11/25/2015 Announcements • SAIS open now – please fill it out − Remaining students: 15 9 in 481 2 0 in 599 • Final Exam: − Posted online after final class − Due before end of scheduled exam time Monday, Dec 9th, 10:00 am 13.3 Magnetics Losses Magnetic Device Losses Copper Loss DC Copper Loss Core Loss AC Copper Loss Eddy Current Residual Hysteresis Skin Effect Proximity Effect Fringing Flux High Frequency Losses 1 11/25/2015 The Kg Method Kg Method 2 11/25/2015 Discussion Alternate Applications • Can be applied to multiple‐winding magnetics as long as design goals apply − Core loss negligible − Saturation is limiting peak flux density • 14.3 shows how the method changes 3 11/25/2015 Allocation of Window Area Chapter 15: Transformer Design 4 11/25/2015 Transformer Design Constraints Power Loss Tradeoffs 5 11/25/2015 Minimizing Total Loss Calculation of Total Loss 6 11/25/2015 The Kgfe Method The Kgfe Method nk n1 Awk nk n1 2 K uWA n2 Verify Bmax < Bsat 7