High Frequency Transformer Winding Power Loss Reduction

减少高频变压器绕组功率损耗

• 批准号: 1611048
• 负责人: Shuo Wang
• 金额: $ 20万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1611048&HistoricalAwards=false
• 关键词: Frequency; Transformer; Winding; Power; Loss

When electrical current flows through conventional transformer windings, the current is not evenly distributed within the windings. High winding power losses are generated where the current has high concentration and the winding is not fully utilized where the current has low concentration. High current concentration generates high winding power loss which leads to reduced energy conversion efficiency and high temperature. High temperature reduces transformer lifetime, so more windings must be used in transformer design to reduce power loss. As a result, transformers are bulky and heavy which increases transformer cost and cannot meet today's demand for highly compact designs. This research pursues a fundamental solution to this problem. It has been preliminarily discovered by the investigator that the current distribution within transformer windings always reaches a minimum magnetic energy state. Based on this discovery, a novel transformer winding design technique is being developed using the relationship between the minimum magnetic energy state and power loss in the windings. The technique can make current much more evenly distributed within transformer windings than is possible with existing techniques. The technique can greatly reduce transformer winding power loss, improve transformer energy efficiency, improve transformer reliability, reduce transformer cost and improve transformer power density. The technique can also be applied to other magnetic components. Transformers and magnetic components are widely used in many electronics and electrical application areas such as consumer electronics, industry products and transportation systems. Thus this technique is expected to bring significant scientific and economic impacts to society. The education plan educates electrical engineering students and promotes diversity.The goal of this research is to develop a novel transformer winding design technique to minimize power loss in transformer windings. The researchers will investigate the minimum magnetic energy state in transformer windings, explore the relationship between the minimum magnetic energy state and winding current distribution and develop a technique to find desired winding current or magnetomotive force (MMF) profiles to minimize transformer winding power loss. The relationship between the winding power loss and magnetic energy windings will be first investigated. The PI has previously found that skin and proximity effects which influence the current distribution within winding conductors and the current sharing among parallel winding conductors comply with the minimum magnetic energy theory. The relationship between the minimum magnetic energy state and the winding current distribution or sharing in high frequency transformer windings will be investigated. A technique to achieve the minimum winding power loss by minimizing the magnetic energy among windings will be explored. A method to solve for the desired MMF profile using the minimum magnetic energy model will be developed. A technique to implement the desired MMF to either series or parallel winding turns will be studied. The theory and techniques to be developed in the research activity can be applied to any transformers and to magnetic component design in many applications. Compared with conventional extensive finite element analysis (FEA) or experiment-based trial-and-error winding design methods, the research can reveal the fundamentals of the winding current distribution and sharing in high frequency transformers. The method should be capable of quickly and directly find the best transformer winding design with the lowest winding power loss. The method should also provide useful guidance in transformer winding design. The methodology will not only help designers understand the current distribution and sharing within transformer windings but also give designers capability to steer the currents within transformer windings based on the desired current sharing profiles. With this technique, the transformer's power losses in windings can be greatly reduced and its power density can be greatly improved. Preliminary research shows that compared with conventional fully interleaved winding structure, 33-41.5% winding power loss reduction should be achievable using the theory and techniques to be developed.

当电流流过传统的变压器绕组时，电流不会均匀分布在绕组中。在电流具有高浓度并且在电流具有低浓度的情况下，产生高绕力功率损耗。高电流浓度会产生高绕力功率损失，从而导致能量转换效率降低和高温。高温会降低变压器的寿命，因此必须在变压器设计中使用更多的绕组以减少功率损失。结果，变压器笨重而沉重，可以提高变压器成本，无法满足当今对高度紧凑的设计的需求。这项研究为这个问题提供了基本解决方案。研究人员先于最初发现变压器绕组中的电流分布始终达到最小磁能状态。基于这一发现，正在使用最小磁能状态与绕组中的功率损耗之间的关系开发出一种新型的变压器绕组设计技术。与现有技术相比，该技术可以使当前电流在变压器绕组中的分布更加均匀。该技术可以大大减少变压器绕组功率损失，提高变压器能源效率，提高变压器的可靠性，降低变压器成本并改善变压器功率密度。该技术也可以应用于其他磁性组件。变压器和磁性组件广泛用于许多电子设备和电气应用领域，例如消费电子，行业产品和运输系统。因此，预计该技术将为社会带来重大的科学和经济影响。教育计划教育电气工程专业的学生并促进多样性。这项研究的目的是开发一种新颖的变压器绕组设计技术，以最大程度地减少变压器绕组的功率损失。 研究人员将研究变压器绕组中的最小磁能状态，探索最小磁能状态与绕线电流分布之间的关系，并开发一种技术以找到所需的绕组电流或磁极磁力（MMF）曲线，以最大程度地减少变压器绕组功率损失。 首先研究绕组功率损失与磁能绕组之间的关系。 PI先前已经发现，会影响绕组导体内电流分布以及平行绕组导体之间的电流共享的皮肤和接近性效应符合最小磁能理论。将研究最小磁能状态与绕组电流分布或在高频变压器绕组中的共享之间的关系。将探索一种通过最小化绕组之间的磁能来实现最小绕组功率损失的技术。将开发一种使用最小磁能模型来解决所需MMF轮廓的方法。将研究一种将所需的MMF实现为系列或平行绕组转弯的技术。在研究活动中要开发的理论和技术可以应用于许多应用程序中的任何变压器和磁成分设计。与常规的广泛有限元分析（FEA）或基于实验的试验和绕组设计方法相比，该研究可以揭示绕组电流分布和以高频变压器共享的基础。该方法应能够快速，直接找到最佳的变压器绕组设计，并具有最低的绕组功率损失。该方法还应在变压器绕组设计中提供有用的指导。该方法不仅将帮助设计师了解变压器绕组中的当前分布和共享，而且还使设计人员能够根据所需的当前共享概况在变压器绕组中引导电流。有了这项技术，可以大大降低绕组中变压器的功率损失，并且可以大大提高其功率密度。初步研究表明，与常规完全交织的绕组结构相比，使用要开发的理论和技术应可以实现33-41.5％的绕组功率损失。