Loading three phased transformer following the quadergy

In this work, the authors propose a simple and fast method to establish the minimal real power for loading a three phased transformer of a specific power, such that power factor does not drop below a previously defined value. The method can be applied to transformers that are placed between a consumer's metering point and the electric power distribution network. In this situation, the billing energy and quadergy include the transformer energy and quadergy losses. This method establishes the moment where, due to low energy consumption, the transformer should be replaced with a lower power one, which still ensures the necessary energy for the consumers behind it. Our analysis has been done on a 100 kVA, an 80 KVA, and a 16 kVA transformer. Applying this method expedites the process of establishing the energy and the power factor where a transformer should be replaced by a lower power transformer, such that the power factor stays in acceptable ranges.