how to calculate power transformer losses?

To calculate power transformer losses, you need to consider two main types: core (or iron) losses and copper losses. Core losses occur due to hysteresis and eddy currents in the transformer core and can be measured at rated voltage and frequency. Copper losses arise from the resistance of the windings and can be calculated using the formula ( P_{cu} = I^2 R ), where ( I ) is the load current and ( R ) is the winding resistance. Total losses are the sum of core and copper losses.