ETD Collection

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Author: search.filters.author.Wright, Jarrad G

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    Formulation of a capacity mechanism for the Southern african power pool(SAPP) for sustaines long-term system adequacy
    (2019) Wright, Jarrad G
    Power system adequacy has been historically insufficient in the Southern African Power Pool (SAPP) region with resulting negative effects on economic growth and electrification efforts. Existing domestic regulatory frameworks and opaque longterm bilateral contracting for procuring capacity in the region have been shown to be insufficient in ensuring system adequacy. The concept of an adequacy product in the form of a Capacity Mechanism (CM) introduced into the SAPP region has not yet appeared in the literature. A Capacity Mechanism (CM) for the SAPP region has been proposed and designed as part of this research to address this. A framework has been developed to consider CMs via the combination of a screening assessment, quantitative (model-based) analysis of more favourable CM options and an identification and quantification of key design elements. The developed framework can also be generalised and applied to other jurisdictions where CMs are under consideration. A regional CM which transparently and explicitly values capacity is proposed in the form of a forward-looking annual Capacity Auction that is locationally disaggregated, supplied by all possible supply-side resources with all feasible SAPP market participants included. The CM should be technology agnostic and account for the dual requirement for firm capacity to meet peak demand and firm-energy to meet annual energy requirements considering the dominance of hydrobased capacity in the region when excluding South Africa. There should be a leadtime of 3-4 years with the possibility of long-term auctions for large hydro-based capacity. Strict market monitoring and adherence to performance incentives and penalties will need to be ensured to avoid exercising of market power considering the dominant size of the South African power system. Appropriately mandated institutions to run Capacity Auctions would include the SAPP Co-Ordination Centre as well as a sufficiently mandated regional regulatory body. A further contribution is made in the form of a public domain power system dataset of the SAPP region with sufficient detail to be used in power system operations and planning efforts by future researchers and practitioners.
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    Design of a reluctance synchronous machine for traction motor applications using the finite element method
    (2011-11-02) Wright, Jarrad G
    Traction motors, specifically in underground shuttle vehicles, often operate in harsh conditions including steep grades, heavy payloads and high ambient temperatures. These motors require maximum torque density as well as cool and robust operation in order to optimise the overall process and to avoid the current requirement for a duty cycle. The contribution of this research is the design of a new traction motor, a Reluctance Synchronous Machine (RSM), via the 2-D Finite Element Method (FEM) as the primary engineering design tool to replace the commonly used Induction Machine (IM). The electromagnetic and mechanical design of the RSM are performed in commercially avaliable FEM software packages FLUX and ANSYS respectively. The electromagnetic design uses the PyFLUX command language and Python scripting to vary five rotor geometric parameters in a linear progression to find where maximum average torque and minimum torque ripple occurs for each parameter. The mechanical strength of the RSM rotor is defined by two geometric parameters whose final values are chosen via a case study based design in ANSYS. The newly designed RSM runs much cooler than the original IM and develops only 8.4% less torque than the IM. As a result, it should not require a duty cycle and will be capable of a higher rating and thus more torque can be delivered to the end process (up to 42% more) while the motor remains in the same motor frame size. Furthermore, there is a large area of research pertaining to the overall electromagnetic design method used. This includes the use of optimisation algorithms, integrated rotor-stator design, mechanical support placement and grading, various torque ripple reduction techniques and the inclusion of permanent magnets or composite powder metals for the RSM rotor.