Thesis (Ph. D.)--University of Wisconsin--Madison, 1942. / Typescript. Includes abstract and vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves [i]-iii).

A power system may be subjected to different types of disturbances. The control strategy to be taken in order to preserve system stability depends on the severity of the disturbance. For very severe disturbances, power system stability can be improved by sudden changes in the electric power network such as the insertion of braking resistors, generator dropping or load shedding. A unified treatment of optimum switching is presented by considering the switching instants to be elements of a generalized control vector. Dynamic optimization is then applied to determine optimum switching instants. Less severe disturbances can be overcome by employing governor and/or voltage regulator controls. The governor control problem for a large signal model of interconnected power plants is investigated via the multi-level concept. A two-level controller for interconnected power plants is discussed. Each plant has a first-level local optimal or suboptimal controller. The second level of control is an intervention control performed by a central co-ordinator. If a sudden system disturbance causes the system angular acceleration to exceed preset tolerances, a priority interrupt to the central co-ordinator initiates intervention control. Angular velocity deviations of all plants are transmitted to the co-ordinator. This data is used to generate coefficient data for each plant. On receiving its coefficient data, each plant generates a local second-level intervention control which augments first-level local control. The Load-Frequency Control problem, due to minor or routine disturbances caused by load changes, is investigated. Since the incremental power demand in a power system is not always known a priori, direct application of the optimum linear-state regulator to Load-Frequency Control is not possible. Furthermore, Load-Frequency Control generally requires the use of an integral-type control operation to meet the system operating specifications. This requirement is introduced into the formulation of the optimum Load-Frequency Control problem presented in this thesis. Two methods are suggested for demand identification. The first method makes use of differential approximation. The second method makes use of a Luenberger observer to identify unmeasured states. The optimum control is a linear function of measured states, identified unmeasured states, and the identified incremental power demand. A method is given for solving, suboptimally, the problem of optimum-load frequency sampled-data control with either unknown deterministic power demand or randomly varying system disturbances. It is shown how to modify an optimum continuous control to obtain optimum control in the case of discrete-data transmission and unknown deterministic demand. The case of random power demand and random disturbances is treated by introducing an adaptive observer. A three stage systematic design procedure is given. The effectiveness of Load-Frequency Control using an adaptive observer is illustrated by an example. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

Climate change is experienced most through the medium of water. The ability of water institutions and the factors that enable or hinder them to purposefully adapt to the new and additional challenges brought by climate change require better understanding. Factors that influence their perception of climate change impacts and initiatives being taken for adaptation are shaped by various enabling factors and barriers through the interaction with both governmental and non-governmental institutions across administrative scales. Better understanding of these adaptation enablers and barriers is essential for devising adaptation strategies. This research aims to identify and expound the characteristics that enable or hinder institutions to adapt for water management, and hence, it evaluates the involvement of key governmental and non-governmental institutions in India and the inter-institutional networks between them. It surveyed webpages and online documents of sixty Union Government institutions and interviewed representatives from twenty-six governmental, non-governmental, research and academic institutions operating at the national level and another twenty-six institutions operating within the State of Himachal Pradesh in India to assess the characteristics that enable or hinder adaptation. While the online projection of institutional involvement and interaction among key Union Government institutions on climate change and water indicate a more centralized network pointing to Planning Commission and Ministry of Environment and Forest, the interview responses indicated a more distributed network with both Ministries of Water Resources and Environment and Forest recognized as key institutions thereby indicating a potential variation in perception of who is in-charge. Moreover, online documents show institutions that are involved in water have less mention of climate change compared to Union Government ministries involved in less climate-sensitive sectors indicating that impacts of climate change on water are potentially ignored. While it is evident that research and consulting institutions engaging with both national and state level institutions play a key role in enabling adaptation, various barriers pertaining to data and information accessibility, inadequacy of resources and implementation gaps exist particularly due to inter-institutional network fragmentations. Although barriers identified in this study bear resemblance to barriers identified by other researchers in other contexts, this research shows similar barriers can emerge from different underlying causes and are highly interconnected; thereby indicating the need for addressing adaptation barriers collectively as a wider governance issue. Since many of the adaptation barriers emerge from wider governance challenges and are related to larger developmental issues, the findings have important policy implications. Among the various issues that the government needs to address is improving the inter-institutional networks between water institutions so that information dissemination, sharing of learning experiences and data accessibility is improved and prescriptive legislations are seen to be inadequate in this regard. Restructuring the way officials in government water institutions are recruited and deployed is suggested as a potential solution for improving the inter-institutional networks. The research elucidates that inter-institutional networks and transboundary institutions are two pillars that supports adaptation and also bridges the gap between adaptive capacity and adaptation manifestation that enable water institutions to cross the chasm of adaptation barriers. Thus the thesis presents an important analysis of key characteristics that enable or hinder water management institutions to adapt to climate change which have been so far under acknowledged by other studies through the analysis of the state of climate change adaptation in India. Therefore, this study provides valuable insights for developing countries, particularly, facing similar challenges of adapting water management for climate change.

Thesis (M.S.)--Tennessee Technological University, 2009. / Title from title page screen (viewed on Mar. 12, 2010). Bibliography: leaves 93-97.

In North American utilities, control area performance of interconnected power systems is assessed by the reliability standards imposed by the North American Electric Reliability Corporation (NERC). NERC standards on control area performance define two indices known as Control Performance Standards 1 and 2 (CPS1 and CPS2) to evaluate control area performance in normal interconnected power system operation. Out of the two indices, CPS1 evaluates the performance of a control area with respect to control of interconnection frequency and tie-line power flows. This thesis proposes a novel method to approximately estimate CPS1 for a two area power system using the probability distribution of load change. The proposed method of estimating CPS1 is validated against the time domain simulation method using a simple two-area test system. In the validation process, it is shown that the proposed method could approximately forecast CPS1 within 5% accuracy. The forecasted CPS1 value could then be used by a control area to design its future control strategies to be in compliance with NERC criteria at the minimum cost. These control actions include, but not limited to tuning governors, reducing non-confirming loads, ensuring adequate operating and spinning reserves etc.

In North American utilities, control area performance of interconnected power systems is assessed by the reliability standards imposed by the North American Electric Reliability Corporation (NERC). NERC standards on control area performance define two indices known as Control Performance Standards 1 and 2 (CPS1 and CPS2) to evaluate control area performance in normal interconnected power system operation. Out of the two indices, CPS1 evaluates the performance of a control area with respect to control of interconnection frequency and tie-line power flows. This thesis proposes a novel method to approximately estimate CPS1 for a two area power system using the probability distribution of load change. The proposed method of estimating CPS1 is validated against the time domain simulation method using a simple two-area test system. In the validation process, it is shown that the proposed method could approximately forecast CPS1 within 5% accuracy. The forecasted CPS1 value could then be used by a control area to design its future control strategies to be in compliance with NERC criteria at the minimum cost. These control actions include, but not limited to tuning governors, reducing non-confirming loads, ensuring adequate operating and spinning reserves etc.

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1993. / Abstract. Includes bibliographical references (leaves 139-143). Also available via the Internet.

Thesis (Ph. D.)--Washington State University, December 2007. / Includes bibliographical references (p. 72-74).

Thesis (M.S. in computer science)--Washington State University, December 2007. / Includes bibliographical references (p. 107-109).

A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering, 2016 / The power system frequency must be kept as close as possible to the nominal value. This is due to the inherent design of electrical equipment to operate efficiently at the nominal frequency. Frequency regulation in an interconnected power system is the duty of all members of the interconnection. However, in the Eskom-ZESA interconnected power system Eskom engineers ignore the contribution of the ZESA system to primary frequency control. This is mainly due to the prevalent assumption that the ZESA control area is small relative to the Eskom control area and its contribution to primary frequency control of the interconnected power system is negligible. This document presents a project that examines the validity of this assumption via determination of the contribution of the ZESA system to the interconnected power system’s primary frequency control. The interconnected power systems background was studied to understand the theory behind the operation of two or more interconnected power systems. System frequency disturbances deemed to be a good representation of the Eskom-ZESA interconnected power system’s performance were selected and analysed to validate the current assumption. The results show that there is a significant support from ZESA during a system frequency disturbance. This proves that the existing assumption is not valid anymore. Furthermore; the generator model that mimics the Eskom-ZESA tie-line governing behaviour was developed. Two different types of governor models were employed; firstly the IEEEG1 governor was tuned to control generator output to match the tie-line performance and then the TGOV5 governor model was used. The IEEEG1 governor model is a simplified governor representation; as a result, it is not easy to tune the parameters to match tie-line response. However, the performance is acceptable and it can be used to represent the tieline governor response. The TGOV5 governor model is very complex as discussed in section 4.2. The model includes boiler dynamics, and this improves performance such that it is possible to tune the parameters to follow the tie-line performance as close as necessary. / GR2016