Synchronverter-based control for wind power

More and more attention has been paid to the energy crisis due to the increasing energy demand from industrial and commercial applications. The utilisation of wind power, which is considered as one of the most promising renewable energy sources, has grown rapidly in the last three decades. In recent years, many power converter techniques have been developed to integrate wind power with the electrical grid. The use of power electronic converters allows for variable speed operation of wind turbines, and enhanced power extraction. This work, which is supported by EPSRC and Nheolis under the DHPA scheme, focuses on the design and analysis of control systems for wind power. In this work, two of the most popular AC-DC-AC topologies with permanent magnet synchronous generators (PMSG) have been developed. One consists of an uncontrollable rectifier, a boost converter and an inverter and a current control scheme is proposed to achieve the maximum power point tracking (MPPT). In the control strategy, the output current of the uncontrollable rectifier is controlled by a boost converter according to the current reference, which is determined by a climbing algorithm, to achieve MPPT. The synchronverter technology has been applied to control the inverter for the grid-connection. An experimental setup based on DSP has been designed to implement all the above mentioned experiments. In addition, a synchronverter-based parallel control strategy, which consists of a frequency droop loop and a voltage droop loop to achieve accurate sharing of real power and reactive power respectively, has been further studied. Moreover, a control strategy based on the synchronverter has been presented to force the inverter to have capacitive output impedance, so that the quality of the output voltage is improved. Abstract The other topology consists of a full-scale back-to-back converter, of which the rectifier is controllable. Two control strategies have been proposed to operate a three-phase rectifier to mimic a synchronous motor, following the idea of synchronverters to operate inverters to mimic synchronous generators. In the proposed schemes, the real power extracted from the source and the output voltage are the control variables, respectively, hence they can be employed in different applications. Furthermore, improved control strategies are proposed to self-synchronise with the grid. This does not only improve the performance of the system but also considerably reduces the complexity of the overall controller. All experiments have been implemented on a test rig based on dSPACE to demonstrate the excellent performance of the proposed control strategies with unity power factor, sinusoidal currents and good dynamics. Finally, an original control strategy based on the synchronverter technology has been proposed for back-to-back converters in wind power applications to make the whole system behave as a generator-motor-generator system

Alternative energy design toolkit

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.Includes bibliographical references (p. 122-127).This thesis concerns the concepts, structure, and applications of the Alternative Energy Design Toolkit. The toolkit is aimed to provide a widely accessible, easy to use, flexible, yet powerful modeling environment for assisting design associated with renewable energy technologies. Exchanges of ideas and knowledge among the users are also highly encouraged and facilitated. The toolkit is composed of three important components: a collection of models that are fundamentals of renewable energy design, a modeling environment called DOME, which is used as the toolkit's enabler, and a supporting Web site. At the beginning, a comprehensive survey of existing tools for renewable energy design is presented. Then, the detailed descriptions and key capabilities of the toolkit's components are provided. In addition, a collection of solar energy models, which is the initial set of models in the toolkit, is also presented. The toolkit is utilized in two design scenarios: a design of a stand-alone PV system, and a trade-off analysis of a hybrid PV-diesel electricity system. In both design scenarios, the models in the toolkit are proven to be useful and convenient resources. The processes of making the representations of the systems are straight-forward, and the analysis mechanisms that the toolkit provides make the design process simple yet effective.by Sittha Sukkasi.S.M

Proceedings of the International Conference on Energising the SDGs through Appropriate Technology and Governance

This volume presents the papers presented at the international conference on Energising the SDGs through appropriate technology and governance. Papers were presented in eight sessions. In addition, there was a keynote speech, a panel discussion, a workshop on Sustainability Compass and a lunch-time poster session. This compendium provides a summary of the event and includes original papers and posters delivered at the conference. These covered various themes, including climate action plan in UK and Japanese cities and their alignment with the SDGs; sustainable energy access; contribution of renewable energies, urban design and sustainable development goals, tools for evaluation and monitoring of progress with the SDGs, and innovations and business models for various services

NASA Tech Briefs, March 1996

Topics: Computer-Aided Design and Engineering; Electronic Components and Cicuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information; Books and Reports

NASA Tech Briefs, November 1990

Topics: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences

Energy: A continuing bibliography with indexes, issue 20

A bibliography is presented which lists 1250 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System from October 1, 1978 through December 31, 1978