Triple Pulse Test (TPT) for Characterizing Power Loss in Magnetic Components in Analogous to Double Pulse Test (DPT) for Power Electronics Devices

Abstract

Power loss modelling of magnetic components becomes increasingly important in the design of modern power electronic converters, especially in the case of higher switching frequencies enabled by emerging wide-bandgap devices. While the modelling of the active power electronic devices is relatively mature and straightforward, the estimation of the passive magnetic component loss remains challenging, including both the core loss and winding (copper) loss. As indicated by recent studies, the accurate prediction of the core loss in power converters relies on rectangular-voltage-excited measurements. To characterize the core loss with high-frequency rectangular excitations and dc-biases, a Triple Pulse Test (TPT) has been proposed and is further extended in this paper. The TPT involves a discontinuous procedure and a bidirectional, half-bridge excitation circuit that supplies transitional high rectangular voltage and high current. The importance and practical considerations of achieving closed dynamic BH loops are discussed. The proposed TPT is analogous to the common Double Pulse Test (DPT) for power electronics devices in terms of the testing circuit, the measurement instruments, and the discontinuous procedure. Moreover, the winding loss characterization can also be achieved by the TPT, given the winding loss can be very difficult to predict especially for randomly wound components where analytical equations cannot be applied accurately. Eventually, a complete loss dataset for one magnetic component design (i.e. same core material, shape and winding arrangement) can be built from TPT, which can be utilized to accurately model the inductor loss in power converter applications.