The magnetising and core-loss components of the no-load current of a transformer are 4,105A and 1,1A, respectively. Calculate the following:
a) The no-load current
b) The no-load power factor
c) the power on open circuit if the transformer is supplied at 1000V
a) The total no-load current can be found by adding the magnetising and core-loss components:
Total no-load current = 4.105A + 1.1A = 5.205A
b) The power factor on no-load can be calculated using the formula:
Power factor = cos(arctan(core-loss component/magnetising component) = cos(arctan(1.1/4.105)) ≈ 0.256
c) The power on open circuit can be calculated as the product of the voltage and no-load current:
Power = 1000V * 5.205A = 5205 VA or 5.205 kVA