The purpose of this work is to evaluate the performance of a specific ac drive topology that is of current interest in industry. With the increasing pressure for compliance with IEEE–519 and other international harmonic standards, many ac drive manufacturing companies are seeking innovative and cost effective solutions for controlling the amount of harmonics produced at the point of common coupling (PCC). The proposed topology is a potential alternative to the three-phase diode bridge which is the conventional rectifier topology for non-regenerative applications. The work of this thesis explains the theory of operation, control algorithms, and potential improvement strategies for the proposed “half-controlled” boost rectifier topology. The entire ac drive system with load is then modeled and the results verified using the Simulink simulation package. It is shown that the proposed topology has several distinct advantages over a traditional diode rectifier such as improved total harmonic distortion (THD) of the current waveforms, dc bus voltage regulation, and power factor control. In addition, these advantages are created at a price point which is significantly lower than that of a conventional fully-controlled pulse-width modulated (PWM) rectifier. The main disadvantage is that the current waveforms in the utility contain even harmonics which may cause significant problems in the power system.

The purpose of this work is to evaluate the performance of a specific ac drive topology that is of current interest in industry. With the increasing pressure for compliance with IEEE–519 and other international harmonic standards, many ac drive manufacturing companies are seeking innovative and cost effective solutions for controlling the amount of harmonics produced at the point of common coupling (PCC). The proposed topology is a potential alternative to the three-phase diode bridge which is the conventional rectifier topology for non-regenerative applications. The work of this thesis explains the theory of operation, control algorithms, and potential improvement strategies for the proposed “half-controlled” boost rectifier topology. The entire ac drive system with load is then modeled and the results verified using the Simulink simulation package. It is shown that the proposed topology has several distinct advantages over a traditional diode rectifier such as improved total harmonic distortion (THD) of the current waveforms, dc bus voltage regulation, and power factor control. In addition, these advantages are created at a price point which is significantly lower than that of a conventional fully-controlled pulse-width modulated (PWM) rectifier. The main disadvantage is that the current waveforms in the utility contain even harmonics which may cause significant problems in the power system.

We introduce the process of the development in the Nuclear Structure Model, the Quantum Theory of the Projected Shell Model and the improvement of the calculating program. Besides we deal with the high-spin superdeformed phenomena. By using the PSM_EO program, the Projected Shell Model is applied to the odd (even-odd) mass nuclei Tb , including 145Tb ,147Tb ,149Tb and 151Tb . The results of theoretical calculations about the transition energy E£^, kinetic moment of inertia J(1) and dynamic moment of inertia J(2) are compared with experimental data to verify the meaning in Physics.

Parenting education, combined with adult basic education and early childhood education, makes the Even Start program a unified family literacy program which helps to break the intergenerational cycle of poverty and low literacy. Research studies have shown that the Even Start program has positive effects on its participants. Even though some of the effects are not explicitly tied to parenting education, they are closely related to parenting education. This study investigated the effectiveness of parenting education as perceived by its participants. The purposes of this study were to identify Even Start program participants’ perceptions of parenting education, to explore issues related to parenting education, and to identify the impact of parenting education as perceived by the program participants. The interviewed parents considered parenting education an important component of the Even Start family literacy program. Findings in this study revealed how the participants used what they had learned in the parenting classes, incorporating their improved literacy skills to facilitate the growth of the whole family. According to the study participants, parenting classes provided a safe and comfortable environment for the parents to learn or validate their parenting practices, to identify themselves with each other, to build up a network of support system, and to practice their literacy skills in a context related to their everyday life. Since their participation in the parenting education, the study participants reported attainment of new insights about being a good parent, better communication with their children and other family members, improved education experience for their children, prolonged parenting values and practices, and improved family relationships. Using Bronfenbrenner’s ecology model to look at the family literacy program, parenting education appeared to be the linkage between all components.

The purpose of this work is to evaluate the performance of a specific ac drive topology that is of current interest in industry. With the increasing pressure for compliance with IEEE-519 and other international harmonic standards, many ac drive manufacturing companies are seeking innovative and cost effective solutions for controlling the amount of harmonics produced at the point of common coupling (PCC). The proposed topology is a potential alternative to the three-phase diode bridge which is the conventional rectifier topology for non-regenerative applications. The work of this thesis explains the theory of operation, control algorithms, and potential improvement strategies for the proposed "half-controlled" boost rectifier topology. The entire ac drive system with load is then modeled and the results verified using the Simulink simulation package. It is shown that the proposed topology has several distinct advantages over a traditional diode rectifier such as improved total harmonic distortion (THD) of the current waveforms, dc bus voltage regulation, and power factor control. In addition, these advantages are created at a price point which is significantly lower than that of a conventional fully-controlled pulse-width modulated (PWM) rectifier. The main disadvantage is that the current waveforms in the utility contain even harmonics which may cause significant problems in the power system.

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Zugl.: Kassel, Univ., Diss., 2006

Univ., Diss., 2006--Kassel