Aiming　at　the　problem　that　it　is　difficult　to　accurately　measure　and　model　the　core　losses　of　high　and　low　frequency　composite　excitation,　based　on　the　detailed　analysis　of　the　limitations　of　the　existing　core　losses　measurement　methods　and　core　losses　models,　a　core　losses　measurement　system　of　high　and　low　frequency　composite　excitation　is　built　based　on　DC　power　method　in　this　paper.　The　measurement　accuracy　is　verified　with　the　air-core　inductor　whose　loss　can　be　accurately　measured.　Finally,　the　core　losses　model　of　high　and　low　frequency　composite　excitation　is　proposed　based　on　the　core　losses　model　of　PWM　wave　excitation　under　DC　bias,　and　the　experimental　results　show　that　the　maximum　relative　error　is　−8.83%,　which　has　high　accuracy.　©2024　Chin.Soc.for　Elec.Eng.