Device and method for determining voltage and power of each phase of a medium voltage network

The method involves calculating three pairs of derived amplitude/angle of voltage for phase conductors of a medium voltage network by modifying pairs of amplitude/angle determined on a low voltage network (7) according to characteristic parameters of a transformer (8). Paired amplitude/angle of the voltage is reconstructed by substituting paired derived angles with voltage angles of respective average voltages. The reconstructed amplitude/angle of the voltage is paired with derived amplitude/angle of intensity for the conductors of the medium voltage network by selecting a specific pair. An independent claim is also included for a device for determining voltage and power of a phase of a medium voltage network.