbulens som uppkommer då terrängen är kuperad. Som ett alternativ till WAsP har olika CFD-program introducerats på marknaden under senare år. Dessa programs modeller är mer avancerade och de kräver därför längre beräkningstid jämfört med WAsP, men förhoppningen är att de skall ge mer tillförlitliga modelleringsresultat. I denna studie har vindmodelleringar i det linjära modelleringsprogrammet WAsP jämförts med modelleringar i CFD-programmet WindSim. Syftet har varit att undersöka om WAsP ger tillförlitliga modelleringsresultat i svenskt kuperat skogslandskap och om WindSims CFD-beräkningar kan ge en ökad noggrannhet i jämförelse. Prestandan hos respektive program har utvärderats genom att jämföra extrapolerade medelvindar med faktiska mätningar. Vindmätningar har funnits att tillgå från en period av 12 månader från två mätmaster med givare på 60, 80 och 100 meters höjd. Avståndet mellan masterna är cirka 10 kilometer.            Resultaten från studien tyder på att WindSim kan ge en något ökad noggrannhet jämfört med WAsP, men resultaten visar samtidigt att en CFD-modellering inte med automatik ger mer tillförlitliga modelleringsresultat. Studien har visat att resultatet från WindSim är starkt beroende av hur modellen sätts upp och det kan därför vara enklare att göra fel i WindSim jämfört med WAsP. Det blev också tydligt att en modell där den simulerad vindskjuvning (variation av vindhastigheten i höjdled) stämde bra överens med den uppmätta inte behöver betyda att WindSim-modellen gör bra extrapolationer av vindförhållandena från den ena masten till den andra. Vidare visade sig WAsP missbedöma effekter från topografin något och om vindmätningar görs på utmärkande höjder är det sannolikt att WAsP överskattar vindförhållandena i de lågt belägna delarna av terrängen. I WindSim undersöktes två olika modelluppsättningar, en med WindSims skogsmodul där skogen simuleras som 3D objekt och en modell där skogen hanteras med på samma sätt som i WAsP med råhetslängd och nollplansförskjutning. När skogsmodulen användes var det inte möjligt att erhålla en modellerad vindskjuvning som stämde överens med den uppmätta i en neutral atmosfär, vilket är WindSims standardinställning för atmosfärsstabiliteten. I en neutral atmosfär med skogsmodulen överskattades vindhastigheten på låga höjder. Om atmosfären simulerades som stabil i medeltal var det möjligt att få den simulerad vindskjuvning att stämma överens med den uppmätta, men extrapolationerna i horisontalled blev inte bra med denna modell. Om atmosfären skall simuleras som stabil i WindSim tyder resultaten från studien på att vindmätningarna måste delas in efter rådande atmosfärstabilitet för den aktuella tidpunkten för mätningen. Det fungerade inte tillfredställande att använda alla vindmätningar i samma modell och försöka hitta ett passande medelvärde för stabiliteten.  Om vindmätningarna skall delas upp efter rådande stabilitet kommer varje stabilitet kräva en egen modellering vilket betyder att beräkningstiden kommer öka markant. Att simulera skogen i WindSim med en råhetslängd och en nollplansförskjutning visade sig fungera bra. En modellerad vindskjuvning som stämde bra överens med den uppmätta kunde erhållas i en neutral atmosfär och denna modell presterade sammantaget bäst av alla undersökta modeller i den här studien. Det studerade området består övervägande av skog och vindmätningarna som använts är utförda inom skogsområdet. WindSim skogsmodul kan tänkas vara mer användbar och viktig om skog förekommer i begränsade partier och då tänkta vindturbiner inte placeras direkt inom skogsområdet. En förhoppning på CFD-program är att vindmätningar utförda på låg höjd skall kunna användas för att förutse vinden på högre höjder med större noggrannhet jämfört med WAsP. Resultat från den här studien visar dock att det kan vara svårt att uppnå en bra modellerad vindskjuvning i WindSim. Även i WindSim är således viktigt att ha vindmätningar från flera olika höjder för att kunna verifiera modellen mot innan programmet kan förväntas förutse vinden på högre höjder korrekt.    Sammanfattningsvis förefaller en bra inställd WindSim-modell kunna ge en något ökad noggrannhet av extrapolerade vindförhållanden jämfört med WAsP, men om extrapolationer skall göras mellan liknade områden i terrängen, till exempel från en kulle till en annan kulle, är det tveksamt om den lilla ökade noggrannheten ger skäl för den ökade beräkningstiden i WindSim. / An evaluation of wind energy software: a comparison of wind resource calculations made with the software WAsP (linear model) and the CFD software WindSim over a hilly forested area.  Results produced from the wind modeling linear program WAsP were compared with modeling results produced by the CFD program WindSim. The aim was to investigate whether WAsP achieves accurate calculation results over a hilly forested area in Sweden, and if the CFD modeling in WindSim provides more accurate results than WAsP. The performance of each program was evaluated by comparing extrapolated average wind speed data to actual measurements. The study shows that WindSim may achieve an increased accuracy of extrapolated wind conditions compared to WAsP, as well as indicates that a CFD calculation does not automatically provide more reliable extrapolations than linear modeling in WAsP. The accuracy of the WindSim extrapolations was highly dependent on how the model was set up, and hence it may be easier to make errors with WindSim compared to WAsP. A model in WindSim with accurate simulated wind shear did not necessarily mean that the model made good extrapolations of wind conditions horizontally. Furthermore, WAsP was shown to slightly misjudge orographic effects, and when wind measurements are made over hilltops, WAsP most likely overestimates the average wind speed in the lower parts of the terrain.     When a good model was established, WindSim provided slightly more accurate results than WAsP, but if extrapolations are to be made between similar areas in the terrain, for example from one hill to another hill, it is doubtful that the small increase in accuracy gives enough reason for the increased time in calculation required by WindSim.
696

Study of the integration method on the control of wind power system

Wang, Tian Xiang January 2009 (has links)
University of Macau / Faculty of Science and Technology / Department of Electrical and Electronics Engineering
697

The Full Cost of Renewables: Managing Wind Integration Costs in California

Savage, William 13 May 2012 (has links)
Wind power will be an important component of California's aggressive strategies to meet its greenhouse gas reduction targets by the year 2020. However, the costs of integrating wind power's variable and uncertain output are often ignored. I argue that California must take prudent action to understand, minimize, and allocate wind integration costs. A review of numerous studies suggests that for wind penetration levels below 20%, integration costs should remain modest. However, costs are heavily dependent on market structure, and I suggest numerous ways that California can optimize its market design to manage wind integration costs.
698

Computational Studies of the Effects of Active and Passive Circulation Enhancement Concepts on Wind Turbine Performance

Tongchitpakdee, Chanin 14 June 2007 (has links)
With the advantage of modern high speed computers, there has been an increased interest in the use of first-principles based computational approaches for the aerodynamic modeling of horizontal axis wind turbine (HAWT). Since these approaches are based on the laws of conservation (mass, momentum, and energy), they can capture much of the physics in great detail. The ability to accurately predict the airloads and power output can greatly aid the designers in tailoring the aerodynamic and aeroelastic features of the configuration. First-principles based analyses are also valuable for developing active means (e.g., circulation control), and passive means (e.g., Gurney flaps) of reducing unsteady blade loads, mitigating stall, and for efficient capture of wind energy leading to more electrical power generation. In this present study, the aerodynamic performance of a wind turbine rotor equipped with circulation enhancement technology (trailing edge blowing or Gurney flaps) is investigated using a three-dimensional unsteady viscous flow analysis. The National Renewable Energy Laboratory (NREL) Phase VI horizontal axis wind turbine is chosen as the baseline configuration. Prior to its use in exploring these concepts, the flow solver is validated with the experimental data for the baseline case under yawed flow conditions. Results presented include radial distribution of normal and tangential forces, shaft torque, root flap moment, surface pressure distributions at selected radial locations, and power output. Results show that good agreement has been for a range of wind speeds and yaw angles, where the flow is attached. At high wind speeds, however, where the flow is fully separated, it was found that the fundamental assumptions behind this present methodology breaks down for the baseline turbulence model (Spalart-Allmaras model), giving less accurate results. With the implementation of advanced turbulence model, Spalart-Allmaras Detached Eddy Simulation (SA-DES), the accuracy of the results at high wind speeds are improved. Results of circulation enhancement concepts show that, at low wind speed (attached flow) conditions, a Coanda jet at the trailing edge of the rotor blade is effective at increasing circulation resulting in an increase of lift and the chordwise thrust force. This leads to an increased amount of net power generation compared to the baseline configuration for moderate blowing coefficients. The effects of jet slot height and pulsed jet are also investigated in this study. A passive Gurney flap was found to increase the bound circulation and produce increased power in a manner similar to the Coanda jet. At high wind speed where the flow is separated, both the Coanda jet and Gurney flap become ineffective. Results of leading edge blowing indicate that a leading edge blowing jet is found to be beneficial in increasing power generation at high wind speeds. The effect of Gurney flap angle is also studied. Gurney flap angle has significant influence in power generation. Higher power output is obtained at higher flap angles.
699

Intelligent Speed Sensorless Maximum Power Point Tracking Control for Wind Generation Systems

Hong, Chih-Ming 29 August 2011 (has links)
The wind turbine generation system (WTGS) exhibits a nonlinear characteristic and its maximum power point varies with changing atmospheric conditions. In order to operate the WTGS at maximum power output under various wind speeds and to avoid using speed encoder in practical applications, it is necessary to improve the controller system to operate the maximum power points in the WTGS. There are three factors to influence wind generator, the wind speed, power coefficient and the radius of blade. The power coefficient depends on the blade pitch angle and tip speed ratio (TSR). The objective of the dissertation is to develop an intelligent controlled wind energy conversion system (WECS) using AC/DC and DC/AC power converters for grid-connected power application. To achieve a fast and stable response for the real power control, an intelligent controller was proposed, which consists of a fuzzy neural network (FNN), a recurrent fuzzy neural network (RFNN), a wilcoxcon radial basis function network (WRBFN) and a improved Elman neural network (IENN) for MPPT. Furthermore, the parameter of the developed FNN, RFNN, WRBFN and IENN are trained on-line using back-propagation learning algorithm. However, the learning rates in the FNN, RFNN, WRBFN, and IENN are usually selected by trial and error method, which is time-consuming. Therefore, modified particle swarm optimization (MPSO) method is adopted to adjust the learning rates to improve the learning capability of the developed RFNN, WRBFN and IENN. Moreover, presents the estimation of the rotor speed is based on the sliding mode and model reference adaptive system (MRAS) speed observer theory. Furthermore, a sensorless vector-control strategy for an induction generator (IG) operating in a grid-connected variable speed wind energy conversion system can be achieved. On the other hand, a WRBFN based with hill-climb searching (HCS) maximum-power-point-tracking (MPPT) strategy is proposed for permanent magnet synchronous generator (PMSG) with a variable speed wind turbine. Finally, many simulation results are provided to show the effectiveness of the proposed intelligent control wind generation systems.
700

Battery Buffered Stiff Micro Grid Structure For A Variable Speed Slip Ring Induction Machine Based Wind Generation System

Bhattacharya, Tanmoy 03 1900 (has links)
Electric power has become a basic necessity of human life. The major share of electric power comes from fossil fuel which results in global warming and pollution. A share of generated power comes from nuclear power which is equally dangerous. Big hydro projects take away lots of fertile land. The continuous usage of fossil fuel also poses a threat of petroleum and coal getting over in the near future. The only way out of this energy scarcity is to depend more and more on renewable sources like solar, wind and micro-hydro. At present, instead of having preference over any particular source of renewable energy, effort should be made to extract power from every possible energy source available in whatever form it is and use it in an optimal way. Like any renewable energy sources, the wind power contains large potential for harnessing energy that has been well understood hundreds of years ago. The importance of wind power generation has come to focus recently both at installation and research level and lot of activities are being carried out for efficient use of wind energy. There are different types of wind turbine designs available in the literature. But the most commercially used model is the two or three blade horizontal axis propeller type wind turbine. Research has shown that variable speed operation of this type of turbine is advantageous over fixed speed operation in terms of total energy synthesis. The most commonly used machines for wind power conversion are synchronous machine, squirrel cage induction machine and slip ring induction machine (SRIM). Variable speed operation using synchronous machine or squirrel cage induction machine requires large ratings of the power converters. However, SRIM based variable speed wind generator is advantageous over other schemes due to its inherent advantages like lower power rating for the converters, higher energy capture and the flexibility of sharing reactive power between the stator and the rotor. SRIM is used for both grid connected and stand alone applications and have been reported in the literature. The grid connected applications have received major attention in the literature whereas there are only a very few instances of its stand alone counterparts. There are many places both within and outside India where utility grid has not yet reached or the available grid is very weak. Moreover, in many of the places, the transmission line is so long that the losses in the system are extremely high. Isolated wind power generation can be of great advantage in such places where the available wind power is harnessed and utilized locally. This has been the motivation to go for proposing an isolated wind power generation scheme in this thesis. The proposed scheme is designed to supply power to the load even when very low or no wind power is available. Therefore, a battery bank is also a part of the system. The power converter assembly of the proposed scheme has three major components. One is the rotor side converter which is connected to the rotor terminals of the SRIM. The second one is the stator side converter with output LC filter which is connected to the stator side. These two converters share a common DC link which is interfaced to the battery bank through a multi phase bi-directional fly-back DC-DC converter. Fig. 1. Overall block diagram of the proposed stand alone wind power generator Functionally, this thesis proposes a system as shown in Fig. 1, which has primarily two components with multiple energy ports viz. (i) the SRIM is one triple energy port component and (ii) the proposed power conditioner is another triple energy port component. The SRIM device consists of (i) a mechanical energy port that is interfaced with the windmill shaft (ii) an AC port through the stator windings that is interfaced with the micro-grid/load and (iii) a third port which is also an AC port through the rotor windings of the SRIM that interfaces with an AC port of the proposed power conditioner. The proposed power conditioner is another triple energy port device which consists of (i) a DC energy port that interfaces with a battery/accumulator, (ii) an AC port that interfaces with the rotor windings of the SRIM and (iii) another AC port that generates the micro-grid that is connected to the load and the stator port of the SRIM. The proposed power conditioner provides the frame work for managing the energy flow from the mechanical port of the SRIM to the rotor and accumulator as well as from the mechanical port to the stator/load and accumulator. Further, energy interaction can also take place between the stator and the rotor externally through the power conditioner. The power interfaces on all three energy ports of the proposed power conditioner poses several challenges that have been discussed in this thesis. This thesis focuses on developing schemes to solve these challenges as explained below. Speed sensorless control is a natural choice for slip ring induction machine because of the flexibility of sensing both stator and rotor currents. There are different methods proposed in the literature which deal with the speed sensorless control of slip ring induction machine. However, the elimination of the measurement noise in the flux position estimation is not sufficiently addressed. It is important to address this issue as this would lead to deterioration in rotor side control of SRIM if the measurement noise is not eliminated. Primarily, the schemes which use algebraic relation between the estimated rotor current in stator reference frame and the sensed rotor current, are prone to measurement noise. On the other hand, the schemes, which use rotor back-emf integration, are affected by DC drift problems, though they are not much affected by measurement noise. The proposed stator flux position estimation scheme incorporates the benefits obtained from both the above schemes while eliminating the disadvantages inherent to them. The rotor flux position is estimated by integrating the rotor back-electromotive force. The stator flux is then obtained from the rotor flux estimate. This integration mechanism leads to several problems like dc drift and lack of error decaying mechanism. This estimation scheme solves the above problems including reduction in the propagation of noise in the sensed current to the estimated rotor side unit vectors. On the implementation front, this scheme also eliminates the need for differentiating the unit vectors for estimating slip frequency. This makes the proposed flux estimator very robust. The proposed scheme is simulated and experimentally verified. There is an internal DC bus within the proposed power conditioner that manages the energy flow through the three energy ports. The internal DC bus is interfaced to an external accumulator or battery through a power interface called the multi phase bi-directional dc-dc converter. It is generally advantageous to have the motor rated for higher voltages in order to achieve better efficiencies for a given power rating as compared to low voltage motors. This implies higher DC bus voltage. On the other hand, it is advantageous to have the battery bank rated for low voltage in order to improve the volumetric efficiency which is better at lower battery bank voltages. Both these are contradictory requirements. The above problem is solved in this thesis by proposing a multi power port topology using a bidirectional fly-back converter that is capable of handling multiple power sources and still maintain simplicity and features like high gain, wide load variations and lower output current ripple. As a spin-off, the scheme can handle parallel energy transfer from even a eutectic combination of batteries without any additional control circuitry for parallel operation. Further, the scheme also incorporates a novel transformer winding technique which significantly reduces the leakage inductance of the coupled inductor. The proposed multi-port bidirectional converter is analyzed by including non-idealities like leakage inductance. The DC bus voltage regulation requirement is not very stringent because it is not directly fed to any load. Therefore, hysteresis voltage regulation with small proportional correction is used for DC bus voltage control. The proposed converter is built and experimentally verified in the proposed system as well as in a hybrid-electric vehicle prototype. The third port of the proposed power conditioner interfaces with the stator of the SRIM and the load. The stator/load needs to be connected to a stiff micro-grid. The control requirement of the micro-grid is very stringent because, even for a sudden variation in the wind speed or the load, the grid voltage magnitude and frequency should not change. The dynamic response of the grid voltage controller has to be very fast. Moreover, the grid voltage must be balanced in presence of unbalanced loading. This thesis proposes a converter called the stator side converter along with three phase L-C filter at its output to form the micro-grid. A generalized control scheme is proposed wherein the negative sequence components and the harmonics can be eliminated at the micro-grid by means of feed-forward compensators included in the fundamental positive synchronous reference frame alone. The theoretical foundation for this scheme is developed and discussed in the thesis. In isolated locations linear loads constitute a significant percentage of the total load. Therefore, on the implementation front, only the compensation of fundamental negative sequence is demonstrated. One more necessity for compensating the fundamental negative sequence is that, the SRIM offers only leakage impedance to the fundamental negative sequence components resulting in high fundamental negative sequence current even for a small fundamental negative sequence voltage present at the micro-grid. The proposed scheme ensures balanced three phase currents at the SRIM windings and the full unbalanced current is provided from the stator side converter. This scheme is validated both by simulation and experimentation. The proposed power conditioner is integrated and used in the implementation of the entire wind power generation scheme that is proposed in the thesis. The maximum power point tracking of the wind power unit is also incorporated in the proposed system. The simulation and experimental results are also presented. Finally, the engineering issues involved in the implementation of the proposed scheme are discussed in detail highlighting the hardware configuration and the equipments used. The wind turbine is emulated using a chopper controlled DC motor. The shaft torque of the DC motor is controlled to give the Cp−λ characteristic of a typical windmill. The control issues of the DC machine to behave as a wind turbine are also explained. Finally the thesis is concluded by a statement of potentials and possibilities for future work in this research area.

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