Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 82-83). Also available via the Internet.

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 134-140).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1957. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 154-156).

Thesis (M. Phil.)--University of Hong Kong, 1996. / Includes bibliographical references.

Thesis (M. Phil.)--University of Hong Kong, 1993.

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains xi, 94 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 90-94).

D.Ing. / Transmission networks change continuously when new supply requests are made, network reinforcements are installed and equipment configuration changes. Therefore, network design, operation and control requirements change. To manage this, controllers are being developed to assist human network controllers who might not always be specialists in equipment operation and characteristics. A transmission network comprises multiple variables, some dependent on others. The resistive portion of a load (PLoad) and the total reactive power (Q) installed close to the load can be set in relation to each other. This relationship forms the basic concept of the QP ratio for a transmission network. This ratio is not standardly used as a variable in network operation or control. This thesis explores this new QP ratio in more depth for application in different networks. This concept is developed and investigated in detail and equations are derived from first principles. The usability of the QP ratio is described and calculations are done for existing networks. It is shown that each network has its own unique QP ratio that can be used as information for human operators or as part of a controller device. This information can assist in determining actions required to be taken by controllers and operators. This thesis investigates aspects related to the use of a QP ratio in transmission networks as far as system operation and network control is concerned. The information provided in this thesis could be developed further to assist in implementing of the QP ratio in transmission network control rooms or systems. This will contribute to the provision of more reliable, robust and controlled electrical networks.

M.Ing. (Electrical Engineering) / Induction heating has been used in practice for many years. The main goal of this study is to investigate the use of a single-turn coil in a typical induction heater. The work starts off with a background study of elecrroheat and specifically high-frequency induction heating. Finite element simulations were conducted on different coil shapes and compared with each other. The converter. with control and driver circuits. used in the, experimental setup, as well as the experimental construction and results are described. The work is concluded with an evaluation of the project.

In this thesis catastrophe theory is applied to the voltage stability problem in power systems. A general model for predicting voltage stability from the system conditions is presented and then applied to both a simple 2-bus explanatory power system and to a larger more realistic power system. The model is based on the swallowtail catastrophe which with its three control variables is able to determine the voltage stability of the system. The model is derived directly from the systems equations. The voltage stability of the system at each specified system bus is determined by comparing the values of the swallowtail catastrophe control variables with those of the unique region of voltage stability. The control variables are calculated from the system operating conditions. If the control variables specify a point inside the stability region, the system is voltage stable; otherwise it is voltage unstable. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

Wind power generation influences on the quality of the power grid. Because wind velocity is consistently changing this change causes unstable wind power generation. Since more wind power is expected to be used in the future, it is crucial to study the influence of the wind penetration level on normalized-damping ratio and damped-resonant frequency. In this thesis three types of calculated data were used to analyze the effect of wind penetration level on the Texas power grid: the percentage of wind power generation in Texas, generator-unit trip damping coefficient, and damped-resonant frequency. The percentage of wind energy was calculated from wind data provided by the Electric Reliability Council of Texas. The damping coefficient and damped-resonant frequency values are the indicators of power system stability and were calculated from synchronized phase data from the Texas power grid. The synchronized phase measurements were collected from the University of Texas at Austin and the wind farm near the Mc-Donald observatory. The data analyzed in this paper were from September 2009 to February 2010. The wind data were correlated to the grid-stability indicators which allowed us to interpret the status of the power grid according to the wind penetration level. When the wind penetration level increased over 11 %, five generator trip events occurred with damping coefficient values ten times higher than those of the regular unit trips. Moreover, during those events, damped-resonant frequency values rose nearly four times higher than the frequency values of other events. The results of this study may lead us to the conclusion that simply increasing the capacity of wind power generation will cause the power system to become unstable, and this will result in low quality of electricity. Therefore, further study is needed to determine the optimum amount of wind power generation without causing instability in the power grid. / text