Understanding the effects of condensation on electrical discharge phenomena in next generation more-electric and hybrid aircraft

了解冷凝对下一代多电动和混合动力飞机中放电现象的影响

• 批准号: EP/R012881/1
• 负责人: David Clark
• 金额: $ 12.87万
• 依托单位: CARDIFF UNIVERSITY
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FR012881%2F1
• 关键词: Understanding; effects; condensation; electrical; discharge

Decarbonisation of the transport sector is a major priority, both nationally and globally. It is estimated that the domestic and international aviation sectors constitute 2% of the global CO2 emissions arising from human activity. The member states of the UN International Civil Aviation Organisation are committed to offset any increases in emissions beyond 2020 which, combined with the drive for increasing fuel efficiency, will stimulate aircraft weight reduction beyond that already achieved through the adoption of composite airframe materials.The more-electric aircraft concept permits higher system efficiencies to be realised through electrification of traditional mechanical and hydraulic aircraft subsystems. It can also be considered a stepping stone to realising a commercial hybrid and all-electric aircraft. Both types of aircraft will be equipped with more diverse and safety-critical subsystems, based on high density power electronic converters and system ratings in excess of 1000 Volts. The increased stress experienced by cable insulation, connectors and other equipment, combined with extreme and dynamic environmental conditions experienced in flight, presents a number of technical challenges.The uprating of electrical power systems requires the aircraft design engineer to control for electrostatic phenomena which will arise within the normal operating regime of the aircraft, and there are a number of factors that must be taken into account when assessing the performance of such systems:- The increased use of switched dc and its influence on insulation stress.- The increase in the system voltage, and its effect on the frequency and severity of temporary over-voltage events.- Changes in altitude and atmospheric conditions (temperature, pressure and humidity) and other effects such as the formation of condensation and ice crystals on cable insulation. - Indirect effects induced by lightning strikes.There is to date very little published work concerned with dynamic atmospheric effects during ascent and descent, or the implications of short term system- and atmospherically-induced over voltages. A fundamental understanding of these parameters in medium-voltage dc systems is critical to the increasing electrification of airborne power distribution, and places renewed emphasis on insulation coordination and the mitigation of partial discharges. The following unknowns have been identified as limitations of the scientific understanding in the up-rating of airborne electrical systems:- Validity of the Paschen for specifying minimum conductor segregation.- Validity of steady-state atmospheric correction factors.- Influence of condensation on electrostatic discharge phenomena.- Dependence of partial discharge inception on the applied voltage wave shape.This research project proposes to quantify the effect of atmospheric conditions on the partial discharge thresholds on the more- and all-electric aircraft. A purpose-built test facility will be established to replicate the dynamic atmospheric conditions to which aircraft systems are subjected in service. Simulations will be performed to determine the appropriate test conditions, which will then be applied to standard test samples to study the mechanisms and thresholds of partial discharge activity, with particular focus on the influence of condensation and icing. The findings will be used to inform a set of correction factors that system designers may use in the robust design of future airborne electrical systems.

运输部门的脱碳是全国和全球的主要优先事项。据估计，国内和国际航空部门占人类活动产生的全球二氧化碳排放量的2％。联合国国际民航组织的成员国致力于抵消2020年以后的排放量的任何增加，再加上提高燃油效率的动力，将刺激飞机的减轻重量，超出已经通过复合飞机材料来实现的，而较高的电动飞机的概念​​可以通过更高的系统效率来实现传统机械和水液压的较高的效率。它也可以被认为是实现商业混合动力和全电动飞机的垫脚石。两种类型的飞机都将基于高密度电子转换器和超过1000伏的系统评级，配备更多样化和安全关键的子系统。电缆绝缘，连接器和其他设备所经历的压力增加，再加上飞行中经历的极端和动态的环境条件，提出了许多技术挑战。电力系统的上升要求飞机设计工程师控制许多将在飞机的正常操作方面中产生的静电现象的许多因素，并且在评估系统中必须考虑到这些效果的效果。压力 - 系统电压的增加及其对临时过电压事件的频率和严重程度的影响。-海拔和大气条件（温度，压力和湿度）的变化以及其他影响，例如形成冷凝水和冰晶对电缆绝缘的影响。 - 雷击引起的间接效应。迄今为止，很少有关于在上升和下降期间动态大气效应的发表工作，或者在电压上造成的短期系统和大气引起的含义。对中电压直流系统中这些参数的基本理解对于空气寄生的电源分布的电气化至关重要，并且重新强调了绝缘协调和缓解部分放电。以下未知数已被确定为空气中电气系统的提高评级中科学理解的局限性： - 帕申（Paschen）指定最小导体分离的有效性。-凝结稳态校正因子的有效性。-凝结对静电排放现象的影响对量化的量化量的影响量的影响，对量化的量化量的影响量的量化量的量化量的量化量的依赖性对大气的依赖性依赖于量化的量化。在更多和全电动飞机上的部分排放阈值。将建立专门建造的测试设施，以复制飞机系统中使用的动态大气条件。将进行仿真以确定适当的测试条件，然后将其应用于标准测试样品，以研究部分放电活动的机制和阈值，特别关注凝结和结冰的影响。这些发现将用于告知系统设计人员在未来空气载电气系统的强大设计中使用的一系列校正因素。

项目成果

Progress Towards Atmospheric Correction for Aerospace Electric Discharge Applications

航空航天放电应用大气校正的进展

• 发表时间: 2022
• 作者: Mavidou S