Harmonic impedance measurements and calculations in the EHV transmission network

The results of a measurement campaign regarding the driving point harmonic impedance of one node of the 400 kV Italian transmission network are presented and discussed, using a method suitable for high order harmonics (up to 50/sup th/). A model of the network has been then set up and the relevant results compared with the measurement, showing the crucial effect of the equivalent impedance simulating the external network.