Is component of non-core heating losses accounted for?

Discussion in 'General Electronics Chat' started by Silhorn, May 17, 2013.

  1. Silhorn

    Thread Starter New Member

    Apr 9, 2013


    Above is a picture of the equivalent circuit of transformer. The losses of transformer are indicated as a resistance.
    R1 = Primary resistance
    R2 = Secondary resistance
    RO = Hysteresis and Eddy current heating from within the core.

    As I know there is leakage flux from both windings indicated by X1 and X2. If any of these leakage flux cuts any exterior conductive parts of the transformer, eddy currents will rise in these parts and create heating losses.

    Is this loss indicated in this circuit? or it's so minimal it is excluded?
  2. t_n_k

    AAC Fanatic!

    Mar 6, 2009
    An interesting question.

    The primary side excitation losses are embodied in Rc (or is it actually Ro??) and this accounts for the majority of magnetic circuit related losses - irrespective of whether they are related to leakage or mutual fluxes. The Rc value is determined from the condition of open secondary (no load) excitation losses and therefore would presumably not include leakage flux losses arising in the secondary side.

    The short circuit test would include any losses arising from primary & secondary leakage flux but these may be swamped by the winding copper losses.

    In any event I suspect the leakage flux loss is probably orders of magnitude lower than the combined mutual flux losses, copper losses & other losses (e.g. acoustic / mechanical).
    Silhorn likes this.