High Frequency Magnetic Toroidal Core Loss Measurement Fixture

A technique for loss characterization of toroidal inductor cores under high power is proposed, and implemented for the frequency range of 2 MHz to 30 MHz. A power-boosted impedance analyzer is used to measure the impedance of the device being tested. The method uses a custom fixture which creates a single-turn inductor with a toroidal core and allows compensation for the winding parasitics so the core losses can be measured. The approach is implemented for excitation levels of up to 10 A; implementation details and experimental results of measuring two ferrite cores using the setup are presented and compared to core loss models supplied by the manufacturer. The setup supports multiple test fixtures and can also be used for general large-signal impedance measurements.