Sustainable energy solutions are aimed to reduce the consumption of fossil fuels by using renewable energy sources and energy efficiency techniques. This thesis presents two new sustainable energy applications in the field of electrical machines.Polyphase induction motors dominate the energy usage spectrum for industrial and commercial applications. The conventional winding structure used in both synchronous and induction machines has a basic unit of the winding with a 60 degree phase belt and a three phase connection either in star or delta. A new winding structure using an innovative Star-Delta Series Connection (SDSC) which has a high winding coefficient and low harmonic content is presented in this thesis. The principle of the SDSC winding is described. The Electro-Magnetic Belt and Electro-Magnetic Space diagram are two important means to be used for optimization of the new winding. Experimental results from two prototypes confirm the theoretical analysis. The efficiency of the new machine at rated load increased by about 3.8% as compared to the standard machine with a conventional winding structure.Wind energy is one of the most attractive renewable energy options. Wind turbines are designed to couple either synchronous or asynchronous generators with various forms of direct or indirect connection with grid or diesel generators. Permanent magnet (PM) generators using high energy Neodymium- Iron-Boron magnets offer advantages such as direct coupling without gear box, absence of excitation winding and slip rings, light weight and smaller size. This thesis presents the design and development of an outer-rotor PM generator suitable for wind energy conversion. The initial electromagnetic design followed by a Finite Element Analysis is presented in detail. A 20 kW prototype machine was built and extensively tested. It was found that the machine could maintain an ++ / efficiency of about 85% for a wide operating range. Equivalent circuit models were developed. The results of the Finite Element analysis matches closely with the experimental and the designed values.

<div>Equipment health is the root of productivity and profitability in a company; through the use of machine learning and advancements in computing power, a maintenance strategy known as Predictive Maintenance (PdM) has emerged. The predictive maintenance approach utilizes performance and condition data to forecast necessary machine repairs. Predicting maintenance needs reduces the likelihood of operational errors, aids in the avoidance of production failures, and allows for preplanned outages. The PdM strategy is based on machine-specific data, which proves to be a valuable tool. The machine data provides quantitative proof of operation patterns and production while offering machine health insights that may otherwise go unnoticed.</div><div><br> </div><div>Purdue University's Wade Utility Plant is responsible for providing reliable utility services for the campus community. The Wade Utility Plant has invested in an equipment monitoring system for a thirty-megawatt turbine generator. The equipment monitoring system records operational and performance data as the turbine generator supplies campus with electricity and high-pressure steam. Unplanned and surprise maintenance needs in the turbine generator hinder utility production and lessen the dependability of the system.</div><div><br> </div> The work of this study leverages the turbine generator data the Wade Utility Plant records and stores, to justify equipment care and provide early error detection at an in-house level. The research collects and aggregates operational, monitoring and performance-based data for the turbine generator in Microsoft Excel, creating a dashboard which visually displays and statistically monitors variables for discrepancies. The dashboard records ninety days of data, tracked hourly, determining averages, extrema, and alerting the user as data approaches recommended warning levels. Microsoft Excel offers a low-cost and accessible platform for data collection and analysis providing an adaptable and comprehensible collection of data from a turbine generator. The dashboard offers visual trends, simple statistics, and status updates using 90 days of user selected data. This dashboard offers the ability to forecast maintenance needs, plan work outages, and adjust operations while continuing to provide reliable services that meet Purdue University's utility demands. <br>

The integration of dispatchable renewable energies like biomass, geothermal and reservoir hydro technologies into an electrical network present no greater challenge than the integration of conventional power technologies for which are well understood by Eskom engineers. However, renewable energies that are based on resources that fluctuate throughout the day and from season to season, like wind and solar, introduce a number of challenges that Eskom engineers have not dealt with before. It is current practice for Eskom‟s generation to follow the load in order to balance the demand and supply. Through Eskom‟s load dispatching desk at National Control, generator outputs are adjusted on an hourly basis with balancing reserves making up only a small fraction of the total generation. Through the Integrated Resource Plan for Electricity of 2010, the Department of Energy has set some targets towards integrating renewable energy, including wind and solar generation, into the South African electricity market consequently introducing variability on the supply side. With demand that varies continually, maintaining a steady balance between supply and demand is already a challenging task. When the supply also becomes variable and less certain with the introduction of non-dispatchable renewable energy, the task becomes even more challenging. The aim of this research study is to determine whether the resources that previously helped to balance the variability in demand will still be adequate to balance variability in both demand and supply. The study will only concentrate on variable or non-dispatchable renewable energies as will be added to the South African electrical network according to the first two rounds of the Department of Energy‟s Renewable Energy Independent Power Producer Procurement Programme. This research study only looks into the balancing challenge and does not go into an analysis of voltage stability or network adequacy, both of which warrant in depth analysis. / Thesis (MIng (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2013.

The integration of dispatchable renewable energies like biomass, geothermal and reservoir hydro technologies into an electrical network present no greater challenge than the integration of conventional power technologies for which are well understood by Eskom engineers. However, renewable energies that are based on resources that fluctuate throughout the day and from season to season, like wind and solar, introduce a number of challenges that Eskom engineers have not dealt with before. It is current practice for Eskom‟s generation to follow the load in order to balance the demand and supply. Through Eskom‟s load dispatching desk at National Control, generator outputs are adjusted on an hourly basis with balancing reserves making up only a small fraction of the total generation. Through the Integrated Resource Plan for Electricity of 2010, the Department of Energy has set some targets towards integrating renewable energy, including wind and solar generation, into the South African electricity market consequently introducing variability on the supply side. With demand that varies continually, maintaining a steady balance between supply and demand is already a challenging task. When the supply also becomes variable and less certain with the introduction of non-dispatchable renewable energy, the task becomes even more challenging. The aim of this research study is to determine whether the resources that previously helped to balance the variability in demand will still be adequate to balance variability in both demand and supply. The study will only concentrate on variable or non-dispatchable renewable energies as will be added to the South African electrical network according to the first two rounds of the Department of Energy‟s Renewable Energy Independent Power Producer Procurement Programme. This research study only looks into the balancing challenge and does not go into an analysis of voltage stability or network adequacy, both of which warrant in depth analysis. / Thesis (MIng (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2013.