The information provided by power inductor manufacturers on their products varies considerably. Some just give the value of inductance, Rdc and saturation current while others provide much more information such as core losses. However, one parameter is generally missing: the Rac of the wire. To my surprise I have found that the Rac of commercial power inductors could be very high as compared to the Rdc at moderate switching frequencies (say, 100kHz). This would increase very much the power loss when a large delta B is expected (high ripple current or in resonant converters). This issue is discussed in the video linked below. Comments and discussions are welcome.