US Patent 7474087 Energy meter system and method for calibration

An energy meter device includes a first analog/digital transformer having an input configured to provide a signal derived from a voltage and a second analog/digital transformer having an input configured to provide a signal derived from a current. A first input of the phase evaluation block is electrically connected to the output of the first analog/digital transformer and a second input of the phase evaluation block is electrically connected to the output of the second analog/digital transformer. The energy meter device also includes a phase correction block electrically connected to the output of the phase evaluation block and configured to correct a phase deviation of a digitized signal that is derived from the current or the voltage.