Magnetic components for Power Electronics Operated in the Megahertz Range Using the Example of an LLC Converter

以 LLC 转换器为例，用于兆赫范围内运行的电力电子器件的磁性元件

• 批准号: 467840481
• 负责人: Professor Dr.-Ing. Joachim Böcker
• 金额: --
• 依托单位: Fachgebiet Leistungselektronik und Elektrische Antriebstechnik (LEA)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/467840481?language=en
• 关键词: Magnetic; components; Power; Electronics; Operated

Novel power electronic silicon carbide (SiC) or gallium nitride (GaN) semiconductor switches allow a considerable increase of the switching frequency due to lower switching losses, which leads to a reduction in size and costs of the magnetic components and thus of the entire converter. Currently, GaN-equipped industrial converters of ratings in the kilowatt range are operated at switching frequencies of approx. 50 to 250 kHz. It is foreseeable that switching frequencies in the megahertz range will soon be reached. At such frequencies, however, phenomena will turn up in magnetic components neglected up to now, namely the emergence of a skin effect not only in the winding but also in the core as well as resonances or standing waves within the core. Both phenomena are not welcome from the viewpoint of the conventional design of magnetic components. The project will therefore investigate which additional measures can be taken to avoid these disturbing effects as far as possible. These include the geometric shaping of the magnetic core and skilled placement of transverse and longitudinal airgaps. On the other hand, it is to be investigated whether the resonance effects in this frequency range can even be beneficially used. For example, a reactance that grows over-proportionally with frequency due to such a resonance can be used in an LLC converter to avoid the need to raise the switching frequency substantially in the crucial situation of low load and small output-input voltage ratio. This hypothesis will also be investigated in the project.

新型的电力电子碳化硅（SIC）或氮化岩（GAN）半导体开关允许由于开关损耗较低而导致开关频率大大增加，这导致磁性组件的尺寸和成本降低，从而降低了整个转换器。目前，配备GAN的工业转换器在千瓦范围内的评级转换器以大约约为开关频率运行。 50至250 kHz。可以预见的是，将很快达到Megahertz范围内的切换频率。然而，在这种频率下，现象将在到目前为止被忽略的磁成分中出现，即不仅在绕组中，而且在核心中，核心的共振或站立波的出现。从传统的磁成分设计的角度来看，这两种现象都不受欢迎。因此，该项目将研究尽可能避免这些令人不安的效果的其他措施。其中包括磁芯的几何形状以及横向和纵向气囊的熟练放置。另一方面，应该研究该频率范围内的共振效应是否甚至可以受益。例如，由于这种共振，可以在LLC转换器中使用频率过高的电抗，以避免在低负载和小输出输入电压比的关键情况下大大提高开关频率。该假设也将在项目中进行研究。