The transformers in general present power losses when they are in operation, these losses are in the copper and in the iron of its structure. Copper losses occur due to heating of the coils, where part of the energy will be dissipated as heat, iron losses occur due to magnetic hysteresis and current parasitic on the iron.
The installation of an energy metering system next to the primary one of a power transformer is more expensive than the installation in the secondary, so the installation of the energy measurement in the transformer low voltage winding becomes less expensive. In this way, with lower insulation class its cost becomes smaller. However, to estimate the energy measurement at the side of the primary, it is necessary to estimate the losses of the transformers to add or subtract them, as the case may be.
The ELO2183 meter has an algorithm to estimate these losses, which is composed of the data collected on the transformer board and data from routine test (losses in copper, losses in the iron and the excitation correction). The technical report validating the loss compensation algorithm of the ELO2183 meter was issued by CEPEL (DTD 15312/2017), which describes the tests performed to verify the performance of the algorithm.