Control of a large scale wind turbine utilizing a fluid drive

As wind turbines grow in size there are added strains within the mechanical structure that need to be mitigated to improve machine life. The current area of greatest concern is the premature failure of the gearbox box due to torque variations along the drive train. This thesis incorporates a fluid coupler into the turbine\u27s drive train. Three different controllers are developed for this model with the goal of minimizing the torque variations seen by the gearbox and providing better generator speed regulation. The result of this study shows that the addition of the fluid coupler is a major improvement to the system. The coupler removes a resonant peak from the transfer function and allows for better speed regulation. Because of this a standard PI-Controller provides good system level performance. The performance can be improved with state feedback controllers, but these are not a necessity when a fluid coupler is present

Planetary benchmarks

Design criteria and technology requirements for a system of radar reference devices to be fixed to the surfaces of the inner planets are discussed. Offshoot applications include the use of radar corner reflectors as landing beacons on the planetary surfaces and some deep space applications that may yield a greatly enhanced knowledge of the gravitational and electromagnetic structure of the solar system. Passive retroreflectors with dimensions of about 4 meters and weighing about 10 kg are feasible for use with orbiting radar at Venus and Mars. Earth-based observation of passive reflectors, however, would require very large and complex structures to be delivered to the surfaces. For Earth-based measurements, surface transponders offer a distinct advantage in accuracy over passive reflectors. A conceptual design for a high temperature transponder is presented. The design appears feasible for the Venus surface using existing electronics and power components

Benefit-cost methodology study with example application of the use of wind generators

An example application for cost-benefit methodology is presented for the use of wind generators. The approach adopted for the example application consisted of the following activities: (1) surveying of the available wind data and wind power system information, (2) developing models which quantitatively described wind distributions, wind power systems, and cost-benefit differences between conventional systems and wind power systems, and (3) applying the cost-benefit methodology to compare a conventional electrical energy generation system with systems which included wind power generators. Wind speed distribution data were obtained from sites throughout the contiguous United States and were used to compute plant factor contours shown on an annual and seasonal basis. Plant factor values (ratio of average output power to rated power) are found to be as high as 0.6 (on an annual average basis) in portions of the central U. S. and in sections of the New England coastal area. Two types of wind power systems were selected for the application of the cost-benefit methodology. A cost-benefit model was designed and implemented on a computer to establish a practical tool for studying the relative costs and benefits of wind power systems under a variety of conditions and to efficiently and effectively perform associated sensitivity analyses

Utilization of renewable energy sources in microgrids

Využití solární energie je jednou z nejoblíbenějších technologií výroby energie mezi několika typy obnovitelných zdrojů energie. Dva obnovitelné zdroje energie, které jsou v současných mikrosítích využívány, jsou v této práci teoreticky diskutovány. Dále je názorně předveden dopad obnovitelných zdrojů energie na mikrosítě a struktura mikrosítí. Součástí této práce je rovněž komplexní simulační analýza distribuční soustavy středního (22 kV) a nízkého napětí (400 V) provedená pomocí softwaru eVlivy před a po připojení PVPPs do distribuční soustavy Středočeského kraje. Analýza zatížení soustavy a napěťový profil v každém uzlu distribuční soustavy středního a nízkého napětí jsou zobrazeny graficky.Solar Power utilization is the one of the most popular power production technology among the several types of renewable energy sources. There are two types of renewable energy sources like solar energy and wind energy utilization in Microgrid structure has been described theoretically. Impact of renewable energy sources on Microgrid and structure of Microgrid has been presented in detail. This master thesis presents a comprehensive simulation analysis of medium voltage distribution line 22kV and low voltage line (400 V) with the help simulation software eVlivy before and after connection of PVPPs into the distribution system in Central Bohemian Region. The load flow analysis and voltage profile at each node of medium and low voltage distribution system has been characterized graphically

Energy harvesting from human and machine motion for wireless electronic devices

Published versio

Urban Wind Generation: Comparing Horizontal and Vertical Axis Wind Turbines at Clark University in Worcester, Massachusetts

Electricity production must shift towards carbon neutral sources such as wind power to mitigate the impacts of climate change. The wind resource in urban environments is challenging to predict but technologies, including computational fluid dynamics software, are making it possible. This software pinpoints suitable placement for wind turbines through models that show wind acceleration patterns over a building. Horizontal axis wind turbines (HAWTs) have dominated the wind industry but vertical axis wind turbines (VAWTs) offer potential to outperform HAWTs in urban environments. VAWTs can handle turbulent and unconventional wind and generate energy at slower speeds, which is beneficial for these areas. A case study at Clark University in Worcester, Massachusetts analyzes the functionality of a HAWT and a VAWT. The machines are compared by their efficiencies due to an imbalance of rated power outputs. The machines’ average maximum power coefficients are similar. However, when the R2 values of the turbine’s power curves are compared the VAWT demonstrates greater capacity to track changes in the wind. This research is the first step in redefining the power systems employed at Clark University and the data will be utilized to find better locations for the wind turbines

A Review of Control Techniques for Wind Energy Conversion System

Wind energy is the most efficient and advanced form of renewable energy (RE) in recent decades, and an effective controller is required to regulate the power generated by wind energy. This study provides an overview of state-of-the-art control strategies for wind energy conversion systems (WECS). Studies on the pitch angle controller, the maximum power point tracking (MPPT) controller, the machine side controller (MSC), and the grid side controller (GSC) are reviewed and discussed. Related works are analyzed, including evolution, software used, input and output parameters, specifications, merits, and limitations of different control techniques. The analysis shows that better performance can be obtained by the adaptive and soft-computing based pitch angle controller and MPPT controller, the field-oriented control for MSC, and the voltage-oriented control for GSC. This study provides an appropriate benchmark for further wind energy research

PERFORMANCE ASSESS OF SELF-EXCITED IG DRIVEN BY WIND TURBINE WORKING WITH FC-TCR

This work presented a self-excited induction generator (SEIG) model controlled by an (FC-TCR) fixed capacitor-thyristor control reactor consisting of a large fixed capacitor in parallel with a thyristor controlled reactor in series with the constant inductance. Induction machines were used because they are capable of working at different speeds. The 3-phase IG was driven by the prime mover that represents the wind turbine. Also, constant voltage and frequency were obtained, regardless of the change in velocity, by using proportional integration (PI control) for each of them. This type of generator is used in isolated rural areas far from power transmission lines. The voltage and frequency are analyzed for each wind speed proposed in the model and calculating the required excitation amplitude and torque required to drive the induction generator. Therefore, it is now a key interest to develop an efficient, viable, economic, and controllable induction generator for harnessing energy from renewable sources. The strategy of control was implemented with MATLAB/Simulink

Compilation of case studies of applying renewable energies to local development transnationally implemented along IN2RURAL project: Stage 2

Compilation of case studies of applying renewable energies to local development transnationally implemented