This dissertation addresses three different problems in power systems. The first problem is related to the fault location in complex topologies such as three terminal circuits with series compensation and mutually coupled line sections and distribution networks with distributed generation. Novel methods are presented by using traveling wave approach and wavelet transformation technique to overcome the difficulties introduced by the discontinuities and integrated components such as Metal Oxide Varistor (MOV) protected series capacitors and distributed generation in complex topologies. Simulation results show good correlation between the actual and estimated fault locations for all the studied cases. The second problem concerns the calculation techniques of voltage profiles along transmission lines. A simple yet effective approach to accurately and rapidly obtain the voltage profile along a transmission line during fault transients is presented. The objective of the presented method is to eliminate the need to use wave equations and line parameters provided that an electromagnetic Transients Program (EMTP) type transients simulator is available for generating bus voltage transients for a given fault. This is accomplished by developing a time series model to estimate the voltage at an intermediate point along the transmission line. The model is formed for each intermediate point separately. Once the model is obtained it can be used to predict the transient voltage at that point along the line during any fault in the system. The approach can potentially be useful as a post processor to a transient simulator and can be used by developers of transient animations and movies for illustrating fault-initiated propagation of traveling waves in power systems. The third problem is the lack of powerful visualization and animation methods, which can help understanding the complex behavior of power systems during transients. The goal of this part of the dissertation is to develop new animation and visualization methods for power system electromagnetic transients for both educational and research purposes. Proposed approaches are implemented in different environments such as MATLAB and Microsoft Visual Studio to show the effectiveness of two and three-dimensional visualization of power system transients. The implementations of the proposed methods provide better understanding of the power systems during transient phenomena due to the faults or switchings.

Faculty of Engineering & Built Environment, School of Electrical & Infomation Engineering, MSC Dissertation / The South African electrical utility,ESKOM, is one of the largest in the world with 40 GW capacity, worth R 965 billion, and an annual income of R 33 billion. The people responsible for the voltage control of the ESKOM transmission grid are highly skilled voltage controllers. An investigation was conducted to identify what constitutes their expertise. This is a ultidisciplinary research project that incorporates the fields of Power System Engineering, Industrial and Cognitive Psychology and Neuro-Linguistic Programming. Observations of the voltage controllers at work were carried out followed by in-depth interviews in order to identify, their Mental Control Strategies, Power System Visualization techniques, and Mental Models. Expert and novice voltage controllers were included in the research as well as one in-house Man Machine Interface (MMI) developer. Some of the main findings are: ·The sophisticated mental strategies that allow controllers to simplify the overabundance of data presented to them. ·The subconsciously created vivid mental imagery that they use to make fast intuitive decisions. Having obtained the above information, MMI design and human controller training can be optimised.