Design and analysis of a novel stator oil-flooded cooling system for aircraft electrical machines with hairpin windings
Growing environmental and economic concerns are driving various sectors to improve energy efficiency. In sectors such as aeronautics, this is achieved through electrification and weight reduction, which necessarily involves replacing conventional pneumatic, mechanical and hydraulic systems with elec...
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| Format: | info:eu-repo/semantics/doctoralThesis |
| Language: | eng |
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Servicio de Publicaciones. Universidad de Navarra
2023
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| Online Access: | https://hdl.handle.net/10171/64979 |
| _version_ | 1793400558709637120 |
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| author | Paredes Puente, J. (Jesús) Elósegui-Simón, I. (Ibón) Prieto-Rocandio, B. (Borja) |
| author_facet | Paredes Puente, J. (Jesús) Elósegui-Simón, I. (Ibón) Prieto-Rocandio, B. (Borja) |
| author_sort | Paredes Puente, J. (Jesús) |
| collection | DSpace |
| description | Growing environmental and economic concerns are driving various sectors to improve energy efficiency. In sectors such as aeronautics, this is achieved through electrification and weight reduction, which necessarily involves replacing conventional pneumatic, mechanical and hydraulic systems with electric drives. In addition, electric machines also offer better efficiency and require less maintenance.
Then minimizing the weight of electric machines is therefore essential to reduce fuel consumption and permanent magnet machines offer the highest power density. The use of hairpin windings can help reduce weight, due to their high slot filling factor and short winding ends, and have already demonstrated their potential in sectors such as automotive. Another key factor in improving power density are cooling systems. Among all the liquid cooling systems, stator oil-flooded solutions are the most promising, both for their cooling capacity and for the improved electrical isolation between conductors that make them suitable for aeronautical applications.
This dissertation deals with the combination of these two aspects, hairpin winding and flooded stator cooling for aircraft applications, and presents a novel cooling system that has been patented. For this purpose, the proposed solution is described and the advantages of this cooling arrangement are detailed. The equations defining its behavior are presented, its potential is experimentally evaluated by using a motorette and design criteria are provided.
Subsequently, the presented concept is applied on an industrialized and field-tested machine for heavy-duty off-road vehicles in substitution of a water-jacket cooling arrangement, ending with a prototype in order to assess gains in power density. Next, the novel cooling arrangement is applied on a conceptual design for an aeronautical application.
Finally, the main results of this dissertation are summarized and the main future research lines are outlined. |
| format | info:eu-repo/semantics/doctoralThesis |
| id | oai:dadun.unav.edu:10171-64979 |
| institution | Universidad de Navarra |
| language | eng |
| publishDate | 2023 |
| publisher | Servicio de Publicaciones. Universidad de Navarra |
| record_format | dspace |
| spelling | oai:dadun.unav.edu:10171-649792023-01-27T10:46:53Z Design and analysis of a novel stator oil-flooded cooling system for aircraft electrical machines with hairpin windings Paredes Puente, J. (Jesús) Elósegui-Simón, I. (Ibón) Prieto-Rocandio, B. (Borja) Electrical machines Permanent magnet Hairpin winding Oil cooling systems Stator oil-flooded More electric aircraft Máquinas eléctricas Imanes permanentes Growing environmental and economic concerns are driving various sectors to improve energy efficiency. In sectors such as aeronautics, this is achieved through electrification and weight reduction, which necessarily involves replacing conventional pneumatic, mechanical and hydraulic systems with electric drives. In addition, electric machines also offer better efficiency and require less maintenance. Then minimizing the weight of electric machines is therefore essential to reduce fuel consumption and permanent magnet machines offer the highest power density. The use of hairpin windings can help reduce weight, due to their high slot filling factor and short winding ends, and have already demonstrated their potential in sectors such as automotive. Another key factor in improving power density are cooling systems. Among all the liquid cooling systems, stator oil-flooded solutions are the most promising, both for their cooling capacity and for the improved electrical isolation between conductors that make them suitable for aeronautical applications. This dissertation deals with the combination of these two aspects, hairpin winding and flooded stator cooling for aircraft applications, and presents a novel cooling system that has been patented. For this purpose, the proposed solution is described and the advantages of this cooling arrangement are detailed. The equations defining its behavior are presented, its potential is experimentally evaluated by using a motorette and design criteria are provided. Subsequently, the presented concept is applied on an industrialized and field-tested machine for heavy-duty off-road vehicles in substitution of a water-jacket cooling arrangement, ending with a prototype in order to assess gains in power density. Next, the novel cooling arrangement is applied on a conceptual design for an aeronautical application. Finally, the main results of this dissertation are summarized and the main future research lines are outlined. La creciente preocupación por el medio ambiente y la economía ha impulsado a varios sectores a mejorar la eficiencia energética. En sectores como la aeronáutica, esto se consigue mediante la electrificación y la reducción de peso, lo que implica necesariamente la sustitución de los sistemas neumáticos, mecánicos e hidráulicos convencionales por accionamientos eléctricos. Además, las máquinas eléctricas también ofrecen una mayor eficiencia y requieren menos mantenimiento. Por tanto, minimizar el peso de las máquinas eléctricas es esencial para reducir el consumo de combustible y las máquinas de imanes permanentes ofrecen la mayor densidad de potencia. El uso de devanados hairpin puede ayudar a reducir el peso, gracias a su elevado factor de relleno de ranura y a sus reducidas cabezas de bobina, y ya han demostrado su potencial en sectores como el de la automoción. Otro factor clave para mejorar la densidad de potencia son los sistemas de refrigeración. Entre todos los sistemas de refrigeración líquidos, las soluciones de estator inundado de aceite son las más prometedoras, tanto por su capacidad de refrigeración como por la mejora del aislamiento eléctrico entre conductores que las hace adecuadas para aplicaciones aeronáuticas. En esta tesis se aborda la combinación de estos dos aspectos, el devanado hairpin y la refrigeración mediante estator inundado de aceite para aplicaciones aeronáuticas, y se presenta un novedoso sistema de refrigeración que ha sido patentado. Para ello, se describe la solución propuesta y se detallan las ventajas de esta disposición de refrigeración. Se presentan las ecuaciones que definen su comportamiento, se evalúa experimentalmente su potencial mediante el uso de un motorette y se proporcionan criterios de diseño. Posteriormente, el concepto presentado se aplica en una máquina industrializada y probada en campo para vehículos todoterreno pesados en sustitución de una disposición de refrigeración por camisa de agua, terminando con un prototipo para evaluar la mejora en densidad de potencia. A continuación, la nueva solución de refrigeración se aplica a un diseño conceptual para una aplicación aeronáutica. Por último, se resumen los principales resultados de esta tesis y se esbozan las principales líneas de investigación futuras. 2023-01-11T16:45:36Z 2023-01-11T16:45:36Z 2022-12 2022-12-16 info:eu-repo/semantics/doctoralThesis https://hdl.handle.net/10171/64979 eng info:eu-repo/semantics/embargoedAccess application/pdf Servicio de Publicaciones. Universidad de Navarra |
| spellingShingle | Electrical machines Permanent magnet Hairpin winding Oil cooling systems Stator oil-flooded More electric aircraft Máquinas eléctricas Imanes permanentes Paredes Puente, J. (Jesús) Elósegui-Simón, I. (Ibón) Prieto-Rocandio, B. (Borja) Design and analysis of a novel stator oil-flooded cooling system for aircraft electrical machines with hairpin windings |
| title | Design and analysis of a novel stator oil-flooded cooling system for aircraft electrical machines with hairpin windings |
| title_full | Design and analysis of a novel stator oil-flooded cooling system for aircraft electrical machines with hairpin windings |
| title_fullStr | Design and analysis of a novel stator oil-flooded cooling system for aircraft electrical machines with hairpin windings |
| title_full_unstemmed | Design and analysis of a novel stator oil-flooded cooling system for aircraft electrical machines with hairpin windings |
| title_short | Design and analysis of a novel stator oil-flooded cooling system for aircraft electrical machines with hairpin windings |
| title_sort | design and analysis of a novel stator oil-flooded cooling system for aircraft electrical machines with hairpin windings |
| topic | Electrical machines Permanent magnet Hairpin winding Oil cooling systems Stator oil-flooded More electric aircraft Máquinas eléctricas Imanes permanentes |
| url | https://hdl.handle.net/10171/64979 |
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