Thomas Davis's education policies: theory and practice

This thesis explores the education policies of Thomas Davis. On the eve of the Great Famine Ireland was economically impoverished and politically dependent. The Irish people had a subservient mentality, were mainly uneducated and were unaware of their potential. He believed that education would develop a self-reliant, self-sufficient people; it would create a new generation of leaders and citizens necessary to transform Ireland into a prosperous, independent nation. This thesis explores his education philosophy which was political in orientation; he called for reform of university education so that it would educate leaders who were knowledgeable, patriotic and responsible. He formulated a curriculum which consisted of knowledge that would have direct use and application in public life; his curriculum included moral philosophy, oratory, philological studies and history. His contribution to the debate on the Queens Colleges bill, 1845, is explored including his public disagreement with Daniel O’Connell on the principle of multi-denominational education. This work also examines his policies on learning methodologies and teaching methods. It provides details of his thoughts on learning by experience, by observation, book learning and learning in the home. It focuses on the deficiencies evident in the system of teaching and learning that operated in Trinity College Dublin and it provides an analysis of his preferred method of instruction: Lyceum teaching. This thesis also explores his national curriculum in history and Irish culture which was designed to forge a sense of national identity, to win support for repeal and to develop the principle of nationality. He formulated a national curriculum to counteract the absence of national knowledge in the state schools, to provide the people with a positive self-image and ultimately to empower them to reclaim Ireland and to develop it. Davis knew the power of education and he used it as an instrument of political and social change.

Electrical machine characterisation and analysis for renewable energy applications

There has been an increased use of the Doubly-Fed Induction Machine (DFIM) in ac drive applications in recent times, particularly in the field of renewable energy systems and other high power variable-speed drives. The DFIM is widely regarded as the optimal generation system for both onshore and offshore wind turbines and has also been considered in wave power applications. Wind power generation is the most mature renewable technology. However, wave energy has attracted a large interest recently as the potential for power extraction is very significant. Various wave energy converter (WEC) technologies currently exist with the oscillating water column (OWC) type converter being one of the most advanced. There are fundemental differences in the power profile of the pneumatic power supplied by the OWC WEC and that of a wind turbine and this causes significant challenges in the selection and rating of electrical generators for the OWC devises. The thesis initially aims to provide an accurate per-phase equivalent circuit model of the DFIM by investigating various characterisation testing procedures. Novel testing methodologies based on the series-coupling tests is employed and is found to provide a more accurate representation of the DFIM than the standard IEEE testing methods because the series-coupling tests provide a direct method of determining the equivalent-circuit resistances and inductances of the machine. A second novel method known as the extended short-circuit test is also presented and investigated as an alternative characterisation method. Experimental results on a 1.1 kW DFIM and a 30 kW DFIM utilising the various characterisation procedures are presented in the thesis. The various test methods are analysed and validated through comparison of model predictions and torque-versus-speed curves for each induction machine. Sensitivity analysis is also used as a means of quantifying the effect of experimental error on the results taken from each of the testing procedures and is used to determine the suitability of the test procedures for characterising each of the devices. The series-coupling differential test is demonstrated to be the optimum test. The research then focuses on the OWC WEC and the modelling of this device. A software model is implemented based on data obtained from a scaled prototype device situated at the Irish test site. Test data from the electrical system of the device is analysed and this data is used to develop a performance curve for the air turbine utilised in the WEC. This performance curve was applied in a software model to represent the turbine in the electro-mechanical system and the software results are validated by the measured electrical output data from the prototype test device. Finally, once both the DFIM and OWC WEC power take-off system have been modeled succesfully, an investigation of the application of the DFIM to the OWC WEC model is carried out to determine the electrical machine rating required for the pulsating power derived from OWC WEC device. Thermal analysis of a 30 kW induction machine is carried out using a first-order thermal model. The simulations quantify the limits of operation of the machine and enable thedevelopment of rating requirements for the electrical generation system of the OWC WEC. The thesis can be considered to have three sections. The first section of the thesis contains Chapters 2 and 3 and focuses on the accurate characterisation of the doubly-fed induction machine using various testing procedures. The second section, containing Chapter 4, concentrates on the modelling of the OWC WEC power-takeoff with particular focus on the Wells turbine. Validation of this model is carried out through comparision of simulations and experimental measurements. The third section of the thesis utilises the OWC WEC model from Chapter 4 with a 30 kW induction machine model to determine the optimum device rating for the specified machine. Simulations are carried out to perform thermal analysis of the machine to give a general insight into electrical machine rating for an OWC WEC device.