Cryogenic Evaluation of Nanocrystalline Cores Using Partial Cancellation

The selection of appropriate magnetic materials is critical for achieving high efficiency in power electronics. Although ferrite is well established in research and industry, new magnetic materials like nanocrystalline boast several benefits as an alternative. These benefits include a high saturation flux density, less fragility, and a wide operating temperature range, making nanocrystalline well suited for applications requiring extreme operating conditions. An example of such an application is the use of superconductors (HTS) as transmitter or receiver coils in an IPT system, since the operating conditions demand stability under a high flux density and extremely low temperatures. For such applications, nanocrystalline core losses and B-H curves are characterised at room temperature and under cryogenic conditions using a partial cancellation method. The core losses and B-H curves are measured up to saturation, both in liquid nitrogen (LN2) and at room temperature.