TRANSFORMER

The technical choice of a transformer is based on a punctual analysis of the technical aspects whereas the economic anlysis isn’t done with the same attention.

From the costs side the choice of a transformer is exclusivly based on the purchase cost or on the initial cost. But for a correct analysis of a transformer it is necessary to consider the running cost also (called Ce); it is the cost of the energy used by the transformer during its life. This element is very important if you consider the energetic saving that every concern has to take into account nowadays.

To verify correctly the running cost of a transformer it is necessary to consider the relation between empty loss and charge loss. The first are independent from the charge and are constant for all the time the transformer is connected to the line (normally 365 days a year) if the voltage and the supply frequency aren’t changed. The charge loss (Pc) are proportional to the voltage square and are variable from the charge oscillation. This means that each extra kilowatt becomes a fix cost on the running cost.